I have recently been dealing with this issue, (having my Magic Mouse randomly drop its connection to my Mac) and thought that you might encounter it at some point as well. So here are a few helpful tips to get you back up and running without having your magic mouse continually disconnect while you are using it.
Disclaimer: This fix worked for me but your results might be different depending on what your actual problem is.
To fix this problem you first need to remove the bluetooth properties plist file (you might be able to fix the problem without performing this step, but if it doesn’t work, come back and try this step first.)
Step 1: Delete the Current Magic Mouse Connection
- Open a New Finder Window
- In the Finder sidebar select your Hard Drive
- Navigate to the system ‘Library’ folder and find the ‘Preferences’ folder
- Inside the ‘Preferences’ Folder Locate the file named ‘com.apple.Bluetooth.plist’
- Delete the file
- Restart OS X
Once your computer has rebooted, it will have loaded up the Bluetooth default settings, and you need to make it a “Favorite” device, to do this follow step 2.
Step 2: Add the Magic Mouse as a FAVORITE
- Click on the ‘Apple Menu’ in the Menu bar
- Select ‘System Preferences…’
- Click on the ‘Bluetooth’ icon
- Highlight your Magic Mouse entry
- Now click the ‘Gear’ icon located to the bottom of the device list
- Select the ‘Show More Info’ option
- Click on the ‘gear’ icon again and mark the Mouse as a ‘Favorite’.
There you have it, you have set your Magic Mouse as a Favorite device. This new setting should keep your Magic Mouse from Disconnecting randomly from your computer. Please post your feedback below and let me know if this helped solve your problem or not.
I used this process on my Mac and it did help my Magic Mouse connection issue… But it didn’t totally solve the problem, occasionally my Magic Mouse does disconnect itself, but the reconnection time does seem to be greatly reduced. Usually it only takes about 10 seconds or less for the mouse to reconnect and have me back on my way. So while this is an amazingly annoying issue with the Magic Mouse it is obviously greatly reduced since I made these changes to my Mac.
and here’s a link to the Apple Support Communities discussion on the same topic…