These simple tweaks can be applied to older versions of Ubuntu
Users running Ubuntu on laptops and notebooks could prolong their battery life with a few simple tricks. This is a simple tutorial that anyone can apply for their Ubuntu installation.There are several ways to save battery power on a laptop running Ubuntu 12.04, but they are not always turned on because it's impossible to predict the hardware configuration of every single unit on the market.
The first step you can take is to enable Aggressive Link Power Management or ALPM. This is a mechanism though which the SATA AHCI controller can put the SATA link that connects to the disk into a very low power mode during periods of zero I/O activity.
Just open a terminal and enter the following command. Keep in mind you will need the root password.
echo SATA_ALPM_ENABLE=true | sudo tee /etc/pm/config.d/sata_alpm
To disable it, just enter the following command:
echo SATA_ALPM_ENABLE=false | sudo tee /etc/pm/config.d/sata_alpm
A second method for saving battery power is to enable i915 Framebuffer Compression. Framebuffer compression reduces the memory bandwidth on screen refreshes and, depending on the image in the framebuffer, can reduce power consumption.
Navigate to ~/etc/default/ and open a terminal. You will need root access to make the necessary changes.
sudo gedit grub
The grub file will be opened. Inside find the following line:
Replace it with:
GRUB_CMDLINE_LINUX_DEFAULT="quiet splash i915.lvds_downclock=1"
Close and save the grub file. Open a terminal and enter this command;
A third method is to use a nifty tool from Intel called PowerTop. Open a terminal and enter the following commands. You will need root access for this application.
sudo apt-get install powertop
With this tool you will be able put the following devices into a "Good" power saving state: Webcam, Audio, DRAM, Ethernet, Wi-Fi, Bluetooth, SATA link, and MMC/SD.
The last advice is related to the laptop LCD display. Surprisingly, the display consumes more power to keep a dark background than one with light colors. Change the background accordingly.
If you don't have Ubuntu 12.04 LTS installed yet, you can download it now from Softpedia.