I have been having a problem lately with batteries dying, or frying really, as soon as I put them in my car and drive or even let it run. The car runs perfectly fine while it is on, but as soon as I turn it off, the turbo timer and everything shuts off, and when I go to turn it back on I get nothing, not even dash lights.

I can jump the car, but as soon as I turn it off again, I have the same problem. I tested the battery while on the car, and it says the alternator is putting out 100%, so that's fine. When I try to charge the batteries out of the car, they will not take or hold charge what so ever.

I am lost, and don't want to ruin anymore batteries. Is there some sort of control on the alternator that regulates how much charge it puts out that could be overcharging the batteries?

Any help would be greatly appreciated.

 

I am not saying you are testing it wrong, but i would have some one else check the alternator. have you installed a grounding kit recently or a big amp? just my 2 cents.

 

What test did you run that says your alternator is working 100%? Have you taking some voltage readings at all?

 

The strange thing is you said the battery won't take a charge when OUT of the car. If the battery is bad, shorted cell inside of it or something else, it won't take a charge. First get the battery charged up by a good charger. A 10 amp auto parts type charger should do the trick. Then you should take that to a shop and have them load test the battery, or take the battery to a shop and have them charge it and test it.

The alternator does have a regulator, probably built in like all other cars now built. It regulates voltage depending on the load the cars electrical system needs, and allows a charge to go back into the battery at all times when driven, engine running.

Engine running, put a voltmeter on the battery. It should show about 14 volts when idling, and also when you turn on the ac, blower fan, wipers, hi beams, load it up, and it should still show 13.5-14 volts charge to the battery. If not, then the fault is in the charging system but first you have to make sure your battery is in good condition or all other tests will be faulty.

 

Like he said, make sure the battery is good first. Sounds like an alternator though, I've killed a couple batteries trying to diagnose it before. Good luck.

 

Thanks guys. I put another battery in it, and when I jump the car, the alternator tester was saying unable to stabilize(or something of that sort). The battery was good when I put it in, but afterwards(and after driving for a few minutes) it was only reading ~6 volts and wouldn't charge any higher than that.

Sound like the alternator?

 

UPDATE:

It ended up being a problem with the positive battery terminal. Replaced it and put a new battery in, now its working fine.