How Do They Calculate Battery Life on a Chromebook?

Your Chromebook ain’t normal laptop. It needs a different treatment when you test battery life too. Don’t you think? The Chrome team also thinks so.

Modern mobile computers are sold with an advertised battery life, ranging from a few to tens of hours. Nonetheless, when these devices are used on a daily basis, many users report the actual battery life doesn’t match up with the advertised numbers. For Chrome OS devices, we wanted to try to report battery life that was as close to what an average user experienced as possible.”

The power_LoadTest was created to emulate average user behavior and measure the resultant battery life.” The team has automated the test, and has put together an open source extension. Source is available here.


So, How do they do it?

Here is the official description, a shameless-copy-paste:

  • [First 60% of the test] Browsing: a new website is loaded every minute.  The web page loaded is scrolled down one page (600px) every 10 second, then scrolled back up at the same rate.
  • [Next 20%] Email: Gmail is loaded in the foreground tab and audio is streamed from a background tab.
  • [Next 10%] Documents: Various Google Docs are loaded.
  • [Final 10%] Video: A full screen 480p YouTube Video is played.

The parameters of the test are as follows:

  • Backlight: Set to 40% of panel brightness.
  • Power management:
    • Dimming, blanking the screen and transitions to suspend-to-RAM state are disabled.
    • Ambient light sensor readings ignored.

The parameters of the system under test are as follows:

  • Battery:USB: No external devices connected
    • Device only powered by battery (no AC power).
    • Battery charged to 100% prior to initializing test. Test continues in 1 hour iterations until battery passes low threshold (currently set at 3%). Initial & remaining battery charge is recorded.
  • Network: Device is associated with a wireless access point via WiFi.

Throughout the duration of the test, there are 5 sites loaded in background tabs. These sites were chosen to represent typical actions of a user on a daily basis:

  • Searching
  • Reading news
  • Checking on finance
  • Shopping
  • Communication

So, as you can see, no photoshopping, or video editing. They are testing you and me, normal Chromebook users do on a Chromebook.

Wait, do they test this on an airplane too? Lots of people said they are not buying a Chromebook because it won’t work on an airplane 😉

via Craig Tumblison Source: Chromium Website

In Category: Chromebook


Dinsan made Google Chrome his default browser within hours of its release. He fell in love with Chromebooks from the day he first touched one and is currently obsessed with Chromecasts.

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