In general, you should benchmark every device you test under the same conditions. For example, you should test every device in the same location, at room temperature, and away from direct sunlight and other heat sources.

The battery must be at least 80% charged before the test will start. The test loops the benchmark until the battery charge drops below 20%. Battery testing can take several hours during which you will not be able to use your device for other tasks. Do not use the charging cable, or connect mobile devices to a PC, while the test is running.

To get accurate and consistent results you should close apps that may be running in the background, and disable notifications before running the benchmark. 

  • Running other apps during the benchmark will affect the results.
  • Avoid touching the screen while the tests are running.
  • Press your device's Back button if you want to stop the test.
Many modern devices have aggressive power saving features built into the operating system. Unfortunately, these features can make it near impossible to run a complete battery life test. If your device is forcing the test to close before it complete, try disabling the power saving features in your device's Settings menu.

Set the screen brightness

Screen brightness can have a significant effect on a device's battery life. To produce comparable results you should calibrate every device you test to the same screen brightness. In practice, this is difficult without expensive, specialist equipment.

From the app's Settings screen, you can display a pure-white calibration screen to help you set the screen brightness. If you don't have access to a luminance meter, you can calibrate your devices by comparing the calibration screen to a reference such as a monitor, lightbox, or similar. Alternatively, place your devices side-by-side and adjust the brightness levels by eye.

Be wary when using a device's built-in brightness setting to calibrate screen brightness. Different screens offer different levels of maximum brightness. The 50% brightness setting on one device may not be equal in luminance to the 50% setting on another device, for example.

Recommended process

  1. Test the device at room temperature, away from direct sunlight and heat sources.
  2. Disable automatic screen brightness adjustment.
  3. Use the pure-white calibration screen to set the device's screen brightness to a defined level, ideally 200 cd/m2 for smartphones and tablets.

Expert process

To produce accurate, repeatable, and comparable results you should test devices under controlled conditions. Our recommendations below match those given in the ECMA-383 standard, Measuring the Energy Consumption of Personal Computing Products.

  1. Test the device in an environment that meets the requirements of ECMA-383: 
  • Temperature: 23 +/- 5 degrees Celsius. 
  • Relative humidity: 10 - 80%. 
  • Ambient light: 250 +/- 50 lux.
  1. Disable automatic screen brightness adjustment.
  2. Use the pure-white calibration screen in the app and a luminance meter to calibrate the screen brightness to 200 cd/m2 for smartphones and tablets.