Battery Life Testing
The XPS 12 uses a built-in 47W/H 6-cell Lithium Ion battery. Based on tests from Dell labs using the MobileMark 2012 benchmark, Dell says users can expect up to 6 hours and 7 minutes of battery life in typical use from an XPS system equipped with 4GB memory, Intel HD 4000 graphics, Intel Core i5-3427U, and 128GB SSD. Our test system has a different CPU but otherwise similar specifications.
To give you an idea of how long the XPS 12 will last and to help you compare the XPS 12's longevity to other systems, we ran two battery tests. For both tests, we set the screen's brightness to 50% and turned off all screen savers and sleep settings.
Keep in mind your usage patterns will significantly impact the XPS 12's battery life. If you are watching videos, downloading files, or putting the ultrabook in sleep mode when the system is not in use, this will impact the time your system can run before needing to recharge.
Our web browsing test is the same one we run on tablets and smartphones. This test is designed to show how long a system can handle simple Web browsing. The test refreshes a page every three minutes and runs until the system shuts down because the battery is depleted. We also use Battery Eater Pro, which runs a heavy workload continuously to show you what the system can do when its CPU, GPU, memory, and storage drive are seeing heavy use. If you plan to use the ultrabook to work with multimedia (or even to do a lot of word processing) the results will give you a picture of what to expect.
The XPS 12 didn't score exceptionally well in either test. In our web browsing test, the XPS 12 outlasted only one other system, the Asus Zenbook Prime UX32VD. The XPS 12 fared a bit better in the Battery Eater test, earning a mid-range score, while lasting for about two hours.