The battery failure was followed (or maybe coincident) with a Windows 10 update. The reboot took a looong time. After it was up, my mouse stopped working. I assumed it was coincidence, and my mouse battery died.
Replaced the battery, no luck. Plugged my backup drive into the usb port the wireless mouse goes into, no reaction. Therefore, the update disabled my usb ports.
How do I fix that? Can I just deinstall the update?