No. Although I don’t think it would be particularly hard to add.
It is however fairly easy to replace the glyph that the battery graph is made of.
It’s defined here:
Note that glyphs are turned 90 degrees.
You may also need to change the “skip” value which basically defines how wide the glyph is here:
(You just change the 16 to something else.)
At some point I need to make it so that images can be used as UV and battery meters. Basically you would just have N images, and it would choose which one to show based on the battery level or sound level.