[Shaummy66]

Hey guys,

With a fully charged battery, how many volts should the battery terminals show when a car is at low idle and no accesories on? Should it show 13-14V or closer to 12?

I'm trying to diagnose whether or not my voltage regulator or alternator are working correctly. Right now, I get about 13 volts with the car running, and nothing on.

It jumps to almost 14V when I have the lights on and the heater running. I just replaced the battery, and charged it to full strength with the charger before installing it.

Iam concerned that the system may be overcharging the battery when it is at full strength already.

Thanks,

 

[Mudcat]

Your OK. The voltage will run between 12.5v - 14.5v constantly depending on RPM. But if you were to put an ammeter on it you would see a drop in amp draw as the battery nears full charge.

 

[woodywrkng]

Your charging system sounds like it's acting properly, by increasing alternator output when you turn on some accessories.