This was originally reported downstream, in Ubuntu 13.10: https://bugs.launchpad.net/ubuntu/+source/upower/+bug/1245287 I am not the downstream reporter. I have experienced this bug in Ubuntu 14.10 and 15.04. $ upower -d [snip] Device: /org/freedesktop/UPower/devices/battery_hid_e8o06o88o43o52od2_battery native-path: hid-e8:06:88:43:52:d2-battery model: Apple Wireless Keyboard power supply: no updated: Sun 07 Jun 2015 11:05:22 AM EDT (27 seconds ago) has history: yes has statistics: yes battery present: yes rechargeable: yes state: discharging warning-level: action energy: 0 Wh energy-empty: 0 Wh energy-full: 0 Wh energy-full-design: 0 Wh energy-rate: 0 W percentage: 0% capacity: 100% icon-name: 'battery-caution-symbolic' [snip] Here's what I see in syslog: upowerd[7898]: (upowerd:7898): UPower-Linux-WARNING **: no valid voltage value found for device /sys/devices/pci0000:00/0000:00:14.0/usb1/1-8/1-8:1.0/bluetooth/hci0/hci0:256/0005:05AC:0239.001B/power_supply/hid-e8:06:88:43:52:d2-battery, assuming 10V
Do you still see the same problem with a recent version (0.99.x) of UPower? If so, could you please paste the output of: for i in /sys/class/power_supply/* ; do find $i/ -type f -print -exec cat '{}' \; ; done This should print the value in sysfs which the mouse offers up.
I can confirm that this now works properly with upower v 0.99.4-4 (Ubuntu 17.04). The keyboard's battery status shows up in Ubuntu's power applet, and I see a valid charge percentage reported by upower -d: Device: /org/freedesktop/UPower/devices/keyboard_hid_e8o06o88o43o52od2_battery native-path: hid-e8:06:88:43:52:d2-battery model: Rick Ucker’s Keyboard power supply: no updated: Fri 15 Sep 2017 09:06:11 PM EDT (94 seconds ago) has history: yes has statistics: yes keyboard present: yes rechargeable: yes state: discharging warning-level: none percentage: 67% icon-name: 'battery-full-symbolic'
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