Weird Electrical Problem, so frustrating... Options

[tonytutino]

All of this started when i got my amp/sub put in last month on the 19th. (Its a 800w amp powering a JL 12inch W3) Well, a couple weeks ago i noticed my battery didn't want to seem to hold a charge and eventually it just quit. So i bought a Duralast Gold battery from Autozone on the 16th of December (having them test my alternator too which worked fine) and it worked great up until today. It just was dead when i tried to start it. Didn't leave any doors open, lights on, etc. so i took it back thinking it was just a bad battery, well they replaced it and tested my alternator again and everything checks out... As soon as i got the new battery i drove 15 minutes to work and that was it. i come out 8 hours later and its dead AGAIN!
I have no clue whats wrong... even if the alt. was bad, i don't see how driving just a few minutes on a battery would drain it... anyone know whats up?

[Cutrara]

I had a problem exactly like this. I had your standard autozone battery/alt tests done, and passed them all. It turns out the the actual alternator was fine, but there is a voltage regulator or the like ATTACHED to the alternator and mine was staying closed and drawing power. Replaced the alternator and it's been fine for over a year. Let me be clear that the actual alternator was working, thats why it passed the test.