Charge indicator for power cells.

I’d like to see a percentage charge indicator for individual batteries and power cells when they’re in the charger and you hover over them.
Or maybe even a general percentage indicator for all types of power cells, so you can see how full they actually are. For example, even for batteries in your inventory or in lockers.
I know there’s a bar, but “my inner Monk” would like to know a little more precisely ;).