Cyanogenmod and other custom android roms use a circle icon for a battery indicator, however they also put the percent of battery left inside the circle, where there is currently a thunderbolt in the breeze theme. Reproducible: Always
Interesting idea. However, with the precise percentage available on hover and in the popup, I think the as-is design is effective at providing sufficient at-a-glance charge information with more detailed information not too far away. My recommendation is to keep the design as is.
Thanks for the suggestion. I agree with Andrew, it's simply too much info and there's not enough space. From Kai (the battery maintainer) "we've had this in 4.10, it was nice, yes, but it won't work with every theme (requiring an "overlay" again) and then it will look ugly with ours. so, yes, wontfix " If someone wants to make a fork on kde-look, that'd be awesome, we can see how that fairs, but we won't do it. Sorry.