i have recently had an electrical problem with my bmw x5. i got up one morning to find my car battary was completly dead, to which i jump started and tested the battary which was faulty, so i cahnged the battary and things were all good. lefted the car on the drive over night, once again got up in the morning to find my battary my battary was completly dead. ive checked the autonater and that is fine, i think somethink is draining the battary while the car is turned off, any ideas? not really sure where to start with this problem.