bunch of lights came on

[mchastings]

Replaced the aux without replacing the main? They're like Romeo and Juliet: they die together.

I am not an electrician, so I can only hypothesis, My wife has a 2015 Rubicon, still factory in terms of mods. Car wouldn't start the other day, I checked battery, Good, fuses, Good, starter, Good, saw a utube video on grounding straps, pulled up a schematic and found every grounding strap/cable and tightened them. Every ground was good with only a couple needing a slight turn, nothing that would cause concern. The damn thing started and has been trouble free for the last 27 days. I had checked for grounding with a multi meter when I started and did show voltage fluctuations (minor) that indicated a ground issue so fingers crossed. So maybe! Getting back to Diesels, my 2020 JL died on me when I was driving last year and it turned out to be the batteries. My electrical system went haywire when it died with lights blinking, wipers moving, dome light and then nothing, not even enough power for the emergency blinkers. (turns it it blew a main fuse) So, my question, since the Aux battery is smaller, doesn't it make since that it will use up its electrons before the bigger one, and when its dying it becomes a parasite to the main battery, and since they are wired in parallel, you really wont be able to tell with a multi meter until the main starts to lose its ability to recharge?

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[Wrangler man]

I am not an electrician, so I can only hypothesis, My wife has a 2015 Rubicon, still factory in terms of mods. Car wouldn't start the other day, I checked battery, Good, fuses, Good, starter, Good, saw a utube video on grounding straps, pulled up a schematic and found every grounding strap/cable and tightened them. Every ground was good with only a couple needing a slight turn, nothing that would cause concern. The damn thing started and has been trouble free for the last 27 days. I had checked for grounding with a multi meter when I started and did show voltage fluctuations (minor) that indicated a ground issue so fingers crossed. So maybe! Getting back to Diesels, my 2020 JL died on me when I was driving last year and it turned out to be the batteries. My electrical system went haywire when it died with lights blinking, wipers moving, dome light and then nothing, not even enough power for the emergency blinkers. (turns it it blew a main fuse) So, my question, since the Aux battery is smaller, doesn't it make since that it will use up its electrons before the bigger one, and when its dying it becomes a parasite to the main battery, and since they are wired in parallel, you really wont be able to tell with a multi meter until the main starts to lose its ability to recharge?

Yep, been there! Happens without warning no matter how proactive you are on maintenance and catching things early. Stalantis knows this very well. This is a huge issue and should have had a recall to fix the failing aux battery issue. Some might assume or others are surprised to find out you cannot jump start your battery. When something of similar battery failure such as yours occurs. If you're not proactive and completely eliminate that auxiliary battery you will experience at some time a similar fiasco that you dealt with. I understand for those that want to keep it stock and avoid voiding the warranty. But we have been given no choice or recall. Talk to an HONEST (HAHA)service manager and he will tell you the same.

 

[mchastings]

Agree, it is a stupid design based on stupid EPA assumptions, much like the EGR systems etc. At least elimination of the aux battery is within my purvey.

 

[Wrangler man]

Agree, it is a stupid design based on stupid EPA assumptions, much like the EGR systems etc. At least elimination of the aux battery is within my purvey.

Agree, Agree, Agree and yes when you're tired of the madness discerning over whether the aux battery has created most of your problems many times after repeated replacements. You come to the realization they are wrong and you find the solution and permanently fix it.

 

[mchastings]

In process of doing just that!

 

[THAW]

So, my question, since the Aux battery is smaller, doesn't it make since that it will use up its electrons before the bigger one, and when its dying it becomes a parasite to the main battery, and since they are wired in parallel, you really wont be able to tell with a multi meter until the main starts to lose its ability to recharge?

Generally speaking, a healthy smaller Aux/ESS battery will "use up its electrons" proportionally to a healthy larger main battery while in parallel; it's the separate discharge during ESS events that causes disproportionate aging.

You can measure voltage on the Aux/ESS battery (and separately on the main battery) by (temporarily) disconnecting its ground wire from the main battery negative terminal.

 

[mchastings]

Thanks Thaw! I do remember part of my Navy DC systems training, although " it was long ago and far away!" nod to Meat Loaf..

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