When I installed Ubuntu on Lenevo z580, the first thing I noticed is the standy time. Though the batter was fully charged , I just got 2 hours as the standy time. While the same thing in pre installed windows 8 was around 4 -5 hours!. Well this was strange for me. On doing some research I got to know that ,its because of the NVIDIA 630M GeForce graphics card and Inbuilt Intel Graphics card ,that I was observing this issue.
I am not a game freak so I had no intention of using NVIDIA Graphics card . I used bumblebee and bbswitch to completely turn off NVIDIA graphics card. Thus on doing so I got the battery stretch to 4 hours ! . Also I installed cpufreqd tool to check the power consumption and It again increased the battery backup.
Open Terminal and enter below commands . Make sure you keep the cpu monitor to OnDemand Mode. Doing so will reduce your power and will increase the battery life.
$ sudo apt-get install cpufrequtils cpufreqd
$ sudo apt-get install indicator-cpufreq
After this try to install bumblebee on to your system. You can read the official document from here.
Open the terminal and enter the following commands. After doing this reboot the system.
$ sudo add-apt-repository ppa:bumblebee/stable
$ sudo apt-get update
$ sudo apt-get install --no-install-recommends bumblebee
If you want to run an application that you think , you require graphics card to be used , then you can use the command optirun followed by the exectuable .
Eg : optirun firefox