Experienced Battery Advice Wanted

[DanFelix]

I run this Harbor Freight charger around once a week on my 2018 JLU. It kept both batteries healthy during the shutdown years because I was rarely driving.

https://www.harborfreight.com/autom...ntrolled-battery-chargermaintainer-63350.html

HtFan:

The instructions for this charger say to only use on one battery. My JL has the second Aux battery. Does your JL have the Aux and have you encountered any problems? Since it is charging two batteries, in parallel, does the voltage readout reflect that? Thanks.

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[olllllo]

I use a CTEK charger for my Corvette that sees about 1,000 per year. The Corvette is plugged in whenever it isn’t being driven, and I’m on almost 6 years on the current battery.

I’d suggest, like others, keeping it plugged into the charger when not being driven.

Just like a Tesla ?

 

[DanFelix]

HtFan:

The instructions for this charger say to only use on one battery. My JL has the second Aux battery. Does your JL have the Aux and have you encountered any problems? Since it is charging two batteries, in parallel, does the voltage readout reflect that? Thanks.

The charger shows red while charging and turns green when done. When I charge the batteries, one at a time, then it shows green when done. If I charge both at the same time, they fully charge, but it never shows green. I know they are fully charged because I can separate them and test and they show green. Hope that helps.

 

[Htfan]

HtFan:

The instructions for this charger say to only use on one battery. My JL has the second Aux battery. Does your JL have the Aux and have you encountered any problems? Since it is charging two batteries, in parallel, does the voltage readout reflect that? Thanks.

I've never had any issues changing/maintaining these batteries in parallel. The charger goes from red to green status with accurate voltage when complete. Of course, I've already tested the batteries individually and know they are healthy.

If you are diagnosing a problem, you should test/charge each battery separately.

NOTE - I've installed a disconnect switch on my Aux battery to make isolating batteries quick and easy.

 

[Rhinebeck01]

The charger shows red while charging and turns green when done. When I charge the batteries, one at a time, then it shows green when done. If I charge both at the same time, they fully charge, but it never shows green. I know they are fully charged because I can separate them and test and they show green. Hope that helps.

@DanFelix

Hmmmm.... never ever seen as you..........

Whenever I use a battery tender / maintainer on a (stock) dual battery JL or JT and I hook up the battery tender / maintainer's cables to the Main battery, the indicator light will go to GREEN if the battery tender / maintainer is left on/working long enough and both batteries are healthy.

 

[FulThrotl]

That's quite true, but Toledo installs AGM batteries in our Wranglers due to the power demands of the vehicle.

With respect to the abbreviated service life of the batteries in the OP's vehicle, I'd suggest that either lead acid batteries were installed in error, or, if AGMs were in fact installed in his Jeep, that possibly there's a malfunction in the charging system.

AGM is absorbent glass mat, which is a lead acid battery chemistry.
instead of having wet acid and lead plates, it is a mat with an acid gel.

as for the OP, the OEM batteries are pretty cheezy.
if you want to resolve the problem, go to genesis offroad, and buy one of
their dual battery trays, that hold two group 25 batteries, and get two
Oddesy group 25 batteries.

each of those batteries has twice the capacity of both batteries currently in your jeep.

 

[DanFelix]

@DanFelix

Hmmmm.... never ever seen as you..........

Whenever I use a battery tender / maintainer on a (stock) dual battery JL or JT and I hook up the battery tender / maintainer's cables to the Main battery, the indicator light will go to GREEN if the battery tender / maintainer is left on/working long enough and both batteries are healthy.

I have two battery chargers. Shumacher SC-7500a and Viking 4amp. For each, I attach + to main + post and - to neg grounding bolt on the frame. When charging both batteries, Schumacher will show little green light (100%) when charging is complete but Viking stays red and “keeps charging,” even though both batteries are charged. I attribute it to the IBS. In all cases, I am pleased with either device. Both batteries test good for voltage and under load. It’s a mystery.

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