battery drainage

[metalkaoken]

Well, when i purchased this car, I installed my own stereo. It took a while to actually drive the car because of "mutilated title" issues. When I went to start the car weeks later, the battery was completely dead. I charged it back up and it drained again. At first, I thought I had crossed the wrong wires, but I double checked. I decided it was a bad battery and swapped it. Seems to be ok now, but if I'm wrong; Is there anything I should check for besides a power-ground short? The alternator works fine BTW. It only happened when the car sat for a while.