snagitseven

The response he gave is a bit vague to me. He says that if the vehicle is unlocked that some systems may be left on but can't say which ones, only that they're "passive". (There is nothing in my manual's three pages discussing energy management about the doors being locked or not). Then he goes on to say that after a "few days", you have to pull on the door handle twice to unlock it. My A6 requires this after maybe 30 min to 60 minutes, probably a part of the first energy saving stage. The MMI full boot stage is required after a few hours.

Regardless, I would guess a fully charged, healthy battery in a warm environment would last a few months before it completely discharged with doors locked or unlocked not making much, if any, difference. There likely wouldn't be much of a current draw remaining after the energy management system stages the car into a full, low battery sleep mode except maybe the clock and whatever standby circuit that activates the starter.

subterFUSE

I generally do not lock my car in my garage.

I have noticed that the car shuts down in stages, and will also shut down systems to save power. For example, when I am lying down inside my trunk adjusting the gains on my amplifier and after a few minutes the trunk lights go out.

I also installed a dash cam system which continues to run while the car is parked. It has a smart power adapter that can detect the battery's voltage. If the voltage drops below 11.8V, then the dash cam shuts down.

What I have noticed is that my dash cam will run for several days while the car is parked and unlocked in my garage. When I open the door to my car and the interior lights come on, that's when the dash cam shuts down because the voltage drops to 11.8V. But then I start the car and it comes back to life immediately.