Ok so i had this problem with my security system beeping. i took the car to audi finally and they did much testing. The battery tested ok but upon further testing the battery very periodically would short itself out. The security system was detecting this I am guessing. It took a few days or more for the sec. system to stop beeping.
A more recent development. My car was having electrical issues and would the battery would die quite frequently. Anyway of course they tried changing the battery because thats always the first thing audi does. The security system now beeps again. I am going to give it a little more time. I'm also wondering that when they were checking the electrical system that they were digging around in the setting and could have changed something. Just thought the suggestion would help.