If your Chromebook is suddenly struggling to hold a charge, or if you are considering purchasing a used device, checking the battery health is one of the most important diagnostic steps you can take. Over time, all lithium-ion batteries degrade, reducing their maximum capacity.
Unlike some operating systems that bury this information, ChromeOS provides a built-in diagnostic tool and a terminal command that allows you to check the exact health percentage of your battery in seconds. Here is how to find it.
Method 1: Use the ChromeOS Diagnostics App
The easiest and most user-friendly way to check your battery health is by using the built-in Diagnostics app introduced in newer versions of ChromeOS.
- Click on the Launcher (the circular icon usually located in the bottom-left corner of your screen).
- In the search bar, type Diagnostics and press Enter, or click on the app icon when it appears.
- When the Diagnostics app opens, look for the Battery section on the left-hand side.
- Under this section, you will see your battery’s current charge level, alongside a metric labeled Battery health.
The Battery health metric is displayed as a percentage. A brand new Chromebook will show 100%. If your health is below 80%, you may notice a significant decrease in how long the device lasts between charges, and it might be time to consider a battery replacement.
Method 2: Use the Crosh Terminal
If you prefer using command-line tools or if your Chromebook is running an older version of ChromeOS that lacks the Diagnostics app, you can use the ChromeOS Developer Shell (Crosh).
- Press Ctrl + Alt + T on your keyboard simultaneously. This will open a new tab in the Chrome browser displaying a black terminal window with a
crosh>prompt. - Type the following command and press Enter:
battery_test - The system will run a brief test (usually taking about 300 seconds, but it will display the health instantly).
- Look at the output for a line that reads Battery is discharging or Battery is charging. Directly below that, you will find Battery health: [percentage].
This method provides the exact same underlying metric as the Diagnostics app but can be accessed instantly using a keyboard shortcut.
Understanding Battery Cycle Count
In both the Diagnostics app and the Crosh terminal, you will also see a metric for Cycle count. A charge cycle is completed when you have discharged 100% of the battery’s capacity, even if it happens over multiple partial charges. Most modern Chromebook batteries are designed to retain up to 80% of their original capacity after approximately 500 complete charge cycles. If your cycle count is unusually high, this explains why your battery health percentage has dropped.