Early Battery Failure?

[nhemenwa]

Hey everyone, looking for some help.

'21 JLUR 2.0L, Colorado.

Last summer I was constantly having battery issues, mostly seen as the message 'Aux Switches Temporarily Unavailable, battery charging'. The ESS almost never was working as well.

So I took it into the dealership in November, and by the skin of my teeth, they replaced both the main and Aux batteries under warranty. Everything started working normally again...

So the past few weeks I noticed the ESS is again not working. The message just shows 'Start/Stop Not Ready'.

I daily drive it about 20 minutes each way to and from work, so I think it should have enough charging time n that basis.

Last night when I got home I put it on my charger, and initially it was reading 80% charge, then I left it charging for a few hours, but it stopped charging at 95%. So I took the charger off, let it sit for an hour, then put the charger back on, and then it finally went up to 100%.

This morning on the way to work...ESS still not working, and same Not Ready message. So I don't know what to make of that.

Is 6 months really long enough for one or both of the batteries to start to die? I know the dealership said they have specific OEM batteries that they had to use on it as part of a warranty replacement (ie: crappy battery).

Should I try to reset the IBS and hope that resolves it somehow?

Just bite the bullet and replace both batteries with better quality batteries?

Bypass the ESS in the future? I don't like it other than it seems to be an unofficial indicator of battery failure when the ESS doesn't engage.

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[Bill_BCNtoNY]

I've read enough horror stories to suggest replacing the OEM batteries with sth better... and as a single data point, my '23 JLUR 12V battery died with less than 1k miles in just a few weeks from owning it and I replaced the battery for a better aftermarket one (I ended up having to lemon-law that Jeep, but for a different reason).

 

[dsgrey]

You need to load test the battery. I recently charged the non-Jeep battery vehicle in a rather short time only to see it had 54 CCA and that battery was only 6 months old. I'm lucky to get 2 years out of a battery anymore for my vehicles and I've bypassed the ESS battery in the Jeep.

 

[garyji]

Not that unusual for OEM batteries to fail regardless of "newness". Put some good ones in there and call it a day.

G.

 

[nhemenwa]

One other aspect I thought I should mention. I have a pair of ditch lights and a 20" light bar. I wired their primary beams to two Aux switches, and then I have all three of their amber backlights wired together on one aux switch. I have that aux switch with the amber backlights running as a DRL.

I'm wondering, do the backlights (I think less than 1A total) put a small load on the aux battery which is too low for the IBS to charge it? I also thought I heard somewhere that the aux battery only gets charged during the first 30 seconds after the engine starts, then only the primary battery for the rest of the time.

 

[THAW]

I also thought I heard somewhere that the aux battery only gets charged during the first 30 seconds after the engine starts, then only the primary battery for the rest of the time.

No; the ESS/Aux battery is alternator charged in parallel with the main battery.

 

[Old Dogger]

The OEM Batteries are not of quality!!!!!!!

 

[Reinen]

I'm wondering, do the backlights (I think less than 1A total) put a small load on the aux battery which is too low for the IBS to charge it? I also thought I heard somewhere that the aux battery only gets charged during the first 30 seconds after the engine starts, then only the primary battery for the rest of the time.

No. Main & Aux are connected in parallel 99.99% of the time. The only time they are isolated and operate independently is while the engine is stopped during an ESS event. Aux powers electronics and Main powers the starter, and typically all owner installed electrical accessories since almost nobody attaches them to Aux.

From this knowledge we can extrapolate all your other questions. Your accessories put a small load on BOTH Main & Aux, except during ESS stops when it's just Main. What you heard about Aux charging is completely wrong since 99.99% of the time they're linked in parallel and function as a single battery. Except during ESS events Main and Aux will always balance with each other, including while parked.

There is one situation where Aux won't recharge. That's if fuse N3 is blown in the High Amp Fuse Array. This fuse is between Main & Aux and if it is blown Aux will always be isolated from Main and the alternator as well. Obviously it will never recharge and will be progressively drained until it is dead.

Finally, since they nearly always operate as a single battery it's really bad to only replace one of them. The new battery will try to charge the old battery 24/7 to a level it can't hold and the new battery will die very quickly.

 

[Mack.]

Hey everyone, looking for some help.

'21 JLUR 2.0L, Colorado.

Last summer I was constantly having battery issues, mostly seen as the message 'Aux Switches Temporarily Unavailable, battery charging'. The ESS almost never was working as well.

So I took it into the dealership in November, and by the skin of my teeth, they replaced both the main and Aux batteries under warranty. Everything started working normally again...

So the past few weeks I noticed the ESS is again not working. The message just shows 'Start/Stop Not Ready'.

I daily drive it about 20 minutes each way to and from work, so I think it should have enough charging time n that basis.

Last night when I got home I put it on my charger, and initially it was reading 80% charge, then I left it charging for a few hours, but it stopped charging at 95%. So I took the charger off, let it sit for an hour, then put the charger back on, and then it finally went up to 100%.

This morning on the way to work...ESS still not working, and same Not Ready message. So I don't know what to make of that.

Is 6 months really long enough for one or both of the batteries to start to die? I know the dealership said they have specific OEM batteries that they had to use on it as part of a warranty replacement (ie: crappy battery).

Should I try to reset the IBS and hope that resolves it somehow?

Just bite the bullet and replace both batteries with better quality batteries?

Bypass the ESS in the future? I don't like it other than it seems to be an unofficial indicator of battery failure when the ESS doesn't engage.

If that battery sat somewhere at 75 or 80% charged for a while It has been compromised. Lord only knows how old those new batteries are. We have a guy in Florida who sells brand new batteries for $50 that are 1 year old because the honest parts houses won't sell old stock to their customers. The guy buys them and wholes them to the public. No more 4 years warranty on Die Hard batteries should tell you a bit about batteries these days.

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