Hi, been snooping for a while, but thought I'd post something interesting I learnt today.

Had my 57 plate 525d for about 6 weeks now - still amazed at its abilities over my old Volvo S60 D5, but had the "Unusual battery discharge" message for the second time this morning.
Fearing the worst, I called out BMW assistance and learnt that the battery monitor is VERY sensitive.

Apparently, if there is an extended drain on the battery, the car starts shutting down the offending equipment to preserve power to start the car !! Even more interesting was that the drain was the dashboard electronics.

Last night I didn't lock the car for about 3 hours after I got home, and the guy said that the car only truly goes 'to sleep' after being locked, hence the drain over the 3 hours. lost time and all the trip details - but at least I know the reason.

Anybody else had the same message or heard the same thing ?

On a better note - I got stuck behine every caravan in the midlands on my 75 mile trip to and from work today :( but doing 55mph all the way there and back returned 49.5mpg - and from a 3 litre auto :D

We all need our sleep :P Congrats on the car and enjoy the forums!! :twoup:

Welcome. If you want to learn more about the complexities of the car's battery/power system, you can read a ton about it in the technical gallery:
http://forums.e60.net/index.php?autocom=ga...i&img=10935

I agree with much of what the BMW assistance guy told you except to say that the car will go to sleep even if it's unlocked. Mine is unlocked inside my garage all the time and it sleeps like a baby... ;)

Hello, Bearders. Welcome to our Forum. You are bound to learn much about E60s, Bimmers and many related issues. And it's a load of fun.

By the way, tell us about more your 520d and your where-abouts.

What is the midlands? In my old age it sounds familiar, but I just can't place it on a map.

And what is "57 plate" 520d?

Again, we welcome you.

:)

I have had the same problem. Do you have comfort access? If so, it might be a portion that is not going to sleep and draining the battery. This is mentioned elsewhere in the forum. I am bringing in my car this Tuesday for a repair of this. I keep losing the time and date in I drive as a result.

I don't think it's comfort access that's the problem with a car that's staying awake. In my experiences, some other module becomes faulty and does not allow the car to sleep. If you have comfort access, you'll notice the problem quickly because comfort access won't allow you to unlock the car if it's fallen into the "increased battery discharge" stage where it starts to turn off non-essential electrical consumers (CA is non-essential...)