How do you know when to replace the auxiliary battery on the 2018 JL jeep wrangler?

[mwilk012]

Its ridiculous that they couldn't find a better way to position the battery in a gasser. It was placed under the main battery tray in the 3.0D. Why couldn't they design the others in such a way that body work isn't required to do the job?

Body work, lol. You remove a fender liner. It’s nothing.

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[jberry187]

Body work, lol. You remove a fender liner. It’s nothing.

You're probably right that it is nothing. But it is body work and it is a ridiculous design.

 

[kah.mun.rah]

I just replaced mine on my 18.
did it from the top as I didn’t want to fool with body clips and fenders.
it wasn’t hard, a bit aggravating with the fuse box connectors flipping in the way.

just remember even with the main battery disconnected the leads are still energized from the aux battery.

I'd rather break a 50 cent fender clip than screw up my electrical system.

 

[rhocking]

Thx for that good info. My thought would be to put another large battery in its place. This might be an advantage to my ecodiesel. More cranking power and longer accessory life when out camping……. Your thoughts?

For the camping scenario I think a dual battery setup may be a good choice. It really depends on how you use your jeep. I considered the Genesis for a while but do not camp much and decided that the cost for a dual battery setup vs the AUX bypass was not the best choice for me but it may be a good choice for some. Before jumping in I would do careful research because the ecodiesel is different and you want to make sure that the dual battery setup will fit the ecodiesel.

 

[mwilk012]

You're probably right that it is nothing. But it is body work and it is a ridiculous design.

It’s not body work. Not even close. It’s a plastic cover held on with plastic rivets and a few small screws. It’s a joke.

 

[jberry187]

It’s not body work. Not even close. It’s a plastic cover held on with plastic rivets and a few small screws. It’s a joke.

Are you referring to simply removing the fender lining at the bottom in the wheel well, or removing the fender with the turn signal assembly? I've seen both and the latter seems to be unnecessary and problematic.
I'm not trying to argue, but rather understand the reasoning behind the design. I guess there are some of us out there that don't want to mess with removing fenders and such when it comes to basic maintenance.
Either way, I'm glad it's an easy task for you (and hopefully others). Enjoy the rest of your day.

 

[skipperw]

Good point. Thx?

 

[TKL223/3]

How do you know when to replace the auxiliary battery on the 2018 JL jeep wrangler?

When they handed you your keys and you drove it off the lot 5 years ago.

 

[mwilk012]

Are you referring to simply removing the fender lining at the bottom in the wheel well, or removing the fender with the turn signal assembly? I've seen both and the latter seems to be unnecessary and problematic.
I'm not trying to argue, but rather understand the reasoning behind the design. I guess there are some of us out there that don't want to mess with removing fenders and such when it comes to basic maintenance.
Either way, I'm glad it's an easy task for you (and hopefully others). Enjoy the rest of your day.

Removing the fender LINER is the actual intended and written repair procedure for replacing the auxiliary battery. After the first time, it takes no extra parts and about 10 minutes if you’re moving real slow.

 

[Skyvet]

Thx for that good info. My thought would be to put another large battery in its place. This might be an advantage to my ecodiesel. More cranking power and longer accessory life when out camping……. Your thoughts?

I have a 2021 ecodiesel and my aux batt was toast in a year. It was a PIA trying to figure out why I was getting all these error codes. And no way was my jeep under warranty as there was few oem parts still on the vehicle lol. There is no room to setup the dual battery system such as the one most gassers use. My solution, like many others, was to remove both batteries, ditch the aux batt, attach the pos from the aux to the main and wrap the aux neg cable (or remove it). Remove fuse 42. Get a taser (I already had it) and use that to bypass ESS (or any of the other products out there). I was then able to install a larger battery as well. Took maybe an hour (I was being lazy that day) and since then have had 100% zero issues.

 

[ObiMatt87]

Yes, same battery across all JL years.
But not model/features. 4XE & ETorque Jeeps do not have the Aux battery, the battery for those features takes over the Aux battery functions.

Main = Group Size 48
Aux = Group Size 400
Both AGM

Yes, interestingly I have a co-worker who has a 2020 Sahara like mine (but mine is 2018). He does not have an aux battery. I wish I didn't, but I do. Not going to go the expensive route of doing the Genesis dual battery setup, as (for me) the cost far outweighs the inconvenience of the aux replacement from time to time. BTW, I did NOT remove my inner fender liner to get to my aux. That is not necessary. Simply went in from the top. When one or both of my replacement batteries dies I'll replace both. I've done a dual swap once at ~the 3 year point and will do them again in the future, but no overly-complicated Genesis system for me. Respect to those who have it! ?

 

[Dragon52]

ESS on my 2020 Rubi diesel has stopped working so I am assuming the Aux battery is toast. Based on all the advice I plan to change the main and aux batteries. For the main I am comparing Odessy and Optima. Any experience or opinions either way? Thanks!!

 

[tawsenior]

UPDATE: Took Jeep to the dealership today, as the above mentioned problems happened yesterday, and guess what? I don't have an aux battery, even though I have the 2.0T with the eTorque. Turns out some Wranglers do and others don't. My ess and all electronics operate off of the main battery. There was a security gateway issue that they said probably caused a momentary disruption in computer signals that initiated my electrical problems and shut everything down. Cleared the code and all is back to normal.

Your aux battery, for Jeeps with eTorque, is actually mounted under the Jeep. It's 48 volts and has it's own cooling system and is covered with a skid plate.

 

[KeithB]

Where under the Jeep is the Aux battery located for the eTorque?

 

[Tncdrew]

Where under the Jeep is the Aux battery located for the eTorque?

Next to the rear driveshaft (opposite the fuel tank)

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