I can confirm the app "Cover Art Grabber" to be a potential battery drainer. After it finished downloading, it remained alive (both app & app service), causing more battery usage than anything else (~ 52%).
Killing it manually restored system back to normal.
This doesn't happen every time I use the app, but it occured several times now, so be sure to check if it closes after download of coverart is complete.
I can confirm this has not been fixed.