Increase Battery Life Edit on GitHub

The biggest single consumer of power is the display backlight. Up to 10% more battery life can gained simply by reducing display brightness. Since our laptops don’t currently have an ambient light sensor, brightness needs manual adjustment with Fn+F8 and Fn+F9.

Every running program in Ubuntu consumes the battery. This could be a program that is part of the operating system, or a program currently in use like Firefox or Libre Office. We recommend using TLP to quickly reduce overall power consumption and using powertop to check what software is consuming the battery.

Useful Programs

TLP is an excellent program for increasing battery life on all of our laptops. TLP is a pure command line tool with automated background tasks and does not contain a GUI. It’s default settings are excellent for most situations and require little tuning. TLP will take care of most of the settings that Powertop autotuning would, and with less trial and error.

To install TLP, run this command:

sudo apt install tlp

TLP will take effect upon restart. To see current configuration settings, run this command:

sudo tlp-stat

The program is highly configurable by editing the settings file. Run this command to edit the file:

sudo gedit /etc/default/tlp

All of the info about the the program can be found with these 2 commands:

man tlp
man tlp-stat

To install powertop, please open a terminal and run this command:

sudo apt install powertop

After installing the program, reboot your computer and calibrate the readings on battery power with this command:

sudo powertop -c

This will take about 15 minutes to run the calibration. The system will turn the display off a few times, and you won’t be able to do anything else on the PC during the process. After it’s complete, HTML reports can be generated with this command:

sudo powertop --html=report

Open the report located at ~/report.html to see the results.

It’s useful to create a baseline by running powertop after a cold startup, without opening any applications, and then run it a few more times throughout the day to get a comparison of different workloads. Make sure to specify a different filename each time for comparison. Take a look at the list of software running and see if anything can be removed or if settings of high consumers can be changed.

Tuning

After looking at running software, head over to the ‘Tuning’ tab. We recommend install TLP first, and then seeing if powertop finds any other tuning suggestions.

powertop provides many suggestions to increase battery life. To test enabling of all of the suggested tunings, please run this command:

sudo powertop --auto-tune

Please test the settings and make sure they doesn’t introduce any instability or oddities. The above command will only last until reboot. To make the new settings persist after reboot, please edit the /etc/rc.local file with this command:

gksu gedit /etc/rc.local

And add:

sudo powertop –auto-tune

above the ‘exit 0’ line, or add the individual tuning options.

Useful Commands

upower -i /org/freedesktop/UPower/devices/battery_BAT0

This will show the information that your computer can read about the battery.

sudo rm /var/lib/upower/*

If the battery life indicator is inaccurate, this will remove the stored statistics. After a few charge/discharge cycles the indicator should be more accurate.