Key battery replacement, error still showing.

[Scubaregs]

Had warning in dash on starting car that key battery was needing replaced. Put a new battery in but still getting the same warning on start up, which disappears shortly afterwards.
Battery came from a sealed blister pack, anyone got any ideas why I'm still getting the warning?

 

[q96169we]

I guess the battery is not from BMW dealer's parts department, right? My past experience told me that batteries not from BMW parts department will less likely to make the car happy. I have no idea of why but that's the case for my past 5 keys. I end up always buy battery from local dealer which is only about £4.5.

 

[Scubaregs]

Just bought two duracells at £4.25 the pair, seems to have cured the problem.

 

[H-J-F]

How old is the car? Reason I ask is I had a message today telling me fob batteries were discharged, so I guess I need to change them. This is after no more than eighteen months. Batteries in all my previous cars had lasted for years before this.

 

[Scubaregs]

How old is the car? Reason I ask is I had a message today telling me fob batteries were discharged, so I guess I need to change them. This is after no more than eighteen months. Batteries in all my previous cars had lasted for years before this.

2020.

 

[r2uzenblot]

I had to replace my battery (Sep 2020 car) in October. Straightforward enough but you do need 'fresh' and good make batteries.