Aux Battery replacement the easy way... pull the fender flare

[mgroeger]

@Rhinebeck01 - do you know if this battery will fit? I think my aux is beginning to fail (dash flashing a few different times right after startup)

https://www.batteriesplus.com/produ...m-L_HPoM-3h7l4iJnnDWs3s3fZl0tBChoCCt4QAvD_BwE

I know you didn't ask me but I too had to replace mine and bought one at the local O'reilly for like $120. The one you are showing should work, make sure you unscreww the two Torx screws that are in the existing battery and transfer them to your new battery.
Funny thing to note, the O'Reilly battery was literally the Mopar battery with a different sticker on it. They were both made from the same supplier and had the same part number of the manufacturer on them.

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[CarbonSteel]

I know you didn't ask me but I too had to replace mine and bought one at the local O'reilly for like $120. The one you are showing should work, make sure you unscreww the two Torx screws that are in the existing battery and transfer them to your new battery.
Funny thing to note, the O'Reilly battery was literally the Mopar battery with a different sticker on it. They were both made from the same supplier and had the same part number of the manufacturer on them.

Thanks @mgroeger! The Duracell had a few more cranking amps in it and I thought that might actually be a bit better but I can always default to the one from O'Reilly's.

 

[Rhinebeck01]

@Rhinebeck01 - do you know if this battery will fit? I think my aux is beginning to fail (dash flashing a few different times right after startup)

https://www.batteriesplus.com/produ...m-L_HPoM-3h7l4iJnnDWs3s3fZl0tBChoCCt4QAvD_BwE

@CarbonSteel

The physical measurements are pretty close. to other's that I know will fit.. but I do not know for sure...

 

[JayInNC]

Good tips/info on this thread. Just replaced mine and it went fairly smooth...

Additional Tips:

1. When installing the threaded studs on the new aux battery, don't tighten them all the way down. If you do, there may not be a lot of threads left for the nuts once you reconnect the terminals.
2. When removing the white fender clips left behind after pulling the fender, there's enough room to get needle nose pliers behind them for a slight squeeze to help gently remove them.

 

[Rhinebeck01]

Good tips/info on this thread. Just replaced mine and it went fairly smooth...

Additional Tips:

1. When installing the threaded studs on the new aux battery, don't tighten them all the way down. If you do, there may not be a lot of threads left for the nuts once you reconnect the terminals.
2. When removing the white fender clips left behind after pulling the fender, there's enough room to get needle nose pliers behind them for a slight squeeze to help gently remove them.

@JayInNC

Yes, your comments are on the money so to speak... Thanks for posting.... we learn from each other's journeys...

When pulling the flare, if you pull from rear ward portion of the flare ... firmly/carefully, you can then get in there and release the JL fender flare clips as you mention... do this an you will be at less risk of breaking clips... Of course, that first pull can see you breaking a clip or possible two clips..

Once flare is off, remove all the fender Flare clips that are left on the JL's body and then place them at the positions on the flare... With all the fender flare clips on the flare the flare pushes on with less ta-do / easier so to speak.

As for those studs... Yup.... Funny some guys try to use the connectors that come with the replacement battery, instead of reusing the studs form the old battery.... not the best way..

.

 

[Rhinebeck01]

A little bit more info that will save someone headaches.... After doing a few aux battery replacements I know the drill well so to speak...

BEFORE you give AutoZone or whomever your old Aux battery for core credit... DO, do remember to remove the 2/both studs on the old battery.

You will want these for use when installing the new Aux battery you bought.... Yes, the new aux will will come with some hardware (no studs though)..... BUT, you will really really want to use (easier/cleaner install) the studs you removed from the old aux....

Do NOT use a plier or such to remove the studs... You will damage the threads on them!

Use a star socket to remove the studs or you can used two properly sized nuts....... Screw them on the stud and lock them / tighten to each other... now / then reverse the bottom one and the stud will unscrew from the battery.

Another hint...... measure how far each stud actually protrudes out of the old aux battery. When you place the studs in the new aux, be sure you place them so the height is the same same as when in the old aux..

 

[JeepJLU402]

I’ve read through this and if I’m understanding correctly my engine start stop display says “not ready battery charging” or similar words. This means my ESS battery is bad and needs to be replaced. So is this a warranty replacement? I have a 2019 with 15,000 miles bought in August of 2019.

 

[laroo]

I’ve read through this and if I’m understanding correctly my engine start stop display says “not ready battery charging” or similar words. This means my ESS battery is bad and needs to be replaced. So is this a warranty replacement? I have a 2019 with 15,000 miles bought in August of 2019.

I've read multiple times on this forum that the batteries are covered under the 3yr/36k mi warranty. I have an appointment next week, so I'll find out for sure then. Mine has been saying "battery protection mode" for a few weeks now, and remote start wouldn't work the last 2 mornings. I'm fully expecting to be stranded at some point before my appointment.

 

[mgroeger]

I’ve read through this and if I’m understanding correctly my engine start stop display says “not ready battery charging” or similar words. This means my ESS battery is bad and needs to be replaced. So is this a warranty replacement? I have a 2019 with 15,000 miles bought in August of 2019.

No... your battery does not need to be replaced.
When you get that message, the only way you are seeing it is by scrolling through the screens to the message center. That is simply telling you the battery is in a charge mode from the alternator which is normal. You will also see other messages there like "driver seat belt not fastened", or "steering wheel is turned", or "battery protection mode" because your engine compartment is hot from off roading all day. Those are simply reasons your ess is not engaging and it does not mean you have a problem with the battery.

When your battery starts to fail you will see actual warning lights on the dash likea yellow A in a circle arrow or something like that, I can't recall exactly what it is, but you will know for sure.

 

[JeepJLU402]

No... your battery does not need to be replaced.
When you get that message, the only way you are seeing it is by scrolling through the screens to the message center. That is simply telling you the battery is in a charge mode from the alternator which is normal. You will also see other messages there like "driver seat belt not fastened", or "steering wheel is turned", or "battery protection mode" because your engine compartment is hot from off roading all day. Those are simply reasons your ess is not engaging and it does not mean you have a problem with the battery.

When your battery starts to fail you will see actual warning lights on the dash likea yellow A in a circle arrow or something like that, I can't recall exactly what it is, but you will know for sure.

Ok. Thank you for the quick reply. I just don’t want to be stranded somewhere. I’ll keep an eye out of a warning light.

 

[BobW]

No... your battery does not need to be replaced.
When you get that message, the only way you are seeing it is by scrolling through the screens to the message center. That is simply telling you the battery is in a charge mode from the alternator which is normal. You will also see other messages there like "driver seat belt not fastened", or "steering wheel is turned", or "battery protection mode" because your engine compartment is hot from off roading all day. Those are simply reasons your ess is not engaging and it does not mean you have a problem with the battery.

When your battery starts to fail you will see actual warning lights on the dash likea yellow A in a circle arrow or something like that, I can't recall exactly what it is, but you will know for sure.

Mgroeger is correct, there's even a message like "hill too steep" (or words to that effect).
Unless: if your ess never operates, you have a problem. Mine just had this problem (~ 16,000mi), even after an hour's driving, it would display "not ready battery charging". After several days of trial & error (I think), dealer got a specialist tech on my jeep. He determined cause was bad primary battery. Replaced (under warranty), all is good again.

While this may not be your problem, it's in the same system...

 

[mgroeger]

Ok. Thank you for the quick reply. I just don’t want to be stranded somewhere. I’ll keep an eye out of a warning light.

There is no harm in having the dealer test your battery if you have a concern. Just make sure they do it right because if they don't isolate the AUX battery during testing they will get a false read from the connection to the main battery. Here's the fun part... once you get that warning light you can have little to no time to replace the battery before you can't start the Jeep.
I had mine at the dealer and they were doing some work and tested the battery and said ti was fine. I get there to pick it up and it won't start. Timing was perfect... it crapped out right there so they jumped me and I bought an AUX battery and took it home and installed it since I was out of warranty.

 

[laroo]

Mgroeger is correct, there's even a message like "hill too steep" (or words to that effect).
Unless: if your ess never operates, you have a problem. Mine just had this problem (~ 16,000mi), even after an hour's driving, it would display "not ready battery charging". After several days of trial & error (I think), dealer got a specialist tech on my jeep. He determined cause was bad primary battery. Replaced (under warranty), all is good again.

While this may not be your problem, it's in the same system...

Yep, my ESS does not operate at all. Guess if I see that warning light that Mgroeger mentioned, I should probably just drive it straight to the dealer.

 

[JeepJLU402]

Mgroeger is correct, there's even a message like "hill too steep" (or words to that effect).
Unless: if your ess never operates, you have a problem. Mine just had this problem (~ 16,000mi), even after an hour's driving, it would display "not ready battery charging". After several days of trial & error (I think), dealer got a specialist tech on my jeep. He determined cause was bad primary battery. Replaced (under warranty), all is good again.

While this may not be your problem, it's in the same system...

My ESS has not worked the last couple days. And on Saturday I was on the interstate for about 50 minutes. It was Sunday that I noticed it not working.

I just called the dealership and they said they could get me in on November 22nd unless I just leave the Jeep for a few days.

 

[JeepJLU402]

Yep, my ESS does not operate at all. Guess if I see that warning light that Mgroeger mentioned, I should probably just drive it straight to the dealer.

How long has yours not been working?

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