I always lock the car (especially with Comfort Access, it makes it fun) and never have battery problems. I think when the car is locked, it turns off any miscelleneous functions/ electronics that can cause battery drain. Try cosistently locking the car when you're not driving it.

I think you should try locking it and see how it works out. However with several of those guys experiencing the battery drain problem back here in Germany and also Spain, locking the car didn't resolve the problem in total (just as changing the battery to a GEL type of battery didn't help all of them). So it seems to have different causes for the battery drain.

As said, BMW mechanics pointed at the Efficient Dynamics programming. I don't get it 100% again, but as far as I remember, battery level might not be reloaded correctly from the alternator while in decreasing speed mode.
However, also changing the alternator didn't resolve the problems in total with some test persons.

So latest I heard is that BMW factory is working on that problem with some engineers. Hopefully they will find the reason(s).

Greetz
X5_Newbie

I have a 2004 X5 and it sits for about a week some times, never had a problem.

My friend has a X3 and his battery did go low, turn out that the GPS system was not shutting down and was causing the drain.

Interesting about locking the door, I once went on a 3 week vacation, unlocked the doors, popped the hood and backed up into the garage 'just in case'. When we got back, car started in a heartbeat, no errors.

The other day the daughter left one of the doors opened wide, I did not see this until about the 3rd day. I shut it and forgot about that until the next day when I noticed 'excessive drain' error when I started, drove for about 15 minutes to run some errands, parked re-started and the error was gone.... nothing since then. Not bothered for now :-)

Well the X went into have the front active anti roll bar replaced last week, because I was getting a lot of extra front suspension noise, and I told the dealer about the flat battery, which happens every weekend now, despite the battery getting a good charge after a long drive.

So he kept it in over night to check it, and he said he could find no fault, and says he put it on charge overnight - 'great' - I could have done that, and guess what , another flat battery this weekend, why dont these idiots listen to what you are telling them !! ? Grrr..:rant: So now I'll need another dealer visit to get the battery replaced !!