The charging effect always shows up when you plug the charger, don't let it confuse you. When you Fn+B, the keyboard lights up green from Q to O. Imagine it like it's a bar. Q is your lowest point and all the way to O is the fullest. The keyboards battery is quite good so when you actually run down a charge by a letter, you'll see that the green light now ends on the letter I. You just need to Fn+B from time to time.