13.4 Low Voltage Warning

[Stuckinthesand]

Most of my driving is under 2 miles, to and from work, grocery store, kid's school. Sometimes, on long drives, the ESS starts working again. I usually hit the ESS Off button when I get in, by habit.




I know it is about time, and I have been looking at H7 batteries, but is getting the AGM style really necessary?
Do you have a link to delete the Aux battery in under 5 min? I do hate that little thing.

Pull fuse F42 for PCR and disconnect negative terminal at the main battery that is running to the aux battery. Tape off and zip tie negative cable to keep it from shorting out and bouncing around and you are done.

https://www.jlwranglerforums.com/forum/threads/jumperless-aux-battery-bypass.95945/

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[DaltonGang]

Pull fuse F42 for PCR and disconnect negative terminal at the main battery that is running to the aux battery. Tape off and zip tie negative cable to keep it from shorting out and bouncing around and you are done.

https://www.jlwranglerforums.com/forum/threads/jumperless-aux-battery-bypass.95945/

Thank you.

..

 

[Rhinebeck01]

Most of my driving is under 2 miles, to and from work, grocery store, kid's school. Sometimes, on long drives, the ESS starts working again. I usually hit the ESS Off button when I get in, by habit.

I know it is about time, and I have been looking at H7 batteries, but is getting the AGM style really necessary?
Do you have a link to delete the Aux battery in under 5 min? I do hate that little thing.

@DaltonGang

For your JL, best be is to go with an H7. An H7 costs a tad more or close to the same price as an an H6. YES, you want an AGM battery.

 

[DaltonGang]

@DaltonGang

For your JL, best be is to go with an H7. An H7 costs a tad more or close to the same price as an an H6. YES, you want an AGM battery.

Thanks. I will look into doing all this, this coming weekend, hopefully.

 

[Rhinebeck01]

.

Thanks. I will look into doing all this, this coming weekend, hopefully.

@DaltonGang

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 you will find fastened into the bottom of the Main's battery holder box. The stay comes out very easily.

For those replacing your JL or JT's Main battery... you are best served going with a higher CCA H7 versus installing a lesser CCA H6. Should also mention that often you will find the H7 costs the same as an H6.

Note: When buying an H7 is is prudent to first remove your current Main battery and measure the length of the box with the plastic stay removed. Compare that length measurement to the physical length of the H7 battery you are thinking about buying..

For your JL/JT , here are some H7's that are known to fit the JL/JT Main battery box with the stay removed:

Interstate MTX-94R/H7 850CCA 80 Ah AGM
Odyssey Performance AGM94R H7 L4
Super Start Platinum H7 SSB94RPLT
NAPA P/N 9894R H7
Duralast Platinum Battery H7-AGM Group Size 94R 850 CCA
Batteries+ X2 Power H7 Group 94R SLI94RAGMDP
EverStart Platinum AGM Battery, Group Size H7 (12 Volt 850 CCA) (Walmart)

 

[Rhinebeck01]

@DaltonGang

For your 2018 JL, when you are leaning over the passenger side fender, the closest cable to you on the Neg side of the Main battery is the one you want (Aux Neg.) to disconnect. It's the thinner diameter cable of the two cables there.

For other's here with newer then 2018 JL's read here about what cable to disconnect in regard to the Aux Neg that goes to the Main battery, Neg.
https://www.jlwranglerforums.com/forum/threads/ess-battery-cable-change.86624/

For the record, I do not suggest taping over or zip tying that disconnected Aux Neg cable you disconnected from the Main battery Neg..

I suggest guys/gal's just use a short length (5-6") of wire loom tubing to fully cover the Neg Aux cable end when they have the Aux Neg cable disconnected from the Main 's Neg terminal. This loom just slides on or off as desired..

Now, get a wing nut and leave on that terminal in case you ever want to easily reconnect the Aux battery Neg. to it.. Some guys will want to do this if they plan to use the Aux battery (if healthy) as a back-up start battery.

Wire Loom Tubing- Split Loom Cord Protectors, Flexible Wire Conduit Automotive, Black

 

[cabnfvr]

From what i read the batteries have to changed in pairs for technical reasons I wonder if this is the symptom of what u mention here. The big battery wasn't replaced I reckon. Just an idea..

Just FYI, you are correct when changing two batteries of the same type, same CCA, etc. That's to keep the old battery from drawing down the new one. Since the aux and main batteries on the JL are different I don't think it would matter, plus they don't draw on each other like a dual battery setup would.

I keep a jumper on the N1 N2 fuse post with a 30 amp fuse inside the fuse box cover for the day when that little battery goes cells up. Pop the fuse the jumper wire and the aux and main are connected. In theory this bypasses auto stop relay and the Jeep should crank even if the aux is dead.

 

[Rhinebeck01]

Just FYI, you are correct when changing two batteries of the same type, same CCA, etc. That's to keep the old battery from drawing down the new one. Since the aux and main batteries on the JL are different I don't think it would matter, plus they don't draw on each other like a dual battery setup would.

I keep a jumper on the N1 N2 fuse post with a 30 amp fuse inside the fuse box cover for the day when that little battery goes cells up. Pop the fuse the jumper wire and the aux and main are connected. In theory this bypasses auto stop relay and the Jeep should crank even if the aux is dead.

@cabnfvr

No need for the old old way, lets call it N1-N2 fused bypass jumper you are keeping.. Read here for a cleaner way to do the deed.
https://www.jlwranglerforums.com/forum/threads/jumperless-aux-battery-bypass.95945/

Also, with stock JL/JT, the dual battery system's 2 batteries are hooked up in parallel. Yes, they can impact each other in a negative fashion.

 

[Rhinebeck01]

Wing nuts ... Sizes you'd use on the Main Batteries connections..

Or you can make your own quick disconnects and use them instead of wing nuts..

 

[Petey]

@cabnfvr

No need for the old old way, lets call it N1-N2 fused bypass jumper you are keeping.. Read here for a cleaner way to do the deed.
https://www.jlwranglerforums.com/forum/threads/jumperless-aux-battery-bypass.95945/

Also, with stock JL/JT, the dual battery system's 2 batteries are hooked up in parallel. Yes, they can impact each other in a negative fashion.

Supposedly the one free battery replacement service requires both batteries replaced .... thats what the dealer did with mine. With what u mentioned about pulling the fuse in the link ...do u know if this will affect the way the interior lights function before startup or after shutdown when tripping off the door switch?

 

[Rhinebeck01]

Supposedly the one free battery replacement service requires both batteries replaced .... thats what the dealer did with mine. With what u mentioned about pulling the fuse in the link ...do u know if this will affect the way the interior lights function before startup or after shutdown when tripping off the door switch?

@Petey

There is no such Stellantis or dealership requirement about both batteries being replaced at the same time. Yes, it is undoubtedly a better way to go, replacing both batteries at the same time.

With Fuse 42 pulled and the Aux battery Negative disconnected from the Main battery Neg. terminal, you will see no change in the behavior you mention...

With the Fuse 42 pulled (Or an N1-N2 fused bypass jumper installed) and the Aux battery Negative disconnected from the Main battery Neg. terminal.....you'd be clueless that you were running on just the Main battery. Well, you would no longer be plagued by ESS related notices about ESS not ready and other such messages.. Just remember to use the ESS button or to install a SmartStopStart unit to do that ESS button push for you automatically. YES, you can still use the ESS feature occasionally if you like.

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