Acer Aspire E5-551G-T0KC has very bad battery life in Ubuntu 14.04.2 compared to what is advertised by the manufacturer

[Amr Ibrahim]

Hello developers,

I have Acer Aspire E5-551G-T0KC
http://www.acer.de/ac/de/DE/content/model/NX.MLEEG.009. It has AMD APU
A10-7300 + R7 M265. It is the same APU found in HP 455 G3 Quad Core +
Ubuntu 12.04 which is sold on http://www.ebuyer.com/ubuntu

The battery life lasts at most 3 hours, where it is advertised to last 7
hours. It lasts 7 hours in Windows 8.1.

The laptop also produces more heat in Ubuntu 14.04.2 than in Windows 8.1.

Please help me to solve this over. I can provide all the needed information.

Thanks a lot!

Amr