Magic Mouse 2 suddenly won't connect

I also had my magic mouse 2 suddenly stop working while fully charged. Full reboot did not fix.

Here is one solution to this (https://discussions.apple.com/thread/8246725)

1. Make sure the mouse is fully charged.
2. Using another (borrowed) mouse or trackpad, open System Preferences > Bluetooth and delete setting for the the non-functioning mouse device. (NB this is difficult to do with Keyboard only, but might be possible)
3. Now Reconnect the device with lightning/usb connector to recreate the setting (same as new Device setup.)

Worked perfectly for me.