I received multiple emails from readers asking me about the "Check battery age" error message that recently started to appear on many Leica M 240 cameras. Thorsten Overgaard has a good explanation on his website:
"It has nothing to do with the actual performance of the battery, and not even the number of cycles it has been charged. The message will activate approximately 34 months after the battery was produced."
So not a big deal really. Leica is supposed to release a firmware update for this issue.