Hello. I am having a bit of a problem with my car. It seems that the battery goes dead resoanbly quickly, like in 1-2 days, and I am pretty sure that driving it around is what is killing it.
When I slow charge the battery at 2A for a day or so it holds a charge great at starts right up, but then it'll get weaker and weaker every time I start and eventually wont start at all....
When the car is running, the voltmeter on the dashboard sit @ the line inbetween 12v and 16v, which I am guessing is 14v? And I can use all my accessories while the motor is running (headlights, rear windows heater, blower, etc).
My rear antenna is not up so I am pretty sure that I didn't leave my radio on or anything......

Anyone have any idea what could be up? I was thinking that my charging system might not be working properly, but then how the heck could I be driving around? Wouldn't iot just suck my battery dry right away trying to run ignition?

 

Charge it up, then take it to a store that will test the battery/alternator. That way you'll know if battery is any good. It sounds as if the battery won't hold a charge.

 

More than likely your alternator has died. This has killed the battery. You will need to replace both or the one that you don't replace will kill the new part...

 

Nah if he is getting 14vdc and can drive for extended periods of time with no problems his alternator HAS to be good. BEsides, you all are forgetting that a dead alternator will illuminate ALL the idiot lights ALL the time. HE is getting charge from the alternator, but a bad cell in the battery can do wierd ****. I would go find the biggest, strongest battery sold (I run a walmart 925cca battery) and put it on, then recheck everything. EVen though you can charge the **** out of your current battery, the fct that it was highly drained one good time means it will never be right from then on...batteries have a memory and continue to get worse with each drain.

I jsut worked on a car with a rel weak battery/bad cell. WIth even a quick boost it would fire right up at full power, and show full charge. As soon as you shut it off, ALL power was gone. IT owuld barely illuminate the idiot lights. I even went so far as to cruise around for 20 minutes, get rolling about 70mph off a big 2 mile hill, shut off the car with the clutch pushed in, and try to refire it...as soon as I shut it off, ALL the lights died. I had to let teh clutch back out, and it rode for about 2 seconds before everything came back to life. That's what a bad cell in an advanced state can do to youl..wierd ****.

Get yor car running and take off one of the battery cables. IF it continues to run, the alternator is good. I can tell you right now from the fact that you see charge while running and that your idiot lights are not on, that your alternator is ok.

 

What has happened is that the voltage regulator inside the alternator has fried, this draining the battery when the car sits. The alternator charges great when it is spinning, but as soon as it stops....Same thing happened to me, and it was a major PITA...

 

Sorry I didn't mention this before, but I actually have a new battery, just 1-2 months old... an ACDelco battery that is a little bit smaller than the battery box. I think it is rated for 650 or so cold cranking amps. It somehow got completely discharged when I left the car without driving it for a week (no idea what...)

I just replaced the alternator with a friend's old one and even after 30 mins of driving, it still cranked very slowly.
I'll do that test of getting it running and pulling the battery ground, see if that does anything....

 

Did you read what I just wrote?

DId you read what I just wrote?

Im not saying this is your ONLY problem, but it is the FIRST youll have to deal with if youre gonna figure this out. Youll also need to find your drain before expecting the new battery to hold charge...remove the negative terminal before letting the new one sit overnight until you figure out your drain.