i’m using Lenovo G580 and facing battery drain fast and yes i do have Nvidia Geforce graphic. I’m using Ubuntu 12.10.

I follow the first step without any problem. However

“open the file /etc/apt/sources.list.d/bumblebee-stable-precise.list for editing as root, for example:
sudo gedit /etc/apt/sources.list.d/bumblebee-stable-precise.list”

There is no file named bumblebee-stable-precise.list, except bumblebee-stable-quantal.list