I changed my cap and rotor last night only to wake up to a dead/weakened battery. The AAA guy said the battery was fiine. The Auto ZOne guy said the battery was no good.

Any ideas?

 

what did the AAA guy do to determine the battery was fine? I assume AutoZone put the battery on their tester to check it?

Did the battery die on it's own or did you drive it at all during that time. Are you sure you didn't have anything on that would have killed the battery?

 

AAA put the battery tester on it - so did Autozone. The battery died on it's own. I drove it after install to see if everything was fine and it was. I am 99% sure I did not leave anything on.

 

so without leaving anything on, did the battery die after being left over night or did it die after driving it for a while?

If it died over night without anything being left on I would suspect a bad battery. If it died after driving the car for a while I would suspect the alternator failed to charge the battery.