Car wont start, battery reads 12.9v

[offthewall]

Car wont start, a couple days ago leaving familys the car was dead. Headlights were left on and a door open. Jumped it and it started right up, drove it home and everything was fine. Restarted fine. Couple days later went to take it and it just clicks. Put a battery charger on it for a few hours until the battery was reading in the 13s. Car still only started when I put the battery charger on the jump start setting. Drove the car around fine, restarted after sitting for 15 mins. Left it for a couple hours and checked the voltage at 12.9 and it wont start, just clicks. Sounds like a relay clicking, not the starter. Left it on the charger over night and still same thing with voltage in the high 12s.

Is there a relay that can go bad? Seems that the battery being in the 12 volt range it should have enough juice to start.

Thanks for any advice

 

[Nughuffer]

Sounds like you have voltage but no current (CCA). Have the battery tested. Id be willing to bet you have a dead cell.

 

[offthewall]

ok thanks, been doing alot of reading about batteries on here and everyone says to go with a OEM battery, any reason not to do an optima red top?

 

[Nughuffer]

Overkill I'd say but as long as it fits & meets specs of OE you should be fine.

 

[whitedog]

To test that battery, charge it, then put your multimeter across the battery. Then try to start the car. I'm betting that you will see the voltage drop way under 7 volts when you try to start the engine.

I just paid $120 for a new battery for my Jetta. Well, actually it was for my Audi, but it takes the same battery.

 

[offthewall]

Battery ended up being bad, thanks for the help guys.

 

[bennybmn]

Sounds a lot like what happened with mine. Glad it's sorted.

 

[scdevon]

Yep. Current is what starts the car. Not voltage.
Actually proper voltage at the proper current is what starts the car.
A 12.xx whatever voltage surface charge means next to nothing.