OS 10.14.6 Yesterday I charged my mouse battery to 100% but when I connected the cable back to the keyboard, it couldn't connect. It took me about an hour to figure out how to free my mouse cursor.

I did this by re-inserting the cable back into the mouse for a few seconds and then NOT putting the cable back into the keyboard.

I was then able to access system prefs>bluetooth and make my mouse 'discoverable' and then connect the cable back into the keyboard.

I seem to remember reading something about not charging the mouse battery too long...?

Is there a correct procedure other than what I did?

jaybass

An observation: Bluetooth has evolved significantly over the years and Bluetooth 5 in current Macs is significantly more reliable than the Bluetooth 4.2 in your 2017 iMac. However, my long standing trick to encourage bluetooth device connections is to switch the device off for a few seconds, and then back on, and if that doesn’t work, plugging unplugging the device.

As far as charging too long goes, that is a recommendation that has gone back and forth over the years but as far as I know it is not an official Apple recommendation for current devices one way or the other. NOTE: that is current for currently sold devices and could be different for older devices. (Did I waffle that enough to make it totally indecisive?) Personally I have never worried about it and although I generally run my Magic keyboard, trackpad, & mouse cordless, they sometimes get plugged in for days on end and have never shown any ill effect.