Battery drain Please advise!!

[Lennyq]

I have an’06 760iL - I have a competent mechanic but after 3 weeks he’s stumped as to drain on new battery. He believes he isolated it to a power seat module but has no idea which one or how to fix problem. I realize I’m probably at the mercy of a dealership now but I would GREATLY APPRECIATE any advice/experience on this topic so I have a guide or expectation of horrors to come!
Thank you
Lenny Q

[Pelican Parts]

Hello and welcome to the forum! Has your mechanic used a BMW specific scan tool to pull the codes? This should give him a fairly accurate assessment as to where the exact issue is coming from.

[AuntJemima]

Hi Lenny,
I am not a BMW RKI (real knowledgeable individual) but I had a battery drain problem on a 1990 525i (e34) that was difficult to identify and/or wasn't worth fixing. I destroyed a few batteries, if they discharge excessively too many times it kills their life. While you are trying to isolate/fix the problem, I suggest turning the "battery store" (can't remember the correct name) switch just under the trunk on the right side of the e65. It turns off almost everything to save the battery during storage, its a simple "on/off" slide switch. If your battery drain is real slow (week+), you might use this technique judiciously to put off the repair for the life of the car!

[Bavarain]

I have a 2006 750li where the driver seat would cause the battery to drain. When I'd get out of the car the seat would slide back but the motor never cut off when it got all the way back. The seat unplugs easily so that solved my problem.

[bsen]

I had similar problem and it turned out to be a defective door handle. I have comfort access system, which I guess a 760 would have. My car would not always enter sleep mode. Verify that the car enters sleep mode by seeing that the light on seat adjust button goes out after about 17 minutes of shutting the car off.