I have gone through other questions as well and somewhere it was mentioned that using percentage policy = true and
gsettings to different level will work and it did work for some time until now. How to get back low power notification, my battery is broken btw.
gsettings are ignored.
I've tested on Ubuntu 18.04 LTS - I've edited
/etc/UPower/UPower.conf (case sensitive). Follow with
sudo systemctl restart upower