lithium dual battery ideas

[Macadamia]

share with me your lithium aux battery setups for inspo.

I've had a traxide USI-160 setup for the last nearly two years and have never really been overly happy with it. realistically an 85ah AGM battery (with usable 45ah?) isn't much use for more than a few days off grid. Even in shared mode when both batteries were relatively new, I'd barely get a couple of days use out of it - running only fridge, camp lights and occasionally a water pump. And that is with a permanently mounted 100w solar panel on the roof.

my cranking battery SS88TI recently failed just outside the 2 year warranty and now my aux battery HVT-70LD is struggling to hold charge at only a year and a half old. And this is happening even with connecting an external battery charger to the rear anderson more than a few times every month. In shared mode there's a constant parasitic draw by the aux battery but without it in shared mode, since resetting the BMS with the new cranking battery, the smart alternator sees the cranking battery in good health and only intermittently charges - not enough to top of the aux battery.

I was thinking of getting a couple of 120ah lithium batteries in the 3rd row foot well or a thin 120ah lithium behind the rear left boot trim where the rear air con would normally be. have an ignition controlled isolator to a ?40amp DCDC charger. Thoughts? Even 1x 120ah lithium is likely to provide more usable capacity than the ss88ti + HVT70LD in shared mode.

[John_D4]

Tim from Traxxide is really knowledgeable in this area and knows the D4 quite well

[scarry]

Interested to see how you go,i have the same issue,and have been thinking what to do.

Different brand vehicle,no smart alternator,with Traxide DT 90,lucky to get two days,usually 1 1/2, out of fully charged batteries,the Aux is 105AH,AGM,which fits under bonnet.

Both the start and Aux are almost 3 yrs old and tired,and i charge them up separately at least once a month,often twice a month,overnight,but still only lasted 3 yrs.

I can fit a Lithium Aux,100/120/130AH under bonnet,with 40A DC/DC,many do this with no issues,and have been doing it for a few years.Leave the start as a wet cell,as it is now.I dont really want a battery in the vehicle.
But that is huge money,around $500 for the DC/DC,anything from $1K upwards for a lithium,when i can get another AGM,for around $400 or less,SS whatever they are,stay with DT90,then i should be fine for another 3 yrs.And in 3yrs time the Lithium tech will probably be even better.

Going lithium i may also need a low voltage cut out module,many use a Victron.So more $.They seem to use hardly any power.ATM the DT 90 is the low voltage cut out.

Not greatly concerned about the $,more so is it worth paying for a lot more for not much gain?Or will it be heaps more gain?I don't know,depends who you listen to.

My son now has a 300W solar blanket,so i was thinking maybe borrow that and use with a new AGM.

[drivesafe]

Hi Maca and I go through this type of situation with my customers, once or twice a week, and more so since Covid.

The problem is not the isolator, or the batteries, or even your vehicle.

It is the way you use your vehicle.

I bet you either do lots of short drives and/or leave the D4 for long periods, because what you have described indicates a classic case of badly sulphated batteries.

If you are interested in seeing if you can recover your existing batteries, have a look at the two links below.


Scroll down the page till you get to “LOAD TEST”
https://www.aulro.com/afvb/the-verandah/246755-line-auto-electrical-info-10.html


Scroll down the page till you get to “Battery Maintenance”
https://www.aulro.com/afvb/the-verandah/246755-line-auto-electrical-info-8.html



With the setup you have, when the batteries are in good condition, even if they are discharged down to the lowest level the isolator will allow, because you can replace that used battery capacity with a constant 100+ amps while driving, in a little over an hours driving, you can have both batteries at over 95% SoC.

Now if you still want to go to lithiums, you may find you have a very expensive but just as disappointing setup, and for the very same reasons.

The problem is now the recharge time.

You could safely use a 50 amp DC/DC device and in a perfect world, you will still be looking at at least 6 hours of constant driving to get those batteries up over 95% SoC.

But because your D4 has a SMART alternator, which you have already pointed out that the voltage drops when the cranking battery is full, most modern DC/DC devices have a maximum INPUT current limit.

With older and some of the cheaper new DC/DC devices, as the INPUT VOLTAGE drops, to be able to maintain a constant OUTPUT CURRENT, these devices increase their draw on the INPUT CURRENT from the vehicle.

This input current draw can be massive and I read of one guy in New Zealand, who was monitoring both input voltage and current as well as the output voltage and current and he noted that his 50 amp DC/DC device was pulling in 98 amps and only charging his batteries at 46 amps. And note, the input voltage was something like 13.5v, which is not that low.

It is pretty obvious what the potential danger is with such a setup.

With new good quality DC/DC devices, for safety reasons, the INPUT current draw is limited, so while the input voltage is high, say 14.5v, the OUTPUT Charging current might be 50 amps.

But as the voltage drops, because the input current is limited, at 13.0v input voltage, you might be getting as little as 30 amp output charging current and at 12.5v, a common operating voltage for any vehicle with a SMART alternator, who knows how little the charging currents is.

So again, as I posted above, your recharge time for those batteries, if in a low state, could be quite a bit longer than 6 hours driving time.


SPECIAL NOTE, if you go lithium batteries, you will need a DC/DC charger that can charge lithium batteries and make sure you set it to IGNITION sense NOT voltage sense, because while the IGNITION will reduce the output charging voltage when the D4’s voltage is low.

With the VOLTAGE setting selected, which most so called experts use, when the D4’s voltage drops below 12.7v, the DC/DC deice will turn off and not charge at all.

[jwb]

I too have the Traxide full setup in my D4.
I'm waiting on delivery of a Defender and need to set up the D4 in case it's needed for our trip next month. My approach is a 'semi-transferable' setup that will transition to a permanent fitout in the L663 (if/when it arrives!)

Battery - PowerPaul Cub Scout 190Ah, 250A BMS
Case - Aldi battery box with a bunch of connectors ready to go so I don't have to source and wire those in the short term.
the battery comfortably fits in the box and I can just secure it in the cargo space initially.
Charger - Victron DCDC 12/30A
I will use the Traxide rear anderson plug to feed the DCDC charger by pulling it into the cargo space.
System will run a 3000W inverter, induction cooktop, coffee machine, 75L fridge/freezer, travel oven as I am not going to use gas anymore.
In the D4 I will still have use of the Traxide set up as well as the lithium and they will be separated while in camp.
Permanent solution will include Victron MPPT solar charger for solar charging.
You'll find PowerPaul on Facebook and he's going to soon have more battery options including slim format. Passion for quality in a locally made and supported product.

[drivesafe]

Both the start and Aux are almost 3 yrs old and tired,and i charge them up separately at least once a month,often twice a month,overnight,but still only lasted 3 yrs.
Hi Scarry, you first need to totally reverse the effects of Sulphation, before you do the once a month followup.

Doing a once-a-month charge does not reduce the sulhpration by much and it soon builds up again.

You need to get rid of as much as the sulphating as you can and then the Once-A-Month charging will help keep sulphating at bay.

Again I suggest you follow the info in the links.

[drivesafe]

You'll find PowerPaul on Facebook and he's going to soon have more battery options including slim format. Passion for quality in a locally made and supported product.
I have been following his Facebook page for quite a while and he sure knows his stuff.

[Macadamia]

I bet you either do lots of short drives and/or leave the D4 for long periods, because what you have described indicates a classic case of badly sulphated batteries.


negative. I drive >30 minutes 2x day, 4x a week. At least twice a week the trip takes up to an hour. Very rarely is the car left for more than a few days. I don't doubt the batteries are sulphated but it won't be because of the reasons you've suggested it is.




If you are interested in seeing if you can recover your existing batteries, have a look at the two links below.


Scroll down the page till you get to “LOAD TEST”
https://www.aulro.com/afvb/the-verandah/246755-line-auto-electrical-info-10.html


Scroll down the page till you get to “Battery Maintenance”
https://www.aulro.com/afvb/the-verandah/246755-line-auto-electrical-info-8.html



I've tried the battery maintenance before with no noticeable effect.

I appreciate the advantage of your systems is charge time but for my purposes - when I'm driving on a trip, I'm driving for a good while, at least a few hours between camps sometimes a lot more, then spending a few nights before moving on. So charge time is less of an issue than capacity is.

If it's weekly or more that someone is having similar issues of premature battery failure, batteries overly sulphating, batteries not charging sufficiently, then perhaps it's just not a suitable setup for a car with a smart alternator? An ignition sensing DCDC charger would at least draw down on the cranking battery when the car is on which would trigger the BMS to ramp up the smart alternator charging.

[veebs]

I appreciate the advantage of your systems is charge time but for my purposes - when I'm driving on a trip, I'm driving for a good while, at least a few hours between camps sometimes a lot more, then spending a few nights before moving on. So charge time is less of an issue than capacity is.

If it's weekly or more that someone is having similar issues of premature battery failure, batteries overly sulphating, batteries not charging sufficiently, then perhaps it's just not a suitable setup for a car with a smart alternator? An ignition sensing DCDC charger would at least draw down on the cranking battery when the car is on which would trigger the BMS to ramp up the smart alternator charging.

The Traxide should be helping on both fronts - draws from the starter and aux with the engine off to maximise capacity, then charges both with the engine on. ie, it ramps up the voltage just as you describe?

That said, my USI160 failed recently, forcing me to link the batteries directly together full time as a workaround. I ended up with far more capacity than I had ever had with the isolator installed - the voltage in the car was higher in the morning than it had been previously (with a fridge running in the back overnight). I accept of course, this is hardly a scientific process, but options were limited whilst on holiday... The difference was start though - typically seeing 12.2 or so at first, and 12.6 after linking. Both, after receiving a full charge prior. I suspect my USI160 unit was faulty for a while though, as the red plastic caps on the terminals had melted on from the heat it was producing!

[drivesafe]

negative. I drive >30 minutes 2x day, 4x a week. At least twice a week the trip takes up to an hour. Very rarely is the car left for more than a few days. I don't doubt the batteries are sulphated but it won't be because of the reasons you've suggested it is.



I've tried the battery maintenance before with no noticeable effect.

I appreciate the advantage of your systems is charge time but for my purposes - when I'm driving on a trip, I'm driving for a good while, at least a few hours between camps sometimes a lot more, then spending a few nights before moving on. So charge time is less of an issue than capacity is.

If it's weekly or more that someone is having similar issues of premature battery failure, batteries overly sulphating, batteries not charging sufficiently, then perhaps it's just not a suitable setup for a car with a smart alternator? An ignition sensing DCDC charger would at least draw down on the cranking battery when the car is on which would trigger the BMS to ramp up the smart alternator charging.

Sorry Maca but it does not work that way.

If the DC/DC device did draw down on your cranking battery while the motor was running, it would mean your alternator was stuffed.

While your motor is running, nothing draws from ANY battery. Your alternator does all the work of supplying power for what ever needs it, including a DC/DC device.

Have you monitored the voltage at your cranking battery, preferable with something that logs the info, like a BM2 monitor.

The reason I ask is that both of your batteries are having short lifespans and this has nothing to do with the Traxide isolator.

It may be the operating voltage of your alternator.

Again, the Traxide isolator is highly unlikely to cause the issue you have.

As there are over 5,000 D3s and D4, worldwide, fitted with Traxide isolators, if there was such a problem, it would have well and truely shown up by now.

With the milage you are doing, you should not be having such short battery life, so again, can you monitor your operating voltages, particularly straight after starting the motor, because I suspect the problem you have will not go away for your cranking battery just because you fit a DC/DC device.

[rocket rod]

This is something I've done and has been working fine.

Lithium Battery Install Instructions (aulro.com) (https://www.aulro.com/afvb/projects-and-tutorials/276570-lithium-battery-install-instructions.html)

[drivesafe]

Hi Rod and that is all good and well but going to a lithium auxiliary battery is not going to fix Maca’s problem and he will still get a short cranking battery operating lifespan.

As I posted, with around 5,000 D3s and D4 with the Traxide systems and VERY few are having problems, particularly like Macas, and with a few hundred customers in Australia now using the SSB batteries and again, VERY few have had any issues, Macas problem is solely with his vehicle.

With the way Maca drives his D4, his batteries should be fully charged and in perfect condition and should last for years more than they are.

I have asked could he monitor the operating voltage while driving, and this is to see if there is a charging algorithm issue.

I have come across charging problems a number of times.

A while back there was a common issue where the D4’s BMS would operate the alternator at 12.2v and allow the D4’s own electrical load to discharge the cranking battery down to 12.2v.

As soon as the BMS detected the cranking battery had been discharged down to 12.2v, the alternators voltage was then be set at a constant 14.7v and remained there while the BMS monitored how fast the battery recharged and how much current was used to recharge the battery.

This was a very clever way to periodically determine the condition of the cranking battery.

BUT in a small number of vehicles, once the cranking battery discharged down to 12.2v, the BMS did NOT increase the alternator voltage and it sat continuously at 12.2v.

As an example of what was going on at the time. I had one customer, who had a pretty good idea of how the electrics in his D4 should be operating but was having a problem with low operating voltages and took his D4 to the dealers.

Like all good dealerships, the first thing they did was point at the Traxide system and told him “That was his problem” and that’s all they did to “FIX” his problem.

Out of frustration, he called me on his way home from the dealers and a plan was struck, to disconnect the Traxide Isolator’s Positive ( + ) cables from the two batteries and leave them disconnected.

I also told him about a software patch that should have been applied to his D4 during one of its services.

As he was not going away for at least a month, after disconnecting the cables, he gave the Optima a good charge, which would keep the battery in good condition for the month.

Then a month later, after seeing the voltage at a constant 12.2v and only rising to 12.3v on a couple of occasions, he took his D4 back to the dealers.

Right on form, the first thing the dealer’s service people said was that the Traxide Isolator was the problem.

He told them it had not been connected to the vehicle for the passed month and that the problem was most likely a software patch that had been overlook by the dealer’s service staff.

They check their records and sure enough, they had not installed the patch.

He was phoning me from his D4 as he drove home from the dealers and he told me his volt meter was displaying 14.7v

Maca, I am wondering if you have the opposite problem.

When the D4 was first sold in Australia, they came with a Wet Cell cranking battery, but part the way through the run, they changed to an AGM cranking battery.

With the wet cell battery, a D4 alternator voltage, particularly during cold weather, could see voltages in excess of 15.0v, which is fine for any wet cell battery.

Once they changed to the AGM cranking batteries, no matter how cold it gets, the voltage applied to the AGM cranking battery never rises above 14.7v

So I am wondering if your D4 was originally supplied with a wet cell cranking battery and the charging software to go with it and at some stage the cranking battery was charged to an AGM but the software has not been upgraded.

AGM batteries can tolerate 15v for a short time WHILE COLD, but once warm, 15v would progressively cook your batteries.

Again, you need to monitor your operating voltages because changing to a DC/DC and lithium battery, 15v would be OK for the lithium battery but if your voltages are high, your are still going to slowly cook your cranking batteries.


Just a suggestion.

[Macadamia]

Have you monitored the voltage at your cranking battery, preferable with something that logs the info, like a BM2 monitor.


This is a seven day graph of the battery state. the first few days pictured are in shared mode and you can see how the aux battery is draining the *BRAND NEW* cranking battery down to a low state of charge in just a half day period. The last few days are in isolated mode and show the cranking battery maintaining it's charge without the drain from the aux/traxide.

186126

The only thing drawing from the aux battery during this time is a dash cam + one of your AGB25 which I have measured is only drawing 0.4a together.

While driving, the alternator is either pumping out ~12.2v, 13.1v or 14.4v (presumably depending on the state of the cranking battery) so I don't think the issue lies with the BMS/alternator charging.

[drivesafe]

This is a seven day graph of the battery state. the first few days pictured are in shared mode and you can see how the aux battery is draining the *BRAND NEW* cranking battery down to a low state of charge in just a half day period. The last few days are in isolated mode and show the cranking battery maintaining it's charge without the drain from the aux/traxide.

186126

The only thing drawing from the aux battery during this time is a dash cam + one of your AGB25 which I have measured is only drawing 0.4a together.

While driving, the alternator is either pumping out ~12.2v, 13.1v or 14.4v (presumably depending on the state of the cranking battery) so I don't think the issue lies with the BMS/alternator charging.
Hi Maca and first off, the MAXIMUM current draw of an ABG-25 is 0.05a or 50 milliamps, not 400 milliamps, so you have a problem somewhere else?

Next, you alternator voltages are way WAY too low and you have found your issue.

Regardless of the state of charge of your cranking battery, shortly after starting your motor you should be seeing 14.7v, and as your cranking battery is always low, you should see 14.7v for quite a long time.

As I posted above, the 12.2v is something that only occurs periodically, and this would be no more than once every 3 or more months.

To see that 12.2v on a regular basis is a clear indication of either a software problem or a faulty alternator and my money would be on some form of software issue.

Thank you for that last bit of data because it rules out the Traxide isolator as the problem and also rules out the batteries as being a problem.

And as you have stated, your driving habits would not contribute to your battery short lifespans but those low voltages most certainly would.

Again as above, my money is on a software issue and I bet it has been that way since the vehicle rolled off the production line.

You need to get that sorted or it is just going to continue to cause more short battery life.

Sorry I can not help you with solving that low voltage issue but at least you have somewhere to start, to fix the problem once and for all.

[Macadamia]

Hi Maca and first off, the MAXIMUM current draw of an ABG-25 is 0.05a or 50 milliamps, not 400 milliamps, so you have a problem somewhere else?


+ my dash cam. point is - it's a very low draw that definitely shouldn't be drawing down the HVT70LD from 12.7v to 12v in 24 hours



Next, you alternator voltages are way WAY too low and you have found your issue.

Regardless of the state of charge of your cranking battery, shortly after starting your motor you should be seeing 14.7v, and as your cranking battery is always low, you should see 14.7v for quite a long time.



It does tend to stay at 14.7v for most of trip. that graph is 7 days compressed down so it looks like brief blips but they're actually at least 20minutes to an hour long.
Here is the graph from today only.
186137
A few points to note:
1: overnight I had a 10amp CTEK battery charger plugged into the rear anderson plug. It had finished it's cycles, indicated full charge and was in the maintenance stage. Hence AUX battery was higher voltage than crank.
2: 25 minute drive to work - voltage remained 14.7v for the entire trip
3: for the 10 hours at work in isolated mode the aux battery fell from 12.7v to 12.3v with [as above] only a 0.4a draw.
4: 40 minute drive home from work voltage for the most part remained 14.7v

My aux battery is clearly failing but with the driving I do and >monthly maintenance charging it shouldn't be in the state it is after only a little over a year.

Anyway, I'll check with the GAPIID if there's an update and source it from GAP or Bell.

[drivesafe]

Hi again Maca and your batteries are not holding a charge because they are stuffed, or at least your auxiliary battery is and it dragging your cranking battery down so quickly.

As I posted in the last reply, you have found your problem, and you need to fix it.

You virtually should never see 12.2v because when the BMS is carrying out the condition test, the instant your cranking battery dischargers down to 12.2v, your alternator voltage will jump to 14.7v, your obviation confirmed your issue.

Mate you have your heart set on fitting a lithium battery, go for it, but because of those low voltage readings, be aware you will still need to replace your cranking in a short time.

[drivesafe]

BTW, one of the voltage readings in you first graph is almost 15v, as stated, your alternator voltage should never go over 14.7, and note, this was not at the beginning of the days drive, so your battery would not be cold and that high a voltage is not good for AGMs once harmed up.

So once again, get your software looked at, thats where your problem is.

[Macadamia]

Mate you have your heart set on fitting a lithium battery, go for it,

I'd rather not but my traxide setup is not working as intended and never really has. What you are suggesting is the cause does not marry up with what I am seeing.

1: I almost never see 12.2v from the alternator. It happened briefly after I reset the BMS when I replaced the cranking battery, it did the same when I replaced and reset it last time also. I haven't seen it since, it's not in a month of data logged by the battery monitor so it is definitely not the cause of my issue.

2: that blip of almost 15v I would suggest is caused by the ISU-160 suddenly isolating the batteries that were previously linked for some reason because the minute before they were linked, then isolated for a minute, then linked again. Is this normal operation. here are the voltages and time stamps.
186147186148186149

And no there are no loose earth cables or loose terminals anywhere. I have checked them all.

For the majority of my driving it sits as ~14.7v and occasionally after a while drops down to around 13.something v. As I understand from what you described this is normal operation and should not be resulting in the premature failure of both of my batteries.

186150

[drivesafe]

2: that blip of almost 15v I would suggest is caused by the ISU-160 suddenly isolating the batteries that were previously linked for some reason because the minute before they were linked, then isolated for a minute, then linked again. Is this normal operation. here are the voltages and time stamps.
Again, you don't really understand how alternators work.

The USI-160 turning off or on, would have absolutely no effect on the voltage level of you alternator.

BUT, the earlier versions of the USI-160 had a 15.1v Over-Voltage shutdown function and it is more likely that your alternator went over the 15.1v shutdown level and NOTE, the voltage has to be over 15.1v for more than 15 seconds before the isolator shuts down.

The 15 second delay is to make sure simple spikes do not shut down the isolator.

If a shut down does occur, the USI-160 will turn back on the instant the voltage drops back below 14.8v

Once again, you have confirmed the isolator is doing exactly what it was designed to do, and that your alternator is operating outside it's specs.

Maca, you posted this thread enquiring about changing the auxiliary battery to a lithium. But like many others, you blamed your Traxide isolator for causing all your continuous short battery life.

I respond to these types of threads as in the vast majority of cases the Traxide isolators are not the problem and I help whoever is having a problem to try to workout what the real issue is.

This thread is a perfect example of just such a situation.

You are obviously not interested in getting to the exact problem and just continually try to blame your Traxide isolator.

Do as you are planning and replace your Traxide isolator and then in a year or so, come back and tell everyone how your cranking battery has again died prematurely.

The isolator is doing exactly what it is supposed to but your alternator is not.

Best of luck to you.

[Macadamia]

Maca, you posted this thread enquiring about changing the auxiliary battery to a lithium. But like many others, you blamed your Traxide isolator for causing all your continuous short battery life.

I respond to these types of threads as in the vast majority of cases the Traxide isolators are not the problem and I help whoever is having a problem to try to workout what the real issue is.

This thread is a perfect example of just such a situation.

You are obviously not interested in getting to the exact problem and just continually try to blame your Traxide isolator.

Do as you are planning and replace your Traxide isolator and then in a year or so, come back and tell everyone how your cranking battery has again died prematurely.

The isolator is doing exactly what it is supposed to but your alternator is not.

Best of luck to you.

okay Tim. I posted this simply saying I was unhappy with my traxide setup. you came in here overly defensive blaming everything and everyone but your product. I have actually contacted you via email a few time for pre-sales enquiries and post sales support without a peep.

At the end of the day what you are describing is simply not happening. I monitor my setup very closely and I don't appreciate the constant condescension. I guess we are at an impasse until I ask my LR indie to advise on the state of my alternator and BMS (though I suspect they will both be perfect).

[drivesafe]

okay Tim. I posted this simply saying I was unhappy with my traxide setup. you came in here overly defensive blaming everything and everyone but your product. I have actually contacted you via email a few time for pre-sales enquiries and post sales support without a peep.

At the end of the day what you are describing is simply not happening. I monitor my setup very closely and I don't appreciate the constant condescension. I guess we are at an impasse until I ask my LR indie to advise on the state of my alternator and BMS (though I suspect they will both be perfect).
Seriously, using the very information you posted up, your alternator is going over 15v.

You have AGM batteries and as such, your alternator should never go over 14.7v

And note, that is not just for Land Rovers, no vehicle with a SMART alternator should ever go over 14.7v or is will stuff the AGM cranking battery.

Oh thats right, your AGM batteries are stuffed.

Your own BM2 monitor shows your alternator is running to high and you think the Traxide isolator has done that.

Please explain how a SWITCHING device can generate a voltage?

[Macadamia]

Not once anywhere have I said or shown it going 15v or over. Near, briefly, for a spike but never at or over and never for more than an instant. As an “automotive electrician with 40 years of experience” you should know what a voltage spike is and what can cause it. You interpret it how you want mate. You’ve show your true colours. I just wish I’d known your after sales support consisted of “the problem is with you and your car” before wasting the money.

[drivesafe]

Not once anywhere have I said or shown it going 15v or over. Near, briefly, for a spike but never at or over and never for more than an instant. As an “automotive electrician with 40 years of experience” you should know what a voltage spike is and what can cause it. You interpret it how you want mate. You’ve show your true colours. I just wish I’d known your after sales support consisted of “the problem is with you and your car” before wasting the money.
You did not have a voltage spike.

A voltage spike will be of less than a second duration, and as such, any such spikes would be immediately absorbed by your cranking battery.

All alternators continually generate spikes of up to 60v, but they never get into the system because your cranking battery acts as a massive capacitor and suppresses these SPIKES.

You had a voltage SURGE, where your alternator raised the voltage to over 15.1v for more that 15 seconds and this caused your Traxide isolator to shutdown.

Your BM2 shows that on at least one occasion, when the voltage was sampled, it was at 14.93v.

But your BM2 only takes a sample once every 2 minutes, so we have no idea just how much higher the alternator voltage actually went, but as the USI-160 shutdown at that point, as according to your own post, so the alternators voltage had to be over 15.1v for at least 15 seconds to cause the USI-160 to shutdown. Thats a SURGE not a spike.

Facts are facts and these are the facts you posted up.

Maca, you have it in your head there is nothing wrong with your vehicle, so be it but the facts state otherwise.

[DiscoDB]

Maca - a few questions for you to make sure you are getting the most out of your current setup (which should also help if you add a lithium battery to give you more storage capacity - keep an eye on what Tombie is up to in the “What happened to your D3/D4” thread as he just replaced two auxiliary batteries with a single ITECH120X lithium battery).

How is your solar panel charge controller connected to your batteries and have your checked it is all working correctly?

In the graphs you posted the only time I see your solar panel charging was when you isolated the auxiliary battery.

A faulty solar controller, or a failed diode on the solar panel could also cause problems and be draining the battery.

And is your dash-cam left permanently on? You mentioned the dash-cam draws 0.4A.

If the dash-cam is alway left on, then between the normal parasitic drain, the USI-160 (if not isolated), and the dash-cam you could be draining close to 0.8A - which over 24hrs is around 19Ah being consumed.

For comparison - this is the typical drain on my cranking battery overnight (D3 not D4) and daily recharge via 80W of solar panels that I see. I fully isolate the USI-160 when the engine is not running, which disconnects the auxiliary battery.

https://uploads.tapatalk-cdn.com/20230707/83bf0e7fd7f6a4e99e770605b9ab770e.jpg

Not shown, but the auxiliary battery drops about 0.05v per week when isolated (with nothing connected to it other than the BM2 monitor).

[Macadamia]

How is your solar panel charge controller connected to your batteries and have your checked it is all working correctly?

In the graphs you posted the only time I see your solar panel charging was when you isolated the auxiliary battery.

A faulty solar controller, or a failed diode on the solar panel could also cause problems and be draining the battery.

It's connected to a renogy MPPT solar controller connected directly to the aux battery. unfortunately where I park my car gets absolutely no sun from about june to october (thanks Melbourne!). I actually disconnected it a couple of weeks ago concerned that it might be a small parasitic drain but it hasn't made a difference.



And is your dash-cam left permanently on? You mentioned the dash-cam draws 0.4A.

If the dash-cam is alway left on, then between the normal parasitic drain, the USI-160 (if not isolated), and the dash-cam you could be draining close to 0.8A - which over 24hrs is around 19Ah being consumed.

yes permanently on. the 0.4a is measured at the 70a fuse when the only things connected/on are the dash cam and AGB25. I'll log a few days with the battery shared and isolated and see if it makes a difference.

[DiscoDB]

The next step I would be taking is to start disconnecting anything that has been added and revert back to the original set up - i.e. cranking battery only with nothing else added.

So no solar, no dash-cam left on, no Aux battery, and no USI-160 (disconnect the earth cable to power it down fully).

Then you will be able to confirm the alternator and cranking battery is all behaving as expected (watch for at least 3-4 days). At the same time see how the auxiliary battery holds voltage with no load on it over the same period.

Only then start adding extra’s one by one and monitor again for a few days each time you add one extra item back.

Personally - I think between the normal parasitic drain, the USI-160, and dash-cam you are already using up a large portion of your AUX battery storage capacity so everything needs to be in a good health just to handle this base load. And the 100W solar should be more than enough to cater for all of this.

Yes a lithium battery will give you more useable storage capacity, but I would want to confirm you don’t have another problem first (or at least better understand what true load you need to cater for).

By the way - I am also in Melbourne and my 80W solar set up performs perfectly fine over winter but where I park it gets full sun during the day. I probably only see 1 or 2 days a month it won’t recharge the battery fully.

[Tombie]

Any USB ports etc in the vehicle?

Those and Dash cams are hard on batteries, it’s quite surprising.

[DiscoDB]

And wouldn’t be the first time the HVT-70D has needed to be replaced whilst still under warranty.

Would be good to do a test on it to see how much capacity it has lost.

[DiscoDB]

Tombie - what made you go with the ITECH120X?

I’ve read mixed reviews on the iTech products and their warranty policy where they reserve the right to deny any claim if they determine the battery was at end of life (even within the warranty period).

[drivesafe]

Tombie - what made you go with the ITECH120X?

I’ve read mixed reviews on the iTech products and their warranty policy where they reserve the right to deny any claim if they determine the battery was at end of life (even within the warranty period).
And because of the way their BMS works, their batteries are usually only good for around 75% of the marked capacity.

Again, not a brand I would buy, but each unto his own!

[Tombie]

A co-worker has been putting the same unit through some decent testing (in his 4wd) for quite a while now.

DCS was on the cards also as both claim to be under bonnet suitable.

In the end, went the Itech route as a single unit. DCS I would have run 2 in parallel and the Itech gives me one space back for fitting other components I want in the vehicle.

All about space packaging in my application.

We will see how it goes longer term, hopefully I have a win.

[drivesafe]

A co-worker has been putting the same unit through some decent testing (in his 4wd) for quite a while now.

DCS was on the cards also as both claim to be under bonnet suitable.

In the end, went the Itech route as a single unit. DCS I would have run 2 in parallel and the Itech gives me one space back for fitting other components I want in the vehicle.

All about space packaging in my application.

We will see how it goes longer term, hopefully I have a win.

Hi Tombie and you are one person who WILL gives us an Honest report on them.

[scarry]

And because of the way their BMS works, their batteries are usually only good for around 75% of the marked capacity.

Again, not a brand I would buy, but each unto his own!

Hi Tim, what brand do you recommend for underbonnet? Maybe none?[biggrin]

Watching what is going on with under bonnet lithiums on the Jap Forums,where there are many fitted,and some a good few years old,i have yet to work out which has the least problems.
Often it is the installer that causes the problems.

[drivesafe]

Hi Tim, what brand do you recommend for underbonnet? Maybe none?[biggrin]

Watching what is going on with under bonnet lithiums on the Jap Forums,where there are many fitted,and some a good few years old,i have yet to work out which has the least problems.
Often it is the installer that causes the problems.
As you suggested, I personally would not run a Lithium under the bonnet of any vehicle.

BUT you would think if any vehicle was suited to having lithium batteries under the bonnet a D3 or D4 would be at the forefront.

Not so as I have some inside knowledge of a D4 with both cranking and auxiliary lithium batteries and it has been a big problem.

I ran a 100Ah STANDARD ( not drop-in ) Lithium battery in the boot of my Tiguan with great success and carried out quite a few different types of tests.

I have had heaps of feedback from customers and learnt heaps from my own testing.

I will be taking the experimenting much further as I develop a Lithium friendly isolator.

But even if I come up with an isolator suitable for lithium batteries, I am pretty sure I will still be recommending the lithium batteries be fitted anywhere but in the engine bay.

NOTE this is not just a problem for lithium batteries. I have quite a few customers who use AGM cranking batteries as auxiliary/house batteries, mounted in the rear of their vehicles and in caravans and camper trailers and they all seem to get much longer lifespans than those who fit their auxiliary batteries under the bonnet.

Go figure?

[scarry]

Thanks Tim,i thought that would be the answer[bigsmile1]

AGM batteries also have a heat spec rating,similar to Lithium,so heat no doubt probably reduces the life of the battery,as per your comment.

[DiscoDB]

A co-worker has been putting the same unit through some decent testing (in his 4wd) for quite a while now.

DCS was on the cards also as both claim to be under bonnet suitable.

In the end, went the Itech route as a single unit. DCS I would have run 2 in parallel and the Itech gives me one space back for fitting other components I want in the vehicle.

All about space packaging in my application.

We will see how it goes longer term, hopefully I have a win.

Looking forward to your review on how it goes.

If I was running an accessory like a dash-cam 24/7, then a lithium battery makes a lot sense. I also like the idea of the slim versions they have for mounting in the cab.

I personally prefer not to run any extra accessories off the cranking battery (when the engine is not running). But yet to land on what would be the best set up - so watching with interest how the ITECH120X goes.

[Tombie]

My dash cam is off the cranking AGM.
It has a LVC on it, so will film 24hours if driven daily.

I’ve made up the mounts for my second solar panel to go “in” the roof rack (front of a Prospeed rack) and that panel will focus on the primary battery.

Currently the bonnet mounted panel just supports cold drinks!

[TerryO]

Maybe it’s just a case of me being overly careful but I’m not keen on running a lithium battery in my D4 or under the bonnet of any ICE vehicle given the number of fires that happen and more to the point if a Lithium battery fire occurs then the vehicle burns to the ground.

I know there are thousands of vehicles out there, both on two and four wheels with aftermarket lithium battery’s fitted that have had no issue, but it does happen. Don’t get me wrong I’d much more prefer to have a lightweight battery that has more than double the usable capacity but at this stage I’m not prepared to risk it.

cheers,
Terry

[Tombie]

Maybe it’s just a case of me being overly careful but I’m not keen on running a lithium battery in my D4 or under the bonnet of any ICE vehicle given the number of fires that happen and more to the point if a Lithium battery fire occurs then the vehicle burns to the ground.

I know there are thousands of vehicles out there, both on two and four wheels with aftermarket lithium battery’s fitted that have had no issue, but it does happen. Don’t get me wrong I’d much more prefer to have a lightweight battery that has more than double the usable capacity but at this stage I’m not prepared to risk it.

cheers,
Terry

That’s why my vehicle is covered for replacement value not market :)

Take that as you will… either way I’ll be happy!

[SimmAus]

Replacement value is fine…so hypothetically, what would you replace it with?

[Tombie]

Replacement value is fine…so hypothetically, what would you replace it with?

RRS TDV8 or FFRR would be likely candidates.

Others in contention: Amarok

[Macadamia]

follow up question not worthy of it's own thread. I bought these terminal covers from some car shop can't remember which one
186258

and they look like they're reacting with the plastic of the battery casing!
186259 186260

they're not melting because I checked how hot they were getting after I noticed it. and also the cover on the positive was red but there is no red residue. and also the covers themselves after I peeled them away were whole and intact.

has anyone come across this before?! I assume they don't all have this issue?

[DiscoDB]

That does look strange Maca. Never seen that happen myself.

How did your monitoring go?

I normally keep the USI-160 off (when the engine is not running) but decided to try ignition and shared mode for a few days.

Prior with the USI-160 off, the solar would keep the cranking battery topped up even on cloudy days.

With the USI-160 in ignition mode, and the two relays active, the solar was not able to get to the absorption stage - even on a sunny day.

With the USI-160 in shared mode, and with only one relay active, the solar today hit absorption stage on both batteries.

Not entirely a meaningful observation as the first few days of the test was cloudy, and the auxiliary battery was probably in need of a recharge so ran the engine for 30mins yesterday to give it a top up.

Once it stabilises again, will change back to ignition mode.

The aim of this test is to see how the solar charge controller reacts to different loads (and to make sure it can overcome the power draw from the USI-160 relays when solar output is low).

[BreakingBad]

follow up question not worthy of it's own thread. I bought these terminal covers from some car shop can't remember which one
186258

and they look like they're reacting with the plastic of the battery casing!
186259 186260

they're not melting because I checked how hot they were getting after I noticed it. and also the cover on the positive was red but there is no red residue. and also the covers themselves after I peeled them away were whole and intact.

has anyone come across this before?! I assume they don't all have this issue?




Any chance you can post a pic showing the terminal covers on the battery? (preferably with the wiring)

[Macadamia]

Scroll down the page till you get to “Battery Maintenance”
https://www.aulro.com/afvb/the-verandah/246755-line-auto-electrical-info-8.html


for the past week I've had the aux battery out and performing this maintenance each night. Now every time I drive the car without fail the alternator is pumping out 14.7v for the entire drive. Where it used to do 14.7v initially then drop to ~13.3v then to ~12.3v it is now just a sustained 14.7v. is that because the cranking battery SOC is lower without the aux battery? is that how it works - in shared mode with the engine off, does the cranking battery "share" the aux battery capacity in the same way the auxiliary battery shares the cranking battery capacity - or is it one way only?

[drivesafe]

Hi Maca, my GUESS is that the two batteries were supporting each other.

Under normal driving conditions, your D4’s BMS can only monitor the cranking battery and it can NOT see what is happening with any other battery connected to the charging system.

This is done by the BMS monitoring the cranking battery’s negative terminal.

When you are driving with two low batteries, the charge is roughly halved. So for instance, you may have 100 amps available for charging, 50 amps will going into the cranking battery and 50 amps will begging into the auxiliary battery.

But the BMS only sees the 50 amps going into the cranking battery and the BMS may consider this to be an indication of an OK battery

With only one battery in the vehicle, the entire current load is now going into one battery and it is showing up at the BMS as the cranking battery is drawing too much load for a fully charged battery, and the BMS has decided to try to fully charge it.

A single 30 minute drive at 14.7v should have had your cranking battery near fully charged.

I would suggest you start by getting the cranking battery LOAD TESTED and then see what comes of that.

Also, at no time should your batteries be regularly discharged down 12.3v. For your D4 to discharge the battery down to 12.3v, the D4 will be applying about a 40 amp load to the battery while you are driving.

This kind of continuous current load is not good for any battery.

You also posted earlier that after each time you replaced your cranking battery you would see 12.2v. That would be very damaging to a new battery, to be discharged by a high current load, before the battery has been properly fully charged first.

As I have posted, your D4 appears to have a serious problem with the charging software, but I am not sure how you can fix this.


As I also posted, your D4 most likely has had a charging software problem from the day it came of the production line.

[Macadamia]

When you are driving with two low batteries, the charge is roughly halved. So for instance, you may have 100 amps available for charging, 50 amps will going into the cranking battery and 50 amps will begging into the auxiliary battery.

But the BMS only sees the 50 amps going into the cranking battery and the BMS may consider this to be an indication of an OK battery

With only one battery in the vehicle, the entire current load is now going into one battery and it is showing up at the BMS as the cranking battery is drawing too much load for a fully charged battery, and the BMS has decided to try to fully charge it.

perhaps I'm not understanding you but sounds like you're saying with both batteries in, the BMS is undercharging them both and falsely assuming the cranking battery is fully charged but with just the cranking battery it's behaving normally and charging my cranking battery normally.


Also, at no time should your batteries be regularly discharged down 12.3v. For your D4 to discharge the battery down to 12.3v, the D4 will be applying about a 40 amp load to the battery while you are driving.

with a new cranking battery installed, both batteries in the car and in shared mode - on a long drive I would initially get 14.7v for a period of time, then 13.3v then 12.3v for a while before it jumped back up and down. does this not indicate the BMS considers the cranking battery is in a near full SOC and is reducing and turning off the alternator?
In any case why this hasn't happened since disconnecting the aux battery?

[Macadamia]

Found these BM6 battery monitors that log temperatures as well as voltage. As someone who loves data, I am interested to see how hot the batteries get in the engine bay and in general use. which may provide some information as to the suitability of lithiums in the engine bay. The app supports up to 4 devices [instead of having to pay for the third party 'multi battery monitor' app to monitor multiple BM2 devices].

186382 186383

I was a bit worried they may use a bit more power than the old BM2 monitors but they seem pretty efficient.
standby power usage is around 1 milliamp [~0.8 to 1.1]
186384

when connected to the app power usage is around 2 milliamps [~1.8-2.2]
186385

[scarry]

This is interesting,in relation to Lithium under bonnet.



DCS Lithium LiFePo4 Update: Why I went back to Lead Acid (under bonnet) 2023 - YouTube (https://youtu.be/vRcSPuBob-I'si=Vv5u58qWbsaZSJ14)

[jwb]

I too have the Traxide full setup in my D4.
I'm waiting on delivery of a Defender and need to set up the D4 in case it's needed for our trip next month. My approach is a 'semi-transferable' setup that will transition to a permanent fitout in the L663 (if/when it arrives!)

Battery - PowerPaul Cub Scout 190Ah, 250A ….

Did the trip in the D4.
Happy to report that my setup worked flawlessly across the Simpson and camping on the way home.
Induction cooktop was heavily used as well as the 12volt oven for evening meals
Nespresso coffee every morning as well as the fridge/freezer running continuously.
Lowest SOC at start of days driving around 50%
Even ran a small hair dryer one morning when a shower was available!
Only issue was slower than 30A charging from the Victron dcdc. Around 20ish which wasn’t a problem with the hours covered each day. When back in internet range found a reference to setting on the smart alternator detect settings which I tried and it worked.

No more gas cooking for us. It’s so quick and clean to set up and use.

[W&KO]

Did the trip in the D4.
Happy to report that my setup worked flawlessly across the Simpson and camping on the way home.
Induction cooktop was heavily used as well as the 12volt oven for evening meals
Nespresso coffee every morning as well as the fridge/freezer running continuously.
Lowest SOC at start of days driving around 50%
Even ran a small hair dryer one morning when a shower was available!
Only issue was slower than 30A charging from the Victron dcdc. Around 20ish which wasn’t a problem with the hours covered each day. When back in internet range found a reference to setting on the smart alternator detect settings which I tried and it worked.

No more gas cooking for us. It’s so quick and clean to set up and use.

Yeah same as you, would never go back to gas induction and travel Buddy

[RANDLOVER]

Did the trip in the D4.
Happy to report that my setup worked flawlessly across the Simpson and camping on the way home.
Induction cooktop was heavily used as well as the 12volt oven for evening meals
Nespresso coffee every morning as well as the fridge/freezer running continuously.
Lowest SOC at start of days driving around 50%
Even ran a small hair dryer one morning when a shower was available!..........

Now we are all wondering what your hairdo looks like. [biggrin]

[peter51]

The original question was about dual lithium ideas - however I learnt a lot from traxide. I have a D2 and D1 - which really like for their simplicity.

Regarding the original question - it depends on your mission. I position my vehicle under the shade in national parks where I do long daily or overnight walks - so no driving and no solar harvesting near the vehicle. I walk to fish mainly - all day.
I don’t camp in the sun unless I’m forced to by the environment I am visiting.

I just have a good cranking battery in both vehicles.

Lion 100Ahr batteries are very light in weight. I have 2 which have internal bluetooth data logging - from a company in south brisbane. (about $700 each). They come in a stainless case. One battery stays in the vehicle to run the fridge - the other is chained via its stainless handle to a tree and connected to a solar blanket maybe 50m from the car wherever I can harvest the most solar in the clearest area from shadows I can find - bearing in mind that the sun remains low on the horizon most of the winter and shadow is the enemy. I swap them over as required.

Because they are so light, why mount them anywhere? Having the ability to swap them out suits my mission. If I do drive for 30 minutes somewhere I will simply charge the low one by direct heavy cable to the alternator - goes through firewall to an anderson behind the drivers seat. The Daly BMS inside the stainless box good for 150amps.

Having 2 gets me by when there is 4-5 days overcast.

I generally cook over a fire, use a jet oil for a quick cup of tea, never blow dry my hair - but I do shower regularly using those good old black plastic solar showers and pop up shower cubicle - solar showers are filled with creek water and put in the sun with the solar blanket.

Obviously driving long distances everyday as your adventure is different and is easy regarding recharging requirements - but not for everyone.

Additionally if I am at a lake - where I have towed my kayaks or tinny - and need to use the electric trolling motor, I simply grab one of the batteries and go. Generally at lakes there is a camp kitchen where I will put the Victron high current charger onto the LION to replace the 30 amps I use chasing fish.

I still camp in the shade in the non-powered area away from the maddening caravan crowd watching their TV shows on the big screen hung under their awnings - why are they really there?

Hope this helps those who operate similarly.

[peter51]

Forgot to mention - if I can’t secure the battery then I chain it to whatever I can and run a 10m extension to the solar blanket - the MPPt(cheapie) is right near the battery to minimise voltage drop. Works well depending on season and sun angle/traverse of course.