How to check the battery health of a Chromebook

Checking the battery health of a Chromebook isn’t just useful for a device you’ve had for a while. It’s also handy — a must, even, IMO — before buying a used Chromebook. And it’s actually quite easy to do if you know where to look for the information.

battery health

First is the battery health indicator, which is a command you run in a crosh terminal. To do this, press ctrl + alt + t on your keyboard, which opens up crosh. Then type battery_test to see the health data: Essentially health of 100% indicates that the battery can accept the full charge of the battery capacity. As time goes on, this figure will slowly degrade. Looks like my Pixelbook battery is still capable of a full charge.

This command also runs a five minute battery discharge test. Note that you can specify the test to run in seconds by typing that number after the command. If you don’t, it will run for 300 seconds.

The second data point I’d look for is the total number of battery cycles, the Chromebook has executed. A cycle is a full charge and you can expect anywhere from roughly 300 to 500 cycles on a typical battery. To find this out, stay in the crosh terminal and type battery_firmware info. * You’ll see various bits of info here, including the battery cycle count. My Pixelbook has gone through 76 cycles, as shown:

battery cycles

If you’re buying a used Chromebook, consider asking the seller to run these commands on the device and show you the results. Once the battery cycle count gets over 200 or 250, I’d be leery of the purchase unless you plan to use the Chromebook plugged in more often than not.

And as far as the battery health, just understand that the percentage is what the device will get on a charge as compared to the same device brand new. So if a Chromebook battery is showing 80 percent health and generally gets 10 hours of battery life as a new unit, you should expect around 8 hours of run time on a single charge at that point.

*Note: If your device doesn’t support the battery_firmware info command, an alternative is to type chrome://system in your browser and look for the power_supply_sysfs field; expand it to see the battery cycle count and additional information.

10 thoughts on “How to check the battery health of a Chromebook

  • June 12, 2018 at 4:40 pm
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    battery_health(??) should this be battery_test?

    battery_firmware info not available on an Asus flip.

    Good article though for newbies!

    Reply
    • June 12, 2018 at 4:57 pm
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      You, sir, are correct! I was having a Twitter convo with someone about battery health and got that stuck in my mind. 😉 I corrected to battery_test and also added a note on how to find the battery cycle count for devices that don’t support the battery_firmware info command. Cheers!

      Reply
    • July 29, 2018 at 1:02 am
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      I have the Asus Flip (C302) and battery_firmware info does indeed work.

      Reply
  • June 13, 2018 at 3:36 pm
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    Interesting stuff! My Pixelbook shows a cycle count of 319. I got it in the first shipment last Fall and have used it every single day since. BUT, I always keep it plugged in. Now you have me worried.

    Reply
    • June 13, 2018 at 5:35 pm
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      Don’t panic! 🙂 It’s likely more important to see what the battery health is because that’s an accurate indicator of how much charge the battery can retain.

      Reply
      • June 13, 2018 at 6:30 pm
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        Whew. Thank you!! My Pixelbook is showing a 101% heath so no worries here. (Also I tested an ancient HP chromebook that I hang onto because it has LTE and one of those T-mobile Data For Life sims. It has a 97% health so, yeah!) Thank you for this and all your good tips, tricks and info.

        Reply
  • June 14, 2018 at 4:22 pm
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    I bought a used/refurb Acer R11 a few months back. Battery test shows I have 89% capacity but a cycle count of 18. Could this mean the battery was replaced at some point and maybe not with the highest of quality? I see roughly 8-10 hours so I am not complaining, just wondering.

    Also noticed the power wash count under the chrome://system is 4. 1 of those was mine, they had this on the dev channel when I got it and I reset it to the stable.

    Reply
    • June 14, 2018 at 4:58 pm
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      I’m a bit surprised that the capacity is down 11% with so few cycles. Could be a refurbed battery but no idea. If it were my device, I’d run it all the way down to an empty battery and fully recharge; 3 or cycles like that. May not do anything as battery “memory” is generally a thing of the past but it wouldn’t hurt. 😉

      Reply
  • June 20, 2018 at 1:10 am
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    HI, I used the power_supply_sysfs–option but the count is displayed as 0 on my Acer CB5-571 Chromebook 15 (2015).

    Reply
  • October 13, 2018 at 1:51 pm
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    Thank you for the information, it was very helpful. However, I’ve inherited some Dell Chromebooks (11 3189 regular model P26T manufacturing year 2017) that will not charge. I’ve run the battery test on them and two indicate they don’t have a battery (of course they do) with the remaining four showing some status of battery health ranging from 99.18% to 98.2%. According to the battery firmware info they have run approximately 14-16 cycles. There is a flag line that states “0x1b AC_PRESENT BATT_PRESENT CHARGING LEVEL_CRITICAL” For the two that don’t sense the battery is a battery replacement the only solution? (Is it even a solution or is there something else wrong?) For the other four what can I try to get them back in the land of the living? Additional info: all will work when plugged in and all had been in storage for about a year with no use or maintenance. Thank you.

    Reply

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