I've purchased a Lenovo ThinkPad S540, which has according to Lenovo '9 hours of battery life'. I was really happy when I tested the device running Windows 8.1, and the battery worked for 6 hours. But as soon as I installed Ubuntu 14.04 on it, the battery got a maximum of 2,5 hours. Why is the battery life so bad with Ubuntu 14.04? I've tried TLP, and other battery-saving tools already but they did not work at all. Any solutions for this?