Apple rechargeable batteries always low

[Let's Sekuhara!]

I got a low battery warning for my Apple Wireless Keyboard so I charged up my spares, overnight. Then the next day I replaced the low batteries for the freshly charged ones. Now a day after replacing them I am getting a low battery warning again!

Could it be that the sensor is falsely detecting a low charge? Or are the batteries likely faulty? Do Apple's rechargeable batteries just not last very long? I've had them for a few years, but recharging is what they are meant to do so I expected to get more use out of them (if that is the issue).

Hoping for some helpful suggestions. Thanks.

 

[hfg]

Standard batteries are rated at 1.5V, but rechargeable batteries have a lower terminal voltage of 1.2V. Most devices do not have a problem with this difference in proper operation, but the voltage sensor in the keyboard, mouse, or trackpad will flag them as low voltage. However, I ignore the warnings and continue to use them until they actually start malfunctioning, then swap them for a pair of freshly charged ones and put the exhausted ones on the charger.

If, after years of usage, you find the service life of the rechargeable to be unsatisfactory, then they have probably reached the end of their service life and should be replaced with new ones.