pro 4

As a tablet, you'd expect the Surface Pro 4 to run all day, but neither the older Surfaces nor this new one are at the bleeding edge when it comes to battery life. In fact, this year's Surface Pro 4 ran for less time in our standard battery drain test than the Surface Pro 3, at 6 hours 32 minutes for the Pro 4 versus 7 hours 46 minutes for last year's Pro 3. This particular test can be tough on some systems, and since last year, we've also had a major OS jump, from Windows 8 to Windows 10.

We went back and re-tested the Surface Pro 3, and after more one year of moderate use, and with a Windows 10 upgrade, it now runs for 6 hour 19 minutes on the same test. Any of these scores should be fine for moderate use through most of the day, but unlike the new Surface Book, there's no extra battery hidden away in the keyboard dock.