My auto stop start saga

[AVGeek99]

Thanks for the detailed response Jay!! A few weeks ago I recall a thread where someone mentioned a dual main battery kit. At the time I thought it seemed like overkill. Are those kits meant to replace the small Aux battery to eliminate the problem of parallel charging two batteries of different size/capacity? If so then would that likely resolve the issues described in this thread?

Thanks!!

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[jeepoch]

Thanks for the detailed response Jay!! A few weeks ago I recall a thread where someone mentioned a dual main battery kit. At the time I thought it seemed like overkill. Are those kits meant to replace the small Aux battery to eliminate the problem of parallel charging two batteries of different size/capacity? If so then would that likely resolve the issues described in this thread?

Thanks!!

Chris,

Yes and no. Yes the third party battery replacement kits, such as that offered by Genesis, completely replaces the mini AUX battery with one that is the same size as the main. So you end up with two similarly sized batteries. Better yet this solution tends to not connect the batteries in parallel so they charge (and discharge) independently. One is generally the primary used for just starting the vehicle, the other is used for peripheral equipment such as refrigerators, lights, sound amps etc. Still even better yet, it has circuitry to guage which battery is the most appropriate to start the vehicle and dynamically will select it with no user intervention.

However the corollary is no, because the ESS system then works for only six cycles. This is because the Engine Controller is led to believe that there is a problem with the ESS system as the two batteries connected in parallel should read the exact same voltage. With two independent (not connected) batteries this will seldom, if ever, occur.

The six cycle limit is reset every ignition-on event and is imposed likely as a compromise in appealing to the environmental bureaucrats so that ESS works some of the time while in reality trying to keep the batteries from dying altogether. Purely a software implemented trade off.

So the third party battery products have both pros and cons. If you despise ESS (like almost everyone) then the battery tray solution has merit. It has the best chance to never strand you anywhere. If however you're like me, (yes, I'm the oddball) and really like not burning fuel when idling, then the six cycle limit is a non-starter (pun intended) and the battery tray provides little value. In addition, the limited ESS will throw DTC codes which may (or may not) effect any electrical system warranty claims depending on the dealership and/or the mood of the corporate bean counters.

So pick your poison.

I've chosen to periodically use a battery tender / maintainer. If nothing else, it's the most economical to implement. The battery tray solutions tend to be very expensive because the proper form factor and capacity batteries are required.

Is limping along using an external charger bulletproof? Certainly not. Will I ever regret being stranded somewhere due to a failed AUX battery? Time will tell. At least I'm cognizant of this mess and will be able to monitor and cope with it when things start going sideways. As with the Marine Corps mantra; improvise, adapt and overcome.

ESS is certainly that. You can't live with it but are unfortunately forced to not live without it.

Hope this helps.
Jay

 

[AVGeek99]

Thank you again for the awesome response Jay!! It sounds like I will definitely upgrade to the dual battery tray setup at some point. I don't even have my JL yet, hopefully this week. The Aux battery will be serviceable for a while anyway so there's no rush.

Thanks again for all the help!!

Chris

 

[XT Carol]

There is a lot of info on aux battery bypass/delete procedures. I just removed my aux battery entirely, pulled the cables back up in the engine compartment, taped off the negative cable, and attached the positive cable to the main battery. Works like a charm.

@Centurion07

I have a 2018 JLUR and never use Start/Stop because I dislike it so much. I also bought a Tazer so I can turn SS off and it remembers this setting. So in a way, problem solved.

I only lately found this thread, so I'm late in posting here.

Now I read that perhaps I could be out somewhere in the boonies, alone, and have my Jeep fail to start if the small Start/Stop (SS) battery is low on voltage or going bad? Like, it will attempt to start a certain number of times but then no more? Even if the main battery is OK? I envision "stranded" here.

It seems I'm at the point I'm ready to get rid of that 2nd small battery, since I don't use that feature anyway and it's actually a risk to me. The question is--can I disconnect exactly like you've done (aux. battery negative taped up; positive attached to the main battery's +), remove the small battery forever, and just run that way? Problem solved?

If that's the case (but I wanted to be sure and ask), that's how I'd go and be rid of needing to worry about anything but the main large battery. So I'm asking for some reassurance before I do the procedure you describe. I assume it doesn't set off any CEL codes in the display, blow fuses, etc?

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