Quote Originally Posted by spendorman View Post
Best put a fuse in the circuit if going direct to the battery. A good and/ or uprated battery should help, Bosch Varta etc. Has the drain on the battery been checked with everything turned off? My old Volvo only has the car clock and the radio station storage drains when everything is off.

I know a little about batteries, in the mid 70's I worked on the design of electric vehicles. Went on courses about batteries and electronic controllers for electric motors.
BMW checked it on their diagnostic computer and all is well, it's just lack of use I think. It's got a Bosch heavy duty battery. I've ordered the AA recommended charger, you can either clip it directly to the battery or plug it into the EOBD socket.