Ok...finally got my X5 looked at by a new dealership. They seem to think they have found the problem with the dying battery. The technician spent the past 2 days testing the car to see what is drawing a current from the battery and they said it was the TCU. They're replacing it under warranty. Not completely sure what the TCU does, but if that was what was causing the current draw, Eddybilt, you might want your service tech to try looking there. Good luck!