Are you having a problem with your Apple Bluetooth mouse disconnecting frequently from your Mac? The battery is fine, but you have to keep clicking to get it to connect again? The solution is so easy. Get your cell phone away from your mouse!
The cell phone emits enough radio noise to jam the Bluetooth signal from your mouse. Smartphones are just packed with radio transmitters. Besides its own Bluetooth transmitter, a phone has a WiFi transmitter (2.4 or 5 GHz), a cell network transmitter and maybe a NFC transmitter. The cellular transmitter is used periodically to maintain contact with the cell site even if you are not making or receiving a call.
That cellular transmitter is powerful — it has to reach a cell site a mile or so away. That’s probably the one that kills your mouse (or keyboard).
It is so easy to sit down and put your phone right next to the mouse without thinking. Moving it just a couple of feet away is probably enough to eliminate the problem.