High Battery Drain issues
 

Haven't seem this topic discussed lately and I have been experiencing it quite frequently over the last month or so on my 2008 4.8 with Comfort Access. 140K miles.

In November I replaced the battery. About two weeks later I replaced the alternator. (left me sitting middle of nowhere / middle of the night)

Some time last month I started getting the High Drain notice. It goes off after driving the car for 30-45 minutes. I have all ideas that it is connected to the Comfort Access system but wanted to know if anyone else has experienced this also. The car will lock itself at random intervals when I walk by it with the key in my pocket. Doesn't unlock, just locks. The drivers door exterior handle doesn't work as well as it should with the Comfort Access function.

Thoughts?

Did they register the new battery in the cars computer system?

Yes.

I'm almost positive that it is related to the Comfort Access system. I have been charging the key in the ignition and fingers crossed it may be happening less often.

The CA remotes have a replaceable battery; they are not charged via the slot in the dash for the key. That is the non CA systems that are charged that way.

Not true. There are two batteries in a CA remote.

Ummm, no. The manual states the CA remote has a replaceable battery; CR-2032. What would the purpose of two batteries be?

Don't know, don't care. Just passing along what the dealer told me.

Plug it in once in awhile. ..... two batteries, one replaceable one rechargeable.

Which battery powers the data collection?

One battery. You dealer lied or is misinformed. Pick whichever makes you feel better.

Oh and dealers are never wrong.

The CR-2032 powers it all.

So now you know the truth and can stop the spread of misinformation.

http://www.bimmerfest.com/forums/att...0&d=1274219732

Nowhere in the paragraph does it say that there is "only" one battery. Do you honestly believe that BMW makes two key housings for an option with probably less than 25% up take? The manual also says plug the key in to the slot at least twice a year. Why? The CA battery isn't rechargeable. ????