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

[Dkretden]

Here is a snip from the Factory Service Manual.. Note, that the service manual says to first, Disconnect and Isolate the negative battery cable(s) . IMPORTANT --They are referring to the negative battery cables up top / in the engine compartment, on the Main battery!

After doing that, you remove the 3 bolts from the supplemental battery tray (Aux's battery tray) and lower the Aux battery down a bit.... just enough so that you can get to and disconnect the pos and neg cables (then isolate them) from the Aux battery. After both the cables are disconnected, your Aux battery is free to drop down and to be replaced.

Are they referring to the main battery negatives only or the negatives on frame? Or both? im guessing that it’s just the negative on the battery but I figured I would check.

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[mgroeger]

Are they referring to the main battery negatives only or the negatives on frame? Or both? im guessing that it’s just the negative on the battery but I figured I would check.

View attachment 362180

They are referring to the ones on the main battery. You don't need to disconnect the ones from the fender.

 

[Dkretden]

They are referring to the ones on the main battery. You don't need to disconnect the ones from the fender.

Got it, thank you.

the drawing that I posted was for mounting Mopar lights (not for battery change..... I should have said that). But, I did want to double check with folks who are much more knowledgable than me.....

 

[rubileon]

Not quite- the ESS battery runs accessory loads during an ESS event. this keeps full voltage available to the HVAC, infotainment and lights when the starter momentarily sucks power. During an extended event (long RR crossing?) the ESS battery voltage will drop, triggering the engine to restart, letting the alternator (huge!) supply ample juice to everything. If you replaced the ESS battery with a capacitor bank, it would be depleted quicker (they have less capacity for physical volume) and might not trigger a restart before it goes flat. A better place for caps would have been the actual starter circuit, as it would have taken load off the main battery.

I'll admit that electrical side of things isn't my strongest. I'll have to think more about this one.

Do you mean to say the if the AUX battery/capacitor falls too low before the engine can auto restart, the main battery will not be used to restart?

 

[mgroeger]

I'll admit that electrical side of things isn't my strongest. I'll have to think more about this one.

Do you mean to say the if the AUX battery/capacitor falls too low before the engine can auto restart, the main battery will not be used to restart?

If it's that low it won't even use the ESS system. If the AUX battery is done there is a high probability you will have starting issues. Also high possibility your main battery is done. At 64,000 miles both batteries are done on my wife's Jeep.

 

[rubileon]

If it's that low it won't even use the ESS system. If the AUX battery is done there is a high probability you will have starting issues. Also high possibility your main battery is done. At 64,000 miles both batteries are done on my wife's Jeep.

I think what MrKnowitall said is if the capacitor has enough charge to trigger an ESS engine stop, but (other) running electricals deplete the capacitor so rapidly to the point that the engine has no time to ESS start, the vehicle might not be able to recover from the ESS stop.

Also, what does it mean if the alternator is showing 14.5-14.6 under all throttle loads and even after driving for 60 miles the ESS is allegedly still charging?

 

[mgroeger]

I think what MrKnowitall said is if the capacitor has enough charge to trigger an ESS engine stop, but (other) running electricals deplete the capacitor so rapidly to the point that the engine has no time to ESS start, the vehicle might not be able to recover from the ESS stop.

Also, what does it mean if the alternator is showing 14.5-14.6 under all throttle loads and even after driving for 60 miles the ESS is allegedly still charging?

Dunno

 

[Rhinebeck01]

.

I think what MrKnowitall said is if the capacitor has enough charge to trigger an ESS engine stop, but (other) running electricals deplete the capacitor so rapidly to the point that the engine has no time to ESS start, the vehicle might not be able to recover from the ESS stop.

Also, what does it mean if the alternator is showing 14.5-14.6 under all throttle loads and even after driving for 60 miles the ESS is allegedly still charging?

Suggest you start reading here:
https://www.jlwranglerforums.com/forum/threads/3-6l-ess-dual-battery-consolidated-information.25377/

 

[SolarWizard]

If I wanted to delete that battery, disable ESS, install larger gauge battery cables and mount a full size battery in the cab and route accessories off it can that be done

 

[Rhinebeck01]

Flare removal tip/hint:

Remove the bolts you need to remove and the pushpin.. Now, grab one end of the flare and pull till you feel/hear/see the first say, 2 clips come loose....... they may or may not break.....

Now, since the flare is partially loose, you can see the back side of each of the remaining white fender flare clips..... you can take a pair of pliers and squeeze the back side barbs of each remaining clip, one by on,e til all are loose.

By squeezing the backside BARBS of the clip, the clip will come free and you will not chance breaking the clip.

 

[HardSell]

Just leave the flare off....kinda looks like the Terminator after a bad day...Yeah! the Terminator Edition.

 

[TJJL19]

Here is a snip from the Factory Service Manual.. Note, that the service manual says to first, Disconnect and Isolate the negative battery cable(s) . IMPORTANT --They are referring to the negative battery cables up top / in the engine compartment, on the Main battery!

After doing that, you remove the 3 bolts from the supplemental battery tray (Aux's battery tray) and lower the Aux battery down a bit.... just enough so that you can get to and disconnect the pos and neg cables (then isolate them) from the Aux battery. After both the cables are disconnected, your Aux battery is free to drop down and to be replaced.

I am going nuts with this ESS second battery. I went to work on my radio and though I had the power off, well I didn't, can anyone help?( see picture)

 

[Rhinebeck01]

Yes, I mentioned that in the opening post here.. I recommended buying a couple before you pull a flare... just in case you break a clip or two.

I actually took my own advice and purchased 8 of these 2 days ago from Quadratec. Cost me $14.00 for 8 clips with shipping. They shipped via Fedex from Quadratec, the day after I ordered them.

My 2018 JL, was assembled/built on 5/5/18 at 3:22am. I know soon, I'll have to be replacing it's two batteries. No way, am I going to pay the dealer parts dept. $15.00+- for a fender flare clip should I break one or more when I pull the passenger flare to do the Aux battery replacement.

 

[ALRUI]

We had to call in the Free Tow Service. He tried a heavy duty booster; but that didn't work. Fellow had it going in about 5 minutes. He hooked up; sat for most of that time. Then we started the JLU following his instructions.

What exactly did he do if booster didnt work & what were the instructions if different then the normal starting of the Jeep? Curious....

 

[Rhinebeck01]

What exactly did he do if booster didnt work & what were the instructions if different then the normal starting of the Jeep? Curious....

@ALRUI

https://www.jlwranglerforums.com/fo...’s-got-one-and-what’s-good.51894/post-1232935

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