BMW Repair: charging problem, 2002 bmw 325xi, bmw 325xi

Question
I have a 2002 BMW 325xi that keeps killing batteries.  I recently put a new battery in the car and it didnt do the trick.  Any ideas what could be draining it?  I purchased a computer deprogrammer which i installed about six months ago, also I connected an ipod system in the trunk which i disconnect when the car is not running. Let me know if you have any ideas, thanks
mark

Answer
Mark, you need to perform a Closed circuit current draw measurement to see how many amps the system is drawing. Does the trans gear selector LED go out after 16 minutes?
(this will tell you if the car is going to sleep or not) 40mA is the maximum amperage draw with the car asleep. You Ideally want it around 20 milliamps is more of a normal reading.
-Evan