[Joe-BMW33]

Got this message this morning. I will change the battery, but I thought I would have been getting a "low battery, change" message before this? No?

[AP]

Perhaps
I've had 1 that warned me and the dealer sorted out for me and another that did not warn , the dealer noticed when in for a service so replace it for me , about £2 I recall

[Qsilver7]

Some BMW models & clusters say "empty" and some say "low"...but the gist (regardless of the translation from German to English) is...it's time to replace the battery.

[Joe-BMW33]

Originally Posted by Qsilver7

Some BMW models & clusters say "empty" and some say "low"...but the gist (regardless of the translation from German to English) is...it's time to replace the battery.

Yup! I changed it yesterday, all good. Just surprised at the term "empty", especially since it still worked fine and from decent distances.

[Qsilver7]

BMW probably engineered the fobs to send a signal when its battery level drops to a specific voltage range BEFORE it gets too low to operate central locking functions or send the signal so the CA aerials.

This would benefit owners that are chronic procrastinators. If the warning appeared right before or after the fob wouldn't work anymore...the complaints would be out the wazoo!

Decades ago when the remote fobs had a red LED that would flash when you pressed the buttons (like my 97 e38 & 99 540iT) it meant that the battery's voltage was between 2.6 volts - 3 volts (full charge). If the LED didn't flash but it would still unlock the doors (but wouldn't lock them)...this meant the battery's voltage dropped between 2.6 volts - 2.2 volts...and it was time to replace the battery. Or if you pressed the buttons and go no flash as well as no response from the remote fob...it was really time to replace the battery because it was below 2.2 volts.

Your experience seems to imply that you were probably in the "in-between" stage where the fob's battery wasn't totally dead but had dropped low enough to trigger the warning...yet still function. This was giving you time to replace the battery before it went totally dead...or give you mutilple prompts (about the battery) in case you are a chronic procrastinator.

[{example from e38/e39 era of remote fob operation in regard to battery voltage}