Is there any way to check the battery percentage of Apple wireless peripherals?

There isn't a GUI for read wireless mouse or keyboard battery data.

You can find useful information on sysfs under /sys/class/power_supply/. For example the Apple Wireless Keyboard is under /sys/class/power_supply/hid-78:CA:39:4E:6F:C7-battery/. In the device directory there is a file named capacity, this is a capacity in percents.

So in summary, for reading Apple Wireless Keyboard battery capacity you should do:

cat /sys/class/power_supply/hid-78:CA:39:4E:6F:C7-battery/capacity

Note that hid-78:CA:39:4E:6F:C7-battery can be different for your device.


In newer Ubuntu (starting from 16.04, I guess), check under Settings -> Power

Here's a screenshot for Ubuntu 16.04 .