Alternator?? Battery??

This is a wierd one. I parked the car, after about an hour and a half, I came to leave the softball field and the battery was dead. I got a jump, but on the way home the defroster was kicking on and off, the headlights were dimming, and the car was trying to die. What gives? ANy ideas???

Battery....did you leave your lights on?

it was the batter. I had it checked and it was pumping like a third of an amp. Anyway, no, I did not leave the lights on, the battery was just worn out

Yeah they will do that. I should replace mine anytime too.