Battery Or Alternator?

[sennis]

Hey Guys,

Ok so I went to start my car the other day, and it wouldn't turn... Battery was dead... Or so I assume... I boost it and she starts up fine... (Runs well)... I then get to a buddies place, go in for a beer, play some video games, and when I come out my car is dead again.... So he boosts me, and I head home...

Go out this morning to start it, and she's dead again... Battery is only 3 months old... Is this a bad battery?

Im guessin best bet is just to have batt. tested, but curious if someone can decipher what the prob is just by hearing what's been going on...

Any help is appreciated.

Cheers,
Steve

[jrhaile]

sounds like battery to me... when my alt took a crap, car wouldn't even start with a jump. Does all of your audio equipment work like cd player, amps, subs? if so, it's not your alt

[BImmerN2B]

I would say alternator because when alternators take a crap, they take the battery with them(new or not). Take a digital voltmeter and test your alternator. or it could be something that you are leaving on in the car that also could be causing that.

[bitcore]

Battery.

Your car apparently runs just fine once it's started, so your alternator is putting out the juice nessicary to operate the car, but the battery is not holding a charge, which makes it so you cannot start the car again.

There could be a simple mystery drain on the battery when the car is off, causing it to go dead again, you'll have to investigate. Regular car batteries are not designed to deep cycle (IE: drain down so very far) much at all, and every deep cycle you do will reduce it's life significantly.

[sennis]

hey guys...

thanks alot for this... Appreciate it.

Im going to go to the dealership tommorow... My battery does have a one year warranty on it, so hopefully we find out it is the battery, and I can simply swap it for a better one...

Cheers,
Steve

[Rooz]

has your electrical system been acting weird?? like radio suddenly stops and turns back on,.... ?

[sennis]

Hi there.. Naw,, everything works great when the car is running...

Electrical system seems fine... Which tends to make me think it's the battery..

Thanks again,
Steve

[jrhaile]

has to be battery.. if it was alt, nothing would work even on a jump start.. alt provides the power to those electrical devices...

[Rooz]

yeap, it's battery!

[rsn48]

The alternator on my son's 318i car just went and it was surging, the lights was surge brighter, then back to normal. Check lites would come on for "check transmission" and "engine check light."

[Cruzin 323is]

a little test for u....??
1- attach jumper cables
2-start car
3- while car is on, disconnect the battery
4-(if car turns off) then its your alternator
5- if car stays on, then its the battery!

[jrhaile]

not true cruzin... example, when my alt died, I was on the freeway. cd player flipped up and lights dimmed big time. but car ran all the way until I got it pulled into a shop. and disconnecting your battery while electrical stuff is functioning I would say is a bad idea :P

[Pegasus]

Originally posted by Cruzin 323is@Feb 20 2005, 11:48 PM
a little test for u....??
1- attach jumper cables
2-start car
3- while car is on, disconnect the battery
4-(if car turns off) then its your alternator
5- if car stays on, then its the battery!

[snapback]295947[/snapback]

You should never do this. You could fry the whole system. Check your manual. It expressly says that you should never disconnect the battery while the engine is running.

[sennis]

Hey Guys,

Just a little update... Took the batt to the dealer... Even though the battery was only 3 months old, it didn't hold a charge... Just a bad batt...

I had a one year warranty, so just swapped another one in, and everything works great. Thanks for the help! This site rocks!

Steve