Keyboard Battery Level always 100%
Lately, I've noticed that my Keyboard Battery Level stays at 100%, and never goes below that, no matter how long I use the batteries. It's an Apple Wireless Keyboard. (The Wireless Trackpad battery level seems to be accurate, though.)
Any ideas what causes this and how to fix it?
MacBook Pro with Retina display, OS X Yosemite (10.10.3)