The last Napa battery I used completely shorted out and died about 2 months after the warranty expired. That batter was DEAD too, I'd never seen a battery die so completely and utterly before and so fast, it was working fine, then all of a sudden came out to start car and doors wouldn't unlock, and dome lights wouldn't come on. I drove it a few miles before I replaced it after I had jump started it. I'm surprised it didn't destroy the alternator actually.