Problems with X6 5.0 2010
It is not normal on any car.
A week is too long for a major current drain, so it has to be something small. A small courtesy light bulb in a storage compartment that is failing to turn off?
Have you added any audio accessories? (amps, DVD players, etc) Sometimes aftermarket accessories have nasty drains and have to be unplugged when the car will be parked for an extended period (months) but if one is draining your battery in a week, it is defective.
The last suspect is computers. This car has multiple computers on it that are supposed to go into sleep mode a few minutes after you shut off the car. Perhaps one of them is not going to sleep? That would not be as tough to diagnose as you might think. You put an ammeter in line with the battery and watch the current flow. It will be high at first, and then drop off after 5 minutes or so. If it is more than 50 mA or so, it is too much, so you start pulling fuses and disconnecting things until the current drain drops down below 50 mA.
On a 2010 X6, you are probably going to have to reprogram a lot of stuff after disconnecting the battery to diagnose this problem.
BMW X6 Series...
on Jun 13, 2011