Two months ago I decided to try a dev built of Rockbox (cannot remember which one), after which my battery life was improved to around 24h of playback. After a month or so, decided to try another iteration, but that one drooped my battery life to like 3h and installing previous one (will edit to exact built) didn't change, and player now days only after 3h of use. Could it be that the rockbox built damaged the battery? I have ordered a new one, but at first I want to find out why old one died. I attach my battery bench file.