The project was a a nice and (relatively) quick solution to my problem.
The README link that stardance shows is wrong, the correct one is in in the plugin folder, although I it a bit lacking to fit the PR requirements. If you use Noctalia you can easily test it by adding it in the settings
This project was originally made for Anvil, so please excuse the lack of devlogs.
The plugin uses upowerd to read the historic battery charge (in a period set by the user) and then displays it with a set granularity (also given by the user)