Here's what I made a few days ago. The two top bars are both battery bars and change colors depending on the battery level:
Red <=20
Blue (same as middle background) - Charging.
Green - Fully charged
The only part I'm a little iffy on is the icons. Criticism and advice appreciated.
Note that this is almost completely ripped from
https://archive.rebeccablacktech.com/w/thread/S1699188#p1699514