I have a 91 Camry 4cyl. I parked on a slight incline, got out of my car, shut off the engine, got back in 30 seconds later, and it wouldn't start. I tried turning the key again, it had power, but no click. The third time no lights came on and I had no power. I tried a few more times, the open door light was on when my door was open, but no other lights were on when I turned the key. I waited 10 minutes, my buddy showed up to give me a jump, I tried again, it started up. It ran for 2 minutes then died again. There isn't any corrosion on the posts to the battery, and they were pretty tightly screwed on. I'm leaning torward it being the battery... any help would be appreciated. Thanks in advance.