Q: Stalling immediately after starting

Hey! I just did a top end rebuild on my 540i and I was having a lot of trouble reconnecting the exhaust pipes. So I decided to start it so I could roll it up on ramps and get some more room to work. Well, I ran down the battery, then found out the cam sensor plate wasn't on properly. So I put it back on right, timed everything perfectly a second time and charged up the battery to give it another start. Now what's extremely bothersome, is it does start and runs for about two seconds, dies, then I it won't start again until I recharge the battery.

Is it possible for a battery to put out the necessary power to crank the starter but not the required voltage the computer needs to function properly?

One other thing. I'm aware that most cars won't run long without an exhaust o2 sensor reading properly, but does this model run especially bad without it? I just need to back it up like 3 feet, after all.

Thanks!

My car has 200000 miles.
My car has an automatic transmission.