Linux Laptop Power Management TLP
TLP is an advanced power management tool I use for my laptop that runs Linux. I have not tested the different settings, but it seems that the battery time is increased compared to not running it. :-) I only use it in battery-mode. There are some extra features for Thinkpad laptops.
TLP settings file Ubuntu: /etc/tlp.conf
Reload config: sudo tlp start
Check TLP status: sudo tlp-stat
Check battery: upower -i /org/freedesktop/UPower/devices/battery_BAT0