Table of Contents

Increasing battery life under Linux

Author(s)

Bill Giannikos (Home Page)

Editing This Page

If you would like to edit this page please first view our Editing Guidelines.

Introduction

This guide with provide you with tips to increase your battery life under Linux when running on a laptop computer.

Tips

Use kernel with dynamic ticks

Since kernel 2.6.21, Linux includes a feature called dynamic ticks. Without getting too technical, the kernel reduces the number of ticks initiated when the system is idle, slightly reducing the cpu usage at this time and therefore extending battery life. Fedora 7 has this feature on by default.

Ensure ACPI is enabled

Not so much a problem anymore as manufacturers are more actively checking that their ACPI implementations work under Linux but you should check that ACPI support is enabled. Without it you will get terrible power management and greatly reduced battery life. You can check if ACPI is enabled and running properly by typing dmesg in the console. If it is not working a kernel or BIOS update may fix the issue, if not then look up your laptop on these pages for more details.

Use CPU power saving

Most modern processors can dynamically reduce and increase their clock speeds. A utility is needed to do this such as cpufreqd or powernowd. My personal recommendation is powernowd, it is a simple program but works very well. These two utilities are included with most Linux distributions.

Blank screen when idle

A simple tip. Set the power settings to blank the screen when idle for a few minutes. The LCD display is one of the main consumers of power and so turning it off when not needed increases battery life greatly.

Use PowerTOP

Intel have developed a utility called PowerTOP. It's aim is to see which applications on your system are using processing power and thus consuming extra battery. PowerTOP is starting to be included with many Linux distributions and you can also get it from the PowerTOP website.