🔋🔧 MAIN BATTERY REPLACEMENT TALK - JL/JT 🪫

[Rhinebeck01]

Is there a Costco interstate option? TIA

IF Costco can get you .... you'd want an Interstate MTX-94R/H7 850CCA 80 Ah AGM

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[jaymz]

I upsized my battery last year and didn’t notice then, but when I installed the LASFIT fuse/relay box the other day I saw that the IBS wire gets stretched pretty tight with the bigger battery.
I didn’t see any easy way to provide any additional slack. It’s not likely to be an issue, but something to keep in mind for those of you switching from the Group 48 H6 to the 94R.

 

[Rhinebeck01]

I upsized my battery last year and didn’t notice then, but when I installed the LASFIT fuse/relay box the other day I saw that the IBS wire gets stretched pretty tight with the bigger battery.
I didn’t see any easy way to provide any additional slack. It’s not likely to be an issue, but something to keep in mind for those of you switching from the Group 48 H6 to the 94R.

@jaymz
@other's

I have installed H7's (different brand H7's) in a few JL's. Yes, you do not end up with a lot of slack on the IBS wires, (a bundle of 2 wires) thanks to the added physical length, of the H7 battery

If you follow the IBS wires (bundle of 2 wires) back toward the firewall, you will find a small plastic wire keeper... take the IBS wire bundle out of that keeper (do not use the plastic keeper) and then just move the IBS wire bundle toward the passenger fender a bit.... do that and with a little bit of rear direction rotation to the metal terminal connector on the Neg, you will end up with enough slack..

.

 

[EU_Wrangler]

Very interesting thread!
Does anyone have a picture of the plastic piece that has to be removed in order to fit a H7 battery?
EDIT: nevermind, I found it when I replaced my batteries (the small piece can be seen at the bottom):

Also, if you don’t want to brake the plastic clip retaining the positive cable, just unbolt the nut in the center and all the piece comes together, so it will be easier to move the positive clamp to the new battery with both outside of the engine bay

 

[813 Fabrication & Design]

@WrangleDangle

A JL or JT with tow package leaves the factory with an H7-AGM Group Size 94R Main battery.

A JL or JT without the tow package leaves the factory with a Group 48 H6 Main battery, which is a tad shorter in length then the H7-AGM Group Size 94R.

With that said, if you go to install an H7-AGM Group Size 94R battery in a JL or JT that left the factory with a Group 48 H6 battery you will, in order to install the H7, have to remove a small plastic stay/cleat you will find in the bottom of the Main's battery holder box. The stay/cleat comes out very easily.

I just bought the Duralast Platimum H7 battery. It fits fine but the negative terminal is a bit smaller and the terminal will not tighten down good enough, it is still loose.

 

[Fast-n-Furious]

Another great post! Thanks @Rhinebeck01!
Just took a look at the battery that comes with the 392 today, if it can be any help to anyone, also to make this thread more informative. Mine does not have the tow package because I don’t plan to tow anything other than 4 bikes.

 

[blnewt]

Had a strange occurrence today~
Installed new H7 battery about 10 days ago, disconnected the negative lug for the aux battery, taped off the lug to keep it isolated, removed fuse 42, and have a Tazer Lite that I've used for ESS bypass and other features.

I must have pushed the ESS bypass button so it wasn't activated "orange" when I was messing w/ the HVAC controls.

I stopped at a stop light w/ the brake pressed pretty hard and the ESS activated and turned off the motor. I noticed the orange ESS switch light was off so pressed it, the light turned orange and the Jeep started up.

Just wondering why the ESS is still working even though I've done what should be what it takes to bypass???

I pushed the ESS switch back on and it's been fine since but wondering if there's something else that I need to do or something I missed?
TIA

 

[Rhinebeck01]

Had a strange occurrence today~
Installed new H7 battery about 10 days ago, disconnected the negative lug for the aux battery, taped off the lug to keep it isolated, removed fuse 42, and have a Tazer Lite that I've used for ESS bypass and other features.

I must have pushed the ESS bypass button so it wasn't activated "orange" when I was messing w/ the HVAC controls.

I stopped at a stop light w/ the brake pressed pretty hard and the ESS activated and turned off the motor. I noticed the orange ESS switch light was off so pressed it, the light turned orange and the Jeep started up.

Just wondering why the ESS is still working even though I've done what should be what it takes to bypass???

I pushed the ESS switch back on and it's been fine since but wondering if there's something else that I need to do or something I missed?
TIA

Yes, with the bypassed Auxiliary battery, ESS still works. I gather you thought it would not.

 

[blnewt]

Yes, with the bypassed Auxiliary battery, ESS still works. I gather you thought it would not.

Yeah, I thought the ESS would be out of the loop w/ that fuse pulled and the aux neg. lead disconnected. Good to know I'm not losing my mind, and since I have the Tazer it's all good. Thanks for your usual clarity @Rhinebeck01

So I guess in short you're just taking that aux battery out of the loop (and any inherent problems that battery can cause to the main system) but keeping ESS intact.

 

[Rhinebeck01]

Yeah, I thought the ESS would be out of the loop w/ that fuse pulled and the aux neg. lead disconnected. Good to know I'm not losing my mind, and since I have the Tazer it's all good. Thanks for your usual clarity @Rhinebeck01

So I guess in short you're just taking that aux battery out of the loop (and any inherent problems that battery can cause to the main system) but keeping ESS intact.

Yes, Aux. is out of the picture and your Main battery is doing all.

You can still use the ESS feature, but do limit it's use.

From what I've read..If you do not use ESS button push, after 6, stop starts, your engine will not turn off any more when you come to a stop. IF, you turn off your ignition then and start driving, you get 6 more stop starts and then once again, ESS won't kick in.

I just mention this behavior so you and others know..

In closing, use ESS if you want when the Aux battery is bypassed but do, limit ESS use.

 

[blnewt]

Yes, Aux. is out of the picture and your Main battery is doing all.

You can still use the ESS feature, but do limit it's use.

From what I've read..If you do not use ESS button push, after 6, stop starts, your engine will not turn off any more when you come to a stop. IF, you turn off your ignition then and start driving, you get 6 more stop starts and then once again, ESS won't kick in.

I just mention this behavior so you and others know..

In closing, use ESS if you want when the Aux battery is bypassed but do, limit ESS use.

Thanks, and no I NEVER want to use ESS

 

[Rhinebeck01]

Repost of an earlier post I made..

Be very careful!

Do, as soon as you pull that bundle off the positive side of the Main battery, to wrap it in a shop rag or such, so there would be little chance that bundle could ground out on anything metal near by.

IF you ground out that bundle you will blow fuse N3 in the Mopar Z Case Fuse Array ..

....Read here about the 2 different / different part number, high amp fuse arrays...

IF you have tow package on your JL/JT you will use a different Mopar Z Case Fuse Array then a JL/JT that does not have tow package.

For Mopar Z Case Fuse Array, info look here:
https://www.jlwranglerforums.com/forum/threads/alert-high-amp-fuse-array-related.65085/

Also..... BE CAREFUL ... Do not overtighten any nuts you find on the Main battery terminal connections... Especially prone to stripping, is the nut that you loosen on the Negative side of the Main battery to remove the bundle there.

 

[Rhinebeck01]

Something that I have been meaning to post about.. It really is a good idea to routinely, monitor/check on your JL's batteries.

Sure, you can buy a pricey metering tool... You can learn to use it ....you can lug it around out on the trails and around town...

Rather then that pricey, larger footprint, metering tool, consider this outfit that is a no brainer to use, takes up little space, handles wear and tear and the elements.. Just toss this outfit in the glove box, etc..

If you want. you can also easily hard wire it right at the battery and Velcro the little meter to the battery blanket and leave it there 24/7/365, so at anytime you can easily spot check battery(s) voltage.

Click pic to enlarge..

The little quality, easy to use, LED readout meter is a Deltran Battery Tender Voltage Indicator Battery Tester, LCD Display with LED Charge Indicator. The meter is sold on eBAY at a decent price here..

Click pics to enlarge..

 

[Fudster]

Something that I have been meaning to post about.. It really is a good idea to routinely, monitor/check on your JL's batteries.

Sure, you can buy a pricey metering tool... You can learn to use it ....you can lug it around out on the trails and around town...

Rather then that pricey, larger footprint, metering tool, consider this outfit that is a no brainer to use, takes up little space, handles wear and tear and the elements.. Just toss this outfit in the glove box, etc..

If you want. you can also easily hard wire it right at the battery and Velcro the little meter to the battery blanket and leave it there 24/7/365, so at anytime you can easily spot check battery(s) voltage.

Click pic to enlarge..

The little quality, easy to use, LED readout meter is a Deltran Battery Tender Voltage Indicator Battery Tester, LCD Display with LED Charge Indicator. The meter is sold on eBAY at a decent price here..

Click pics to enlarge..

I agree that checking battery voltage every now and then is useful.

I agree that the linked tool is as good as any to do so.

Where I take issue is the technique owners may use to apply this tool in a diagnostically useful way.

To point: stick this device on the main battery's leads and what it will read is--provided you haven't deleted your ESS/Aux battery and otherwise have one in your model JL, is a composite voltage of both batteries....which you can get from your EVIC screen.

It may be more useful to temporarily disconnect the factory black cable that connects to the negative lead of the main battery, that is NOT the one connected on the other end to the body ground, and then put a device like the one linked prior up to the main battery's terminals, it will read the main battery's voltage only, not a composite of both battery's voltages.

Be careful not to touch this dangling cable to ground/metal, but shift the voltage meter's negative side to this dangling cable (even as you keep its positive side on the main battery) and you'll get a voltage read of only the ESS battery (where equipped.)

Don't forget to put that battery cable back.

Finally, voltage is a great first method to test a battery, but load testing (with a load tester) is the gold standard--also involving the same cable disconnects discussed above for isolating the two battery's independent voltages.

 

[Wes420]

I can say with certainty that the Duralast H7 main and AUX 14 fit in the JLURDs. Super simple swap. Just have an E5 torq socket to change over the posts for the AUX.

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