Leica M Warning Message: Check battery age
"Check battery age”: I first saw this error message on the day I collected the demonstrator M262 from Leica UK. If it had been my own M-P with a battery that could be several years old I would have worried. As it was, I assumed that the battery in this demo camera would be reasonably new and that there must be some technical explanation.
Still, I decided to check on the forums and discovered that this was a common occurrence. Leica owners all over the world were asking what this error message meant and what should be done about it.
The short answer is that it is a camera firmware bug and will be put right at the next update. Thorsten von Overgaard has some more background:
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.
This is certainly a strange one and I haven't encountered such a message with any other consumer electronic device. For starters, when you buy a new battery you should expect a good three years' use out of it. Even 34 months is a bit of a disappointment. Secondly, you should expect the clock to start ticking from the date of purchase, not from some distant past date when the battery left the production line. I wouldn't mind betting that some are three years old before you buy them.
Let's hope this is just a firmware glitch and that our expensive batteries are not programmed to fail automatically after a predetermined time.