Aux Battery Question

[G-Oil Guy]

Which negative post is the one to the aux battery?

I had my Noco genius 10 amp charger on for a few hours today and the ESS is still reading “not ready battery charging”

Rhineback has been very helpful but he doesn’t have a diesel so he can’t help with this specific question.

Any help is welcome

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[GATORB8]

Someone may correct me, but I don’t think they’re disconnected key off, so you charged them both.

 

[G-Oil Guy]

If you connect them to the main post on the battery (given how the negatives are connected to the main battery) that’s correct. I wanted to try connecting just the aux specifically.

 

[GATORB8]

If you connect them to the main post on the battery (given how the negatives are connected to the main battery) that’s correct. I wanted to try connecting just the aux specifically.

Negatives will all be frame grounded.

Out of my direct knowledge here, but if that’s true, pull the main positive, confirm the voltage is there, and you should be able to charge there.

Or, I know there’s a positive on the bus bar in the fuse box. Should be able to pull the positive and check for voltage on those against ground.

guessing your SOL if your alternator isn’t charging it, anyways.

 

[G-Oil Guy]

Voltage on the main is fine and has been. Just the ESS stopped working. My wrangler isn’t my daily driver and I’ve been told that the aux can die if not driven regularly and for decent distances.

 

[GATORB8]

Voltage on the main is fine and has been. Just the ESS stopped working. My wrangler isn’t my daily driver and I’ve been told that the aux can die if not driven regularly and for decent distances.

Just a note, check out someone who has done a through fender aux swap, should save some time.

I meant if you haven’t been able to charge the aux through the charger or the alt, one or the other is bad.

 

[Jebiruph]

Which negative post is the one to the aux battery?

I had my Noco genius 10 amp charger on for a few hours today and the ESS is still reading “not ready battery charging”

Rhineback has been very helpful but he doesn’t have a diesel so he can’t help with this specific question.

Any help is welcome

That message is for the main battery, not the aux battery. If you think it's wrong, unplug the battery sensor to reset it and see if that clears the problem once the sensor relearns the battery.

 

[BroncoHound]

I haven't gotten my hands on my Ecodiesel yet, but on the Pentastar the ESS battery negative is the separate studded cable on the negative terminal (the top one in the red circle in the picture; I didn't do a very good job of outlining which one I was pointing at in this picture):

 

[G-Oil Guy]

That message is for the main battery, not the aux battery. If you think it's wrong, unplug the battery sensor to reset it and see if that clears the problem once the sensor relearn the battery.

Thank you. Can you give me a general idea where that sensor is located?

 

[G-Oil Guy]

Nevermind I think I found it. It’s mounted below the two negatives.

I tested both batteries. Both reading 12.55v.

I’m betting the sensor went bad. Oh well. Time to call the dealer. Yay warranty.

I should note I did disconnect the sensor and will let it sit for a few minutes before I reattach it and see if it relearns the battery.

 

[Rhinebeck01]

Nevermind I think I found it. It’s mounted below the two negatives.

I tested both batteries. Both reading 12.55v.

I’m betting the sensor went bad. Oh well. Time to call the dealer. Yay warranty.

I should note I did disconnect the sensor and will let it sit for a few minutes before I reattach it and see if it relearns the battery.

@G-Oil Guy

Take a minute and read this whole thread.. it talks about the IBS...
https://www.jlwranglerforums.com/forum/threads/ibs-clear-reset.67955/

 

[GSLSE21B]

Just a note, check out someone who has done a through fender aux swap, should save some time.

I meant if you haven’t been able to charge the aux through the charger or the alt, one or the other is bad.

Jl diesel takes less than 5 minutes to remove both batteries

 

[G-Oil Guy]

@G-Oil Guy

Take a minute and read this whole thread.. it talks about the IBS...
https://www.jlwranglerforums.com/forum/threads/ibs-clear-reset.67955/

As always you are a wealth of information. Thank you.

 

[G-Oil Guy]

Just following up for people who may be following this thread:

I hooked the sensor back up last evening and started the vehicle. It still read “not ready engine charging” that was before @Rhinebeck01 posted the IBS reset procedure. So I let it sit all evening. Then I went to bed. This morning after 9 or so hours from previous start. The screen now just read “not ready” no other statement. So I drove to my girlfriends home. This would be a 20 minute drive.

After about 5-10 minutes of driving I came to a red light and low and behold the ESS kicked in.

So for the time being it appears to be working again. I will monitor the situation and continue to follow the IBS reset procedure to completion and I will continue to leave the jeep on a trickle since it usually only gets driven once or twice a week

 

[G-Oil Guy]

Further updates just to keep this as accurate as possible.

Drove home from my girlfriends with the jeep sitting for maybe 4 hours ish.

Voltage reading on the dash read 12.9
ESS just “not ready, driver seatbelt unbuckled”
Buckled seat belt
ESS read “not ready” nothing more.
ESS did not kick in the whole way home but about halfway I did turn on the AC which I’ve read can get prevent the ESS from working but the message in the dash did not change from “Not Ready” (again no other qualifier).

The jeep will continue to sit for the evening and I have errands to run in the morning so I’ll see if it kicks in then as it does appear the jeep is still going through learning the battery.

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