BMW Repair: 2003 bmw x-5, car batteries, telephone control

Question
i have gone thru 3 car batteries in 4 weeks replaced the alternator and new bmw battery replaced.  car dead again after 1 week.

Answer
You have a draw on the battery. If it i discharging while off you need to see what is staying powered on and correct the problem. Most liking causes are the auxiliary fan, the IHKA(climate control), or TCU (telephone control unit). Also just make sure there are no new consumers left plugged in when the vehicle is off. Let me know if you want me to walk you thru checking the problem. You will need a multimeter that reads DC amps.
              Kimber