I had this problem last year.

My one turned out to be the IBS lead needed replacing.

This is the intelligent battery sensor wire and it checks whether the battery is being charged correctly.

Have you got anything aftermarket (non BMW even) wired up to the car as this can also affect it.

The dealer (or you) could do a drain test on the battery to see if it still drawing power after it should have gone to sleep.

Normal cars go to sleep after 30 mins but if you have bluetooth and / or car kit installed it will take around 1hr and 15mins to go to sleep.

Best way to check if it has gone to sleep is if the orange light is on by the P in auto gearbox.

If it is off then the car has gone to sleep.

The dealer can force it into sleep mode.

It could be that battery needs replacing or something such as a module is still drawing power. Diagnostics is best way to go.

 

Your one sounds like IBS lead as that was a simular problem to mine. Fully charged up and then 7 hours later drained and alarm went off til dead battery!

Replaced battery. Still had problem, then changed IBS lead (intelligent battery sensor wire)

 

I've had a new battery replaced in December. Just a few weeks back(April) I had to get another battery replaced. I've replaced the bulbs on the doors, front foot lights, and two trunk lights to LED. I've tried sitting in the car after turning it off and setting the alarm. About 10mins later the Nav DVD starts to spin. Something is automatically running and being turned on...wth??? Then about 5 mins later it's all silence again. Is this normal? If so, no wondering our cars are draining battery faster then other vehicles! I'm glad I'm still under warranty but if this keeps happening I'm screwed! A new battery ever 4 months??? I live in Houston. I drive about 40 miles each way to work, not including going out afterwards. I would say I avg about 2500 miles a month. My battery should be well charged but somehow this is a problem. What should I ask my dealership to check? Please advise.

Thanks,
JL

 

my soundsystem is the cause of my high battery drain msg -.-

 

When I got my 08 535i in July 2009, I had the 'high battery discharge' message three weeks in a row (one week apart each time).
The first cause was the Comfort Access main module not going to sleep (others have reported any number of individual door sensor problems); the second one was for a faulty electronic gear shifter (LCI cars only) not going to sleep and; third was the unknown-to-me aftermarket Boomerang anti-theft system that thought the car had been stolen and was trying to 'phone home' (it was removed by the manufacturer since the contract had not been passed on).
Since August 2009 the car has only had one message when I was washing the car and left all the doors open for an extended period but it never left me stranded. I have used a battery charger twice in 2 years.
The car is driven little and with the warranty expiring April 30, 2011 I took the car in for its final 'warranty service' and was pleased to see that the dealer replaced the original 4 year old battery with a new one.

 

Had the same high-drain error message... had several time/date resets & consequential iDrive "Freak-Outs"... My trickle charger wasn't resolving anything... On warranty, took car to dealer for diag., dealer said car wasn't sleeping properly & also cited the infamous unfavorable driving profile... Dealer charged batt overnight "to full".. Have only had ONE instance of time/date reset since.. Car works great


I'll never forget the afternoon I called-out my SA on BMW's "unfavorable driving profile" b.s.
.............only to be met with a 20-some page printed report with trip-log details & charge retention levels explaining said profile. Lol, burned! (Issues resolved, on warranty, free of charge, of course!)

 

I have a pre-LCI manual stick shift... How can I tell if/when the car has gone to "sleep"

 

Good question hmmm ill have to lullybye it to make sure it has gone to sleep

 

i get it too from my subwoofers. it drains the juice. the other day i was washing the car at night. doors open trunk open key out. interior lights on. 1 hour later. dead battery. just a weak battery. i wouldnt think tiny ass interior lights would drain my batt dry in 1 hour