Sorry for late reply
For about 4 hours i beleive. Though it used to be longer as i have had it for over a year and the battery not like it used to be.
Kde is the default desktop eviornment.
It helps that its a non systemd init system so it doesnt pull as much resources on the backend since systemwide is controlled via scripts.
If i were to run a lighter one such as xfce, qtile or dwm it would run longer(varies on configuration though)
Lol i cracked up when i saw that too. Slackware user myself. Though i do dabble in mint, arch, artix and netbsd