Thanks for confirming the directory, first try this with the pods connected via BT, if they are not connected then they will definitely not show up for either of the below:
In newer Ubuntu OS's you can check under All Settings -> Power and see if the pods show up like the keyboard in the screenshot and then set the 2nd option as shown so you can see it in your taskbar, this may or may not work:
If you do not see the pods listed then you can try this using the directory you checked:
You can find useful information under /sys/class/power_supply/. For example the Apple Wireless Keyboard is under /sys/class/power_supply/hid-MAC_HERE-battery/. In the device directory there is a file named capacity, this is the battery in percents.
So for example reading the Apple Wireless Keyboard battery capacity you would:
cat /sys/class/power_supply/hid-MAC_HERE-battery/capacity
HID being the default for keyboards and mice so you will want to see how your pods show up in the system while connected to BT.
Note that the device type(hid) will change along with the make, while the -batter/capacity should be the same, you will just need to try each one and see which matches your pods with the pods connected via BT to your Ubuntu machine.
Hope the above works for you.
AC, andBATO.