When i wrote grep -r . /sys/class/power_supply/*hid* I got this when laptop ux31e is connected to energy and connect my bluetooth keyboard device: /sys/class/power_supply/hid-cc:c5:0a:05:02:87-battery/type:Battery /sys/class/power_supply/hid-cc:c5:0a:05:02:87-battery/power/control:auto /sys/class/power_supply/hid-cc:c5:0a:05:02:87-battery/power/runtime_active_time:0 grep: /sys/class/power_supply/hid-cc:c5:0a:05:02:87-battery/power/autosuspend_delay_ms: Error de entrada/salida /sys/class/power_supply/hid-cc:c5:0a:05:02:87-battery/power/runtime_status:unsupported /sys/class/power_supply/hid-cc:c5:0a:05:02:87-battery/power/runtime_suspended_time:0 /sys/class/power_supply/hid-cc:c5:0a:05:02:87-battery/scope:Device /sys/class/power_supply/hid-cc:c5:0a:05:02:87-battery/capacity:47 /sys/class/power_supply/hid-cc:c5:0a:05:02:87-battery/online:1 /sys/class/power_supply/hid-cc:c5:0a:05:02:87-battery/status:Discharging /sys/class/power_supply/hid-cc:c5:0a:05:02:87-battery/uevent:POWER_SUPPLY_NAME=hid-cc:c5:0a:05:02:87-battery /sys/class/power_supply/hid-cc:c5:0a:05:02:87-battery/uevent:POWER_SUPPLY_PRESENT=1 /sys/class/power_supply/hid-cc:c5:0a:05:02:87-battery/uevent:POWER_SUPPLY_ONLINE=1 /sys/class/power_supply/hid-cc:c5:0a:05:02:87-battery/uevent:POWER_SUPPLY_CAPACITY=47 /sys/class/power_supply/hid-cc:c5:0a:05:02:87-battery/uevent:POWER_SUPPLY_MODEL_NAME=Bluetooth Keyboard /sys/class/power_supply/hid-cc:c5:0a:05:02:87-battery/uevent:POWER_SUPPLY_STATUS=Discharging /sys/class/power_supply/hid-cc:c5:0a:05:02:87-battery/uevent:POWER_SUPPLY_SCOPE=Device /sys/class/power_supply/hid-cc:c5:0a:05:02:87-battery/model_name:Bluetooth Keyboard /sys/class/power_supply/hid-cc:c5:0a:05:02:87-battery/present:1 /sys/class/power_supply/hid-f4:1b:a1:31:34:fc-battery/type:Battery /sys/class/power_supply/hid-f4:1b:a1:31:34:fc-battery/power/control:auto /sys/class/power_supply/hid-f4:1b:a1:31:34:fc-battery/power/runtime_active_time:0 grep: /sys/class/power_supply/hid-f4:1b:a1:31:34:fc-battery/power/autosuspend_delay_ms: Error de entrada/salida /sys/class/power_supply/hid-f4:1b:a1:31:34:fc-battery/power/runtime_status:unsupported /sys/class/power_supply/hid-f4:1b:a1:31:34:fc-battery/power/runtime_suspended_time:0 /sys/class/power_supply/hid-f4:1b:a1:31:34:fc-battery/scope:Device /sys/class/power_supply/hid-f4:1b:a1:31:34:fc-battery/capacity:73 /sys/class/power_supply/hid-f4:1b:a1:31:34:fc-battery/online:1 /sys/class/power_supply/hid-f4:1b:a1:31:34:fc-battery/status:Discharging /sys/class/power_supply/hid-f4:1b:a1:31:34:fc-battery/uevent:POWER_SUPPLY_NAME=hid-f4:1b:a1:31:34:fc-battery /sys/class/power_supply/hid-f4:1b:a1:31:34:fc-battery/uevent:POWER_SUPPLY_PRESENT=1 /sys/class/power_supply/hid-f4:1b:a1:31:34:fc-battery/uevent:POWER_SUPPLY_ONLINE=1 /sys/class/power_supply/hid-f4:1b:a1:31:34:fc-battery/uevent:POWER_SUPPLY_CAPACITY=73 /sys/class/power_supply/hid-f4:1b:a1:31:34:fc-battery/uevent:POWER_SUPPLY_MODEL_NAME=Apple Wireless Trackpad /sys/class/power_supply/hid-f4:1b:a1:31:34:fc-battery/uevent:POWER_SUPPLY_STATUS=Discharging /sys/class/power_supply/hid-f4:1b:a1:31:34:fc-battery/uevent:POWER_SUPPLY_SCOPE=Device /sys/class/power_supply/hid-f4:1b:a1:31:34:fc-battery/model_name:Apple Wireless Trackpad /sys/class/power_supply/hid-f4:1b:a1:31:34:fc-battery/present:1 But if i dont have connected to the power, i got: /sys/class/power_supply/hid-cc:c5:0a:05:02:87-battery/type:Battery /sys/class/power_supply/hid-cc:c5:0a:05:02:87-battery/power/control:auto /sys/class/power_supply/hid-cc:c5:0a:05:02:87-battery/power/runtime_active_time:0 grep: /sys/class/power_supply/hid-cc:c5:0a:05:02:87-battery/power/autosuspend_delay_ms: Error de entrada/salida /sys/class/power_supply/hid-cc:c5:0a:05:02:87-battery/power/runtime_status:unsupported /sys/class/power_supply/hid-cc:c5:0a:05:02:87-battery/power/runtime_suspended_time:0 /sys/class/power_supply/hid-cc:c5:0a:05:02:87-battery/scope:Device /sys/class/power_supply/hid-cc:c5:0a:05:02:87-battery/capacity:47 /sys/class/power_supply/hid-cc:c5:0a:05:02:87-battery/online:1 /sys/class/power_supply/hid-cc:c5:0a:05:02:87-battery/status:Discharging /sys/class/power_supply/hid-cc:c5:0a:05:02:87-battery/uevent:POWER_SUPPLY_NAME=hid-cc:c5:0a:05:02:87-battery /sys/class/power_supply/hid-cc:c5:0a:05:02:87-battery/uevent:POWER_SUPPLY_PRESENT=1 /sys/class/power_supply/hid-cc:c5:0a:05:02:87-battery/uevent:POWER_SUPPLY_ONLINE=1 /sys/class/power_supply/hid-cc:c5:0a:05:02:87-battery/uevent:POWER_SUPPLY_CAPACITY=47 /sys/class/power_supply/hid-cc:c5:0a:05:02:87-battery/uevent:POWER_SUPPLY_MODEL_NAME=Bluetooth Keyboard /sys/class/power_supply/hid-cc:c5:0a:05:02:87-battery/uevent:POWER_SUPPLY_STATUS=Discharging /sys/class/power_supply/hid-cc:c5:0a:05:02:87-battery/uevent:POWER_SUPPLY_SCOPE=Device /sys/class/power_supply/hid-cc:c5:0a:05:02:87-battery/model_name:Bluetooth Keyboard /sys/class/power_supply/hid-cc:c5:0a:05:02:87-battery/present:1 /sys/class/power_supply/hid-f4:1b:a1:31:34:fc-battery/type:Battery /sys/class/power_supply/hid-f4:1b:a1:31:34:fc-battery/power/control:auto /sys/class/power_supply/hid-f4:1b:a1:31:34:fc-battery/power/runtime_active_time:0 grep: /sys/class/power_supply/hid-f4:1b:a1:31:34:fc-battery/power/autosuspend_delay_ms: Error de entrada/salida /sys/class/power_supply/hid-f4:1b:a1:31:34:fc-battery/power/runtime_status:unsupported /sys/class/power_supply/hid-f4:1b:a1:31:34:fc-battery/power/runtime_suspended_time:0 /sys/class/power_supply/hid-f4:1b:a1:31:34:fc-battery/scope:Device /sys/class/power_supply/hid-f4:1b:a1:31:34:fc-battery/capacity:73 /sys/class/power_supply/hid-f4:1b:a1:31:34:fc-battery/online:1 /sys/class/power_supply/hid-f4:1b:a1:31:34:fc-battery/status:Discharging /sys/class/power_supply/hid-f4:1b:a1:31:34:fc-battery/uevent:POWER_SUPPLY_NAME=hid-f4:1b:a1:31:34:fc-battery /sys/class/power_supply/hid-f4:1b:a1:31:34:fc-battery/uevent:POWER_SUPPLY_PRESENT=1 /sys/class/power_supply/hid-f4:1b:a1:31:34:fc-battery/uevent:POWER_SUPPLY_ONLINE=1 /sys/class/power_supply/hid-f4:1b:a1:31:34:fc-battery/uevent:POWER_SUPPLY_CAPACITY=73 /sys/class/power_supply/hid-f4:1b:a1:31:34:fc-battery/uevent:POWER_SUPPLY_MODEL_NAME=Apple Wireless Trackpad /sys/class/power_supply/hid-f4:1b:a1:31:34:fc-battery/uevent:POWER_SUPPLY_STATUS=Discharging /sys/class/power_supply/hid-f4:1b:a1:31:34:fc-battery/uevent:POWER_SUPPLY_SCOPE=Device /sys/class/power_supply/hid-f4:1b:a1:31:34:fc-battery/model_name:Apple Wireless Trackpad /sys/class/power_supply/hid-f4:1b:a1:31:34:fc-battery/present:1 This is on ux31e ubuntu 13.04 x64. Hope it will be usefull.