[V8] battery light on dash came on and a few days later dead

[chris brown]

well on Friday night when i was driving home from work the battery/voltage light went on. And its been on pretty much all the time for 3 days but not always. Today it went on and about 3 minutes later the car stalled and my battery was totally dead. I started it up just a little while ago and it started and the battery light didnt immediately come on. My question is Does this Audi have a complex electrical system that when it notices a shorts of some sort it will disable the alternator from charging? I once had a volvo do it to me. I turned out the alt was fine on the volvo and the battery too. It was a short under the dash my guy found.    I dont know which one i want to do? replace the alt, or start to look for a short?