'03 540i - Sometimes Master Remote Works, Sometimes Not

[peter540]

I've got an '03 540i sport. Love the car, and many of you gave me some great tips several months ago. I have a problem with my remote key fob -- sometimes it will work to lock or unlock the car, sometimes it won't. Sometimes, if it doesn't work and I tap the fob against a hard surface, the remote will work.

I'm not driving the car as much as in the past, and in searching this board, I found previous posts on this sort of issue. I didn't realize that the remote is recharged when in the ignition. We're not driving the car as frequently right now; perhaps the remote isn't charging long enough?

Also, there's no error message appearing in the dash MID.

My main question is: If I want to recharge the remote, do I HAVE to have it in the ignition, and does the key HAVE to be turned to the "on" position? Would the battery recharge if the key was simply left in the ignition?

Any other thoughts on what could be the problem? I'm assuming Fuse 52 or 53 wouldn't be the issue, since I can get the remote to work with some prompting / whacking.

Thanks for your help, as always!

--Peter

[Qsilver7]

EDIT: while looking up key info for another thread...I ran upon the info in pic below that states in "black-n-gray" that the ignition must be turned ON in order for the battery in the key to be charged. Take note of the {WORKSHOP HINT} gray box on the bottom right:

http://memimage.cardomain.net/member_images/7/web/739000-739999/739005_165_full.jpg
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Hmmm, I would take the instructions from the owners manual to mean that the ignition must be on to charge the key.

If you notice the wording (in the text that is highlighted in pic below...plus the mention of the spare master key further down in the paragraph) it clearly states that the key charges as you drive...then again for a spare key it says...use it at least once a year while driving for an extended period to charge the battery.

Just inserting the key into the ignition without turning it OUT of position 0 (off) doesn't qualify for what those two instructions above infer..."as you drive" and "while driving for an extended period" infers that the ignition is on and the engine is running.

http://www.bimmerboard.com/members/q/original/new%20style%20BMW%20key%20set.jpg