How To Replace Jeep JL Main & Aux Battery The Easy Way! Test & Guide!

In this video, I'm demonstrating how to replace BOTH batteries in a Jeep JL 2018 & up! There are 2 ways of doing this, one is removing the fuse box to get to the auxiliary battery which carries risk of damaging connectors & pis. The second & easier way is to remove the fender flare which is much easier & the preferred method.
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Group 94R (H7) Battery on Amazon: amzn.to/3ftzOfE
Battery Load Tester On Amazon: amzn.to/3cF8HfQ
Interstate Battery Used: www.interstatebatteries.com/p...
Aux Battery Used: shop.advanceautoparts.com/p/e...
Fender Clips Used: www.quadratec.com/p/omix/fend...
My Amazon Storefront: www.amazon.com/shop/ponds
Filmed with iPhone XS Max: www.apple.com/
Disclaimer: This video and description contains amazon affiliate links, which means that if you click on one of the product links, I potentially can receive a small commission. Thanks so much!!!

[@thomasdabb8393]

Thank you for the time spent doing this educational video. I have a 2020 with the 2.0 Turbo - awesome engine I will add. I reached now 41k. Aux battery died about 1 year ago. I press the button turning the stop/start off routinely. This is on my mine and will get the batteries and tackle this soon. One thing I'll say, I've heard the inner fender only has to come off, not the fender extension. Cheers, happy wheeling.

[@ashish2999]

Thanks a ton!!! This method to change the AUX battery was a breeze. It took me 1hr30min to do it all. Thank a lot for putting in the efforts to create and share this video with everyone. Couldn't have done it without your video.

[@Pondsisawesome124]

You're welcome! Glad it helped you:-)

[@jeffm3273]

Going through the fuse box is so much easier and not fussing with clips. Also, if you have a 2.0T engine, you might NOT have an aux battery. I have a 2019 Rubicon Unlimited 2.0T...no Aux battery and thank goodness I went through the fuse box because it was quick and easy.

[@crack_of_dawn]

How can I find out if I have an aux battery? I have a 2023 2.0T, no idea if there is an aux battery or not. I'm guessing I do because I think it's only the etorques that dont have them right?

[@wjsmithiii]

just replaced both and did it through the fuse box. tooking maybe 30 minutes

[@necrotoaster94]

Great video! 2020 Rubicon 2.0T and same problem at 21k miles.

[@fedewrangler]

thanks for the video. it was very helpful to me. an Italian Jeepers 💪🏻

[@Pondsisawesome124]

Glad it helped!

[@NathanParsell]

So funny. Just passed 40k miles also and the exact same thing happened to me. Like it’s on a timer. Thanks for the vid!

[@burkhardtdan]

Bro! Same- will try to replace tomorrow.

[@NathanParsell]

@@burkhardtdan tbh over a year later and I never even replaced the aux battery and zero issues.

[@Brittanygallo6]

I’m going through this now, we replaced the aux and I’m going to get a new main battery this week and I really Hope it solves the issue

[@Pondsisawesome124]

They usually both crap out at the same time.

[@goldandsilverstack3]

Literally what happened to me the other day. I replaced both batteries and its as good as new.

[@PhantomPhixer1]

Well done!

[@Pondsisawesome124]

Thanks man!

[@bobbyg7552]

What a fantastic video, you explained very clearly all the procedures you showed us. Thanks for such a great video. How long would you say it took you from start to finish to replace both batteries? I have the painted fenders as well, so I really appreciated this video.

[@Pondsisawesome124]

Thanks! It probably took about an hour and a half start to finish I’d say

[@augustmoon0004]

You don't have to take off the fender! Just turn the tire all the way to the left, unclip the left side of the liner and you can access the battery.

[@Frostytravels]

you need to change the ground lead your using for your steps to the body. If it is on the battery ground it causes a feed back loop problem and drains the battery over time. Jeep recommends not attaching anything to the negative battery terminal as it is their self test feedback loop.

[@walterostrenga9815]

Nice video. Be sure to disconnect the negative terminals first when removing the battery and installing them last when reconnecting the new battery in. If you ground out your wrench on the positive terminal while the negative is still connected...it goes boom.

[@Pondsisawesome124]

Great point!

[@EmiratiAuto]

is that battery voltage which is showing in off road screen 1:27 is that for the aux battery or the main battery ?

[@Pondsisawesome124]

Since the batteries are essentially connected in parallel that would be a downstream voltage probably pulled from the BCM or PCM.

[@thejeepinrealtor5742]

Mine started this this week. All lights are fine. Does the click like yours did on the last try in first part. Battery has over 13 volts. Guess I’m going digging

[@Pondsisawesome124]

Test the starter & connections. Also www.jlwranglerforums.com/forum/ is a great source of info on these Jeeps.

[@veronicamurphy9535]

We recently had a similar issue. (This is our FIRST JEEP) About to run an errand in our 2019 Jeep Wrangler Unlimited Sport edition. I HIT THE AUTO START AND NOTHING just click click click. All the lights came on, cameras came on just fine. Everything’s Nice and bright, musics playing. But it’s not starting, Wth??🤔My husband is very knowledgeable under the hood and he thought maybe I left a light or something on. (I thought the same thing, Even though I never use any of the anterior lights. But I still could’ve accidentally hit one of the light switches just grabbing a bag or something from the back.Ya Never know) So after more research under the hood, he noticed a nut from the starter that runs to the smaller battery was loose. I think he had to disconnected the main battery terminals, so he could hand tighten the starter nut. Jeep immediately started. No other issues. So far lol

[@gs-nt6nf]

Can you hook up a battery charger extension cable to the auxiliary battery for a trickle charger?

[@Pondsisawesome124]

It's discussed here, worth reading.

[@effortlesslygaming3150]

Some JLs don’t have an Aux battery , pulled the main, battery, fuse box ect and it was empty in our 2018 wrangler sport . Ours is fitted with the H-7 battery, while I was at it we removed the right most plunger that controls the auto start “/stop feature hopefully reducing the wear on the battery. I’m probably completely wrong but not having an AUX battery equipped may be adding additional stress on the alternator and main battery from that feature .

[@Pondsisawesome124]

All of the 3.6 units have the aux battery. There are a LOT of write ups here as to the correct bypass fro the start/stop. There are a couple plug N play units but they run about $100 www.jlwranglerforums.com/forum/

[@applefanboy1770]

Cool

[@habibehdeyhim7713]

yes the thermo guard would just fit H6 not the H7. I spoke to many part shops and they indicated it is a good to have protector, & won't hurt if I don't cover the battery. Seems like. yours fit properly on H7 thought, I wonder if Sahara models by default comes with a larger thermal guard so I can call the part department and order the part for Sahara instead of sport s.

[@Pondsisawesome124]

Yep, that all makes sense:-)

[@user-vb9kd3lg1s]

I just went to swap out my auxiliary battery for a new one, and come to find out my jeep does not come with one. I was so upset after removing everything too it the space empty

[@poksopheaktra2389]

I would like to know if any risk if i replace the Aux battery (under fender) without shut down the engine . Which mean keep engine on running, the reason to keep memory of Radio / AC and all other system.

[@Pondsisawesome124]

Don't attempt that, yes there's several risks. Just reset the settings, write them down first or use your phone to snap pics of settings. There's also something like this which uses an external 12V source to save settings though I haven't tried it on the Jeep myself: www.amzn.com/B009PHKPI6/

[@jeffkelly2446]

What is the part number to order new clip’s from Amazon took the fender of of my 2022 Wrangler to find I don’t have a secondary battery and I do have the start/stop feature on it

[@Pondsisawesome124]

Some of the engines use the eTorque for start stop instead of the Aux battery. Here's a link to the clips on Amazon but at $10 each, YIKES www.amzn.com/B084BYW8JD - look around you should be able to find them for closer to a buck each. eBay, Mopar, Quadratech are all good sources.

[@maximusvonce1381]

My 2020 jeep wrangler unlimited sport 3.6l had main battery fail at 18k miles, but my auxiliary battery still like new pulling 217cca.

[@Pondsisawesome124]

I've heard of others fail with fairly low miles/time as well, lots of posts about this on the forums.

[@dialarbelanio955]

Question, i just changed my battery on my JL but after changing it,Everything works but the shifter is stuck to park and also the lights on the shifter is dead. It also says "Sevice shifter". Is there any possible fuse i pop? Kindly help please. Thank you

[@Pondsisawesome124]

Possibly, did you replace the aux battery by going through the fuse box or did you remove the fender?

[@quatre0492]

This is one of the reasons I bit the bullet on a dual battery system both batteries are on top now

[@Pondsisawesome124]

Yeah, I have studied that, good choice!

[@MattHatchett]

I'm at 55K and this same exact thing just happened to me. Thanks for the video!!

[@Pondsisawesome124]

No problem:-)

[@irvingpaez2159]

Changed aux battery still not working says battery charging

[@Pondsisawesome124]

I'd check this forum, LOT'S of good info: www.jlwranglerforums.com/forum I know there's a relay by that Aux battery that can cause issues but test everything before replacing. Also it's generally a good idea to test both main & aux as they usually crap out at the same time. Hope this helps!

[@lrncephil80]

How did you change out the terminal post from the oem aux battery to the die hard battery?

[@Pondsisawesome124]

The new battery came with a bag of assorted screws and I used the ones that were the correct length for the Jeeps terminals. That said I would seek out a battery with terminals like the original battery - I believe the one Oreilly's sells is a better match.

[@lrncephil80]

@@Pondsisawesome124 thank you for the swift reply

[@Pondsisawesome124]

No problem:-)

[@EmiratiAuto]

how to jump start jeep JL if your Aux Battery is dead ?

[@Pondsisawesome124]

The image here on the JL forum is an outstanding look at the system: www.jlwranglerforums.com/forum/attachments/underhood-jumper-3a-png.238738/

[@habibehdeyhim7713]

What if the sleeve doesn't fit the new Interstate h7-94R AGM?

[@Pondsisawesome124]

That's the correct battery, by "sleeve" do you mean the black cover? The cover should fit unless your Jeep came with the slightly smaller H6 battery -

[@outlander5678]

Hi.. I need help, after replace the 2 battery error come out " service vehicle protection system"

[@Pondsisawesome124]

The code should clear up after a couple of re-starts. If not bring it to Auto Zone or someone and have them clear the code.

[@jamesronjeremy4547]

Has anyone been able to bypass the aux battery? It is such a pain for just the start/stop feature which no one likes anyways. I know you can turn it off and I saw a switch that always keeps it off but I am talking about wiring the batteries so that the aux battery is no longer needed. Right now my wifes aux battery went bad and the jeep would not start at all even though the other battery seemed good and my battery charger would not charge it since it was reading as good.

[@Pondsisawesome124]

Lot's of discussion here: www.jlwranglerforums.com/forum/ search and read to understand how the system works and the proper way to do this as if done wrong you risk damage/injury, etc.

[@upinya5223]

Why would you replace the aux battery, it’s just going to kill your main battery again

[@richardgatling4663]

How many fender flare clips are needed?

[@Pondsisawesome124]

Depends on how many if any break. Get several just to be sure, they're cheap & good to have on hand for next time:-)

[@maximusvonce1381]

Auxiliary start shop battery is 200 amps right?

[@Pondsisawesome124]

Yes, here's the O'reilly one I wanted to get but they were out of stock at the time: www.oreillyauto.com/detail/c/platinum/super-start-platinum-auxiliary-battery-group-size-400/ssbq/aux14?q=AUX14&pos=0

[@maximusvonce1381]

@@Pondsisawesome124 Warranty covering our battery. But thanks anyways

[@guitarsandjeeps]

The auxiliary battery looks like an ATV battery and in a ridiculous place. Unless I'm missing something, If you put a battery tender/charger on the main battery, it should also charge the auxiliary battery.

[@Pondsisawesome124]

The system is very complex & it's best to isolate whichever battery you want to charge, you can read about it here: www.jlwranglerforums.com/forum/threads/ess-dual-battery-management.60034/

[@guitarsandjeeps]

@@Pondsisawesome124 thanks for the link, it is an interesting read, i learned that 2018 models are wired differently than my gladiator, but they still have the same general battery setup.

[@DS-fx2jn]

Why take the fender off? I believe just taking off the tire and liner would provide enough room.

[@Pondsisawesome124]

I know others have tried that, not sure it's easier and/or better. Give it a go:-)

[@mackenzieclancy959]

The inner liner is riveted to the fender with about a dozen plastic rivets, also the same bolts that hold the fender on pass through the liner. It takes less than two minutes to take the fender off

[@TheCgilbert9935]

How do you test a battery that not charged ?

[@Pondsisawesome124]

Fully charge then do a load test on it.

[@pdagemini6976]

39,005 battery replacement Jeep Wrangler 2020

[@MrGerryoc]

How is that easier than pulling the tipm

[@Pondsisawesome124]

It's easier because there's zero risk of damaging a pin upon reassembly thus is also why it's the Jeep recommended way of doing it.

[@maximusvonce1381]

Main battery failed at 18k miles 2020 jeep wrangler unlimited sport 3.6l

[@emmcee476]

I cna confirm that a 2019 2.0 Wrangler I worked on, does NOT have an auxiliary battery And for those who have one with a second battery, yes going thru the fuse box is much easier

[@Pondsisawesome124]

Going through the fuse box is very risky due to the risk of bending pins.

[@emmcee476]

@@Pondsisawesome124 i did not bend any pins when I was in there to check if this vehicle had an auxiliary battery. Honestly it seems more daunting to mess with body parts and clips

[@jwat2396]

Why take the fender off? Just take the wheel liner off.

[@Pondsisawesome124]

Perhaps, the method described is per FCA (now Stellantis)

[@ron8975]

There isn't a single 10mm bolt involved with this job. Every bolt touched is a 6mm bolt that requires a 10mm wrench.

[@fiftyshadesofurban]

Why does every video have to say "and then you have to do X and Y and then your'e done.." and then INSTEAD of showing it you just transition to it being done.. Hooking the negatives back up is what I WANT TO SEE and HEAR explained because when I touch the negatives together it sparks and it goes through the ratchet and I don't see how I can connect them and reconnect the nut without getting shocked!!!!!! OMG!!! Some people do NOT know how to do this.. when you make how to videos DO NOT SKIP ANYTHING!!!!!

[@adamwillis908]

You connect the negatives before you connect the positive terminal, that would be one way

[@EgoFiveFiveSix]

Removing the fender is not the easy way. 😂

[@Pondsisawesome124]

Do it your way which is the fusebox removal and when you bend a pin you'll not only figure out the fender is the "easy" way it's also why the Jeep service data tells you to do it the way shown:-)

[@EgoFiveFiveSix]

@@Pondsisawesome124 lmao...remove the wheel, pull back the liner and there it is. i'm sorry you're a sucker.

[@j.r.777]

Here is a much easier way to replace the auxiliary battery without having to take off the fender. kzbin.info/www/bejne/oKeUp5ykg5eXfcU

[@Pondsisawesome124]

That is NOT the method described in the manual by Chrysler and you risk damaging the pins on the connectors in the fuse box. At the end of the day do your research and choose whichever method you prefer - either way its more of a PIA than it should be :-)