Aux battery is still charging

[Tim]

Not just these trucks, but with Grand Cherokees as well........ according to our dealer shop.

My wife’s Cherokee (not of the Grand variety) also had 2 bad batteries about a year into owning it.

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[Bonanza]

Update-- After replacing both batteries, Resetting the IBS by disconnecting and isolating the wires, my ESS works as intended.

 

[Rainman519]

was at my dealer yesterday for oil change/tire rotation. Asked them again about the battery replacement. Tech stated that if I can't bring the JT in while the warning message is on the screen, then I'd have to drop it off overnight for the diagnostics/replacement. Guess I'm going to bite the bullet and have it done before winter sets in (not that I'm all that worried about the ESS and aux battery, but I'm concerned about any parasitic drain on the main battery).

 

[obrianmcc]

2020 with Start Stop Not Ready, battery Charging ....

I opted to install the new batteries this weekend vs play the back and forth dealer game ... and it was very straight forward. Yes the aux battery is buried under the PCM, but it is very easy to get to. Some recommendations are to access through the wheel well, but I've been in both ways and I prefer the top down method.

After install of the new batteries the system did not immediately work, in fact the battery charging message persisted making me think the issue might be elsewhere. However, after driving around for about 30 min the system started to work normally.

Assuming it was the AUX battery giving me grief I pulled out my battery tester. What I found was a starter battery testing at 12.6v, 629 CCA, and 4+ Impedance ... while the AUX battery tested 12.44v, 230 CCA, and 10+ impedance. Also to note that you can check the system if you switch the ignition to Aux (not start) and cycle through your vehicle settings to battery voltage. this will give you a static reading. If done so while the vehicle is running it will give you an active reading as being fed by your alternator.

My conclusion was that it is indeed my Aux battery ... the 12.44v is low as with the impedance being slightly high. Also while checking the system static voltage I was previously at 12.2v and then back up to 12.7v with the installation of new batteries.

While an ESS system can stop working for various reasons ... I was confident that my system was charging. If my system would not have reset ... my next step would have been to look at the power control relay between the two parallel batteries.

 

[ShadowsPapa]

You know right away it's not fully charged or not holding a charge just by the 12.44
Anything less than 12.6 is less than fully charged. (if I recall GM used to say 12.65 or something like that, I'd have to look at my GM training charts)

 

[jmdwifi]

Well, they replaced the aux battery last year. It's doing the same thing but it's out of warranty now. I wish they could just remove this stupid system that doesn't work.

 

[ShadowsPapa]

Well, they replaced the aux battery last year. It's doing the same thing but it's out of warranty now. I wish they could just remove this stupid system that doesn't work.

What's the weather like down there now? Cold? 40s or 30s? Doubtful but just wondering.

Didn't someone here say that their IBS sensing could be tweaked? Is that doable via software like AlfaOBD or JSCAN?

Just thinking aloud.

 

[dcmdon]

Is there any kind of consensus as to whether the Aux batteries are failing because they are inadequate or defective, or if they are failing because they are not being cared for / charged properly by the electrical system?

If its the former, then maybe the answer is to purchase something like an Odyssey AGM battery of similar size as a replacement. (assuming out of warranty)

I don't know if it was in this thread or another but I had an Odyssey PC680 that I used as a starting battery on my airplane and it gave 7 years of service!!

 

[ShadowsPapa]

Is there any kind of consensus as to whether the Aux batteries are failing because they are inadequate or defective, or if they are failing because they are not being cared for / charged properly by the electrical system?

If its the former, then maybe the answer is to purchase something like an Odyssey AGM battery of similar size as a replacement. (assuming out of warranty)

I don't know if it was in this thread or another but I had an Odyssey PC680 that I used as a starting battery on my airplane and it gave 7 years of service!!

MY service writer said it was "bad batteries".
Of course - that was a year ago and - he's not the tech. But those were his words. And they'd seen a lot of them in various Jeeps (I was talking Grand Cherokee which has the same system)
OK, back to your thoughts -
We know that improper charging can cause batteries to fail.
We have the service writer's comments.
So do we have both, or was one causing the other?
We also have at least one case in the forum where the battery was fine and the system was fine but the IBS was feeding info the system said was too low.
The IBS (for lurkers, I bet Don knows this) is the Intelligent Battery Sensor and it provides battery status information used by the ESS system to determine if there is enough power to restart, I assume among other things.
So, if the AGM battery is OK but the IBS threshold is wrong, the system will be basing a decision on Bad BS and not IBS HAHAHA, ok bad pun, sorry.

I recall someone here saying their IBS -assuming in the "system" was reset to a different threshold and all was fine with the world again. Well, maybe not that far, but it worked and has been fine.

So - is the battery not being correctly charged - leading to either:
Battery failure
or
IBS sensing low battery

OR

Is the battery fine and the IBS reporting it's fine but the "system" not accepting that answer as good because it's told the voltage must be xx.yyy and the IBS is saying xx.zzz but xx.zzz is actually just fine?

Or have I simply run out of diet pepsi and thus caffeine and need a recharge?

 

[Mr._Bill]

I still have the original AUX battery in my Overland. I usually turn it off, but the ESS system is functioning as it should. The build on my truck was started 3/28/19, and I bought it in July. I'm in an area where a lot of batteries die after three summers.

 

[jmdwifi]

What's the weather like down there now? Cold? 40s or 30s? Doubtful but just wondering.

Didn't someone here say that their IBS sensing could be tweaked? Is that doable via software like AlfaOBD or JSCAN?

Just thinking aloud.

It is getting colder but it’s been doing this for a few months. I’ve been waiting on emergency brake parts and they just came in. That ticket was written before I went out of warranty . A new message I’ve had a few times and today after work says “Battery too low, aux switches unavailable“

 

[Glad_he_ate]

Had my aux replace a couple weeks ago. Claims a bad cell in the aux I’m curious if it’s a higher rate of failure on say the diesel be the gas. Or is it the same across the platforms. If my def heater is drawing things down while it sits and the gas obviously is not then one could think the diesel would be more prone to issues with the batteries?? Idk just spit balling

 

[Delhux]

https://www.wikihow.com/Organize-a-Class-Action-Lawsuit?amp=1

 

[Tim]

Well, they replaced the aux battery last year. It's doing the same thing but it's out of warranty now. I wish they could just remove this stupid system that doesn't work.

So I replaced my own aux battery with one from Napa and also replaced my main battery with an Oddesy about a year ago and havent had an issue since. My JT is no longer my daily driver and it recently sat parked for 10 days. The ESS worked at the first stoplight about 2 miles from my house yesterday morning when I drove it. The temps over the last few weeks here have been in the high 20s/low 30s at night and 40s or maybe 50 during the day. That said I let it warm up for a few minutes on the driveway before heading out but you get the idea.

I don’t think it’s that the system doesn’t work, but rather, it‘s poor sourcing of batteries by FCA/Stellantis.

 

[ShadowsPapa]

It is getting colder but it’s been doing this for a few months. I’ve been waiting on emergency brake parts and they just came in. That ticket was written before I went out of warranty . A new message I’ve had a few times and today after work says “Battery too low, aux switches unavailable“

Definitely an issue that needs to be checked out as it could leave you stranded.
You can check the REAL or actual voltage measurements yourself at the batteries if you wish.
That may help determine where you're at with things.

Luckily the only times my wife had the issues with her GC battery/batteries it was at home. Each time I charged it at least 12 hours it lasted her for a couple of days - then one morning I went out and pulled the charger off, measured voltage and instead of over 12.6 it was 11.2 or something like that. (I was lucky - she'd have been pissed if I had sent her out that day!)

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