Beware Charging Dual Battery in D4. [Archive] - Australian Land Rover Owners

RoverLander

13th September 2010, 09:24 PM

I have installed a dual battery system in a D4 TDV6 3.0. I also had a GME remote head UHF Radio fitted which is powered directly from the dual battery system. Luckily the GME radio has a setting that allows you to constantly see the voltage being supplied. :)

I soon learnt that the second battery was often not being charged even when it should have been (ie voltage of dual battery was between 11.9 and 12.7 volts). I then replaced the normal dual battery isolator with a DC to DC charger (Redarc BDC1220). This will start charging a second battery when the main vehicle battery is above 13.2v and will stop charging when the main vehicle battery drops below 12.7v. It also progressively stops charging the second battery when it becomes fully charged.

This set up also has problems with not always charging the second battery when needed and I have finally worked out why.

By monitoring the GME radio voltage I noticed that the second battery would only receive a charge when I was rolling down a long hill or rolling to a stop. When I drive on a relatively flat freeway the second battery would receive no charge.

The D4 trick is to only charge the vehicle battery when the car is slowing down. This is so fuel and power are saved when cruising or accelerating by not driving the alternator. When cruising the main battery does not receive any significant charge from the alternator and therefore the voltage does not go above 13.2V and therefore the second battery isolator (or DC to DC charger) does not charge your second battery. Only when you are rolling to a stop and the car charges the main battery does the voltage momentarily exceed 13.2V.

It is also interesting to note that the D4 will let the battery drop below 12.7V from time to time. I know this because the Redarc stops charging when the voltage drops below 12.7.

So if your second battery in your D4 is either not fully charging or taking a long time to charge then you now know why. I don’t have a solution yet so if someone does then please let me know. I also don’t know if this also affects the TDV6 2.7.

By the way the battery is an Allrounder 60AH under the bonnet and a second Allrounder 60AH in the cargo area.

Peter

drivesafe

13th September 2010, 09:35 PM

I don’t have a solution yet so if someone does then please let me know.

Hi RoverLander, simply fitting one of my SC80-LR dual battery isolators will resolve your problems in one single and cheap move.

Graeme

14th September 2010, 05:46 AM

Has the Q093 update been done? There were problems with early vehicles even with only the main battery so circumstances may have changed.

gghaggis

14th September 2010, 10:32 AM

Hi RoverLander, simply fitting one of my SC80-LR dual battery isolators will resolve your problems in one single and cheap move.

Yup, I have one fitted - runs the Waeco 40L fridge 24/7, never had an issue with lack of charge!

Cheers,

Gordon

Duck's Guts

14th September 2010, 10:37 AM

Yup, I have one fitted - runs the Waeco 40L fridge 24/7, never had an issue with lack of charge!

Me too!

roamer

14th September 2010, 03:16 PM

Me as well, I actually think the second battery & traxide stops me getting the "battery low start engine" warning
Cheers Ken

drivesafe

14th September 2010, 03:30 PM

Me as well, I actually think the second battery & traxide stops me getting the "battery low start engine" warning
Cheers Ken

And thats the type of feedback I’m getting and not just from here, I’m getting the same type of info from overseas customers.

Cheers.

RoverLander

14th September 2010, 07:16 PM

Hi RoverLander, simply fitting one of my SC80-LR dual battery isolators will resolve your problems in one single and cheap move.

Sounds good. So how does the SC80-LR work out when to extract charge from the main battery?

Peter

Blknight.aus

14th September 2010, 07:31 PM

Im going to guess and this is soley to see how close me and drive safe think.

a voltage comparator function with a low voltage cut out.

when the main battery is receiving charge and is at a higher voltage than the second battery then the 2 are coupled together. Once the battery voltage of the main battery drops below the threshold then it cuts the second battery off.

drivesafe

14th September 2010, 08:15 PM

Hi RoverLander and Blknight, and close Blknight.

I don’t actually use comparators but similar.

Where the operation of my isolators differs other isolators and corrects the low voltage problems the others suffer from is that all other isolators simply cut-out once the motor has stopped running or shortly there after.

My SC80 keeps the cranking battery and any number of auxiliary/house batteries connected and what ever loads are applied to the auxiliary/house batteries is shared with the cranking battery.

When the common voltage of all the batteries reaches 12.0v, the isolator cuts out and protects the cranking battery from any further discharging.

This is not aimed at you Blknight, but a correction of a commonly stated but totally misleading bit of advertising hype, used by most dual battery isolator sellers and thats the myth that an isolator whats till the cranking battery is fully charged before connecting the auxiliary/house batteries.

There is no polite way to put this because it is just total crap, with the exception of one or two very expensive DBS, isolators have absolutely no idea whether the cranking battery is fully charged or dead flat.

All isolators, including mine, monitor the voltage applied to their input terminal. When the motor is started and the alternator raises the vehicle's voltage to a set level in the isolator, the isolator cuts in and that’s all there is to it. The cut in level has nothing to do with the State of Charge of the cranking battery.

This myth is just one of a number of cons used to win over unsuspecting customers.

Now back to the SC80. Because it keeps all the batteries connected until the common voltage drops to 12.0v, unless there is something seriously wrong with your D3/D4, all your auxiliary/house batteries will have no problems charging while you drive.

RoverLander

14th September 2010, 08:53 PM

When the motor is started and the alternator raises the vehicle's voltage to a set level in the isolator, the isolator cuts in and that’s all there is to it. The cut in level has nothing to do with the State of Charge of the cranking battery.

Thanks Drivesafe... you just saved me a phone call I was going to give you tomorrow.:) Two more questions:

What is the cut in voltage level? I assume its somewhere above 13V? Also if the voltage drops below that level but stays above 12V then I assume it stays connected. This would overcome the D4 droping below 12.7V while driving.

Also I have allrounder batteries which are Calcium. I'm thinking this wount work as I need to get them up to 15.2 volts. This is the neat thing with the Redarc as it has a Calcium setting... although it doesn't charge properly as described in my original post.

Thanks for the good info... I wish I knew all this when I started down this path.

Peter

drivesafe

14th September 2010, 09:43 PM

What is the cut in voltage level? I assume its somewhere above 13V? Also if the voltage drops below that level but stays above 12V then I assume it stays connected. This would overcome the D4 droping below 12.7V while driving

Hi again Peter, you have it in one and the cut-in voltage level for my isolators is 13.15v.

As to needing a special charger to fully charge Calcium/Calcium ( Ca/Ca ) batteries, this is just another one of the many cons being used to get people to think they need to buy a specific product when there is no need to.

You can NOT fully charge a Ca/Ca battery buy an alternator, a true statement. The problem is that when you read some of the advertising hype about these Ca/Ca batteries, while the advertisers never actually state how high you can charge Ca/Ca batteries with an alternator, the impression you get and it’s deliberately intended, is that you are going to end up with a battery thats just got enough power to start your motor, if your lucky.

Again this is nothing short of a truck load of horse dodo.

According to info supplied by battery manufacturers, like Exide, while a standard vehicle alternator can not fully charge a Ca/Ca battery, it can charge them to between 95 and 97% SoC.

Further more, using the experience from the use of Ca/Ca cranking batteries in D3s, most give above average life spans and yet very, VERY few of these batteries have ever been fully charged.

Add to this the fact that within a very short time from now, MOST automotive batteries will be Ca/Ca type batteries because they are cheap but are proving to be excellent value because of the above average reliability and Ca/Ca Batteries have numerous other advantages over the rest of the batteries in use now, so again don’t get caught by the advertising B/S.

Blknight.aus

15th September 2010, 05:18 AM

Hi RoverLander and Blknight, and close Blknight.

I don’t actually use comparators but similar.

My SC80 keeps the cranking battery and any number of auxiliary/house batteries connected and what ever loads are applied to the auxiliary/house batteries is shared with the cranking battery.

When the common voltage of all the batteries reaches 12.0v, the isolator cuts out and protects the cranking battery from any further discharging.

This is not aimed at you Blknight, but a correction of a commonly stated but totally misleading bit of advertising hype, used by most dual battery isolator sellers and thats the myth that an isolator whats till the cranking battery is fully charged before connecting the auxiliary/house batteries.

ok so OOC

which side of your units are you sensing the voltage for cutout from, the crank battery or the aux battery? (Im assuming the crank)

whats the end effect of the aux batteries getting charged to a higher state of charge than the crank battery (say youve flattened the batteries to the point of cut out over night and then during the day the solar system on the aux battery has charged the aux battery)

drivesafe

15th September 2010, 06:48 AM

camoo

15th September 2010, 07:11 AM

Hi guys n gals. For a newbie LR man like myself these forums are fantastic. Just as I am thinking what to do with the next little project you have thought through it and my little D4 is turning into an awesome machine. It doesn’t matter wether it is bull bar, power, tyres or rack!

Just a note of thanks to all you who contribute regularly to the forum.

well done, keep up the good replies....

David
"one day I dream of being able to state something that is technically sound"

Blknight.aus

15th September 2010, 07:57 AM

Hi Blknight, correct, the existing SC80 and SC80-LR take their voltage readings from the cranking battery input.

The effect of charging the auxiliary/house batteries after the SC80 has isolated the cranking battery, would be that the auxiliary/house batteries would be charged but even if their voltage rose above the cut-in threshold, the cranking battery would remain isolated and only once the motor was started, would all the batteries be parallel connected again.

Over the years I have considered connecting the cranking battery to the auxiliary/house batteries if they were charged by some other source, such as solar or battery charger, but, if the cranking battery is in good condition, at 12v the cranking battery still has heaps of power reserved to be able to start the motor.

On the other hand, if the cranking battery is faulty and was the cause of the common battery voltage dropping down to 12v and the SC80 isolating the cranking battery, connecting up to a fault cranking battery has two major potential drawbacks.

1. There would be a fair waste of power and the cranking battery would continually pull the auxiliary/house batteries down to 12v, preventing them from charging to a higher level.

2. A more serious situation could also be caused by reconnecting the auxiliary/house batteries to a faulty cranking in that the auxiliary/house batteries could actually mask the faulty cranking battery to the point that you are unaware of a faulty cranking battery until the auxiliary/house batteries fail, and at this point, you could be stranded.

thats about how I had it figured.

have you considered fitting or setting up the units with a manual bypass/reset that will allow you to hook the 2 batteries together for a self jumpstart/recharge? from a couple of experiences with some people who have your units but dont carry the full plethora of gear (read no jumper leads, why would I? I have dual batteries) the ability to trickle charge/jumpstart the crank battery from the AUX battery with the push of a button after some dolt left the park lights on all night would be a good thing.

whats your preferred method of hooking solar onto a traxride dual battery system?

Is there scope within the SC80 to equip it with an auxillary charge socket so that seting up solar is as simple as connecting the solar regulator output to the dedicated port on the SC80?

(I'm currently getting questioned about dual batteries+solar VS gensets with the leadup to school holidays/xmas prep)

irondoc

15th September 2010, 08:46 AM

hi drivesafe, can i ask one or two questions?

-is it true what roverlander said - that the D4 only charges when the car isn't under acceleration - ir coasting or going down hill?
-what is the reason that the Redarc's don't work - i have had a couple of redarcs in my previous landcruiser and really liked their simplicity and especially the function Blknight talks about - of being able to flip a switch and connect the second and cranking battery for starting?

thanks very much, this is an informative thread
lucas
looking to buy a D4 2.7

Blknight.aus

15th September 2010, 09:11 AM

RoverLander

15th September 2010, 08:33 PM

from personal experience

the redarcs are as dumb as a post. if anything goes wrong with the system they fail in the position they failed in, which typically is with both batteries hooked together which means 2 flat batteries.

Hi Blknight,

I dont have any experience with Redarc isolators. My set up is a DC to DC charger. Basicaly this draws power from the main battery when it is between 12.7 and 32V (for 24 volt vehicles) and converts it to a charge of 20amps and upto 15.2V. The advantage of this is that the second battery gets a full charge regardless of what the car alternator may put out.

As described above, the problem is that the D4 lets the voltage drop below 12.7 on a regular basis while driving which means that it can take longer to charge the second battery.

After more investigation today I wonder how any isolator system can ever charge a dual battery system in a D4. The way that the alternator is regulated it never makes any real attempt to fully charge the main battery let alone any additional batteries. The fact that it lets the batteries run down below 12.7V demonstrates this.

The only answer I can see is a DC to DC charger that activates by detecting that the vehicle ignition is on. This device does not yet exist. I understand the LC200 has the same problem and that people are working on an answer.

I readily admit that I'm far from an expert on Auto Electrics but this is what I've worked out so far from my experience with trying to get my setup working correctly.

Drivesafe, I accept that your system works. Its just that I can not see how it can fully utilise the capacity of the additional batteries. People are getting adequate time from their batteries because they are also drawing from the main vehicle battery (down to 12V). This is a solution that works best at the moment but it is not ideal.

Peter

Blknight.aus

15th September 2010, 08:59 PM

Hi Blknight,

I dont have any experience with Redarc isolators. My set up is a DC to DC charger. Basicaly this draws power from the main battery when it is between 12.7 and 32V (for 24 volt vehicles) and converts it to a charge of 20amps and upto 15.2V. The advantage of this is that the second battery gets a full charge regardless of what the car alternator may put out.

As described above, the problem is that the D4 lets the voltage drop below 12.7 on a regular basis while driving which means that it can take longer to charge the second battery.

After more investigation today I wonder how any isolator system can ever charge a dual battery system in a D4. The way that the alternator is regulated it never makes any real attempt to fully charge the main battery let alone any additional batteries. The fact that it lets the batteries run down below 12.7V demonstrates this.

The only answer I can see is a DC to DC charger that activates by detecting that the vehicle ignition is on. This device does not yet exist. I understand the LC200 has the same problem and that people are working on an answer.

I readily admit that I'm far from an expert on Auto Electrics but this is what I've worked out so far from my experience with trying to get my setup working correctly.

Drivesafe, I accept that your system works. Its just that I can not see how it can fully utilise the capacity of the additional batteries. People are getting adequate time from their batteries because they are also drawing from the main vehicle battery (down to 12V). This is a solution that works best at the moment but it is not ideal.

Peter

actually said device does exist. have a look at dc-dc 12 battery chargers jaycar has some but they dont have huge amperages. They are designed to allow you to run exotic batteries on dumb as a post vehicle electrical systems (S1-D1 or in landrover years 1948 to about 1999) in ultra laymans terms they act as a "current shaper" so that you dont dump too much power into a delicate battery when its flat and then change over to a voltage shaper so that regardless of the voltage thats present at the input side (so long as its withing the limits of the charger) you correctly and given enough time fully charge the aux battery.

2 drawbacks 1. price 2. not all that efficient.

As a rough mechanical equivalent charging a battery is kind of like accelerating a car it doesn't take much to get the process started but as you get closer and closer to full charge (speed) you have to apply more effort for a longer time. the return you get from say the top 5% of the battery charge is a lot less than the effort you goto to get that top 5% into the battery.

Hoges

15th September 2010, 09:29 PM

FWIW : just completed a 6000km jaunt to Cape York and fitted a SC80 just prior to leaving.... It is located in the vacant slot behind the main battery in the P38. the aux batteries are in a trailer...2 supercharge 105AH "All rounders" linked in parallel so they are essentially one battery as far as the SC80 is concerned. Ran a Bushman fridge 24/7, lighting and a CPAP machine most nights from a 500W pure sine wave inverter. Charged up by the next day's running, the SC80 kept the cranking and trailer batteries at /above 12.9V ....

drivesafe

15th September 2010, 10:21 PM

Drivesafe, I accept that your system works. Its just that I can not see how it can fully utilise the capacity of the additional batteries. People are getting adequate time from their batteries because they are also drawing from the main vehicle battery (down to 12V). This is a solution that works best at the moment but it is not ideal.

Peter

Hi again Peter, and mate, you, like many others, have been sucked in by the garbage these DC-DC makers put in there advertising hype.

Fact, even though the SC80’s operating procedure is now over 20 years old, because of the way it works, an SC80 dual battery set up is still the FASTEST system for replacing used battery capacity.

The DC-DC devices are great for topping off auxiliary batteries but they can not compete with the way the SC80-LR works when fitted to a D3 or D4, or any other vehicle.

The more power you use between charges while driving, not only does the SC80-LR replace used battery capacity in a short drive time than any other set up, because of the way it works, it is also much safer for your batteries.

If you have a 100 Ah AGM auxiliary/house battery in your D4 and you use 80 amperes of power while free camping, with any other set up, you have to discharge your 100 Ah auxiliary/house battery down to 20% SoC.

With an SC80-LR, your battery only gets discharged down to about 57% SoC and check any battery manufactures info and they all say that regularly discharging any battery below 50% SoC begins to shorten their life span and the deeper the discharge, the shorter the life span.

Also note, that at 20% SoC, your have all the power you are going to get out of an AGM battery, and a flooded wet cell battery should not be taken below 30%, with the SC80-LR, at no extra cost, if you need more than 80 amperes, you have up to 125 amperes if you chose to take your 100 Ah auxiliary/house battery down to 20% SoC.

With any other set up, the only way your are going to get 125 Ah is to add another battery, BUT, now your are going to need to drive for a much, MUCH longer time to recharge this amount of Ah when using one of the DC-DC toys.

Where as with an SC80-LR and taking into account the lower operating voltage of the D4, you will still replace the used battery capacity in a much shorter driving time.

Sorry Peter but the is NOTHING out there that does anywhere near as good a job as the SC80 and SC80-LR do.

BTW, why is it not ideal to take a cranking battery down to 50% SoC ( 12.0v )?

drivesafe

15th September 2010, 10:38 PM

Peter, one more point, if you find that with your DC-DC set up, you do need to add another battery, if you discharge them down a fair way, you will now need to drive for up to 90% longer to allow your DC-DC device the time it needs to full charge the two batteries.

If you need to add a second auxiliary/house battery to an SC80 set up, at most you may need to add 20% to your driving time and if you add a third battery, it’s still about the same time.

If you need to add a third battery to your DC-DC set up, add another 80 to 90% to your drive time.

It always amazes me how the sellers of these DC-DC devices always neglect to mention that the more auxiliary/house battery capacity you have and use, the much longer you have to drive to fully charge them.

RoverLander

16th September 2010, 08:11 PM

Ahh Drivesafe... i'm enjoying our debate. I'm sure I'm an amateur grappling with an expert but let me have another go

So I see the advantages of the DC-DC "Toys" as:

1) will deliver a steady 20AMP at 15.5v regardless of what the vehicle alternator decides to do. (Well it would if the low voltage output of the D4 didn't get in the way).

2) They are capable of fully charging your second battery(s).

3) They deliver the higher voltages that the calcium battery makers recommend (I talked directly with Supercharge).

4) You end up with a fully charged vehicle battery that stays fully charged. I don’t want to run my main battery down to 50% out in the bush thank you.

5) I suspect it wouldn’t put as much strain on the electrical system as it doesn’t allow the alternator to try to charge all connected batteries at once possibly putting a significant load on the full alternator.

Disadvantage of DC-DC toys:

1) Doesn’t currently work due to D4 low voltage!!
2) It may not charge as quickly initially as the alternator in most cars will deliver more that 20AMP but at a lower voltage (14.5 I think)

Advantage of the SC80 “partial charger” – you started it :p
1) Cheaper that DC-DC charger
2) Faster initial charge
3) Simpler
4) Works today

Disadvantage:
1) Risks your main battery being partially discharged
2) Never fully charges your batteries (the D4 drops down to less that 12.7V once the batteries are partially charged to save precious fuel!
3) May put a strain on your electrical system that you don’t want.

The choice is up to each of us. But let’s try to make sure that we have the information to make our choice. Things have changed a lot in 20 years and the D4 is at the bleeding edge. If you are happy to partially charge your batteries and partially run down your main battery then choose a “partial charger”. If you want a full main battery and full second batteries, although taking longer to charge (possibly) then choose the DC-DC “toy”.

By the way I have two batteries connected (2X60AH). Charging works fine other that the problem already mentioned.

drivesafe

16th September 2010, 09:34 PM

Hi RoverLander, the SC80’s operating set up may be 20 years old but it’s more relevant to day than any of these toys.

Now to your arguments, you TOY DC-DC device does not charge at 15.5v until the battery is nearly fully charged.

Again, it’s not much use having a device that will supposedly fully charge your Ca/Ca batteries if you don’t drive long enough to charge them in the first place.

As posted earlier in this thread, as the SC80 charges quicker than your TOY can so you are actually more likely to damage your auxiliary battery using your TOY because you are highly unlikely to fully charge them in the first place, a point that I see you have also conveniently neglected to mention.

BTW even with the way a D4 varies it’s charging voltage, I have yet to come across a single D4 owner with my SC80 in their D4, that does not fully charge ALL the batteries when they do their daily drive, so another myth with no substance. Especially when we take into account that you continually state your set up does not work!

Now this one did give me a laugh, how on earth can make up such farcical statement that one "would put a strain on the electrical system in a D4".

The D4 comes with a 180 amp alternator and have you ever had a look at the size on the cables LR put in the D4’s charging circuit. That statement is pour desperation in trying to make a point when there is no evidence to back it.

As for discharging your cranking battery down to 50%, whats the problem. Being as you can start most modern vehicle from as little 11.5v and thats 20% SoC, and this includes a D4, if you can’t start your D4 with a battery voltage of 12.0v, you already have a problem and your not going to start it with a full battery.

You can invent all the arguments you want but if someone is using a fair bit of power while camping, at the end of the next days drive, you are far, FAR more likely to have fully charged batteries when using an SC80 set up than you will ever have when using one of those TOYs.

Again, if you do tend to use a fair bit of power, your batteries are going to have a long operating life span if you use an SC80 rather than a DC-DC device, because a DC-DC device is much harder on your auxiliary battery, because you have to discharge the auxiliary battery twice as low as you do with an SC80 set.

Again, you can invent all the arguments you want and while your set up does not work, with all the people now, with D4s and my gear fitted, have you come across any of these people having your sort of problems?

So the SC80 is not only heaps cheaper but it will actually pay for itself by extending the life of your batteries.

Graeme

16th September 2010, 09:37 PM

My D4's batteries don't seem to suffer from not being charged enough using my VSR setup and I really don't care if they are not fully charged as long as they do the job. However I am somewhat torn between Drivesafe's system that has the advantage of being able to more quickly recharge multiple batteries that have been discharged a little (eg charging at up to 20A per battery) than a single battery that has been discharged a lot (still only charging 20A but for double the time) and having a 50% discharged starting battery being discharged further by the D4's electronics to the extent of endangering the ability to start the engine. While my VSR does the job I will stick with it but if my 2nd battery fails to recharge in time and slowly goes flat over a number of day's use (which did not occur with my TD5 D2) and the D4 proves reliable in not flattening its starting battery in normal use then I'll readily replace my VSR with an SC40.

drivesafe

16th September 2010, 10:26 PM

Hi Graeme, I recently had a customer with a D3 who was having problems.

The cranking battery was going flat if the D3 was left for two or more days.

He went to two different auto electricians and both carried out load tests on the battery and both said the cranking battery was fine and the SC80 was causing the problem.

Well he rang me to tell me what the auto electricians had stated and then told me that he had to jump start from the auxiliary battery.

The SC80 was not only not the problem but had done it’s job in reverse.

He still had the problem a few days later and so went to e third A/E. Same story, so this time after he had been driving for 7 hours straight, he disconnected the SC80.

The battery was flat the next morning. While the SC80 was connected, the auxiliary battery was slowing down the discharge rate of the cranking battery.

At the end of this days drive, again quite a few hour of driving, he disconnected the cranking battery neg lead to see if it was the battery or something in the vehicle.

After just two hours he measured the voltage across the cranking battery’s and it was already down to 12v and was flat the next morning.

So much for the knowledgeable A/Es.

As a side note, when he jump started his D3 off his auxiliary battery, the first time when the SC80 was still connected, the auxiliary battery had been pulled down to 12v, the SC80 had disconnected the two batteries and then the auxiliary battery continued to power his fridge over night, but still had enough power to over come the flat cranking battery and jump start his D3 at the same time, the next morning.

So the point is clearly demonstrated that you can SAFELY discharge your cranking battery down to 12v and still have heaps of power to be able to start your motor when needed.

In tests, I have take the D4’s cranking battery down to 11.5v ( that’s 20% SoC ) and still been able to start the D4.

Graeme

17th September 2010, 05:05 AM

Thanks Drivesafe for the background reports. The battery is huge and the engine starts immediately, unlike some vehicles of old.

I can't tell if my VSR is cutting in and out as I drive but I do have a tailored dual LED battery voltage indicator setup that reveals the aux battery gets connected shortly after startup on cold mornings when the LEDs indicate that both batteries are overcharging by older standards. I could setup a remote LED from the VSR if I really wanted to know.

I have noticed since Q093 that the time before accessory shutdown has been significantly reduced, presumeably to save battery drain.

kingo

17th September 2010, 02:21 PM

Hi Drivesafe, It's been interesting reading the replies regarding battery set up. Can I ask some advice. I have a D3 and a D2 and have removed the dual batteries from the D2 and want to install in the D3. The set up I used and also had in a GU Patrol prior was to link and separate the batteries using a 200amp solenoid. This was switched using the ignition, so car on batteries connected and charging, car off batteries isolated. My thoughts are a very simply system and never let me down. Can this be used on the D3? Would appreciate your advice.

drivesafe

17th September 2010, 03:23 PM

Hi kingo, you should have no problems fitting that set up in a D3 but just keep in mind that a solenoid can be operated from as little as 9v, so if your cranking battery is stuffed to the point it won’t start the D3, it will still have enough power to energise the solenoid and you can be unknowingly starting off your auxiliary battery.

The above situation is a VARY common occurrence and the only way you find out your cranking battery has given up the ghost is when your auxiliary battery fails as well.

Just a suggestion, put a switch in one of the wires to the coil of the solenoid, and even if you don’t do it every time, every so often switch the coil off before you try to start the motor to make sure the cranking battery is OK.

PaulGOz

18th September 2010, 07:14 AM

This conversation is very informative. Can i simplify the solenoid scenario further. If i just wire two or more batteries together do I effectively achieve additional storage caapacity with maximum recharge capability with the only disadvantage being that I do not have the safety of protecting the cranking battery from over discharge? If the additional aH storager capacity then exceeds my maximum power usage by an appropriate margin then have I avoided the need for a DBS or alternatively could install at a later date?

kingo

18th September 2010, 09:22 AM

Thanks Drivesafe. Had that very situation on the D2, cranking battery died and as the system is made up using HD battery cable the car continued starting without any signs. So also made up a volt meter that can be switched to either battery, so voltages and charging volts can be monitored. The meter is mounted in a small box form Dick Smiths, so it looks ok as well. Will set this up in the D3, only problem is the D2 had a 12 inch battery, so not sure where I can mount this and the battery is quite new. Any ideas?

RoverLander

19th September 2010, 08:52 PM

Hi Drivesafe, a slow reply.. i've been out and about.

The facts remain:

The SC80 PARTIALCHARGER dischargers your main battery. The D4 has a mind of its own when it comes to keeping lights and other accesories running. I still want my main battery as full as possible. The DC-DC charger delivers that.

The SC80 PARTIALCHARGER will never get a battery upto 15.2V because the D4 never charges up to that voltage. This is a FACT as I've witnessed it while driving my D4. The DC-DC charger does as I've also seen that. Are you confirming that the SC80 PARTIALCHARGER will reach 15.2V?

The SC80 PARTIALCHARGER will suffer from voltage drop if the second battery is placed more that a metre or so from the main battery. The DC-DC charger will deliver full voltage as you can place it close to the battery to be charged and it will deliver full voltage.

The SC80 PARTIALCHARGER will provider faster initial charge before it stops when partialcharge has been achieved. The D4 may be able to deliver 180AMP but I never want to go near the upper end of that capacity... I'm not THAT confident in Landrover electronics and computers. I know that the DC-DC charger will never compromise the vehicle electronics because it has a set draw limit. The SC80 PARTIALCHARGER will expose the electronics to whatever is connected.

You are correct that my current DC-DC charger has an issue. I identified that. It is still fully charging my batteries... it is just taking a little longer than it should due to the charge stopping at times due to the D4 voltage dropping below 12.7V. A solution to this is being found but is a refinement.

I'm about to head of for 3 weeks of bush camping... I'll let you know how the DC-DC charger goes... I sure hope I don't come back asking for a SC80 PARTIALCHARGER! :D

drivesafe

19th September 2010, 10:14 PM

RoverLander, you really have been sucked in by the advertising hype surrounding these DC-DC toys.

I have no idea what your reference to the SC80 as being a partialcharger is about, if anything, that’s what your DC-DC toy is. If your auxiliary battery is low, you will never drive long enough to get your auxiliary passed a partial charge.

If anything, the SC80 should be called a multiple battery BULK CHARGER, and something your toy could never hope to do.

For a starter, if you have “A” low battery, and I emphasise a “single” battery, because that’s all these DC-DC toys could hope to charge, but if you have a low auxiliary battery, you will have a MUCH bigger voltage drop at the auxiliary battery with a DC-DC device than you will with an SC80.

I’ll clarify this point, I am not talking about the voltage drop at the input of the DC-DC device, I’m talking about a large voltage drop at the output of the DC-DC device. This is the voltage at the auxiliary battery.

As posted earlier in this thread, these DC-DC devices CAN NOT deliver high voltages while charging, until the battery is nearly fully charged, so an SC80 does not charge your auxiliary battery with as low a voltage as these DC-DC toys do. Get your FACTS right.

You really need to learn a lot more about the way your toy works before you comment about the SC80 or anything else in this field.

You, like many others, have been conned by the advertising hype.

Also, if you don’t trust the D4, why the hell did you buy one.

roamer

20th September 2010, 05:59 AM

The facts remain:

The SC80 PARTIALCHARGER will never get a battery upto 15.2V because the D4 never charges up to that voltage. This is a FACT as I've witnessed it while driving my D4.
the charge stopping at times due to the D4 voltage dropping below 12.7V.

----------------------------------------------------------------------------------------------------------------------------------------------------------------------------------

Hi RoverLander
Have read this post with interest, because I have second battery in car and 315A\H batteriers in van, no troubles in last 4yrs, (in D3,last 10mths in D4),with SC80,so I thought I would check myself, I put up the diagnostic menu on satnav, there is a section for "vechicle readings" then , "battery voltage."
When I first brought up screen (car off) 12.1v, start car voltage worked itself up to 15.4v, then when driving along fairly flat ran at 14.8v-14.4v, after a 55km trip most of it at 100k\h Hiway) stopped turned off, battery voltage at 12.6v., pretty much the same readings on the way home, but there is a big long steep up hill, so I floored up there, even at 3800 rpm, voltage never dropped under 13.7v.
Hence D4 can generate more than 15.2v, and mine never dropped under 13.7v, maybe you have a problem elsewhere.
Cheers Ken

drivesafe

20th September 2010, 06:44 AM

Hi roamer and thanks for that info.

The point is, I have well over a thousand D3s equipped with my gear, both here and overseas, and in all sorts of climates from the heat of the Middle East to countries up in the Arctic Circle and no one has ever reported a problem relating to a design fault.

There are now quite a few D4s fitted out and again, no problems reported.

That gives my gear a 100% success rate, whereas RoverLander has tried one set up with his gear and because of a design incompatibility, it’s not working, so correct me here but that gives his set up a 100% failure rate.

It’s not rocket science to workout which system works and which system is an expensive mistake!

RoverLander

20th September 2010, 04:29 PM

The facts remain:

I thought I would check myself, I put up the diagnostic menu on satnav, there is a section for "vechicle readings" then , "battery voltage."
Cheers Ken

Thanks for this Ken... This is very good information. I have searched for "diagnostic menu" on my satnav and can't find it. I assume you are talking about the built in Satnav? I'd like to have a look at my readings. If they are as you say then I've definetly been led up the garden path and I think I would owe Drivesafe a case of beer.

Are you able to tell me how to get into diagnostic mode?

drivesafe

20th September 2010, 05:17 PM

If they are as you say then I've definetly been led up the garden path and I think I would owe Drivesafe a case of beer.

Hi RoverLander, you won’t owe me anything.

I have been bitching about the misinformation that is being used to promote these DC-DC toys for a couple of years now and while your the meat in the sandwich, you prove my point but I see no reason why should owe me anything.

If nothing else, thanks to your thread, a lot more people will be wary of the short falls in the info being put out about these devices.

Cheers.

Duck's Guts

20th September 2010, 06:21 PM

...I put up the diagnostic menu on satnav, there is a section for "vechicle readings" then , "battery voltage."
When I first brought up screen (car off) 12.1v, start car voltage worked itself up to 15.4v, then when driving along fairly flat ran at 14.8v-14.4v, after a 55km trip most of it at 100k\h Hiway) stopped turned off, battery voltage at 12.6v., pretty much the same readings on the way home, but there is a big long steep up hill, so I floored up there, even at 3800 rpm, voltage never dropped under 13.7v.
Hence D4 can generate more than 15.2v, and mine never dropped under 13.7v, maybe you have a problem elsewhere.
Cheers Ken

... I have searched for "diagnostic menu" on my satnav and can't find it. I assume you are talking about the built in Satnav? I'd like to have a look at my readings. ...
Are you able to tell me how to get into diagnostic mode?

Anyone else know about this "diagnostic menu" and how to get to it?

This weekend I went camping about 3.75hrs drive each away (combination of tar & dirt, 40-110km/hr, steep hills & long flats, i.e. all terrain covered).
I plugged a digital volt meter into one of the accessory plugs near the D4's transmission lever. The voltage observed only ranged between 13.74 & 13.86V, now matter whether accelerating, braking, coasting, idling, or doing anything else. With the engine off I got a voltage of 12.6~12.7V.
So, either the accessory plug supply is regulated during alternator charging, or I'm getting very different results to Roamer.
I'm confused, can anyone shed some light?

By the way, I've enjoyed the education I'm getting from this thread.:)

roamer

20th September 2010, 06:55 PM

Hi RoverLander
Hidden diagrostic is in LR satnav screen,
You need to go to "Home Menu", at top of that screen is a grey bar, hold finger in centre of bar for 6secs, then hold finger at left hand corner of bar for 3secs (about over H in home screen) then hey presto, new screen asks for code, 7 5 3, from there you get sub menus for all sorts of stuff, best one is you can run the rear view camera while you drive along (check that the van hitch is still good,) :cool::cool:
Cheers Ken

RoverLander

20th September 2010, 08:33 PM

Ken... that case of beer is going your way... thats a pearler piece of information! I will use that to see what is happening with my main battery voltage.

I can't help but wonder if the electrics in the D4 also include some form of voltage control to the vehicle. By that I mean that the battery may be at one voltage but that power is passed to the rest of the vehicle via some form of converter so as to ensure an even power supply while the alternator does other things with the battery.... am I thinking about this too much :confused:

I've run out of time.. I'm leaving for a trip for several weeks. So no more posts from me for a while...

Peter

mickyd24969

20th September 2010, 09:05 PM

Hey Drivesafe,

Hope you're still reading this post....

Can you recommend a fitter of your systems in BrisVegas? Preferably on the northern side (I'm in Wavell Heights).

Thanks,

Michael

Blknight.aus

20th September 2010, 09:19 PM

googlemaps has me a little over an hour away, if you cant get someone closer I'll fit it up for you,

Just make sure that you have the security codes and sequences written down for everything before you go getting it fitted.

CaverD3

21st September 2010, 11:53 AM

............ if you can't get someone closer I'll fit you up..................

Very kind of you Blknight. :angel:

drivesafe

21st September 2010, 07:34 PM

Duck's Guts

22nd September 2010, 06:43 AM

This weekend I went camping about 3.75hrs drive each away (combination of tar & dirt, 40-110km/hr, steep hills & long flats, i.e. all terrain covered).
I plugged a digital volt meter into one of the accessory plugs near the D4's transmission lever. The voltage observed only ranged between 13.74 & 13.86V, now matter whether accelerating, braking, coasting, idling, or doing anything else. With the engine off I got a voltage of 12.6~12.7V.
So, either the accessory plug supply is regulated during alternator charging, or I'm getting very different results to Roamer.
I'm confused, can anyone shed some light?

Diagnostic menu on sat nav reports the same: constant 13.7-13.8V with engine on no matter what type of terrain/driving, and 12.6-12.7V engine off.

roamer

22nd September 2010, 08:19 AM

Diagnostic menu on sat nav reports the same: constant 13.7-13.8V with engine on no matter what type of terrain/driving, and 12.6-12.7V engine off.

Thats strange ,:confused: my voltage does vary , even just with slight acceleration not much 14.4v down to 14v, and down to 13.7 with heavy accel. However I do think my main battery is suspect (always has been), maybe its trying to charge battery up. PS I have unplugged fridge to make sure there is no draw.
Does yours not run up to 15.4v just after start for abit ?
Cheers Ken

drivesafe

22nd September 2010, 08:22 AM

I won’t say the you won’t get readings down to 12.7v or lower, but I have not seen them that low and like others, the lowest I can get my D4’s voltage to is 13.6 ( got 13.2v a number of times on the D3 ) and even at this level, during tests, I was getting 64 amps going into three batteries ( total Ah of 265 Ah ) located in the cargo area and managed to raise the batteries from 50% Soc to over 85% Soc in just 2.5 hours of driving.

There can be a number of causes for low voltage readings and the point where the D4 takes it’s readings from will govern the accuracy of any voltage reading.

I don’t know the exact reference point the D4 uses, but most vehicles take their voltage reading from the power supply wire going into the ECU.

This will meet all the requirements for the vehicle’s management system but is no true indication of the voltage level at the cranking battery. This is the voltage we need to know to be able to determine whether auxiliary/house batteries are going to charge.

When the voltage is monitored elsewhere in a vehicle, if there are any other devices switched on, such headlight, sound systems, air conditioning and so, if these devices are on at the time the voltage readings are being taken, they WILL cause a significant voltage drop on the supply wire to the ECU.

The ONLY way to get an accurate voltage reading is to measure the voltage at the cranking battery’s terminals.

Blknight.aus

22nd September 2010, 04:44 PM

Hi Michael, if you take up Blknight’s offer, make sure you do half the work. That way you’ll learn for yourself.

Hi Blknight and don’t worry about the security codes, thank god, they are now a thing of the past in MOST new vehicles.

He'd actually wind up doing most of it, I'd just make sure he didnt pooch anything or let the smoke out... Bugger of a job getting it back in.

outbacktourer

23rd September 2010, 01:16 PM

Just found the diagnostic screen and checked the volyage on a trip to the city and back. Sure enough, charges only when coasting/brakeing. At other times 12.7-12.8V. Mine is a 3.0L

OBT

Duck's Guts

24th September 2010, 05:07 PM

Ahhh, maybe thats the difference? My results are on a 2.7TD D4.
Is it possible that the 2.7 & 3.0 have different charge control systems?

Graeme

24th September 2010, 06:58 PM

Is it possible that the 2.7 & 3.0 have different charge control systems?
That's quite possible because as far I could establish, nothing on the MY10 2.7 engine was changed from the MY09 2.7, not even upgrading the a/c compressor to the 3.0 version to stop it pumping when not required.
New alternators and starter motors were sourced for the 3.0 too although that could have been only to do with better waterproofing.

roamer

25th September 2010, 04:44 AM

Just found the diagnostic screen and checked the volyage on a trip to the city and back. Sure enough, charges only when coasting/brakeing. At other times 12.7-12.8V. Mine is a 3.0L

OBT

Hi OBT, my readings are from 3lt, when you say only charges when coasting\ brakeing, what volts is it then. :confused: Tim may be able to correct me, but I think ya need around 14.4v to give battery a decent charge.
Cheers Ken

drivesafe

25th September 2010, 05:21 AM

Hi Roamer, if a battery is low, say at 12v, you can charge it with as little as 12.2v and this is how both battery chargers and DC-DC converters work.

As long as the voltage being applied to the battery is higher than the State of Charge of a battery, no matter how small the difference, the battery will charge.

the D3 fully charges batteries with as little as 13.2v.

The advantage of having high charge voltages, such as 14.4v, is that the battery will fully charge sooner.

I have a lot of testing ahead of me where the D4 is concerned but this relates to the time required to charge batteries, no whether auxiliary/house batteries will charge.

There are well and truly enough D4s now out there, equipped with my DBS to show my DBS work.

Again, there is a need to get voltage readings at the cranking battery and not relying on the data being displayed in the cab.

Any voltage readings taken anywhere other than at the cranking battery terminals, is going to be erroneous for the data that is needed to determine whether there is suitable voltage levels for charging batteries and not just the cranking battery but any batteries connected to the D4’s electrical system.

If anybody is interested in setting up their D4 to get some accurate voltage readings at the cranking battery, I can show you how to set up a crud, cheap but accurate wiring connection to do so.

roamer

25th September 2010, 06:06 AM

Hi Tim, thanks for info, do you think the D4 may be able to act like a battery charger (ie, different stages of charge, and or temp variation) hence all these different readings. :confused:
My DB system works a treat,and thats a 55ah in car and 315ahr in van (does have solar, which I guess would back feed to charge all batteries including crancking )
I will set my meter up off cranking battery, and check out differences between the two. (you haven't seen crude till ya see what I can do) :wasntme:
Cheers Ken

outbacktourer

25th September 2010, 06:43 AM

Hi OBT, my readings are from 3lt, when you say only charges when coasting\ brakeing, what volts is it then. :confused: Tim may be able to correct me, but I think ya need around 14.4v to give battery a decent charge.
Cheers Ken

It's in the 14-15's. I'm going for a run to bathurst today and go to school on it and report back...

OBT

outbacktourer

25th September 2010, 04:46 PM

It's in the 14-15's. I'm going for a run to bathurst today and go to school on it and report back...

OBT
As per previous findings the charging is occurring while coasting. Voltage when charging is around 14.7 +- .1 Static voltage (when under power) does move around a bit. I saw 14.2 at one point (after a fair bit of stop-start motoring) but mostly low 13's and 12.7 was the lowest (and most common). 2010 3.0 TDV6

OBT

BarryH

26th September 2010, 02:49 PM

Does anyone know what the MOST FOT temperature reading is in the secret vehicle readings screen is from? :confused:

BarryH

Duck's Guts

29th September 2010, 06:41 AM

What does FOT stand for?

roamer

29th September 2010, 08:19 AM

Does anyone know what the MOST FOT temperature reading is in the secret vehicle readings screen is from? :confused:

BarryH

Media Oriented System Transport.....Fibre Optic Transceiver :eek:
But, BarryH don't ask what it is., cause I don't really know
Cheers Ken

Phil

3rd October 2010, 11:35 AM

Hi BarryH,

The MOST FOT temperature is the operating temperature of the computer under the dash.

If you have a look at the DTC faults in the same service screen, you will see code U210A85, which describes it and has good advice... Wait for it...., keep waiting.....

"Park under a tree and turn the AC on" ...... its true! have a look! What a classic!

Phil.

BarryH

3rd October 2010, 03:50 PM

Hi Phil
I was hoping that in amongst all it might have shown the garbox and engine temp, would be handy if it did.

BarryH

drivesafe

3rd October 2010, 04:13 PM

Thanks to Phil doing a hell of a lot of driving yesterday, a lot more accurate info is now known about D4 voltage operations and Phil’s D4 operations with and without the SC80-LR connected.

In short, the addition of an SC80 dual battery system has no effect on the operation of the D4’s electrics.

The good thing is that thanks to Phil and quite a bit of feedback from other D4 owners, it now seems clear that the SC80-LR not only performs flawlessly with the D4, but it now appears that the SC80-LR is the ONLY dual battery isolator that will work properly in a D4.

Phil and I spent hours driving around, testing the D4 system with and without the SC80-LR connected and no matter what situation we put Phil’s D4 through, there was absolutely no difference in the operation of the D4’s electrics, and more specifically, the voltage levels, whether the SC80-LR, with an auxiliary battery, was connected or not, the D4’s voltage response was exactly the same.

Also now confirmed, again thanks to Phil’s assistance, that the way a standard SC80-LR operates, means that the auxiliary/house batteries are going to get a good sustained charge, whereas every other isolator that I am aware of will continually cut in and out, if they manage to cut in at all, and this is going to be an even bigger problem with DC-DC converters.

Ipanema

10th October 2010, 03:17 PM

Recently returned from 3 weeks/7000km of travel in my D4 with a Traxide SC80 DBS and a 2nd battery (Optima D34) in the rear for the fridge.

Installation was as Tim has described (about 2-3 hours, taking my time), and the setup worked flawlessly.

Certainly pleased I went with the Traxide setup and self-installation instead of the $1500 quote given to me by a retailer for them to do a similar setup with another product.

mickyd24969

10th October 2010, 03:22 PM

Hey Ipanena, with the installation did you find all the cables were run to the back of the car as described? I had a quick look in the back of mine and wasn't sure they are there?

Michael

Ipanema

10th October 2010, 03:54 PM

Hi Michael,

The cable to be run to the back is a heavy gauge (6mm?) dual cable which goes through the firewall near the accelerator pedal, underneath the kick board/door trim, under the base of the B-pillar, and under the internal trim in the back to the hatch for the jack. I've installed a pair of of oulets on the right, opposite the factory one on the left. If I were to do it again, though, I'd probably install one of them facing downward in the recess in front of the jack access, to keep my fridge plug a bit out of the way. Will probably do this anyway when I get time. Picked up a (cheap) hole saw kit at Bunnings before tackling the the big step of nervously DRILLING INTO my beloved vehicle!

The Anderson plug for the second battery tucks away behind the trim, or can be brought out under it when in use.

Regarding threading the cable through the small hole in the firewall, a paperclip strightened out and then formed into a small hook was passed from inside the cabin to the engine bay, and hooked with a straigtened out coat hanger shaped to form a small hook. I had string tied to the paperclip, and was then able to draw the heavy gauge cable through quite easily.

The other internals all came apart and went back together exactly as Tim describes in his comprehesive instructions for non-mechanics and non-electrical engineers like me!

RoverLander

14th October 2010, 09:13 PM

Hi All,

I’ve just returned from a 3 week 6,500K trip in the D4 3.0. I learnt some more info on the trip. As from previous posts I have a DC to DC charger installed to charge up 2 x 60 AH batteries. I was having some problems with the voltage in the D4 dropping below 12.7 resulting in the DC to DC charger not charging up the batteries.

This got worse on the trip. On several occasions and particularly while cruising in flat country at over 100KMH the voltage on the diagnostic screen would sit at 12.1V!! The car seemed quite happy to sit at that voltage. Take the foot of the accelerator and coast for a while and it would pop up to 13.7 for a little while but as soon as I resumed cruising it would drop back to 12.1V. Things were getting desperate as my second batteries were now not charging which could have resulted in warm beer!:mad:

I then remembered seeing another post about connecting accessories to the D4. Something about the car measuring total current draw by some device between the negative battery terminal and the earth on the car.

The DC to DC charger was connected directly to the positive and negative terminals of the battery. I then moved the negative connection of the DC to DC charger to a good earth point. This changed everything.:) The car then steadily ran at 13.7V while cruising. It still varied up and down between 12.7 and 14.2. Now the DC to DC charger happily charged the second batteries at 20 Amps up to 15.2V and then cycled down to a 13.1V trickle charge. No more problems!

A DC to DC charger is an option but must be wired up as described. Positive to battery and negative to earth.

The advantage of the DC to DC charger is that you get a full charge in the second batteries and that it will not let your main battery drain below 12.7V. Charging is also independent of the voltage that the D4 may decide to charge up to, which seems to be somewhere around 13.7V.

The disadvantages are the cost (about $500) and the initial charge rate may not be as fast as batteries connected through an isolator (although I’m not sure if more that 20amps is good for a battery anyway?).

Whichever type of charger you use I would suggest that you wire the negative to earth rather than the negative battery terminal.

Peter

Duck's Guts

17th October 2010, 07:48 AM

Hi All,
Whichever type of charger you use I would suggest that you wire the negative to earth rather than the negative battery terminal.

Peter, great to see that you found, what turns out to be, a simple solution.

I'm guessing that this advice also applies not only to battery chargers/isolators, but also to all other accessories. Such as driving lights and winches.
Perhaps some of the forum's illustrious auto electrickery engineers could comment?

Graeme

17th October 2010, 08:26 AM

Having been advised by peope on this forum who work at dealerships never to use the battery negative terminal for jump-starting due to the battery monitor attached to it, I am not surprised that an auxilliary battery controller or charger connected to that terminal will not function as expected.

In the same vein, I have never seen why one would want to have a wire connection between the cranking battery negative terminal and an auxilliary battery negative terminal when the best method is to use the body as the earth path, made mandatory on the D4.

stig0000

11th March 2011, 10:24 PM

I think iv writen on here b4 some were how the compleat charging sys works on the 3L... but basicly its a genorator not a aultinator...

drivesafe

5th May 2011, 04:15 AM

Hi Peter ( RoverLander ) Have you done anymore trips and do you have any more feedback info on your set ups operations?

Wilbur

6th May 2011, 07:39 AM

drivesafe

6th May 2011, 11:28 AM

In extremely cold weather, or if an accidental over-use of accessories occurred, one could become stranded.

Again another case of seeing one thing and jumping to the wrong conclusions.

Cold whether and a low battery have little to do with one another.

You can have a battery with a an SoC of 50% and the vehicle will have no problems firing up in the coldest temperatures.

Not only do I have hundreds of customers in the UK and Europe who have never had a problem in winter, I have customers up in the Arctic Circle and none have ever complained of not being able to start the D3s after a camping stay, and this is with the cranking battery being down to 50% SoC.

So that myth doesn’t hold water.

On the other hand, if your cranking battery is on it’s last legs, cold temperatures are usually the final cause of the battery giving up the ghost.

In this case it wouldn’t matter if the battery was near flat or fully charged, or whether you had an isolator or a DC-DC converter or anything else. If the battery is stuffed, it’s stuffed.

So Wilbur, once again you’re making nothing but scare mongering statements that have no substance in the real world.

As for “accidental over use of accessories”, thats what the SC80 is designed to protect against, so people won't get stranded!

Blknight.aus

6th May 2011, 11:45 AM

TerryO

6th May 2011, 12:13 PM

Here we go again... :angel:

cheers,
Terry

roamer

6th May 2011, 01:20 PM

Hi
I've got an interesting observation on charge rate.

Original LR battery has always been suspect, and I thought the aux battery and traxide had been hiding the fact, so car was going to dealer and I disconnected jumper between batteries, sure enough main battery went down to 11V overnight, dealer replaced battery.

Had run fridge off aux battery (no recharge) and it went down to 11.5v then fridge cut out.
Put on diagnostic screen it shows main battery 12.7v, (motor off)
Hooked up aux battery .
Start car voltage goes to 14.7v and stays there for 1hrs drive, no reduced voltage when motor underload (which it does when batteries are charged).

Would seem that car knew battery needed charging and did so, not going into a float stage,even though main battery was fully charged

Could be wrong, but now both batteries fully charged and all is good

Cheers Ken

drivesafe

6th May 2011, 01:28 PM

Hi roamer, this is something that may or may not be a problem, but the SC80 does hide problems with a cranking battery but it also helps a cranking battery that’s on the way out, to last that bit longer.

Still can’t make up my mind if this is a good thing or not, although it will help you get back to civilisation if your cranking battery is on the way out.

BTW this is an observation I’ve made over the last couple of years, Calcium/Calcium batteries ( the standard LR cranking battery ) seem to be much harder to load test and get a correct indication of whether the battery is OK or on it’s last legs.

Blknight.aus

6th May 2011, 03:08 PM

simple reason for that is they push out more amps for their given rating on a CCA test.

I test them as a combo battery (deep cycle test then the CCA test) on the good meter at work and that seems to pick it correctly about 80% of the time for the more exotic batteries.

the new electronic testers get them right more often as the tests have been adapted to the new battery standards, older units will give a dying battery a pass. If a calcium battery fails on an old school unit (assuming you set the test up correctly) then its well and truely dead.

drivesafe

6th May 2011, 04:01 PM

older units will give a dying battery a pass. If a calcium battery fails on an old school unit (assuming you set the test up correctly) then its well and truely dead.

This would be the reason MOST auto electricians can’t pick up a dying Ca/Ca battery and only when it is dead, is the owner assured the battery is stuffed.

Wilbur

6th May 2011, 07:37 PM

Again another case of seeing one thing and jumping to the wrong conclusions.

Cold whether and a low battery have little to do with one another.

You can have a battery with a an SoC of 50% and the vehicle will have no problems firing up in the coldest temperatures.

Not only do I have hundreds of customers in the UK and Europe who have never had a problem in winter, I have customers up in the Arctic Circle and none have ever complained of not being able to start the D3s after a camping stay, and this is with the cranking battery being down to 50% SoC.

So that myth doesn’t hold water.

On the other hand, if your cranking battery is on it’s last legs, cold temperatures are usually the final cause of the battery giving up the ghost.

In this case it wouldn’t matter if the battery was near flat or fully charged, or whether you had an isolator or a DC-DC converter or anything else. If the battery is stuffed, it’s stuffed.

So Wilbur, once again you’re making nothing but scare mongering statements that have no substance in the real world.

As for “accidental over use of accessories”, thats what the SC80 is designed to protect against, so people won't get stranded!

Yes, I agree, having a half flat cranking battery most times won't cause problems. However, motor car manufacturers tend to only spend what they need to, and would be unlikely to put in a battery of twice the needed size.

They obviously see reasonably possible circumstances that may require a fully charged battery of the capacity they specify for the vehicle.

Blknight.aus

6th May 2011, 07:44 PM

actually...

they allow for the primary starting battery (when new) to be down to about a 70-60% SOC and still be able to reliabley start the vehicle.

Graeme

6th May 2011, 09:09 PM

actually...

they allow for the primary starting battery (when new) to be down to about a 70-60% SOC and still be able to reliabley start the vehicle.
They didn't put a big enough one in the D4s for the showroom floor, with so many of them with a flat battery from people opening the doors for a squiz.

drivesafe

6th May 2011, 09:43 PM

They didn't put a big enough one in the D4s for the showroom floor, with so many of them with a flat battery from people opening the doors for a squiz.

The D4 is just the latest with this problem and is not as bad as the first version of the L322 Range Rovers.

You will often see battery chargers pushed under the showroom vehicles while customers are around.

drivesafe

6th May 2011, 09:57 PM

actually...

they allow for the primary starting battery (when new) to be down to about a 70-60% SOC and still be able to reliabley start the vehicle.

Hi Dave, I’ve tested quite a few new vehicles and taken their cranking batteries down to 20-25% SoC and had no trouble stating them and they were all cold starts.

Over 20 years ago, when I first started making the isolators, I tested a good few vehicles back then and most could be started using batteries at 30-35% SoC but a few older ( back then ) diesels would not start at much below 50% and that’s why I set the SC80 at 50% for the cut-out.

Not only have the vehicles improved, with the likes of fuel injection but today's standard cranking batteries are a quantum leap ahead of the old ones.

Wilbur

6th May 2011, 10:02 PM

actually...

they allow for the primary starting battery (when new) to be down to about a 70-60% SOC and still be able to reliabley start the vehicle.

Thanks blknight, 50% SOC (state of charge) IS well below the 70-60% required by manufacturers if what you say is correct.

drivesafe

6th May 2011, 10:40 PM

Thanks blknight, 50% SOC (state of charge) IS well below the 70-60% required by manufacturers if what you say is correct.

So Wilbur, what your saying is that 10% difference between what I use, 50% and the 60% that Dave has quoted is a huge difference but 40% lower than your claim of needing a fully charged battery to start a vehicle is not that much different.

Mate, as previously posted, you wouldn’t know what the truth was if it jumped shook your hand.

Blknight.aus

7th May 2011, 06:00 AM

yep now you can, back in the day.....

IMHO it falls into the same sort of catagory as the calcium batteries.

This "new" Style of battery that performs worlds ahead of the old batteries is still tested and speced as per the old standards so to create a rough example what was once a battery that would class as a 700CCA battery that needed to have a SOC of 70% to pass the testing standard is now a 700CCA battery that can pass the test with a SOC of 30%. (for now I'll refer to this minimum SOC as the "reserve of charge"

the problem with this is....

where an old school battery which needed a higher SOC to do the job usually dies off gradually as its capacity deminishes the new school battery which has a lower SOC requirement to do the same job keeps on cranking with no apparent loss of ability untill their capacity drops too low and then they dont have the reserve to go close enough to doing the job.

the reason behind why?

simple modern cars have a lot higher residual draw on the battery than an old school car.

unseenone

7th May 2011, 06:22 AM

Any word on when those new cable-less kits are coming?

drivesafe

7th May 2011, 06:50 AM

Hi Dave and the lowest you could repeatedly cycle, as you put it well, an “old style“ cranking battery was 50% with out harming the operating life span of the battery.

The Ca/Ca batteries haven't been round long enough to see if they can be cycled to a lower SoC and still have a good life span.

I haven’t come across anything indicating the manufacturers are are changing the 50% SoC cycle rates for Ca/Ca cranking batteries, Dave have you seen anything different to this.

drivesafe

7th May 2011, 06:51 AM

Any word on when those new cable-less kits are coming?

Hi unseenone, I’m working on the changes to the installation instructions all this weekend and will have kits ready early next week.

I’ll PM you as soon as they are ready.

Blknight.aus

7th May 2011, 07:30 AM

no the intent of that post wasnt to post the vehicle OEM spec for the SOC of the battery but more to point out that the newer batteries do the same "work" at a much lower SOC than an older battery.

Ca/Ca batteries have been around for about 10 years now the information should be out there but as the calcium batteries werent widely used outside of heavy industrial and exotic use for the first 5 years or so while the battery tech cheapend up

I've always maintained that you shouldn't discharge a lead acid battery (regardless of if its open, closed, sealed, calcium, SLA GEL, AGM or other) below about 60% soc to get maximum life and reliability out of the battery.

if you take the voltage at various stages of dischage from an old school flooded cell and a newer calcium "sealed" battery you might find it looks something like this (and yes these are made up numbers just to emphasize the point but the pattern is similar to in real life)

old school V, soc %, New school battery V , plain english as to what the expected fail point is

12V, 100%, 12V
11.5V, 90%, 11.9V
11V, 80%, 11.8v
10.5V, 70%, 11.6v, at this point if you had a new engle/wayco set to its most conservative setting it would turn off on your old school battery you might still be able to start an electronic car or a diesel
10V, 60%, 11.3v, at this point an older battery does not have the ability to power up the ECU if its cutout voltage is set to 10.5V it may crank the engine over but it wont start you probably wouldnt get a diesel to start
9.5V, 50%, 11V, on an old school battery an engle/wayco on its most agressive power use setting will have shut down and your ability to start an old school high compression petrol engine is questionableand is now at the point where its going to fall off of the voltage curve with additional loss of SOC dropping the voltage at an exponential rate.
8.5V, 40%, 10.6V the old school battery will struggle to start a low compression petrol
7V, 30%, 10.2V, the old battery will struggle with anything resembling a decent load (think headlights and parklights not startermotor) and the newer battery is now below the cut out voltage for you ECU but should still crank the engine over well enough for a start if the ECU didnt cut you off. The new battery is now going to start dropping voltage at an exponential rate with loss of SOC.
5v, 20%, 9.5V your old school battery is basically useless unless you have 2 of the same and can remove them and wire them up in series to get your start. The newer battery probably wont start a diesel but should still be able to start a petrol engine providing the ECU lets it or its old school
3v, 10%, 8v, the newer battery wont start much but will still give you your lights.

If you plot it out on a graph youd notice.

the older batteries voltage drop is linear for longer than the newer styles battery but the voltage drop rate is steeper. The newer battery is not completely linier but it stays above the older school batteries curve.

lets substitute SOC for battery health..

the old battery still falls off faster than the new battery BUT.. its ability falls off in the linear section of discharge before it hits its exponential drop. The newer battery is starting into exponential discharge and is well into the curve before it fails as a battery.

I know its not entirely accurate but for 8 oclock on saturday morning with no coffee its the best Im going to do.

Wilbur

7th May 2011, 07:49 AM

They didn't put a big enough one in the D4s for the showroom floor, with so many of them with a flat battery from people opening the doors for a squiz.

....and the same could apply to camping - people getting in and out of the car for various reasons. Having the battery half flat on top of this sounds risky.

Wilbur

7th May 2011, 07:53 AM

So Wilbur, what your saying is that 10% difference between what I use, 50% and the 60% that Dave has quoted is a huge difference but 40% lower than your claim of needing a fully charged battery to start a vehicle is not that much different.

Mate, as previously posted, you wouldn’t know what the truth was if it jumped shook your hand.

But surely there must be some reason why Land Rover spec such a large (expensive) battery? If half the capacity was adequate in all foreseeable situations, surely they would save the money and weight and fit a smaller battery?

drivesafe

7th May 2011, 08:03 AM

Wilbur

7th May 2011, 08:07 AM

First of Wilbur, the LR battery is NOT an expensive battery, it is in fact quite a moderately priced battery.

An Optima of half the size and twice the price will do the same job.

Next, again stating that a 10% difference is worse that a 40% difference is nothing but out and out dishonesty.

But even so, surely a battery half the size would be cheaper? Why would they put in a battery twice the size it needs to be?

Not sure what you mean by 10% and 40%?

bee utey

7th May 2011, 08:21 AM

But even so, surely a battery half the size would be cheaper? Why would they put in a battery twice the size it needs to be?

Not sure what you mean by 10% and 40%?

I would suggest the primary reason for choice of battery size would be to be adequate for 98% of normal customers or suchlike, ie to reduce warranty claims to an acceptable level. Most new vehicles get used daily but enough get used 1-2 times a week for this to figure in engineers calculations of battery size. This is how manufacturing works, to optimise production for lowest cost overall.

Blknight.aus

7th May 2011, 09:16 AM

But even so, surely a battery half the size would be cheaper? Why would they put in a battery twice the size it needs to be?

Not sure what you mean by 10% and 40%?

the reason they put such a large battery in is simple..

its a requirement for the electrical system to operate the vehicle for a given period of time following Alternator failure. ((Duh hows the battery supposed to help you in an emergancy if its dead?)

its also a requirement for the battery to be able to start the car reliably from a lower state of charge.

sure a battery thats just about big enough will start a vehicle from a fully cahrged condition but wont do it from say 80% charged.

you can start a td5 from a motorbike battery if you want to... try running a td5 for 30 minutes with the alternator disconnected from the same motorbike battery.

bbyer

7th May 2011, 09:58 AM

But surely there must be some reason why Land Rover spec such a large (expensive) battery? If half the capacity was adequate in all foreseeable situations, surely they would save the money and weight and fit a smaller battery? At -40C, very few batteries seem large enough, particularly when you are on the Tundra; it is dark all the time in the winter, and no go means you probably freeze to death in less than 3 hours if not properly dressed. Also my Land Rover is not by any means the only LR3 around here - there are many to the north in the land of the midnight sun and that means dark 24 hours per day and cold for five months a year, and then 24 hours of daylight for about 2 months solid and still cold.

I installed a second battery, the same CaCa as the main starting battery, using the Traxide system, not because I have a fridge to run, (that we get free here), but because I do not wish to look like the contents of the icebox.

Here in the Great White North, there is no such thing as too large a battery or battery's. It was the physically large battery and the provision for a second that most impressed me when I was looking for a new vehicle. This is the reason all Ford, Chev, and Dodge pickups here also have provision for a second battery, and most of the true field work trucks are ordered that way - nothing special so to say, just what is needed for the job - that and when in the field, we sometimes do not turn them off - some not all winter, (the diesels), and they remain running when being fuelled. I might also add the the LR3 has a very good heater and yes, my 3 to date, has always started so I guess the conditions were foreseeable by Land Rover.

I attached a typical picture of the North in the late spring; can't take a picture in the winter.

drivesafe

7th May 2011, 10:07 AM

not because I have a fridge to run, (that we get free here)

:lol2: :lol2: :lol2: :lol2:

bbyer

7th May 2011, 10:44 AM

Also we do not need a fridge to carry around treats for the polar bears either. Just peering under a hood can make you the treat. They are not herbivores and like their meat fresh, mostly seals, but they are not fussy.

Even the small one in the picture below when standing towers over an LR3. Gaining entry into anything smaller than a Kenworth is pretty easy so one does not want to be just parked anywhere.

This one is a small one, but it is hard to tell as there is nothing to scale against, very scenic background however, but not much to hide behind. The paws will give you a feel however; they can be contrasted against a typical roo's paws. Also we do not install bear bars here as it is sort of futile.

It is also difficult to find a picture of a big polar bear; you see them from a helicopter, but on the ground, for some reason, pictures are rare.

Big bears, yes, but too big a battery, have not seen one yet.

drivesafe

7th May 2011, 11:33 AM

LOVEMYRANGIE

7th May 2011, 11:48 AM

Love that bear, and if you ever come to Australia, watch out for our Koala bears, they can be really dangerous, like they tend to **** on you.

Actually, they only seem to do that when politicians hold them. Perhaps not such a dumb animal after all.

bbyer, do they mix petrol with diesel in Canada. They use to do it in some of the Scandinavian countries, to help with winter starting.

I'd be more afraid of the drop bears. You need to be careful when sitting under trees.
They're kind of a crossbreed between a Tasmanian Devil and Koala. No ones actually managed a photo yet as they keep getting their heads mauled when they drop and subsequently die :angel:

I am not a moderator, I am a human being!!!

bbyer

7th May 2011, 12:22 PM

bbyer, do they mix petrol with diesel in Canada. They use to do it in some of the Scandinavian countries, to help with winter starting. Not any more. The oil companies now blend what they call winter diesel, (Diesel #1 and variations thereof), which has a somewhat different pour point or what is properly called "low cloud point" per below.

Also attached is a BP pdf related to Australian "winter" diesel; (Alpine Diesel to be proper about it), well that must mean you guys normally use Desert Diesel, something I have never heard of here.

The Cloud Point is the temperature at which paraffin, which is naturally present in #2 diesel fuel, begins to form cloudy wax crystals. When the fuel temperature reaches the cloud point, these wax crystals flowing with the fuel coat the filter element and quickly reduce the fuel flow, starving the engine. Typical cloud point temperatures range from: -18°F (-28°C) to +20°F (-7°C), but may occasionally be as high as +40°F (4.4°C). #1 diesel fuel (or kerosene) contains very little paraffin, and therefore has cloud and pour points near -40°F (-40°C).

Also some of the big highway trucks here have fuel heaters installed to warm the diesel coming out of the fuel tank assuming it will flow out as -40C fuel is not always low enough and why once you get an engine going, you do not shut it down.

This is also one of the reasons LR is not importing the diesel engine versions here - it is just too tough to get them started and keep them running in the winter, battery or batteries regardless. Even Mercedes has its problems here - they have not got it quite figured out yet whereas Kenworth, GM, Ford, and Dodge has.

We used to pour gasoline into aircraft radial engine crankcases upon shutdown and then upon startup in the morning, the gasoline would boil out. Now, electric blankets or propane or diesel Herman Nelson heaters are more common.

Actually it is the cassowary that in your parts, scares me. They kick good - did a bit of a number on my Uncle when he was over there chasing roos in a Rover when he should have been on the rig floor. Limped for the rest of his years.

bbyer

7th May 2011, 12:42 PM

I'd be more afraid of the drop bears. You need to be careful when sitting under trees.
They're kind of a crossbreed between a Tasmanian Devil and Koala. No ones actually managed a photo yet as they keep getting their heads mauled when they drop and subsequently die :angel: I am not a moderator, I am a human being!!!

Helicopter photos of the rascals are not possible either because of the jungle canopy, so I have heard. At least our polar bears are easy to see coming at you - kind of like the Jaws movies.

I understand that Vegemite seems to protect one if you consume enough for a long enough period prior to visiting down under. Unfortunately, Vegemite is banned here in the Colony but we have all developed a good appetite for Marmite; hence I wonder if I would be protected?

LOVEMYRANGIE

7th May 2011, 12:46 PM

Helicopter photos of the rascals are not possible either because of the jungle canopy, so I have heard. At least our polar bears are easy to see coming at you - kind of like the Jaws movies.

I understand that Vegemite seems to protect one if you consume enough for a long enough period prior to visiting down under. Unfortunately, Vegemite is banned here in the Colony but we have all developed a good appetite for Marmite; hence I wonder if I would be protected?

They seem to know the difference somehow. I guess being a uniquely Australian animal they don't approve of that foreign muck! :p

I am not a moderator, I am a human being!!!

bbyer

7th May 2011, 01:12 PM

They seem to know the difference somehow. I guess being a uniquely Australian animal they don't approve of that foreign muck! :p Gee, I had hoped I was protected. I did watch all the Crocodile Dundee movies so I thought I knew everything about Australia.
At the same time, I do not seem to recall seeing Mick save the Shelia from that fate; ah well, probably because being rich, she was able to bypass the import restrictions on Vegemite and yes, there is a difference.:angel:
This is one of the reasons I find this forum so fascinating - the things I learn. One has to stay awake here. :)

RoverLander

8th May 2011, 05:25 PM

Roverlander, GSM in Queensland make an excellent DC-DC convertor that is ignition controlled rather than voltage controlled. I agree with you entirely, you always want the maximum possible charge in your cranking battery. In extremely cold weather, or if an accidental over-use of accessories occurred, one could become stranded.

Paul

Hi Paul,

I tried to find GSM Queensland to get more info but no luck... Do you have any more info please? I would like to look at the specs.

I will also post a separate update and some photos of my current setup.

Drivesafe, you may be a little upset to hear that it is working perfectly....and always with a completely full main battery... And separate set of second batteries in case I need to jump start from them.

Peter

Wilbur

8th May 2011, 06:23 PM

drivesafe

8th May 2011, 08:13 PM

Drivesafe, you may be a little upset to hear that it is working perfectly....and always with a completely full main battery... And separate set of second batteries in case I need to jump start from them.

Hi Peter, and I am neither upset nor surprised and was simply after any updates.

From what you have posted, you never gave the standard set up a real try so yes I am not surprised it works for you, it's just that others have achieved similar and better results for a fraction of the cost.

RoverLander

8th May 2011, 08:15 PM

Hi Drivesafe,
A quick update on the Dual Battery set-up and how it has been performing. I have described the setup in earlier posts. See attached photos.

After 9 months of operation and some 20K Kms all is well. Key things discovered so far:

This setup fully charges the Calcium batteries up to 15.1 volts. It then trickle charges at a constant 13.1V. This is not possible with other systems as the car will do a maximum of 14.7V. All this regardless of what the complex D4 electronics do.

The system only worked properly after moving the negative connection from the main battery to a ground on the car. There are two very convenient ground posts complete with nuts between the main battery and where my second battery is. I suspect they were put there for the purpose of grounding any accessories. Connected this way the Discovery Charging system seems to be able to detect the current draw and compensate for it.

The main battery and its complex management systems are not affected in any way from operating the way that Land Rover intended. There is simply more power drawn by the DC/DC charger just like every other accessory in the car.

Charge time for the second batteries (120AH in total) is difficult to estimate. Longest has been about 4 hours driving after several days of camping with the Waeco connected. Charge rate is 20Amp. I suspect that systems connected via Drivesafe’s system may charge faster as they are directly exposed to the charge rate output from the car. I’m not sure what the maximum charge rate for a battery is...the Redarc guys ask you to check that your battery can take 20Amps so I suspect it’s not much more.

So overall I’m very happy with the setup. It is more expensive than others but I have total piece of mind that I’m not mucking around with the D4 3.0L’s complex electric system.

A couple of photos to show where it is installed. You can see the DC/DC charger just in front of the second battery. There is a 3rd battery in the cargo area between the fridge slide and the cargo barrier.

35738

35739

35740

35741

35742
Peter

drivesafe

8th May 2011, 08:47 PM

Hi Peter and thanks for the update, going on the info you have provided, you have charged the 120 Ah from about 45% SoC to fully charged in 4 hours but, you are now going to take at least 7 hours to bring the two batteries up from 45% SoC.

That’s a lot of driving time.

This is the problem with these devices, if you find you have to add more battery capacity, the device becomes redundant. It actually become a drawback.

RoverLander

8th May 2011, 09:09 PM

Hi Drivesafe,

Not sure that I understand your post. I have 1 standard battery and 2x60AH 2nd/3rd batteries. I am charging the two extra batteries in about 4 hours driving but I cant tell you from what state of charge. All I know is that I am not concerned about the time it takes to charge them... although 10 minutes would be nice :)

Peter

RoverLander

8th May 2011, 09:15 PM

ahhh and a couple of questions Drivesafe....

What would the rate of charge into the secondary batteries be when they are directly connected to the car charging system as they would be with the Traxide?

Also do you know what the maximum charge rate is that most batteries can take?

What happens when the main battery is say at 80% SoC and the secondaries are at 50% SoC and the car is then started. How does the Traxide system now correctly charge batteries that are different SoC?

Peter

Blknight.aus

8th May 2011, 09:53 PM

comes down to the types of batteries.

good wet cells that arent below say 50% soc will take a 100Amp charge rate if you need them to but you dont want to try to push that into them once they hit about the 80% charge point..

in super simple terms and without involving the complexities of line drop, temperature, age, damage or charging with a load applied.

if you have all your batteries hooked up in parallel then the ones that have the lowest SOC will draw down on all the other batteries until the batteries all reach about the same SOC

when parallel charging the batteries that need the most current to charge take the lions share of the current until everything's equal and then the rate evens out.

drivesafe

8th May 2011, 10:11 PM

Hi again Peter, first off, from the info you posted, it’s just some basic math that gives a VERY rough idea of how low your two 60 AH batteries were when you started your drive.

On average, if you have taken 4 hours to fully charge the 120 Ah capacity you have, working backwards, ( it will make sense soon ) as it would take your DC-DC device about 90 to 120 minutes to get your batteries from around 80% to 100% SoC. Remember Dc-Dc devices do not charge the last 15-20% of the battery’s capacity at 20 amps, it tapers off as the battery reaches the last stages of it’s charge.

So this leaves 120 to 150 minutes to get the batteries up to around 80% ( about 96 Ah ), which means at 20 amps an hour, you have put 40 to 50 amperes back into you batteries, which in turn means your batteries were not likely to be any lower than about 45% SoC. This equates to about 75 Ah used.

This means if you had an SC80 system, and used the same amount of power, your cranking battery ( a 110 Ah battery ) and you two 60 Ah auxiliary batteries will only be discharged down to about 67% SoC EACH.

So it will take your alternator a lot less time to being all the batteries simultaneously back from 66% SoC to say 95% than is takes your DC-DC device to get your two 60 Ah batteries from 45% to 95%.

As to maximum charge rates, most Standby type AGMs take full inrush currents but this full inrush current can damage them if it’s too high and Standby type AGMs are actually current limited to somewhere between 20% to 35% of the total capacity. For example, a give brand of 100 Ah AGM might have a charge/discharge maximum rate of 25%, so the 100 Ah battery will only tolerate up to 25 amps of charge current.

You need to check the specs for each specific brand and model of Standby type AGM to get the exact charge/discharge maximum rate for that battery.

Flooded wet cell batteries are literally self-regulating and this means you can apply any amount of charge current you want but these types of batteries will only take what the want. This includes Ca/Ca batteries.

Last but not least, if you have one of my SC80 systems fitted then the cranking battery and the auxiliary battery would both be at 75% SoC not 80% and 50%.

unseenone

9th May 2011, 12:51 AM

drivesafe

9th May 2011, 01:28 AM

Hi Unseenone, in most cases where the D3 and D4 are concerned, the Optima D34, 55 Ah battery is a perfect fit and while there are other batteries that come close, they usually need some form of modification to be done to get them to fit.

The D34 just drops straight in.

There is a nice advantage to using the D34 in a D3 or D4. The yellow top charges at a much faster rate than most other batteries so in situations where people regularly don’t drive long enough after starting the motor, to fully charge the cranking battery, the Optima in conjunction with the way the SC80 isolator works, means the cranking battery can get a bit of a topping up from the Optima.

This helps to extend the operating life of the cranking battery that would normally, in these situations, end up going flat regularly and having a short life span.

I have had quite a few customers, who were getting low battery messages prier to fitting an SC80 DBS, but once the system was fitted, they never got the message again.

Note, this was not a planned design feature in the way the SC80 works, it just turns out to be an additional benefit to the other features of the way the SC80 works.

bbyer

9th May 2011, 02:00 AM

Duplicate message, but could not figure out how to delete it.

bbyer

9th May 2011, 02:12 AM

Because you are on a great battery explanation, let me ask a couple of added questions. Why do folks use a "yellow top" battery as a second battery with 2nd battery charging systems, versus an adding a second identical battery as OEM (in my case an MTP-H8 Interstate). . The link below is to my Gallery on disco3 where I show off my Traxide dual battery install on my LR3. The battery I used is a CaCa type that looks and acts just like the Interstate H8.

I did try to purchase an exact Interstate H8, but could not get a similar sized one to fit in the driver's side location due to the brake reservoir taking up a bit more space than desirable and also my unwillingness to trim off some plastic angle reinforcing in the lower front of the second battery box area. If I had have trimmed the plastic, I think an Interstate H6 would have fit as it is shorter in length.

My dual battery link section has a number of pdf files of locally available USA sized batteries. The battery I did install was a Made in USA Deka brand; the main reason for the CaCa type was I wanted a shallow cycle battery for engine starting purposes in cold weather, not a deep cycle for running fridges and the like.

DISCO3.CO.UK Photo Gallery - Traxide Dual Battery install in LHDrive (http://www.disco3.co.uk/gallery/thumbnails.php?album=3738)

Wilbur

9th May 2011, 06:26 PM

Hi Paul,

I tried to find GSM Queensland to get more info but no luck... Do you have any more info please? I would like to look at the specs.

I will also post a separate update and some photos of my current setup.

Drivesafe, you may be a little upset to hear that it is working perfectly....and always with a completely full main battery... And separate set of second batteries in case I need to jump start from them.

Peter

Hi Peter,

Not surprised you had trouble finding GSM.... it is actually GSL. Sorry about that.

Website is GSL Electronics | Home | Manufacturers Of Quality Power Products (http://www.gsl.com.au), phone 02 9620 9988.

I just had a look at mine, and note that it only has switch positions for Flooded Cell, AGM and Gell batteries, but not calcium. Mine is a few years old - by now they may have included calcium.

I chose this one because it is ingnition not voltage controlled, which means if a disaster happens and the cranking battery is flat, by reversing the connections the house battery can be used to charge the cranking battery. Even quite flat house batteries will be sufficient to charge the cranking battery enough for a start.

You seem to have a full understanding of how all this works - I am sure if you gave this information to Redarc they would cheerfully modify your unit, and probably be just a little embarrassed that they hadn't foreseen the problem.

Cheers,

Paul

RoverLander

9th May 2011, 08:04 PM

Thanks Paul,

I had a look. Initialy it looked good. Its great that it is ignition controlled as there is no dependency on the variable voltage we seem to get in the D4. Also 25Amp charge rate.

One problem.... there is a cooling fan in the unit! My RedArc DD/DC charger is mounted under the bonnet. Dust and sometimes water everywhere. I dont think the GSL unit would last long. The RedArc is fully sealed. It gets hot but it doesn't seem to bother it.

I had a look at the RedArc web site tonight. They have just released a new model. It charges at 40Amp and can also regulate a solar panel. Not sure but the diagram shows an ignition wire to a relay so it may also be ignition controlled. Pricey little sucker though... $670:(

BCDC1240 Available Mid April | Redarc Electronics (http://redarc.com.au/news/bcdc1240-available-mid-april)

I think I will stick with my setup for now.

Peter

RoverLander

9th May 2011, 08:39 PM

Thanks Paul,

I had a look at the GSL site. The unit looks good. 25Amp charge rate and ignition controlled so it is not impacted by variable voltage that the D4 seems to have.

One problem however... it has a cooling fan! My RedAcr is mounted under the bonnet.... dust and sometimes water everywhere. I don’t think the GSL unit would last long!

The RedArc is completely sealed. It gets fairly hot at times but this is part of the design. I had a look at the RedArc site tonight and they have just released a new unit. It charges at 40Amps and is also a Solar Panel regulator. It also seems to have an ignition wire in the diagram but I’m not sure if this controls the charging. This is one neat unit. Pricey little sucker though... $670!:(

http://redarc.com.au/products-and-services/dc-battery-chargers/bcdc1240-dc-battery-charger (http://redarc.com.au/products-and-services/dc-battery-chargers/bcdc1240-dc-battery-charger)

Guess I will just stick with what I’ve got as it works well.... I would like it to charge a little faster though based on what Drivesafe was saying.

Lots of good info guys... I love this forum! :)

Peter

drivesafe

10th May 2011, 01:34 PM

I would like it to charge a little faster though based on what Drivesafe was saying.

Hi Peter, you are in the perfect position to test out different set up configurations and see which one gives the best results for your requirements.

If you need any help with testing, post away!

bbyer

10th May 2011, 02:07 PM

. It charges at 40Amps and is also a Solar Panel regulator. It also seems to have an ignition wire in the diagram but I’m not sure if this controls the charging. This is one neat unit. Pricey little sucker though... $670!:(

http://redarc.com.au/products-and-services/dc-battery-chargers/bcdc1240-dc-battery-charger (http://redarc.com.au/products-and-services/dc-battery-chargers/bcdc1240-dc-battery-charger)

Guess I will just stick with what I’ve got as it works well.... I would like it to charge a little faster though based on what Drivesafe was saying.

Lots of good info guys... I love this forum! :) Peter

I assume I misunderstand but in reading the pdf on the RedArc website I see a solar cell set up and a wire going going to the vehicle ignition.

I assume there are no solar cells in a typical vehicle setup, but the wire to the ignition and the relay is I suppose to make certain power does not transfer from the starting battery to the fridge battery when the engine is off.

I then got to wondering if I was sitting fat, dumb, and happy in the 3 listening to the radio with the engine not running, would sooner or later, the radio stop and then I also would discover that while the beer in the fridge is nice and cold, that the 3 will not now start?

Wilbur

10th May 2011, 02:09 PM

Guess I will just stick with what I’ve got as it works well.... I would like it to charge a little faster though

Peter

There may be limits Peter, most battery manufacturers specify a maximum charging rate of 20% of battery capacity. In your case this means 120AH/5 or 24 amps.

Check with your battery supplier, but this is a common maximum charge rate.

Roger on the GSL - definitely not an under-bonnet item!

Rgds,

Paul

Wilbur

10th May 2011, 02:17 PM

I assume I misunderstand but in reading the pdf on the RedArc website I see a solar cell set up and a wire going going to the vehicle ignition.

I assume there are no solar cells in a typical vehicle setup, but the wire to the ignition and the relay is I suppose to make certain power does not transfer from the starting battery to the fridge battery when the engine is off.

I then got to wondering if I was sitting fat, dumb, and happy in the 3 listening to the radio with the engine not running, would sooner or later, the radio stop and then I also would discover that while the beer in the fridge is nice and cold, that the 3 will not now start?

Good point bbyer. They don't say much on their website - it may be ignition controlled, or it may be voltage controlled and the ignition lead is just to disable the solar panels, not to enable the DC-DC convertor. Makes their website not very useful for anyone who wants to understand what they are buying.

Don't know about the D3 but cars I am familiar with have both accessory on and ignition on positions. If this Redarc IS ignition controlled, you could connect to the "ign on" part of the car and use the radio in accessory position.

Cheers,
Paul

drivesafe

10th May 2011, 02:32 PM

There may be limits Peter, most battery manufacturers specify a maximum charging rate of 20% of battery capacity. In your case this means 120AH/5 or 24 amps.

Check with your battery supplier, but this is NOT a common maximum charge rate.

Wilbur, would you care to supply a list of the “most manufacturers”.

Most batteries used in RV use are still flooded wet cell types and derivatives of same.

As such, MOST batteries in RV use have no restrictions on the amount of charge current applied to them because they are literally self regulate themselves, based on the voltage being applied, not the current being applied.

Spiral wound AGMs like Optima actually tolerate full inrush currents when charging.

It’s only standby type AGMs and similar, that have a charger and discharge current limitation, and even this varies from one battery model and make to another, and the variations can be anything from 20% to 35%.

Taking an educated guess, I would put the number of batteries in RV use that have a flat 20% charge current limitation at about 5%, at best, of the total number of batteries in RV use.

So your statement that “MOST battery manufacturers” is nothing more than another GROSS exaggerations.

Wilbur

10th May 2011, 02:47 PM

So your statement that “MOST battery manufacturers” is nothing more than another one of your GROSS exaggerations.

Yeah, well I disagree with you, but I did suggest that Peter checks with his battery supplier. Not worth risking the batteries for the sake of a quick phone call or hunt on the web.

drivesafe

10th May 2011, 03:38 PM

Wilbur, I don’t ask whether you agreed or not, I ask would you care to supply a list of these “most manufacturers” as you claimed.

Wilbur

10th May 2011, 03:54 PM

Wilbur, I don’t ask whether you agreed or not, I ask would you care to supply a list of these “most manufacturers” as you claimed.

No, that is too time consuming, that is why I suggested Peter check with his battery supplier.

drivesafe

10th May 2011, 06:56 PM

Wilbur, would you care to supply a list of the “most manufacturers”.

So your statement that “MOST battery manufacturers” is nothing more than another GROSS exaggerations.

No, that is too time consuming, that is why I suggested Peter check with his battery supplier.

No good enough Wilbur, if people think that you're posting accurate info, they may then think they have to spend a fortune on something they just don’t need.

This specific bit of garbage about “MOST” batteries being limited to a 20% charge current will have people thing they need to have some form of charge limiting device to protect their batteries.

The reality is that even with the few batteries that do have as low as a 20% charge current limitation, because they should never be mounted under a bonnet, and as such, they will need a fair length of cable to connect them to the vehicle’s charging system. This long cable run acts as a quasi voltage/current regulator so there is no need for any form of current limiting.

I am so feed up with having to waste heaps of my time and customer’s time on the phone, explaining why they don’t need loads of gear, when customers have been scared into thinking they need to spend heaps on gear that will not benefit them, all because some know-it-all-know-nothing has posted up a load of garbage.

Wilbur, you posted up the statement, so where are all these battery manufacturers to back your claim.

One more point, more so for Peter’s benefit. Peter your batteries are Calcium/Calcium batteries and as such, are not charge current limited.

RoverLander

10th May 2011, 08:10 PM

drivesafe

10th May 2011, 08:27 PM

Hi Peter and it’s not just a case of defending my product, I’m not going to ease up until your mates stops posting up nothing but garbage.

As posted above, he’s made a statement that’s anything but correct, but even if it was, it would be virtually meaningless when everything relating to how they are used in an RV situation is factored in.

As your batteries are “SEALED” Calcium/Calcium batteries, it's the voltage you have to consider, not the current, as posted, and if the manufacturer hasn’t posted up a limitation, then any automotive situation is fine.

Note, your batteries are AUTOMOTIVE batteries, meaning they are specifically designed designed to be used in automotive situation, without the need to limit voltage or current, just connect to any alternator and let the alternator do what it’s designed to do.

BTW Peter, Calcium/Calcium batteries can charge at up to 1/3 quicker than standard flooded wet cell batteries, BUT this is only something you can take advantage of when charging off an alternator.

Blknight.aus

10th May 2011, 10:11 PM

wet cell batteries will normally handle a c1 charge rate. (assuming you can get a charger to kick that much into them and shape it the same way an alternator does)
SLA batteries the same depending on its internal construction.
gel batteries are typically .1c
AGMs dont like being pushed above .5c but if you need to you can (but it wont have a long life)

some battery manufacturer reccomend a .2C rate Because this is the most cost effective way of putting charge into a wet cell type battery and generally results in a battery being charged in a reasonable time frame not because its all the battery can handle, if it was everytime you fired up your car with your 180a alternator in it and it spiked all the amps down range from the battery voltage being low following cranking the engine over (particualarly if the crank battery was below say a 60%soc) then we'd all toast our batteries in about 6-12 months.

hows this work...

simple pushing more amps means making more heat so roughly if you push 1amp and make one degree of heat in the wire and you push 100amp and make one hundred degrees in the wire which ones being more wastefull of energy. On top of this building a low capacity charger is a lot easier and cheaper than building one that can pump the big amps

it also works on the same concept as dicharging a battery. lets take a 100 AH battery of dual purpose generic flooded cell design so we can ignore the end effect of using a high CCA battery as a deep cycle or a deep cycle as a cranking battery.

if you draw from your battery at 1AH it'll last 100 hours
at 2 it might last 48
at 5 18
at 10 7
at 20 3
at 50 1
at 100 .4

if you multiply the numbers out (If Ive guessed them up correctly) you'll notice that the harder you draw on the battery the less effective amp hours your getting out of it. the same fractioning applies to the battery. If you push 100 amps into the above battery for an hour, once the battery has "settled" it will only be about half charged (In reality it would be approaching fully charged as you would normally have disconnected the load at the 50% soc point)

Wilbur

11th May 2011, 05:54 AM

No good enough Wilbur, if people think that you're posting accurate info, they may then think they have to spend a fortune on something they just don’t need.

This specific bit of garbage about “MOST” batteries being limited to a 20% charge current will have people thing they need to have some form of charge limiting device to protect their batteries.

The reality is that even with the few batteries that do have as low as a 20% charge current limitation, because they should never be mounted under a bonnet, and as such, they will need a fair length of cable to connect them to the vehicle’s charging system. This long cable run acts as a quasi voltage/current regulator so there is no need for any form of current limiting.

I am so feed up with having to waste heaps of my time and customer’s time on the phone, explaining why they don’t need loads of gear, when customers have been scared into thinking they need to spend heaps on gear that will not benefit them, all because some know-it-all-know-nothing has posted up a load of garbage.

Wilbur, you posted up the statement, so where are all these battery manufacturers to back your claim.

One more point, more so for Peter’s benefit. Peter your batteries are Calcium/Calcium batteries and as such, are not charge current limited.

Drivesafe, I am not your enemy. I openly acknowledge that you sell a good product that has served a lot of people very well for many years.

I also believe that in these days of sophisticated vehicle electronics there is also room in the marketplace for a more sophisticated system of charging dual batteries.

Yes, it will be more expensive but for those who can afford it there can be real benefits.

Please just allow me to make posts without you getting all hot under the collar. I am not a "know-it-all-know-nothing" and I am not posting "garbage".

unseenone

11th May 2011, 06:06 AM

:bat:

Wilbur

11th May 2011, 06:14 AM

Hi Wilber, I tried ringing my battery manufacturer about 8 months ago to find out what voltage I should charge my battery up to. The nice receptionist passed me onto someone who answered as being the warehouse manager. When I asked him if I had a calcium battery he said "yes mate" but couldn't provide more info on the maximum voltage. Their web site contained no such information. Nothing available on maximum charge rate either. I suspect you are right and that a charge rate of 25 amp is safer and will help keep the batteries lasting longer. Before you jump in drivesafe, no I have no sound basis for that statement... Just a hunch.

Drivesafe, I enjoy our discussions and I know you have your product to defend from the competition but I find you overly aggressive in your responses. I respect you making your points and the informationn you provide but sometimes it's lost in your approach.

Peter

Hi Peter,

Yes, that sort of useless response is pretty common. It is sometimes hard to get onto the right person. Warehouse managers just don't really cut it for tech support.

I have found that via email both Fullriver (China) and Concorde Lifeline (USA) are very responsive and give highly detailed information. A few years ago I was working on a project using Sonnenschein batteries and they were also very helpful, but that was quite some years ago. I would expect them still to be helpful - their products are mighty expensive!

Paul

drivesafe

11th May 2011, 07:55 AM

Please just allow me to make posts without you getting all hot under the collar. I am not a "know-it-all-know-nothing" and I am not posting "garbage".

Wilbur you have to be kidding!

The very reason I posted up that you are a “Know-It-All-Know-Nothing” and that you had posted up nothing but “garbage” is because that is exactly what you are doing, posting up garbage.

The perfect example is your warning to Peter that there may be current limits for his batteries because most batteries can only be charged with 20%. Well that’s garbage.

You told Peter, in his case his batteries could only be charged with 24 amps. Again, that’s garbage.

You instructed Peter to check with his battery manufacture because this 20% charge current limit was “common”. Once again, that’s garbage.

Being as Peter has already post what type of batteries he has, he even went so far as to post pictures, and as such, if you knew the slightest bit about batteries, you would know Calcium/Calcium ( Ca/Ca ) batteries are not current limited while charging because like standard flooded wet cell batteries, they are literally current self regulating while charging.

The only thing Peter might need to do, if his batteries were NOT automotive grade Ca/Ca batteries, was check to see if they were “VOLTAGE” limited.

Again, being as Peter’s batteries ARE automotive grade Ca/Ca batteries, he can hook them straight up to his alternator, and his batteries will be fine, no matter how much current his alternator can produce. But you didn’t know that and did nothing but post up some scare mongering “GARBAGE”

And just to prove my point that unsuspecting people need to be protected against garbage like yours, Peter states, “I suspect you are right” when in reality, Wilbur, like most of your “ADVICE” this “ADVICE” is “GARBAGE and you have it completely wrong.

BTW, I’m still waiting to see your list of “most battery manufacturer’s” who state that their batteries must not be charged with more than 20% SoC.

You did make this statement, so according to you, there must be heaps of battery manufacturers making this declaration, so here is your opportunity to discredit my claim that you are posting nothing but “GARBAGE”! Post up your list!

Wilbur

11th May 2011, 10:44 AM

Wilbur you have to be kidding!

The very reason I posted up that you are a “Know-It-All-Know-Nothing” and that you had posted up nothing but “garbage” is because that is exactly what you are doing, posting up garbage.

The perfect example is your warning to Peter that there may be current limits for his batteries because most batteries can only be charged with 20%. Well that’s garbage.

You told Peter, in his case his batteries could only be charged with 24 amps. Again, that’s garbage.

You instructed Peter to check with his battery manufacture because this 20% charge current limit was “common”. Once again, that’s garbage.

Being as Peter has already post what type of batteries he has, he even went so far as to post pictures, and as such, if you knew the slightest bit about batteries, you would know Calcium/Calcium ( Ca/Ca ) batteries are not current limited while charging because like standard flooded wet cell batteries, they are literally current self regulating while charging.

The only thing Peter might need to do, if his batteries were NOT automotive grade Ca/Ca batteries, was check to see if they were “VOLTAGE” limited.

Again, being as Peter’s batteries ARE automotive grade Ca/Ca batteries, he can hook them straight up to his alternator, and his batteries will be fine, no matter how much current his alternator can produce. But you didn’t know that and did nothing but post up some scare mongering “GARBAGE”

And just to prove my point that unsuspecting people need to be protected against garbage like yours, Peter states, “I suspect you are right” when in reality, Wilbur, like most of your “ADVICE” this “ADVICE” is “GARBAGE and you have it completely wrong.

BTW, I’m still waiting to see your list of “most battery manufacturer’s” who state that their batteries must not be charged with more than 20% SoC.

You did make this statement, so according to you, there must be heaps of battery manufacturers making this declaration, so here is your opportunity to discredit my claim that you are posting nothing but “GARBAGE”! Post up your list!

Okay, fair cop on that one. I hadn't noted that Peter was using Calcium as his house batteries. If I had, I wouldn't have made that post because I haven't seen any definitive specs on Ca-Ca batteries. The only thing I have seen is a vague comment that Ca-Ca batteries can be charged at a higher rate than AGM's without over-gassing.

Apologies for that.

Would you be willing to tell me where I can see specs for Ca-Ca batteries please?

gghaggis

11th May 2011, 10:47 AM

Wilbur

11th May 2011, 11:07 AM

Hi Wilbur,

As someone who has no stake in this discussion (but finds the technical aspects interesting), it would be nice if this topic could be kept civil. However ........

Wilbur, you seem to have a habit of making firm statements of fact and then moving on to the next statement, whilst ignoring concerns posted about your earlier statement??

As an example, your statement "most manufacturers specify a maximum charging rate of 20% of battery capacity".

This is not the same as "many manufacturers specify ..." or "some manufacturers specify ..." or "in my experience, manufacturers specify ..."

Other posters, not just Drivesafe, have posted contrary opinions. I think the onus is on you to post which manufacturers you know of who actually state a maximum charging rate for a car battery. Otherwise, qualify your statements with "in my opinion/experience" etc.

I understand that Drivesafe's getting hot under the collar is upsetting you, but just reading this thread, it's easy to see that that is driven by frustration - you never seem to provide any concrete basis for your points (however, I'd agree that perhaps Drivesafe could tone down his language a little? Please??).

If it's something you can't back up, then simply retract the statement, apologise, no harm done. I've had to do the same myself on occasion :blush:

Cheers,

Gordon

Fair enough Gordon, I probably do just bash out responses without being sufficiently careful with my wording. In future I will put in a few "..in my experience"s or "many manufacturers recommend"s.

However, 'in my experience' very few people do give references supporting their posts. It can be enormously time consuming finding documentation for something that one knows as a basic truth. As I posted earlier, I am sure that blknight knows that you shouldn't put valve grinding paste in the sump, but I bet he would be hard pressed to find a reference for that.

I should also remind you that on my very first innocent post on this subject, drivesafe and blknight attacked me so hard that a newbie commented on it in his first post.

That is not the way to shut me up.

Cheers,

Paul

gghaggis

11th May 2011, 11:17 AM

drivesafe

11th May 2011, 11:28 AM

(however, I'd agree that perhaps Drivesafe could tone down his language a little? Please??).

Hi Gordon and you're right, but I just get fed up with people who go out of the way to post up bogus info, and for the life of me I can’t understand their reasoning.

Hi again Peter, I use a number of different batteries for experimenting and testing. Like a couple of Federal 6v 220 Ah batteries, a couple of Exide N200, Optimas, Amp-Tech and so on.

I also use the same battery as yours, the MRV48 ( 60Ah ) and an MRV70 ( 105Ah ) allrounder and find these batteries perform perfectly in both testing situations and in use in a D3, I have yet to carry out extensive testing in a 3Lt D4.

You on the other hand are already set up to do some experimenting both with the DC-DC device and without the device. Are you interested in trying some different set ups to see which achieves what, based on your Allrounders?

Wilbur

11th May 2011, 12:59 PM

No one's trying to "shut you up" - at least I hope not!!

However, you're skirting my point - yes it is often hard, time-consuming and even impractical to reference every point made in a discussion. Especially on points that reflect a "basic truth", as you point out. But stating something like "most manufacturers recommend" or "you can purchase item X for $Y" are statements that CAN and if asked, SHOULD be supported.

I see you've gone some way to acknowledge that in your last post to Drivesafe, so perhaps we can now move on?

Cheers,

Gordon

While I disagree with you about no one trying to shut me up, I will take it as read.

I don't think I was skirting your point - for the sake of peace I didn't point out that in my previous post on the subject, I provided (amongst other things) a graph from Fullriver batteries that proved precisely my point that you can't satisfactorily charge batteries form a low voltage. This proof was completely ignored and I was still accused of talking crap.

It gives me little incentive to go to a lot of effort to provide proof.

But I take your advice, and I will move on.

drivesafe

11th May 2011, 01:28 PM

I don't think I was skirting your point - for the sake of peace I didn't point out that in my previous post on the subject, I provided (amongst other things) a graph from Fullriver batteries that proved precisely my point that you can't satisfactorily charge batteries form a low voltage. This proof was completely ignored and I was still accused of talking crap.

Wilbur, your will say anything that pops into your head.

That graph was was NOT ignored, it was discredited, and not by me but by someone who actually uses Fullriver batteries.

Try reading all the replies again!

CaverD3

11th May 2011, 02:32 PM

Drivesafe
I can understand you getting frustrated and your frustration is not just with Wilbur but with a general idea that many think is true; that one needs a complicated system for the D3/4.

We know your system works well and there have been no issues with it. I have one but do not have a large power useage.

However there are other systems which others have fitted with no issues.

I bought yours due to it having few reported issues and any there were you sorted by informing on the correct wiring.

But I would add there are many who have discovered problems with systems by businesses that are used to fitting them on old Tojos etc.

You both have a point that the D3/4 works differently.

Maybe a good question would be: "Is there any reason why this (insert details here) set up would not work?"

drivesafe

11th May 2011, 04:01 PM

Hi CaverD3 and I agree with you, but what is needed is some HONEST independent testing and comparing.

No one is prepared to do that.

A number of 4x4 mag articles have appeared over the last couple of years but they have been so advertiser oriented that they where a total waste of time and one was so obviously weighted in favour of the big advertises that many who read the article not only commented on how unfairly biased it was but they gave the magazine credibility a big thumbs down.

As for these DC-DC devices and your comments, I have NEVER stated that these devices are not capable of fully charging batteries.

The problem arises when you read the misleading advertising used to promote these devices.

For example, one brand has a graph that shows their device can fully charge two 100Ah batteries from 75% SoC in ( from memory ) 150 minutes while, according to their graph, an alternator will take 180 minutes.

Now the info is probably correct, but where the deception comes into it is the fact that the graph started with batteries at 75% SoC.

First off, why would anyone have two 100Ah batteries if they never intend to discharge them below 75%. It would be far cheaper and more realistic to use just one battery and discharge it down to 50% SoC.

But these little anomalies don’t fit into the advertising hype.

If the graph had started with the batteries at just 5% lower, at 70%, it would show a break even situation. Not good for sales.

If the graph started with batteries at 50%, a far more realistic house battery use level, it would show the alternator fully charging the two batteries in more than an hour quicker than their DC-DC device could do. Definitely not likely to improve sales of their device.

Note, the alternator set up would be using a conventional battery isolator, if you work the same graph using one of my SC80 isolators, you would probably get at least a 2 hour advantage over their Dc-DC device.

CaverD3, this is what I mean by the need for honest independent testing.

CaverD3

11th May 2011, 04:10 PM

It's called marketing Drivesafe. :Rolling:

This is why forums are useful in that you can at least get an unbiased feel for what works and what doesn't.

The bigger adverisers get better treatment in the mags look at what Overlander did to my suspension system. :mad: :angel:

RoverLander

11th May 2011, 07:44 PM

You on the other hand are already set up to do some experimenting both with the DC-DC device and without the device. Are you interested in trying some different set ups to see which achieves what, based on your Allrounders?

Hi Drivesafe,

I've had enough experimenting in getting to the answer I have. I'm not willing to risk doing more to my car. I suspect though that experimenting would show:

SC80 charges faster than a 25AMP DC/DC converter (assuming low Soc)
DC/DC converter takes a CA/CA Battery to a fuller charge (as it can get upto 15.2V)
DC/DC converter is less disruptive because it does exactly the same thing regardless of the state of the second set of batteries. I dont know if disruptive causes issues... enough working SC80s around seem to suggest not.
It is essential that either approach connects negatives to vehicle Earth (not negative battery post) so that the D4 electronics can detect the current draw. I believe that when I had it connected to the negative battery post it resulted in the vehicle running on approx 12.6v (and not charging my second batteries).
So thanks for the offer Drivesafe but I'm going to enjoy my time going bush instead :)

Peter

** all claims above are the sole opinion of the writter and are not supported by any scientific or independent testing. Any claims for damages may be directed to our lawyers.... that should about cover me I hope :D

Blknight.aus

11th May 2011, 10:29 PM

be carful with your selection of "DC/DC Charger"

Ive blown up another one this week.... Admitedly 24/12V and not 12/12..

DC/DC chargers apparently dont like trying to charge a battery thats below its normal safe discharge level while you're also trying to run loads, more info to come if they give me another charger

not naming brands or suppliers until I can confirm whats killing them.

A new concept in battery tech is around the corner in the form of ultra high density capacitors, if you think the current arguements about battery charging are entertaining wait till we open that can of worms.

Wilbur

12th May 2011, 07:30 AM

Wilbur, your will say anything that pops into your head.

That graph was was NOT ignored, it was discredited, and not by me but by someone who actually uses Fullriver batteries.

Try reading all the replies again!

I couldn't find the bit where the Fullriver graph was discredited. What proof did this writer give in their post?

I am not sure why I have been singled out as the only one who is required to post proof for everything I post, but so be it.

I will start a new very brief thread for my last comment on this subject, and will include full proof of what I write. I just ask that anyone objecting to it also provide proof of why they object.

Redback

12th May 2011, 08:44 AM

I have a question regarding these DC-DC chargers.

Is the Arrid Twin(smart) charger a DC-DC charger:confused:

We use this in conjunction with Drivesafes SC40 and never had an issue with charging both the second battery in the car and the camper battery, I'm hoping that when we update to the SC80 for the D4, we can keep the Arrid in the camper, you know the old saying(if it ain't broke don't fix it)

Do you know if it will be OK with the D4 system, being that the Arrid is quite old:confused:

Baz.

drivesafe

12th May 2011, 10:11 AM

Hi Baz and yes it is a DC-DC converter and I also know your CT set up, when get your D4, you won’t need to change your CT set up.

Hamjam

12th May 2011, 11:07 AM

Hi RoverLander, I have the Traxide USI- 160 unit and I run 3 Batteries of this unit without any problems. I highly recommend this unit for trouble free use.
I am not in any way connected to this company and I recommend this unit only by my own experience with the USI- 160.

Regards

James

RoverLander

12th May 2011, 07:18 PM

Hi James,

Im glad your setup works and that you have no problems with it. Here's to cold beer (which I also enjoy with my setup).

Peter

drivesafe

13th May 2011, 04:26 AM

I've had enough experimenting in getting to the answer I have.

Hi Peter and to be honest, my suggestion to you to do some additional testing was really to show you, through your own testing, that you could save yourself a bucket load of money.

As already posted, when you add that new battery, you will make the use of the DC-DC device a waste of time because you will now need to do so much more driving to allow your device time to charge your batteries.

But just to give you a comparison of what you could have achieved for a lot less money.

If instead of spending around $500 for your DC-DC converter and now an additional $200 on a 3rd auxiliary battery and this doesn’t include all the additional cabling, to set up a system that will take quite a few hours of driving to charge your 3 batteries, if all your batteries are low.

OR

If you had spent say around $350 on an SC80-LR kit, which includes all the cabling, not only would you have a set up that works perfectly first time in a D4 ( you posted you had to work out how to wire your DC-DC device to eventually get it to work ), but because of the way the SC80-LR works, you would not need that 3rd battery that your current system requires, which means you would also save the loss of space and having to carry the additional weight needed to accommodate the 3rd battery.

Just a another suggestion that would actually make you some money. You could flog off your DC-DC converter on Ebay, buy and SC80-LR and by installing an SC80-LR, you would save even more money by not having to buy that 3rd battery.