I have read many threads on CA fobs and the "remote battery discharge" warning. There was one thread that cast a new light and seemed to be plausible so I thought I would give it a re-airing.
It was stated that there were 2 batteries in the fob, one used to unlock etc, and a second which maintained the memory settings. This second battery is rechargeable, this theory certainly supports the reason why the warning is still showing even after replacing the CR2032 battery. And as I mentioned, I did notice that my GPS settings were suddenly different.
This forum is doing an excellent job with diagnosing and illustrating many of the 750i maladies but this key fob issue never seems to go away and never seems to be completely resolved. I have to admit that with BMW's attention to detail they would have either removed the dashboard recharge port for CA cars or been very specific on its obsolescence?
I intend looking at my cars trunk battery to determine the manuf, does anyone know which manuf. supplied the OEM battery? My car is 5 years old and perhaps this is about the time when failures begin?
During my thread search I came across the situation where the CA fob died and there was no way of opening a door, I had assumed that the key contained in the fob would have opened something in the event of fob failure? My apologies for the ramble but I hope this will draw some concise answers and put this "Remote battery discharge" to bed once and for all