I have been having problems with my yellow top for the last couple of months.If the car sits for a couple of days it would be completely dead the next time I try and start it up. The battery would get extremely hot to the point you couldnt put your hand on it for more than a couple seconds. Luckily I saved my receipt from Autozone and took it back. I had to leave it for an hour for them to run a test on it. Came back and the guy said that it charged fully and was holding a charge, so he couldnt swap it out for me. he went to go get it and couldnt bring it to me because of how hot it had gotten. he got a towel and put it on counter. I asked him to show me with his meter that it says its a good battery. So he hooked up the hand held meter and began the test. a couple of seconds later "bad cell" popped on the screen. the only answer the gu could come up with on why the tester said it was good was because it was designed specifically for duralast batteries but could be used for any battery, guess not. he then said that this was the first time he has ever had to warranty a optima yellow top. hope this can help sum1