Bad battery?

Medic203

Member
Joined
Jun 21, 2018
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25
Location
Pittsburgh
06, 4.0 auto trans.

My battery is somewhere in the ballpark of a year old. I had surgery in October, any I left it sit for a month. When I went to drive it, battery was dead.

Took it to auto zone, they said it was totally dead and would need to be charged before they could test it. After an hour went back, they said it was all good. Took it home and everything was all good. That was about 2 months ago.

Leaving work tonight, wouldn't start again. Leaving it there for tonight but... if I had a bad alternator I wouldn't get 2 months out of the battery I imagine right?

How likely is it that the battery is bad? Its still within the warrantee period.
 
One hour on a charger is nowhere nearly enough for a dead battery. Charge it overnight on a bench top charger (not a trickle charger) and I suspect it will be fine afterwards. Keep in mind letting a battery go completely dead causes an irreversible loss of battery capacity.
 
One hour on a charger is nowhere nearly enough for a dead battery. Charge it overnight on a bench top charger (not a trickle charger) and I suspect it will be fine afterwards. Keep in mind letting a battery go completely dead causes an irreversible loss of battery capacity.

Jerry thanks! So I don't have a way to do that myself. I don't have any kind of charger.

If it going dead causes damage, this is the second time now. Can I just insist on a replacement?
 
@Jerry Bransford Got one of those ordered, will be here Sunday.

@longshould i just take it up there tomorrow and exchange it then?
Ive never actually done a warranty exchange. Should i just say its the second time the battery has died in the past 2 months.

Guess I'm still wondering if there's some underlying issue. I don't have anything aftermarket on there.
 
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The electronics in Jeeps and cars will eventually drain the battery. Both the radio and PCM continuously draw a little power when the engine's not running. Keeping a battery maintainer, kind of like a trickle charger but smart enough to not overcharge the battery, connected to the battery when it's not being driven much would prevent future dead batteries.
 
Leaving work tonight, wouldn't start again

Has it sat for an extended time again in those 2 months?

Mine sits for weeks several times a year with no issues starting.
Let them check your alternator.
If they say it's good, then they should give you a new battery.
Keep in mind, they usually don't warranty the second one.
 
If they charge and test it and it passes they may not offer a warranty. Follow Jerry’s advice and get it properly charged overnight. Avoid letting it set for weeks without a start up.
 
06, 4.0 auto trans.

My battery is somewhere in the ballpark of a year old. I had surgery in October, any I left it sit for a month. When I went to drive it, battery was dead.

Took it to auto zone, they said it was totally dead and would need to be charged before they could test it. After an hour went back, they said it was all good. Took it home and everything was all good. That was about 2 months ago.

Leaving work tonight, wouldn't start again. Leaving it there for tonight but... if I had a bad alternator I wouldn't get 2 months out of the battery I imagine right?

How likely is it that the battery is bad? Its still within the warrantee period.

If your alternator is good it should charge the battery fully while driving from 30min to an hour. If your typical driving is very short trips of 10-15 min then it may have a hard time keeping up, and it may get so low it won’t start. The bench charger will work too.

Your capacity decreases from day 1, But it should still be good within the warranty period.

Did they test your alternator? You should see 14.2V while running.
 
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Has it sat for an extended time again in those 2 months?

Mine sits for weeks several times a year with no issues starting.
Let them check your alternator.
If they say it's good, then they should give you a new battery.
Keep in mind, they usually don't warranty the second one.

No, I drive it every day. It was basically the month after my injury where I couldn't drive.

Though my work commute is short, I usually run it for a while on the weekends just to make sure.
Im planning to check the alternator with a multimeter once I get the battery charged up.

@Gollywomper I don't do that regularly. I got hurt in October and had to have surgery, so didn't drive for about a month. Hasn't sat since.
 
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So pulled the battery and took it to autozone. They showed it as having a charge, but then had a problem when load testing it. Was saying the voltage was dropping when they tried to load test it. He mentioned possibly a cell went bad.

Anyway they swapped it under the warranty, and I have the tj back home. Thanks all for the help!
 
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The electronics in Jeeps and cars will eventually drain the battery. Both the radio and PCM continuously draw a little power when the engine's not running. Keeping a battery maintainer, kind of like a trickle charger but smart enough to not overcharge the battery, connected to the battery when it's not being driven much would prevent future dead batteries.
I have one of these.

https://www.amazon.com/gp/product/B07QX9PKK8/?tag=wranglerorg-20

The idea is to freshen up my Oddessey every couple months since most of the time jeep is just doing short trips.

Also matters what kind of battery you have. Some can stand more abuse than others. Your basic cheap battery will be damaged from just a couple full discharges.
 
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Hi Jerry!

I have a 240Ah 12v Lifepo4 setup here for backup power in my Hamshack. I have a 20A 120v charger and I can also trickle charge with one of these. It does a fail over if the power drops as well. My main power supply is an Astron 50A.

https://paradanradio.com/products/dc40
Behind all that i have 480w of solar panels. Thats for after it gets really windy and it rains alot here in south florida lol.

The lifepo4 setup is nice. The batteries have a BMS that prevents overcharging as well as over discharging.

Setup is good for a couple thousand cycles.


73
 
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