alternator battery help

[ChillenNcali8]

After five hours of cleaning my car and listening to music my battery died (big surprise i know) I hooked it up to a trickle charger for 25 min and got it started. On my way to dinner with my girlfriend it started sputtering and the electrical would shut off and turn back on until it was finally dead. I called some friends and they came and jumped me. We left it on for increasing amounts of time because soon after taking the cables off the car would sputter and die.

Anyway I finally got it home and checked the battery and alternator with a voltmeter. The battery was down to 4 volts. After a night of trickle charging the battery and alternator read around 12 volts. Car seems fine now, but I have to go back to school on Monday and don't need any surprises on the 5 hour trip.

Any suggestions on seeing if my alternator is bad?
Does the alternator need to run voltage above the battery?

Thanks
Kevin

 

[Lsredy2kstang]

Take it to an auto parts store and have the alt/battery tested. Sounds like you have a draw on the battery and that may mean that the alternator is shot.

 

[Skymarshal]

Your alternator is probably fine. I'd be more worried about your battery!

It isn't good for batteries to completely discharge them. There's even a risk that one or more of the individual cells may reverse in polarity, and then you're in for a new battery.
Anytime you completely discharge the battery, once you get the car jump started, just let it idle for about 15 minutes- no lights, fan, or radio. If you drive the car right away, the battery is trying to recharge at the maximum rate, and all the other accessories might overload your alternator.

You probably haven't done any permenant damage, since the battery takes a charge now. I'd drive it and just be more careful next time!