Wanted: ESS battery removal / eliminator kit

[Fudster]

I'd like someone to make a kit that removes the ESS battery from the electrical schematic of those JLs with dual battery setups, but that allows the alternator to continue to charge it, along of course with the main battery, and allows the owner to quickly add or substitute this ESS battery to crank the rig should the main battery give out.

Maybe such tech can't be sold for more than the cost the next best thing: a portable jump starter.

Jerry @Jebiruph published methods to run such dual battery JLs as per factory, on one (either) or both batteries all the time but the benefits of disconnecting the ESS battery from the vehicle's electrical schema seemed to also come with the downside of it no longer getting charged by the alternator.

Thoughts?

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[aldo98229]

Don't f*ck with it if you want your dealer to continue honoring the warranty.

These days dealers are looking for the smallest excuse to deny warranty work.

 

[entropy]

I'd like someone to make a kit that removes the ESS battery from the electrical schematic of those JLs with dual battery setups, but that allows the alternator to continue to charge it, along of course with the main battery, and allows the owner to quickly add or substitute this ESS battery to crank the rig should the main battery give out.

Maybe such tech can't be sold for more than the cost the next best thing: a portable jump starter.

Jerry @Jebiruph published methods to run such dual battery JLs as per factory, on one (either) or both batteries all the time but the benefits of disconnecting the ESS battery from the vehicle's electrical schema seemed to also come with the downside of it no longer getting charged by the alternator.

Thoughts?

Probably not a profitable idea. portable jump starters are less than $100. Also plugging the aux back takes less than 10 seconds and can be done every 2 weeks to get it recharged. A Noco 5 genius would also charge it in less than 5 hours. So also not worth it for the consumer.

 

[jaymz]

GENESIS has already put a kit together if it's worth it to you.

 

[mwilk012]

To hell with warranties.

This shouldn’t be too hard to do, in theory. Placement of relays/diodes may be annoying though. Mounting next to the Power Control Relay may be a good idea.

 

[Fudster]

@aldo98229 : I hear that; I'd want it to be highly reversible.

@entropy : I hear you on cost. Like @mwilk012 I'm thinking this is $30 in parts.

@jaymz: Yeah, I agree, like a Genesis light...real light

 

[jludave]

Thoughts?

Have you seen tis thread?

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

 

[Fudster]

Have you seen tis thread?

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

I have Dave. My goal is to bypass the ESS battery for purposes of tapping it for power unless I expressly seek its reserves, while it is charged solely from the alternator and neither cannibalizes, nor is cannibalized by the main battery.

 

[STW]

Let's say you kept your Aux battery disconnected at the neg terminal and with the F42 fuse removed, but you kept it charged up by means of a battery charger every other week or so...

...If you did find your main battery too low to start the Jeep, could you just put the Aux neg cable back on and put the F42 fuse back in, and then start it up that way?

The Jeep would then register the Aux battery's existence again and use it for starting?

Using a small jump box to start the Jeep is easier and better, of course.

And if it did work to use the Aux as a kind of jump box like that, you'd want to disconnect the Aux again pretty soon because the Main would be cannibalizing it pretty quick? And the alternator wouldn't keep them both happy and not messing with each other?--which it doesn't necessarily manage to do anyway, as many of us have found out.

 

[Fudster]

Let's say you kept your Aux battery disconnected at the neg terminal and with the F42 fuse removed, but you kept it charged up by means of a battery charger every other week or so...

...If you did find your main battery too low to start the Jeep, could you just put the Aux neg cable back on and put the F42 fuse back in, and then start it up that way?

Yes. But please don't allow much time to lapse between your electrically reconnecting the aux battery and attempting the crank, precisely for the cannibalization reasons you sight below.

The Jeep would then register the Aux battery's existence again and use it for starting?

Register is a funny word, but yes. If I may let me delve into the behind the scenes workings.

You attempt to cold crank. One of the first things that happens is the vehicle attempts to energize a relay that separates the two batteries in order to test the ESS battery. If Fuse 42 is pulled that relay lacks the power to isolate teh batteries and this test is against whatever battery or batteries are connected. If Fuse 42 is intact, the test is at whatever lies at the end of the cables, if anything, which connected to the ESS battery from the factory.

After this test both batteries are reconnected in parallel, if present, to energize the crank.

Using a small jump box to start the Jeep is easier and better, of course.

Don't sell yourself short. Jump boxes have a way of developing legs and finding their way into your wife/parent's and kid's vehicles. Charged ESS batteries to do not.

You could even disconnect the main battery for the crank. Energized ESS batteries can crank a JL in isolation.

And if it did work to use the Aux as a kind of jump box like that, you'd want to disconnect the Aux again pretty soon because the Main would be cannibalizing it pretty quick?

...particularly on a resting JL where the alternator is not trying to make up for the main battery's canabalization.

And the alternator wouldn't keep them both happy and not messing with each other?--which it doesn't necessarily manage to do anyway, as many of us have found out.

That the smart alternator could ramp up to compensate for the main battery's "theft of current" I imagine might be specific to how bad shape the main battery is in.

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