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 test is implemented as an open source Chrome extension which anyone can install and run.
The power_LoadTest is run as a series of one hour long iterations until battery exhaustion. Within each iteration, a load mix known as “60/20/10/10” is run:
The parameters of the test are as follows:
The parameters of the system under test are as follows:
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:
If you are interested in running power_LoadTest on a Chrome OS system, you will need a Chrome OS image that has been modified to run tests. If you would like to reproduce reported battery life numbers, please ensure that your system under test matches the parameters outlined above.
While the initial version of power_LoadTest seems to emulate well what users experience every day on Chrome OS devices, this test will be constantly improved. As we learn more about how users use Chrome OS devices and how experienced battery life differs from tested battery life, we will use this data to refine the test, potentially changing the load mix or the parameters of the test.
Our goal is to ensure that when you purchase a device, you know - with reasonable certainty - how long that device will last in your daily use.