I have been having issues with my Magic Mouse losing its connection. It was happening so often that it was driving me crazy. I had to do something about it.
I started by doing a google search for “Magic Mouse keeps losses connection”. I found a forum where other folks were having the same problem. This suggestion by sbeddoesdesign in an Apple Discussion Forum solved my problem:
I had this problem too, turns out a slight design flaw with the mouse is that smaller batteries come loose and power is lost, so the bluetooth dies. You’ll probably find that it loses connection when you’re moving it around quite a lot, in particular, when you lift it up off of the desk and put it back down again. See, different brands of battery tend to be ever so slightly varied in size, and smaller ones tend to be more ‘loose’ in the mouse and an be shaken loose when moving the mouse around.
The best solution (the one which worked for me) is to grab a set of Apple’s own rechargeable batteries from their store as they are just the right size to fit in the mouse without ever being shaken loose.
If you can’t do this, some people find that wedging a bunch of paper between the two batteries and between the batteries and the mouse door can help keep them in place.
Wedging a bunch of paper between the two batteries and between the batteries and the mouse door worked for me. If you’re experiencing the same problem with your Magic Mouse I hope this solves the problem for you as it did me.