I wrote a small patch that add more info in battery applet tooltip (battery voltage, remaining capacity in mAh, battery current and power in units of watts. It is posible to add it to portage tree? it works fine for me. And some advanced users may value this extra informations. I made an ebuild patch too. Reproducible: Always Steps to Reproduce:
Created attachment 143308 [details, diff] gnome-applets patch that add more info about battery to the tooltip
Created attachment 143310 [details, diff] patch for gnome-base/gnome-applets-2.20.0 to use power_info patch
So... why don't you send such stuff to upstream?
the patch doesn't look too complicated but this is really upstream material. Please forward upstream.