Severely discharged battery

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Something on my Charger (car, not device) has caused the battery to go from full to 8.5V (as indicated in the instrument cluster) in just 2 days. It's the factory battery - a little over a year old.

I'm re-charging that battery right now, and will run a CCA test and will monitor for parasitic drain. I realize such deep discharge is very bad for a lead-acid battery, but I don't want to toss it either since it's fairly new. I guess I'll keep an eye on it, realizing its life may have been shortened by his incident.

Other than trying to find the source of drain, is there anything else you would do at this point?
 
My 2007 1500 with a 5.7 hemi had a parasitic drain of 200ma and it would kill the battery like that. I had the meter on it and pulled all the fuses one at a time to try and find the drain. No stuck relays either. I finally took the handle of my screwdriver and tapped on the PCM panel. Suddenly there was no more drain. I just attribute the problem to a fried ant or some type of bug in the PCM. I bought a leaf sucker used and the guy had put a new motor on it just 2 years before and it wouldn't start. He had taken it somewhere and they couldn't fix it. Got it home and removed a spider webb from behind the kill switch. Started right up. Bugs can really bug up your electric items
 
8.5VDC is bad! If you're able to charge it, I'm guessing it's with a dumb charger, as most "smart" chargers wouldn't even recognize it as salvageable.

I'd replace the battery.
 
I would make sure everything is turning off before leaving it sit overnight. Lately I need to shut the door twice to get the radio to shut off.
 
Originally Posted by Quattro Pete
Something on my Charger (car, not device) has caused the battery to go from full to 8.5V (as indicated in the instrument cluster) in just 2 days. It's the factory battery - a little over a year old.

I'm re-charging that battery right now, and will run a CCA test and will monitor for parasitic drain. I realize such deep discharge is very bad for a lead-acid battery, but I don't want to toss it either since it's fairly new. I guess I'll keep an eye on it, realizing its life may have been shortened by his incident.

Other than trying to find the source of drain, is there anything else you would do at this point?



I had an odd battery dying situation with my Subaru Forester. But part of the issue was the key in ignition on OFF. Its not the same as no key in ignition. Cannot fully explain, but that is part of it.
 
Originally Posted by gathermewool
8.5VDC is bad! If you're able to charge it, I'm guessing it's with a dumb charger, as most "smart" chargers wouldn't even recognize it as salvageable.

I'd replace the battery.

My ProLogic charger will charge normally anything above 7V. For anything below that, it'll do a soft start first.
 
If you need to recover the battery temporarily you could leave a jump pack connected for 20-45 min to build up some power then throw the smart trickle charger on it and it should work, but it's not going to go back to 100% capacity and if you live in a hot/cold climate plan on a new battery in the next month or two at most.
 
If you need to recover the battery temporarily you could leave a jump pack connected for 20-45 min to build up some power then throw the smart trickle charger on it and it should work, but it's not going to go back to 100% capacity and if you live in a hot/cold climate plan on a new battery in the next month or two at most.
 
Check the light in your trunk. I had a car that kept killing the battery and was tearing my hair out trying to find the current draw when I finally discovered that the trunk light was staying on.
 
Most starting batteries can take a deep cycle or two. 10 cycles not so much. You did take a year or so off the life of the battery. There is no way I would replace it until the cause of the drain was found.

Charge it good before driving, recharging a dead battery with the alternator is not good for the battery, it used to kill alternators but most of them these days are very robust.

Rod
 
Most starting batteries can take a deep cycle or two. 10 cycles not so much. You did take a year or so off the life of the battery. There is no way I would replace it until the cause of the drain was found.

Charge it good before driving, recharging a dead battery with the alternator is not good for the battery, it used to kill alternators but most of them these days are very robust.

Rod
 
I charged the battery on our Caprice ( rarely driven ) on slow charge last time . Left it on for 1 - 2 days .

If you can find nothing else causing the drain , I have read a bad diode in the alternator can cause this ?

Once you get the problem solved and the battery fully charged , I would not immediatly replace it . Just keep a close eye on it . Especially , going into winter .
 
OK, so it appears the battery may be hosed... it won't take a charge. After 24 hours of charging at 10A, it's still only at around 11V at rest with no load. It fails CCA test quite spectacularly.

Drain seems to be only at around 20 mA once the usual systems go to sleep, but I haven't monitored it for too long yet.

Gonna try to talk to the dealer to see if they'll give me a new battery.

[Linked Image from i.imgur.com]
[Linked Image from i.imgur.com]
 
Originally Posted by Quattro Pete
Gonna try to talk to the dealer to see if they'll give me a new battery.


IF they give you a new battery? If it's still under warranty they HAVE to give you a new battery.
 
The car is under warranty, but I wasn't sure if the battery is under some separate warranty, kind of like tires.
 
Originally Posted by Quattro Pete
Originally Posted by gathermewool
8.5VDC is bad! If you're able to charge it, I'm guessing it's with a dumb charger, as most "smart" chargers wouldn't even recognize it as salvageable.

I'd replace the battery.

My ProLogic charger will charge normally anything above 7V. For anything below that, it'll do a soft start first.


Have you ever replenished a battery and had it last after it was that low?
 
Originally Posted by gathermewool
Have you ever replenished a battery and had it last after it was that low?

I never had a battery this low before.
 
Originally Posted by Quattro Pete
The car is under warranty, but I wasn't sure if the battery is under some separate warranty, kind of like tires.


3 years 36,000 miles.
 
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