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

[Rhinebeck01]

I don't know why they have a short life span but I can tell you that I have had the Auto Start/Stop on my 2018 JLUR "turned off" by using the JLTazer shortly after I bought my Jeep 3 yrs ago and my aux battery just went bad. It started with the dash warning the start/stop and Aux switches were temporarily unavailabe, a few days later my jeep wouldn't start but was able to be easily jump started. I replaced the aux battery and things have been fine for the last few days.

A Tazer JL or say a SmartStopStart unit does no more then push the button for you in essence.. Yuor Aux battery is in play always, unless you disconnect it.

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[mgroeger]

I don't know why they have a short life span but I can tell you that I have had the Auto Start/Stop on my 2018 JLUR "turned off" by using the JLTazer shortly after I bought my Jeep 3 yrs ago and my aux battery just went bad. It started with the dash warning the start/stop and Aux switches were temporarily unavailabe, a few days later my jeep wouldn't start but was able to be easily jump started. I replaced the aux battery and things have been fine for the last few days.

What you experienced sadly seems to be the norm and you should be good now with the new ess battery. FYI, you may want to have your main battery checked with both cables removed from it. Changes are it's starting to be on the low side.

 

[Rock Hopper]

Actually, your ESS is not disabled.. Sure, you may have purchased an adjunct which in essence does the ESS button push for you..

As for whether to access the Aux battery by pulling the PDC... Sure you can do that but all you are doing is asking for problems doing it that way..

Most you can damage peeling back a fender liner or pulling a flare is some plastic rivets or clips.
Pulling the PDC ... if things go just a little a muck, it can costs you hundreds.. FCA tells techs to peel back fender liner and for valid reasons.

@Rhinebeck01, While turning it off is essentially my definition of disabling it, I have not disconnected it. I appreciate your comments/reply and want to understand the best way to eventually eliminate it so that I don't run into future problems. The last thing I want is to be stranded by a dead battery that I do not and will never use. I know there are other JL owners that feel the same way and are looking for a easy solution. Pulling a fender (flare) doesn't sound fun. I also understand that messing with the electronics has the possibility of making things worse.

I probably have not spent enough time researching this, but it is beginning to sound like peeling back the fender liner may be the best solution to get access to the ESS battery.

For those of us that will never use the ESS, what is the best solution to this issue? All I want is my JL not to leave me stranded and behave like the vehicles that I grew up with! You know the ones-one battery, that is readily accessible and replaceable!

Thanks for any advice-

 

[mgroeger]

@Rhinebeck01, While turning it off is essentially my definition of disabling it, I have not disconnected it. I appreciate your comments/reply and want to understand the best way to eventually eliminate it so that I don't run into future problems. The last thing I want is to be stranded by a dead battery that I do not and will never use. I know there are other JL owners that feel the same way and are looking for a easy solution. Pulling a fender (flare) doesn't sound fun. I also understand that messing with the electronics has the possibility of making things worse.

I probably have not spent enough time researching this, but it is beginning to sound like peeling back the fender liner may be the best solution to get access to the ESS battery.

For those of us that will never use the ESS, what is the best solution to this issue? All I want is my JL not to leave me stranded and behave like the vehicles that I grew up with! You know the ones-one battery, that is readily accessible and replaceable!

Thanks for any advice-

Search the forum for the ESS battery thread. In there they show you how you can jump out the ESS battery using the fuse block termination points to jumper the regular battery 12V over to the ESS battery 12V.

 

[Rhinebeck01]

@Rhinebeck01, While turning it off is essentially my definition of disabling it, I have not disconnected it. I appreciate your comments/reply and want to understand the best way to eventually eliminate it so that I don't run into future problems. The last thing I want is to be stranded by a dead battery that I do not and will never use. I know there are other JL owners that feel the same way and are looking for a easy solution. Pulling a fender (flare) doesn't sound fun. I also understand that messing with the electronics has the possibility of making things worse.

I probably have not spent enough time researching this, but it is beginning to sound like peeling back the fender liner may be the best solution to get access to the ESS battery.

For those of us that will never use the ESS, what is the best solution to this issue? All I want is my JL not to leave me stranded and behave like the vehicles that I grew up with! You know the ones-one battery, that is readily accessible and replaceable!

Thanks for any advice-

@Rock Hopper

As already mentioned, do a forum search using the word ESS. You will find LOTS of talk regarding the JL's Dual Battery system and ESS...

It is really easy to separate out the Aux/ESS battery and use it for a back-up battery while you use just the Main, for your day to day use... About the only caveat of doing so is you would also not want to use or limit your use of ESS.

Here is a thread that talks STOCK dual battery management... Read at this thread and again search "ESS" on the forum and read read..
https://www.jlwranglerforums.com/forum/threads/ess-dual-battery-management.60034/post-1340536

 

[Rock Hopper]

@Rock Hopper

As already mentioned, do a forum search using the word ESS. You will find LOTS of talk regarding the JL's Dual Battery system and ESS...

It is really easy to separate out the Aux/ESS battery and use it for a back-up battery while you use just the Main, for your day to day use... About the only caveat of doing so is you would also not want to use or limit your use of ESS.

Here is a thread that talks STOCK dual battery management... Read at this thread and again search "ESS" on the forum and read read..
https://www.jlwranglerforums.com/forum/threads/ess-dual-battery-management.60034/post-1340536

Thank you! That is exactly what I was looking for-especially since I will NEVER use my ESS.

Sorry I didn't find that thread on my own-must have overlooked it. Again, thanks for the tips.

 

[Taxman]

Thanks to this thread, I just replaced both my auxiliary and main batteries in under an hour. I ordered my Odyssey 48 and SuperStart AGM batteries in January, but it has been a cold and wet winter, so they've been sitting quietly in their boxes until today when temperatures reached 50 degrees and the sun was shining!

The main battery took all of 5 minutes to remove. Disconnected negative and positive leads and set them aside. Removed the 10mm bolt with an extension socket and the battery came right out.

The fender flare removal took about 10 minutes, but was very easy. The four 10mm bolts are easy to remove, especially if you have a Rubicon or a suspension lift since you'll have plenty of space to work in the wheel well. There's a Christmas tree plug toward the front of the fender by the grille that's pretty tough to remove. Despite being patient and using the proper tools, I tore the Christmas tree plug to shreds and need to replace it eventually.

There are a total of eleven white fender clips along the edge of the flare. As careful as I was in removing the flare, I broke five of the clips. The video in this thread showing the removal of the flare was likely done with a brand new Jeep when the plastic was still soft and flexible. My Jeep is three years old and is parked in the sun all day. The plastic clips were hard and brittle and didn't take much effort to break them. Luckily I had purchased ten clips from Quadratec last week and had them with me.

Once the flare is removed, the aux battery is very accessible. There are three 10mm bolts holding the bucket in place. Once the bolts are removed, the bucket drops and the battery is inside. Remove the negative and positive leads, remove the battery from the bucket, replace the battery with a new one, reinstall the leads and bolt the bucket back in place. This took about another 10 minutes.

I installed the main battery after installing the aux battery and before re-attaching the fender flare just in case my aux battery was bad or the connection was bad. I didn't want to remove the fender again. Installing the main battery was easy, but the Odyssey size 48 battery is slightly shorter in length than the stock battery, so be sure to seat it against the PDC box. There is a lip at the bottom of the PDC housing that helps hold down the battery. Once it's in, I secured it and reattached the fender. This took about another 10 minutes or so.

All in all, it was about a 45-60 minute job depending on how accessible your tools are, and if you count clean up and battery disposal. Thanks to all for the helpful tips and suggestions.

 

[Rhinebeck01]

Thanks to this thread, I just replaced both my auxiliary and main batteries in under an hour. I ordered my Odyssey 48 and SuperStart AGM batteries in January, but it has been a cold and wet winter, so they've been sitting quietly in their boxes until today when temperatures reached 50 degrees and the sun was shining!

The main battery took all of 5 minutes to remove. Disconnected negative and positive leads and set them aside. Removed the 10mm bolt with an extension socket and the battery came right out.

The fender flare removal took about 10 minutes, but was very easy. The four 10mm bolts are easy to remove, especially if you have a Rubicon or a suspension lift since you'll have plenty of space to work in the wheel well. There's a Christmas tree plug toward the front of the fender by the grille that's pretty tough to remove. Despite being patient and using the proper tools, I tore the Christmas tree plug to shreds and need to replace it eventually.

There are a total of eleven white fender clips along the edge of the flare. As careful as I was in removing the flare, I broke five of the clips. The video in this thread showing the removal of the flare was likely done with a brand new Jeep when the plastic was still soft and flexible. My Jeep is three years old and is parked in the sun all day. The plastic clips were hard and brittle and didn't take much effort to break them. Luckily I had purchased ten clips from Quadratec last week and had them with me.

Once the flare is removed, the aux battery is very accessible. There are three 10mm bolts holding the bucket in place. Once the bolts are removed, the bucket drops and the battery is inside. Remove the negative and positive leads, remove the battery from the bucket, replace the battery with a new one, reinstall the leads and bolt the bucket back in place. This took about another 10 minutes.

I installed the main battery after installing the aux battery and before re-attaching the fender flare just in case my aux battery was bad or the connection was bad. I didn't want to remove the fender again. Installing the main battery was easy, but the Odyssey size 48 battery is slightly shorter in length than the stock battery, so be sure to seat it against the PDC box. There is a lip at the bottom of the PDC housing that helps hold down the battery. Once it's in, I secured it and reattached the fender. This took about another 10 minutes or so.

All in all, it was about a 45-60 minute job depending on how accessible your tools are, and if you count clean up and battery disposal. Thanks to all for the helpful tips and suggestions.

@Taxman

Glad it went aok and that this thread was helpful.

Indeed, not a major deal to swap out the little ESS and the Main on a JL/JT.

I have done the deed 3 times so far... On 3, Rubi's and they were not my vehicles.. I did one out in the rain... All were 2019's. Was by myself...

I broke no more then 4 clips each time I did the deed... I do make sure I have 8 on hand as I figure I won't break all 11 clips..

I'm 72 yo and have no trouble doing the deed.... BUT, each time I pulled the flare off, I cringed... takes some real yanking lets say. I try to start on one end and when I can, I finesse the barbs a bit in an attempt to keep them from breaking..

Anyway, quite easy and yup, do have at least 8 clips... JL clips, not JK clips..

?... was the Aux "bucket" / box on your JL dry inside... All 3, I did were bone dry, but all the ones I did were just daily driver's.... none had been offroad.

Apparently, there is a problem with the small drain holes in the box, getting plugged and moisture or water staying in there and creating issues..

 

[Rhinebeck01]

@Taxman

Forgot to mention.... now that you have both Main and ESS replaced, do consider from now on running with just the Main and using the Aux as a back-up start battery... Easy to set-up and will cost you say less then $10 to do... Can tell you, doing this really will give you a comfy feeling so to speak...

 

[Taxman]

@Taxman

?... was the Aux "bucket" / box on your JL dry inside... All 3, I did were bone dry, but all the ones I did were just daily driver's.... none had been offroad.

Apparently, there is a problem with the small drain holes in the box, getting plugged and moisture or water staying in there and creating issues..

Mine was dry inside, although it was dirty and had leaves and dirt. But other than that it was dry. I do a moderate amount of off-roading mainly on loose gravel trails with some mild water crossings no more than a foot in depth. I dislike mud and try to avoid it as much as possible. I did a bit of snow wheeling this winter, but nothing too deep that would have reached the aux battery box.

I had been dreading this install for almost two months, but it was actually not difficult at all. Just be sure to have some extra fender clips and Christmas tree plugs on hand.

 

[Rhinebeck01]

Mine was dry inside, although it was dirty and had leaves and dirt. But other than that it was dry. I do a moderate amount of off-roading mainly on loose gravel trails with some mild water crossings no more than a foot in depth. I dislike mud and try to avoid it as much as possible. I did a bit of snow wheeling this winter, but nothing too deep that would have reached the aux battery box.

I had been dreading this install for almost two months, but it was actually not difficult at all. Just be sure to have some extra fender clips and Christmas tree plugs on hand.

@Taxman

I use heat .... carefully apply right at xmas tree barbs (careful not to heat wires) and then use my pry tool with the cut V and they all came out.... Also, 2019 JL's and in warm weather.

 

[SolarWizard]

@Taxman

Forgot to mention.... now that you have both Main and ESS replaced, do consider from now on running with just the Main and using the Aux as a back-up start battery... Easy to set-up and will cost you say less then $10 to do... Can tell you, doing this really will give you a comfy feeling so to speak...

how do I do this And can I use the factory batteries? Getting a brand new one in two weeks

 

[Rhinebeck01]

how do I do this And can I use the factory batteries? Getting a brand new one in two weeks

@SolarWizard

There's lots of info about doing this on the forum...

Here is one thread with talk of ESS Dual Battery Management and running with just the Main.
https://www.jlwranglerforums.com/forum/threads/ess-dual-battery-management.60034/

 

[ALRUI]

My son created a video of replacing both batteries on our Jeep JL the other day using this method which I think is the best way to perform the task:

 

[Jeepneck]

Just a crappy design for the location and removal of the ESS battery....when mine dies I’m not sure what I will do but my first thought is to jumper N1 to N2 and remove the ESS negative and let the ESS battery stay where it’s at....long term I’m not sure of any damage with it left there

I was thinking the same thing. Mine is sitting on the side of the road right now with this issue. I'm heading to O'Reilly's to pick up the fused jumper and hopefully fix it.

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