Sometimes it is the little things that piss you off and then finding a simple solution is downright astonishing.

My 10 year old mouse that uses the AA batteries has been pissing me off on a regular basis, dropping the bluetooth connection while you are trying to surf or do spreadsheets or whatever.

Finally decided there had to be something done and Googled looking for a fix. Eureka, found it and it worked!!

Cut two small pieces of tin foil, wrap around the negative end of the batteries and re-insert batteries into mouse. Make sure the two pieces of foil are not touching one another or you get a short circuit, the mouse doesn't work and the batteries heat up, (not that I would do something stupid like that!)

Apparently the little spring device that is in the mouse negative terminals gets weak and doesn't get a good connection. The foil adds just enough thickness to provide a positive connection, and the mouse hasn't dropped BT since I added the foil.

Original article link, with other solutions as well:

https://www.lifewire.com/fix-m...ect-problems-2260761

One of life's little victories!!

 
I recently had the same experience with my 2011 Magic Mouse, when I changed batteries. The solution, in my case, was to clean the battery contacts inside the mouse with a Q-tip and denatured (or isopropyl) alcohol. It has been working fine since.
 
I have not had any problems yet with the springs. I still have to push the battery negative end down firmly to seat the battery.

I think I had a similar problem with an older Eotech. They sent me some kind of upgrade kit, been fine ever since.