Crap "dual" battery system

[B92 8NW]

I've just had a decent examine of the dual battery setup in my disco and its simply a great big heavy lead joining both positive terminals, and an earth strap on the 2nd battery. Whoever set it up was insanely stupid.

What is the recommended dual battery controller, sensibly priced and works effectively?

[incisor]

have a look at drivesafe's website www.traxide.com.au (http://www.traxide.com.au) ..

either an sc40 or an sc80 depending on your needs..

i use one and it has been great....

some prefer the big switch approach, but i am too forgetful for that to work reliably for me...

[Chenz]

I have this one installed in the Defender and it is great. The only thing I would not do again is install a deep cycle battery as the second battery as they take too long to recharge once run down. On the other side they take longer to run down.

The Piranha DBE 150S MKII Electronic Isolator
https://www.aulro.com/afvb/

The Piranha DBE 150S MKII Electronic Isolator is our new generation of isolator expanding on the DBE 100S and DBE 150S. It has all the positive features of both predecessors and includes even more reliable circuitry and mountings. It also has a LED display to indicate when the auxiliary battery is charging. The major benefits being: 1.5 Year Warranty 2.LED Indicator 3.Military Spec. ABS Plastic 4.The installation kit includes cable, earth strap, heat shrink and terminals 5.DBE 150S MKII is suitable for all vehicles 6.Voltage Sensing Isolators -optimises alternator output to dissimilar batteries 7.Electronic current limiting. 8.Spike protection 9.Starts on main battery only 10.Australian built 11.3/5 year warranty 12.Well Priced The improved housing is now military grade and the warranty on the DBE 150S MKII has been increased to 5 years unlimited kilometres.

https://www.aulro.com/afvb/

Contact Piranha for more information on the Electronic Battery Isolator (http://www.piranhaoffroad.com.au/contactus.htm?comments=Please%20send%20me%20some%2 0information%20on%20the%20Eectronic%20Battery%20Is olator)

[WedWon]

Hi Joel
From an affordability point of view, you could mount a relay in the positive to positive lead (probably need to use a relay mounting block) and wire it to the ignition circuit. Then run most of your power hungry accessories off the second battery.
When the ignition's on (engine running) the second battery charges, when the ignition's off (engine off) the second battery (and accessories) will not pull the primary battery down.
And if your primary battery does run low (lights left on or something silly) the ignition activated relay will effectivly jump start the primary battery from the second one
Total cost about $80.00 (relay, relay base and possible a second fuse box to run the accessories through)

Cheers

Jason

[awabbit6]

I have a DualMate system. I fitted it 12 months ago and it's great. All automatic with digital voltage display for both batteries (which others don't have) and visual and audible alarms when something goes wrong. They can be bought direct from the manufacturer in WA and he posts anywhere in Aust. I think they retail for $299 and are well worth it.
You can download the manual from his website to have a good look at the features and installation:

http://www.acecom.com.au/dualmate.htm

[drivesafe]

Hi Joel, before you do anything, what do you intend to mostly use your auxiliary battery for.

This can make deciding on the type of controller a lot simpler.

Cheers.

[streaky]

I have this one installed in the Defender and it is great. The only thing I would not do again is install a deep cycle battery as the second battery as they take too long to recharge once run down. On the other side they take longer to run down.

The Piranha DBE 150S MKII Electronic Isolator
http://www.piranhaoffroad.com.au/images/Battery/150_s2/DBE150SMKII.jpg

The Piranha DBE 150S MKII Electronic Isolator is our new generation of isolator expanding on the DBE 100S and DBE 150S. It has all the positive features of both predecessors and includes even more reliable circuitry and mountings. It also has a LED display to indicate when the auxiliary battery is charging. The major benefits being: 1.5 Year Warranty 2.LED Indicator 3.Military Spec. ABS Plastic 4.The installation kit includes cable, earth strap, heat shrink and terminals 5.DBE 150S MKII is suitable for all vehicles 6.Voltage Sensing Isolators -optimises alternator output to dissimilar batteries 7.Electronic current limiting. 8.Spike protection 9.Starts on main battery only 10.Australian built 11.3/5 year warranty 12.Well Priced The improved housing is now military grade and the warranty on the DBE 150S MKII has been increased to 5 years unlimited kilometres.

http://www.piranhaoffroad.com.au/images/Battery/150_s2/DBE150SMKII%20wiring.jpg

Contact Piranha for more information on the Electronic Battery Isolator (http://www.piranhaoffroad.com.au/contactus.htm?comments=Please%20send%20me%20some%2 0information%20on%20the%20Eectronic%20Battery%20Is olator)

I just bought one of those.....mine looks different though. The main components box is a grey colour....no bling label on it.
Has anyone ever fried one of these DBE 150S units because of too higher temperature under the bonnet?

I have been using a constantly rated solenoid and relay for the past 7 years on my Discovery. I found it to be reliable in use apart from having to occsasionally replace the components as they got older.
I also heard through a couple of forums that solenoids can create spikes which could end up damaging my ECU...hence I went all out and bought the Piranah unit.
I have not yet installed it and was hoping for some feed back regarding the under bonnet temperatures etc.

Regards.

S.

[drivesafe]

Spike protection is not done to protect your precious ECU, it’s done to protect the device that it is in and every device you buy for automotive electrical use has spike protection built-in, even your humble relays used for your headlights has spike suppression built-in.

This type of advertising is just done to make you think the item is doing you a big favour when in actual fact, the protection has to be there to protect the device that is advertising it.

Your ECU is already self protected with similar spike protection BUT the biggest spike producer on any vehicle is your starter motor solenoid and it doesn't have spike protection yet your ECU still works fine.

Be careful of some of the hype you read and this is not aimed specificity at any one brand because a hell of a lot of brands make similar claims and the point is, if they didn’t put the spike suppression in, the only device that would be damaged is their own.

Cheers

[Nathan]

I've had an ARB one and it's worked well for quite a few years - reasonably priced as well, for ARB... :p

Nathan

[97discotdi]

I have a Redarc battery isolator seperates batteries when voltage drops below 12.5V and charges main battery first untill it reaches 13.2V then starts charging 2nd battery. Has a dash mounted switch to parrallel the batteries if required for starting. Cost $100 seems good:D

[amtravic1]

I have a Pirahna one and it works ok as far as I can tell. If I was you I would buy one from the person that supports this forum. I have one of Drivesafes units as well but as the Pirahna one still works I have not fitted it yet. I like the way the Drivesafes units can keep the batteries connected down to a preset voltage. The only question I have about that is that I usually run accessories from the second battery (power tool chargers etc) and I have a voltage sensing alarm.

Ian

[drivesafe]

I have a voltage sensing alarm.

Ian

Hi Ian, any idea of what the setting is in your voltage sensing alarm is.

Cheers.

[County3.9]

I have a Redarc battery isolator seperates batteries when voltage drops below 12.5V and charges main battery first untill it reaches 13.2V then starts charging 2nd battery. Has a dash mounted switch to parrallel the batteries if required for starting. Cost $100 seems good:D

I've got a similar set-up with a marine voltage sensitive relay. Tough, no voltage drop (like a diode isolator), simple and designed to withstand marine environments, and only about $100 from BIAS boat shops.

[DerekB]

I've just had a decent examine of the dual battery setup in my disco and its simply a great big heavy lead joining both positive terminals, and an earth strap on the 2nd battery. Whoever set it up was insanely stupid.

What is the recommended dual battery controller, sensibly priced and works effectively?

When deciding on an isolator you need to decide what you will be using it for and also the battery type and size.

The Redarc, Piranha, Sidewinder and Trackside all have their place.

The more advanced units will take the alternator charge and direct it to the battery that requires the charge. Like my friend drivesafe has said, spike protection is included in most circuits and isolators now have it as well but is a double up in protection.

[George130]

I don't know what mine is. It's a maze of wires and there is a red flashing LED:). It starts and the LED makes me feel good when I look in there and wonder what it all is.

[camel_landy]

I've just had a decent examine of the dual battery setup in my disco and its simply a great big heavy lead joining both positive terminals, and an earth strap on the 2nd battery. Whoever set it up was insanely stupid.

What is the recommended dual battery controller, sensibly priced and works effectively?

Nothing wrong with that setup... It just depends what you want it to deliver.

Wiring the batteries in parallel, like that, is quite common if you're doing a lot of winching. However, if you want to run things like fridges while camping, the split charge is definately the way to go.

M

[drivesafe]

Wiring the batteries in parallel, like that, is quite common if you're doing a lot of winching. However, if you want to run things like fridges while camping, the split charge is definately the way to go.

M

Hi camel_landy, I’ll just do a bit of interpreting for you. ;)

For the non British amongst us, Split Charge is the pome name foe a dual battery set-up.

Cheers

[camel_landy]

Hi camel_landy, I’ll just do a bit of interpreting for you. ;)

For the non British amongst us, Split Charge is the pome name foe a dual battery set-up.

Cheers

Yeah, I'm familiar with the terms...

I was just pointing out to Joel that his statement:


Whoever set it up was insanely stupid.

...Many not actually be the case as there are legitimate reasons why you may want to wire a pair of batteries in series. :p In fact, IIRC the old RaRo TurboD used to have just that. 2x batteries, wired in parallel, just so there was enough grunt to start the fecker!

Maybe he was a little bit silly for assuming that just coz there were a pair of batteries in the car, they were isolated from each other. There's not enough information in thread to gauge. ;)

M

[drivesafe]

Yeah, I'm familiar with the terms...

You would be but I think you will find most over here would not be and the info was for their benefit.


...Many not actually be the case as there are legitimate reasons why you may want to wire a pair of batteries in series. :p In fact, IIRC the old RaRo TurboD used to have just that. 2x batteries, wired in parallel, just so there was enough grunt to start the fecker!

Maybe he was a little bit silly for assuming that just coz there were a pair of batteries in the car, they were isolated from each other. There's not enough information in thread to gauge. ;)

M

Yep, a lot of yotas come with two paralleled starting batteries but none of the discos sold here came with dual starting batteries as standard.

I think Joel’s suspicions are pretty well on track, that it was a sus attempt at doing a dual battery set-up.

Cheers

[scrambler]

Drivesafe, what wold the characteristics be if you had a standard cranking battery in parallel with a deep-cycle? Would you get high CCA with a "tail" of charge from the deep cycle? OR would you just wreck both of them?

Not planning on doing it, just wondering.

[drivesafe]

Hi Steve, I’ve never found any real problem with paralleling dissimilar batteries and we have been doing so for many years.

A couple of thing to consider though, standard deep cycle wet cell batteries are not designed for large current dischargers but they will still start a vehicle and doing so, once every blue moon, will not have any real detrimental effect on the life span of these batteries.

On the other hand, if you continuously use this type of battery for cranking, you are going to shorten it’s operating life.

In the case of you question, as you are sharing the load over two batteries, effects on a standard deep cycle wet cell battery is not going to be as hard so although you will probably still shorten its operating life span, this will probably be only a minimal difference and on the flip side, again because you are sharing the load, you will probably extend the operating life of the cranking battery.

In both cases though, the differences would only be marginal.

Another point to keep in mind when paralleling dissimilar batteries, they will most likely charge at different rates meaning it will take longer to charge one type of battery compered to the other.

This again is not a major problem, particularly if either you do a long drive after using them or if they have only had a small amount of their power used before starting to charge them.

If you do discharge them down a few bit and then drive for only and hour or so, when you stop the motor, there is a good chance that one battery will have a higher State of Charge ( SoC ) than the other.

What will happen in this situation is that the lower charged battery will simply burn off the higher battery’s SoC difference until the higher charged battery has the same SoC as the lower battery and this will not cause any problems, it will just be a waste of power.

No matter how high the higher battery’s SoC is or how low the lower battery’s SoC is, both batteries will eventually end up with the same SoC as the lowest battery and the lower charge battery WILL NOT gain any charge at all.

Cheers and hope this answers your question.

[Chenz]

Hi Steve, I’ve never found any real problem with paralleling dissimilar batteries and we have been doing so for many years.

A couple of thing to consider though, standard deep cycle wet cell batteries are not designed for large current dischargers but they will still start a vehicle and doing so, once every blue moon, will not have any real detrimental effect on the life span of these batteries.

On the other hand, if you continuously use this type of battery for cranking, you are going to shorten it’s operating life.

In the case of you question, as you are sharing the load over two batteries, effects on a standard deep cycle wet cell battery is not going to be as hard so although you will probably still shorten its operating life span, this will probably be only a minimal difference and on the flip side, again because you are sharing the load, you will probably extend the operating life of the cranking battery.

In both cases though, the differences would only be marginal.

Another point to keep in mind when paralleling dissimilar batteries, they will most likely charge at different rates meaning it will take longer to charge one type of battery compered to the other.

This again is not a major problem, particularly if either you do a long drive after using them or if they have only had a small amount of their power used before starting to charge them.

If you do discharge them down a few bit and then drive for only and hour or so, when you stop the motor, there is a good chance that one battery will have a higher State of Charge ( SoC ) than the other.

What will happen in this situation is that the lower charged battery will simply burn off the higher battery’s SoC difference until the higher charged battery has the same SoC as the lower battery and this will not cause any problems, it will just be a waste of power.

No matter how high the higher battery’s SoC is or how low the lower battery’s SoC is, both batteries will eventually end up with the same SoC as the lowest battery and the lower charge battery WILL NOT gain any charge at all.

Cheers and hope this answers your question.

The $64 question is then how can you charge up a deep cycle battery quicker. The problem I had on my last trip was on days where we cranked the k's the deep cycle one only just got back to full charge but when we stopped for a few days at a "nice spot" the battery ran right down powering the fridge etc. Then it took heaps to get it back up again.

Can you fit a bigger alternator or some other way of getting the charge back in quicker.

[B92 8NW]

You could fit solar chargers, or bin the A/C and fit dual alternators, or bin the standard alternator and shoehorn a big Bosch one in. A less permanent solution would be one of those small 2stroke battery chargers.

[drivesafe]

The $64 question is then how can you charge up a deep cycle battery quicker. The problem I had on my last trip was on days where we cranked the k's the deep cycle one only just got back to full charge but when we stopped for a few days at a "nice spot" the battery ran right down powering the fridge etc. Then it took heaps to get it back up again.

Can you fit a bigger alternator or some other way of getting the charge back in quicker.

Hi Chenz, the short answer is, to shorten the charging time and as such speed up the charging of any automotive battery, you need to increase the charge voltage.

Current is nowhere as much an issue as voltage is when it come to the time it takes to charge a battery.

Now the seemingly obvious thing to do is to raise your regulator voltage.

Surprisingly though, this usually is not the end all to the problem.

You need to start by measuring the voltage at your cranking battery, while the motor is running and you need to measure the voltage at your auxiliary battery.

The voltage at the auxiliary battery can vary greatly, depending on the State of Charge ( SoC ) of the auxiliary battery, the length of cable between the two batteries and probably the most important item, the thickness of the cable.

Anyone of the above can cause an unnecessary voltage drop that will have a major effect on how your dual battery system performs

These and bad earth returns cause most of the problems with auxiliary batteries not charging properly.

Of the above, using too thin a cable and/or not installing a negative cable probably accounts for about 90% of under performing dual battery system's problems.

Cheers.

[modman]

like drivesafe says above, take accurate readings of the voltage going into the aux battery with stereo, a/c fan and fridge running. i'v installed a few duel battery systems for mates since i'm a sparky and the old man used to teach auto elec. i allways link the batteries with minimun 10mm 2 core double insulated flex when the battery is in the same vehicle, 16mm when the battery is in a trailer/van.
after the poxana bd 150 s(hit) died a coulpe of months ago and took out a exide orbital blue top ($320) i am constructing a voodoo doll of poxana parts that have died. they have offered to fix the controller for free but i will never trust it again, certainly not with a gel cell ($) connected to it.
david

[amtravic1]

Hi Ian, any idea of what the setting is in your voltage sensing alarm is.

Cheers.

I don't know if the alarm triggers at a preset voltage. I think it operates more on the principal of a sudden voltage loss such as opening the door and the interior lights causing a voltage drop, however that does not work since I fitted led globes to the interior lights. The alarm is a Cobra brand.
I run 12 volt chargers regularly during day often dropping the second battery to quite low voltage. Also the alarm works the central locking and when I go camping and have the fridge running I suspect the fridge starting will set the alarm off if the batteries are not completely isolated. I may be wrong about the way the alarm works but I cant find the instructions, they are in the garage somewhere.
I have noticed recently that the alarm is of little use anyway. people just smash your windows, take what they want and everyone else just ignores the alarm. Probably better with just an ignition cut out so the whole car cant be taken!

thanks,
Ian

[drivesafe]

Hi Ian, after both designing and manufacturing car alarms and working in the security business for many years, some years ago now, I've found the best security is exactly what you posted.

An engine immobiliser is the best way to give your vehicle SOME protection. If they really want your wheels, they will knock it off with a tow truck, but for protection against the average car thief, an engine immobiliser is the way and as you have unfortunately already found out, there is no real protection against smash and grab thieves.

If decide to remove the Cobra then the SC40 will cause no problems with anything else in the vehicle.

Cheers.