Created attachment 438726 [details, diff] Patch stolen from Debian There seems to be an issue with the interface between upower and the Cinnamon settings daemon. I shamelessly used a patch from Debian's cinnamon-settings-daemon-2.8.4-2 which fixes the problem. Looks like they got the same problem. The patch is attached. The symptom is that the battery status does not get updated on the Cinnamon desktop.
this should work with 3.0.1