Trickle Charging Procedure

[DanFelix]

1. Should the negative (black) connector from the charger unit attach at the frame grounding bolt or at the clamping bolt for the negative post on the body? Looking at the wiring diagram, the difference would be the inclusion or exclusion of the IBS during the charge. It might be moot but I am not sure.

2. Various mentions in multiple battery-related posts suggest keeping the trickle charger on overnight. I have always disconnected when 100% charge is reached. Is there a charging reason to keep it on any longer?

Thanks.

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[DanFelix]

Understood. My charger self disconnects at 100% charge. I have never observed any ghost discharges on the battery. JeepScares, if I condense your explanation then I understand it to mean connect the charger to the frame so that it includes the IBS. Thanks for the explanation, it helps.

 

[DanFelix]

Thanks for the explanation. Is there a way to charge just the Aux battery? If I place the pos charger cable on the main battery pos, disconnect the main battery neg cable, and connect the neg charger cable to that disconnected neg cable, would that send charge only to the Aux?

Thanks.

 

[cbrenthus]

Thanks for the explanation. Is there a way to charge just the Aux battery? If I place the pos charger cable on the main battery pos, disconnect the main battery neg cable, and connect the neg charger cable to that disconnected neg cable, would that send charge only to the Aux?

Thanks.

Yes, exactly!

 

[DanFelix]

Perfect! Thank you.

 

[DanFelix]

Well. I charged both batteries to 100% and the ESS Battery Charging message persisted. So, I have no clue how the ESS thinks, which is why I don't own a cat. If I drive for about 30 min at 45+ mph I can clear the message but it is a mystery.

 

[Gee-pah]

Thanks for the explanation. Is there a way to charge just the Aux battery? If I place the pos charger cable on the main battery pos, disconnect the main battery neg cable, and connect the neg charger cable to that disconnected neg cable, would that send charge only to the Aux?

Thanks.

Yes exactly, just as @cbrenthus said...but let's be clear on which negative battery terminal gets disconnected, as in the 3.6L JL there are two from the factory:

Disconnect the one that is closer to the passenger's side front quarter panel: the one on which the IBS is NOT found. That cable's other end is connected to the ESS/Aux battery.

The cable on which the IBS sits (the more distal to the passenger's side front quarter panel) has as its other end the body ground of the vehicle.

If after driving around for a while, where the IBS will regulate the amount of charge put into both batteries depending upon those batteries' need (and the engine warms up,) if ESS fails to engage, you may what to try the following (or try another charger):

Instructions available upon request in other posts if you desire, you can placed a fused wire between the N1 fuse in the Power Distribution Center (PDC): that black rectangular box on top of the engine bay nearest the front passenger's seat and EITHER, N2 (the fuse next to N1) or (it makes no difference) the positive terminal of the main battery along with disconnecting the negative cable described above.

(The N1 fuse is in the extreme driver's side front of the PDC.)

What the action I describe above does is fool the 3.6L JL into thinking that its communication and energy draw/supply to the ESS/Aux battery is, in actuality rerouted to the main battery.

You can see if ESS works then. If it does, it would suggest that your ESS/Aux battery has some issue.

I do NOT recommend this a permanent fix if you plan on running the ESS system. This is because ESS events with this wiring rob the cranking battery of energy during ESS events, unlike the factory design.

While 1 battery ESS systems in other vehicles are common, the 3.6L JL's two battery system may tax the ESS battery (normally the ESS/Aux battery) more than in 1 battery systems under the premise that during normal operation, the big main battery is left pretty much untouched during ESS events, preserving its power for the post ESS event engine crank.

Don't forget to reverse the cable changes on both the positive and negative sides if you intend on running ESS. And if you want to take your chances running this way with ESS, you will not get more than 6 ESS events for any one cold crank of the engine...a safety feature of the vehicle when in perceives the voltages of the ESS/Aux and main battery to be identical in 6 tests during ESS events.

The vehicle of course will see those voltages as identical because checks of what it thinks are the ESS/Aux battery are checks of the main battery in this wiring design.

Links are available on request as well regarding best practices in swapping out an ESS/Aux battery if it's your problem and you'd rather do this yourself.

 

[DanFelix]

I fully disconnected the neg cable on the Main leaving its negative post unconnected to anything in the car. Thanks.

 

[Gee-pah]

I fully disconnected the neg cable on the Main leaving its negative post unconnected to anything in the car. Thanks.

I hope you are explaining what you did to charge your ESS/Aux battery and not something you've just done.

The removal of all cables from the main battery's negative post runs the vehicle off the ESS/Aux battery alone and disconnects the body ground such that all appliances that ground themselves via the JL's body no longer conduct current.

 

[DanFelix]

Disconnected only during the connection to the trickle charger. All is reconnected as normal. No anomalies encountered upon reconnection.

 

[PatrickM]

With COVID I've found that I'm just not driving - a 5 minute run to the stores once a week, and now I'm getting a flat battery.
So I got a NOCO Genius10 Smart charger that seems to work fine. I know not nothing about car electrics, but I connect to the two top battery terminals as per the charger's user manual. So far, its been a week, and the lights all glow a healthy green. So I'm guessing it is working ok.

But its a bitch to open the bonnet to get to the battery every time. I'm wondering if I could plug the charger into the rear power socket? Thats the one on the left side in the back of the JLUR? Its live to battery.

 

[Heimkehr]

You would be using the same battery to power the charger that you are wanting to charge. This will not work.

Can you clarify? I use an unswitched 12V Powerlet outlet (aka BMW plug) to connect a 120V Battery Tender to a motorcycle battery. The former maintains the latter during seasonal storage, exactly as expected. PatrickM seems to want to do the same on his Wrangler, also using an unswitched receptacle.

 

[PatrickM]

You would be using the same battery to power the charger that you are wanting to charge. This will not work.

The charger is plugged into a wall socket in my garage. The cables from that go to the battery. I’m asking if they could go to the power outlet in the Jeep’s rear.

 

[PatrickM]

Can you clarify? I use an unswitched 12V Powerlet outlet (aka BMW plug) to connect a 120V Battery Tender to a motorcycle battery. The former maintains the latter during seasonal storage, exactly as expected. PatrickM seems to want to do the same on his Wrangler, also using an unswitched receptacle.

That’s correct. Cheers

 

[Elementad]

With COVID I've found that I'm just not driving - a 5 minute run to the stores once a week, and now I'm getting a flat battery.
So I got a NOCO Genius10 Smart charger that seems to work fine. I know not nothing about car electrics, but I connect to the two top battery terminals as per the charger's user manual. So far, its been a week, and the lights all glow a healthy green. So I'm guessing it is working ok.

But its a bitch to open the bonnet to get to the battery every time. I'm wondering if I could plug the charger into the rear power socket? Thats the one on the left side in the back of the JLUR? Its live to battery.

That’s what I do. I have a ctek battery conditioner connected to mine. Works fine. Just check that the 12v socket is live when your ignition is off. Some suggest the fuses can be loaded incorrectly meaning that some wranglers don’t have the 12v rear cargo socket permanently live. It SHOULD be. Mine was/is and the ctek works fine.

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