Low battery logic is somewhat broken

1. start computer / xfce with battery at say 10% and charger plugged in
2. use computer while it charges to 30% or whatever
3. unplug charger
4. use computer until it turns off instead of going to sleep as it should because something's broken in the battery logic

idk what's going on there, but if I start the computer and login to xfce with battery at 80% or something like that and it drain then the power manager realizes that battery is below the 20% threshold and acts. that works. if the battery level is low on startup, on the other hand, then the power manager will just do nothing until/unless it's restarted with a high battery level. this is very unfortunate.