I find the ability to get my android devices' battery info on my desktops via cli to be extremely convenient. I used to be able to this with KDE Connect easily, but things have just changed. Since I can't find any documentation on how to do this, and since I just stumbled on the answer myself, I though I might share what I know here. Please note that in the examples below, I will be using {device-id} as a placeholder for the string that KDE Connect uses to identify to my devices.
That said, I used to be able to get my various devices' battery status through gdbus through the following:
gdbus call --session --dest org.kde.kdeconnect --object-path /modules/kdeconnect/devices/{device-id} --method org.kde.kdeconnect.device.battery.charge
However on Arch, I now get the following error: Error: GDBus.Error:org.freedesktop.DBus.Error.UnknownInterface: No such interface 'org.kde.kdeconnect.device.battery' at object path '/modules/kdeconnect/devices/b04294f19e8767f5'. I don't get this message on Ubuntu 2