Optimizing laptop battery life with AcpiTool and PowerTOP
Calibration
If the rows for design capacity and last full capacity clearly differ, individual cells are more or less exhausted. This can be partially reversed by recalibrating the battery. To do this, drain the battery several times to the final discharge voltage and then fully charge it again.
For proper discharging, adjust the threshold in the energy manager of the desktop environment so that the computer switches off at minimum battery charge level (Figure 3). This ensures a clean shutdown of all processes and applications and minimizes the risk of data loss. Additionally, it avoids an accidental deep discharge, which can damage the battery.
Charging the battery for two to three hours after each complete discharge completes the recalibration and brings the last full capacity values back up to something approaching the design capacity. This accordingly extends the laptop's battery life.
Switching Off Unneeded Components
Switching off components and services that you do not need for operations helps to extend a laptop's battery life. For example, modern devices often have WiFi modules that you can switch off to save power. Besides a permanently running disk, a bright display is one of the biggest power guzzlers.
Although Linux now offers mature energy-saving options, which you can conveniently adjust through a graphical interface on the desktop, they do not include the full range of sensible energy management capabilities: To locate power-hungry components and services on Linux off the beaten track, you will find Intel's PowerTOP a useful companion.
PowerTOP is found in the repositories of many distributions. If you find two versions of the program, then install the 2.x version: This is the first version to include the code that supports convenient control of individual laptop components. If no packages are available for the distribution you are using, download the PowerTOP source code [5] and build the program by following the how-to.
Next, run the program in a terminal as an administrator by typing the
powertop
command. The tool lists the status of the hardware it finds in an ncurses interface and updates the data in real time. You will see not only the level of utilization for individual components, but also for services (processes). If PowerTOP permanently shows a value of 100 percent for individual subsystems, this means the components do not support power-saving mechanisms.
In the tab bar at the top of the screen, you will find a Tunables option on the right. The matching list details the computer components and specifies whether their current settings save energy or impede energy management (Figure 4). It makes sense to modify the settings for components listed as Bad.
To do so, select the device with the arrow keys and press Enter; a dialog for editing the settings is then displayed. PowerTOP automatically determines better settings and implements them when you press Enter again. Pressing R checks to see whether the program has made the changes.
Thanks to the descriptive names in the list, it is easy to identify hardware that you rarely use and thus does not need to be switched on permanently. Because PowerTOP makes the settings permanent, you can genuinely save power thanks to smart changes.
Conclusions
The high level of component integration in current laptops makes it difficult to configure meaningful energy-saving options. AcpiTool and PowerTOP are two useful tools that help keep your battery in good health and achieve the maximum lifetime to boot. Controlling these little helpers is extremely simple, allowing you to identify and disable the power hogs on your system.
Infos
- ACPI and Microsoft: http://techrights.org/2008/07/25/foxconn-bios-acpi/
- AcpiTool: http://acpitool.sourceforge.net
- "Inxi" by Erik Bärwaldt, Linux Pro Magazine, issue 164, July 2014, p. 70, http://www.linuxpromagazine.com/Issues/2014/164/Inxi
- Memory effect: http://phys.org/news/2013-04-memory-effect-lithium-ion-batteries.html
- Download PowerTOP: https://01.org/powertop/downloads
« Previous 1 2
Buy this article as PDF
(incl. VAT)
Buy Linux Magazine
Subscribe to our Linux Newsletters
Find Linux and Open Source Jobs
Subscribe to our ADMIN Newsletters
Support Our Work
Linux Magazine content is made possible with support from readers like you. Please consider contributing when you’ve found an article to be beneficial.
News
-
Canonical Bumps LTS Support to 12 years
If you're worried that your Ubuntu LTS release won't be supported long enough to last, Canonical has a surprise for you in the form of 12 years of security coverage.
-
Fedora 40 Beta Released Soon
With the official release of Fedora 40 coming in April, it's almost time to download the beta and see what's new.
-
New Pentesting Distribution to Compete with Kali Linux
SnoopGod is now available for your testing needs
-
Juno Computers Launches Another Linux Laptop
If you're looking for a powerhouse laptop that runs Ubuntu, the Juno Computers Neptune 17 v6 should be on your radar.
-
ZorinOS 17.1 Released, Includes Improved Windows App Support
If you need or desire to run Windows applications on Linux, there's one distribution intent on making that easier for you and its new release further improves that feature.
-
Linux Market Share Surpasses 4% for the First Time
Look out Windows and macOS, Linux is on the rise and has even topped ChromeOS to become the fourth most widely used OS around the globe.
-
KDE’s Plasma 6 Officially Available
KDE’s Plasma 6.0 "Megarelease" has happened, and it's brimming with new features, polish, and performance.
-
Latest Version of Tails Unleashed
Tails 6.0 is based on Debian 12 and includes GNOME 43.
-
KDE Announces New Slimbook V with Plenty of Power and KDE’s Plasma 6
If you're a fan of KDE Plasma, you'll be thrilled to hear they've announced a new Slimbook with an AMD CPU and the latest version of KDE Plasma desktop.
-
Monthly Sponsorship Includes Early Access to elementary OS 8
If you want to get a glimpse of what's in the pipeline for elementary OS 8, just set up a monthly sponsorship to help fund its continued existence.