Battery Life and Portability

Battery Life – Is it good enough?

As with all notebooks and tablets, one of the primary considerations is the battery life – how long can you use the device without being tethered to a wall outlet? Both the Surface Pro 4 and the Surface Book are using Intel’s latest processor and platform, codenamed Skylake, and thus should offer the best overall efficiency available on the market. Intel has definitely spent a lot of time and engineering hours working with Microsoft to tweak and modify the OS, the hardware and the firmware to present the Surface devices as the best of the best.

That being said, battery size trumps all and while the Surface Book has a tremendous combined battery size of 69Wh, 18Whr in the tablet and 51Whr in the keyboard dock, the Surface Pro 4 has a 38 Wh battery, actually a slight decrease from the battery in the Surface Pro 3.

Our battery testing is done using a custom application that uses a web browser and goes through a number of different sites, scrolling and navigating along the way. It’s a fairly intense Wi-Fi browsing test with new pages being loaded every 30 seconds.


The Surface Pro 4 was able to get 5.8 hours in our test while the Surface Book was able to reign in 9.23 hours! The Pro 4 result is good considering the somewhat smaller than average battery it includes (my XPS 13 has 50 Wh) but the Surface Book really impressed me, increasing battery life by 59% over the Pro 4, despite having the discrete NVIDIA GeForce GPU as part of the keyboard dock. That kind of battery life is definitely the “all day” category and is the primary reason I am considering retiring the XPS 13 in favor of the Surface Book.  Clearly the combination of Intel’s new Skylake architecture, improvements to Windows 10 power management and an optimized system design are bringing strong dividends for Microsoft’s hardware division.

If you read online about battery life on the Surface Pro 4 and Surface Book, you probably know about poor battery life when in sleep mode – coming back to a notebook with 20% less battery when left unplugged but asleep overnight. I definitely experienced this bug, but the most recent Windows Updates and firmware changes to the hardware seem to have corrected it for me. If you own either device, and you still have issues, definitely let me know in the comments below.

Portability – Weight and Size

Though I touched on it in the design section of the story, since we are talking about battery life and mobility, it makes sense to bring up the portability of both the Surface Pro 4 and the Surface Book again here. Clearly the Surface Pro 4 with the Type Cover is the slimmer and lighter offering of the two. It is slim and sleek, easy to toss in a bag, purse or even an urban satchel (we won’t call them purses) and it will not weigh down your shoulders. The Surface Book is bigger physically, thicker (because of the unique hinge design) and heavier as well. Those sacrifices are what allow for the added connectivity, better battery life and improved performance if you get the model with the discrete GPU in the keyboard.

The chargers for both machines are small and light, and, though it’s a minor thing, are built perfectly to take up only a single plug on a 110v outlet.

Though I am used to lighter notebooks like Dell’s XPS 13, I don’t think the increase in size and weight on the Surface Book is going to be enough to scare me away from migrating over to it. Those that are very sensitive to weight and size and bulk, the Book is likely just on the edge of acceptance. 

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