Battery

Hello,

I have a 2002 40th Anniversary Grand Prix GTP. The battery is still the original one that came with the car. I haven't had any problems with starting up the car, but since it's seven years old I was wondering if I should change it. I can no longer see the "green eye" glowing. I have read various information on the internet on what the voltage reading should be. Since there appears to be no consensus I am seeking your thoughts.

With the car running today I got a voltage reading of 13.15. However, is the best time to test the battery the morning after leaving the car parking without the engine running? If so, what should the range of the voltage reading be?

Thanks.

The recommended lifetime of a battery under normal operating conditions is 7 years. If you have other auxiliary stuff hooked up then it could change, such as subwoofers and amplifiers, fog lights, LED's, neon underbody lights, etc. If it's been 7 years I'd change it anyway, even if you don't have any extra stuff on the car. You can get a good battery for around $100 bucks so give your car some TLC and replace it. Just my suggestion though, plus it keeps everything running at optimal conditions.

I agree with Nick07 that the battery is probably due for replacement. The alternator voltage should be 13.8 volts but it will vary especially if the battery is fully charged so 13.15 is not that bad.