Disable "Mouse battery low" spam notification
OK, I hit the same issue. Reasons are similar; my Logitech M570 is fed on "dead" batteries as it lasts MONTHS on a very low voltage alkaline. So I use batteries in other things and keep the dead ones for my M570.
The best answer I've found was to lower the Power Plugins critical level warning. This way you can customise when it nags.
You need dconf for command line or dconf-editor for the GUI version (for GUI you'll need to do sudo apt-get install dconf-tools, although that package may not be available for newer versions, so just get dconf-editor and its dependencies).
Setting is generically for batteries though, so if you're on a laptop or a UPS then you will be altering the warning levels for those, which may be non ideal.
For Ubuntu 17.10 (Artful Aardvark) go to org → gnome → settings-daemon → plugins → power. Alter the "percentage-low" setting to what you want. I changed from 10% to 4%.
It is not a perfect answer if you have a laptop, but it is fine for a desktop computer and better than filling landfill with batteries or being nagged.
for Ubuntu 20: settings -> notifications -> power and then toggle off the notifiction-button .
Ubuntu 18.04 on a desktop computer here, so I'm not having issues that laptop could potentially have with that solution.
You can test whether what you made is working by restarting upower service:
sudo systemctl restart upowerI managed to solve it by altering upower's config file:
sudo nano /etc/dbus-1/system.d/org.freedesktop.UPower.conf
I simply commented out whole config, leaving empty
<busconfig></busconfig> tag.