Ubuntu 12.04 Battery problem

I had the same problem! Installing Bumblebee really worked for me!

sudo add-apt-repository ppa:bumblebee/stable

sudo add-apt-repository ppa:ubuntu-x-swat/x-updates

sudo apt-get update

sudo apt-get install bumblebee bumblebee-nvidia linux-headers-generic

As the comments suggest, this is most likely related to the kernel bug, which drains laptop batteries quite fast due to an inefficiencies and too many wakeups and I/O errors.

All you can do at this stage is wait, or contribute to the kernel.

try to setup the laptop tools :

sudo apt-get install laptop-mode-tools

powertop went from a discharge of +/- 42W to an average 30W.