Charging Help

[jduckworth]

Thanks for the help, I tried searching but couldn't find anything specific to my problem.

Here we go - I only drive the car on the weekends.

My 3 month old battery died a couple of weeks ago. Prior to charging, the battery had about 9V, and only took 15 minutes to bounce back up to 12.80V. I installed the battery and the car started fine. At cold idle the meter read 13.68V. I drove the car all weekend (~45 miles) without incident.

I went to start the car this weekend and noticed a weak start. I measured the voltage directly after the start and it measured 13.65V. I drove the car about 15 minutes and the radio started cutting out. I pulled over and measured the battery and got 9.79V.

All the cables are tight and clean. My battery idiot light comes on before starting and goes out after starting. The light has never come on during any time of the above.

Can alternators charge intermittently ? Regulator?

Thanks for the help.

[Rot 911]

You have a bad battery. Probably letting it discharge to 9 volts did it. If you have an Optima, you might be able to bring it back to life. If not, take it in to a place like Autozone and they can test the battery for you.

In the future get a Battery Tender and leave it on when you are not driving the car.

[jduckworth]

Thanks Rot.

One more thing, the voltage did not change when I revved to car to 2500 rpm yesterday.

Thanks.

[Joeaksa]

Agree with Kurt (why am I always saying that!!??) that your battery is prolly bad.

They need to load test it, then see how it goes.

Get a known good battery in the car then watch the voltage. It should change when you put the defrosters or high beam lights on, otherwise be pretty steady.

Joe A