My cyberpower UPS works well. There's a service you can run to shut your computer down or whatever when it goes to battery power (check arch wiki) but it also works with GNOME (its displayed how a laptop battery would be displayed, but its labeled as a UPS) and it works well with NUT too.
Their PowerPanel Personal and Business editions both seem to work with all of their UPS models. I used to run PowerPanel Business on a basic tower-style model.
My cyberpower UPS works well. There's a service you can run to shut your computer down or whatever when it goes to battery power (check arch wiki) but it also works with GNOME (its displayed how a laptop battery would be displayed, but its labeled as a UPS) and it works well with NUT too.
I have 3 cyber power UPSs on my network and I haven't had any issues with them. The web interface isn't the best but it does it job
There's also a linux command line interface for at least business class cyberpower UPSs. (Not sure on consumer end.)
Worked like a charm for me on a headless machine.
Their PowerPanel Personal and Business editions both seem to work with all of their UPS models. I used to run PowerPanel Business on a basic tower-style model.
https://www.cyberpowersystems.com/products/software/