The Microsoft Surface Book 2 (15-Inch) Review: Second Time's The Charmby Brett Howse on December 21, 2017 8:00 AM EST
The original Surface Book we tested was the Core i5 model, and it offered amazing battery life that the Core i7 model with a discrete GPU couldn’t quite match. With the Surface Book 2 15, the battery capacity has increased, although so has the display size and resolution, so it’ll be interesting to see how that impacts the results.
Our battery life tests include our older 2013 web browsing test, a newer 2016 web browsing test which is more demanding, and a movie playback test. All of our browsing is done with Edge, and movie playback with the built-in Films and TV software, with the display set at 200 nits of brightness.
You feel kind of greedy when you feel like almost 14 hours of browsing isn’t enough, but it felt like the Surface Book 2 might really set a new record with the large 85 Wh of battery capacity. The new model handily outperforms the outgoing Surface Book Core i7 though, despite the larger display and higher resolution.
The tablet itself will still get several hours away from the base, which is more than enough time for the use case of the tablet, which is going to be for short sessions away from the base.
Our newer web test is more demanding of the CPU, and on devices like the Surface Book 2, where the CPU power usage is a significant factor in the overall power drain, the result is less battery life than our older, easier test. At almost ten hours of battery life though, the Surface Book 2 still offers a lot of time off the mains.
By removing the battery capacity from the equation, we can see the efficiency of each device. Here, the larger battery size is removed, and the Surface Book 2 ends up about midfield. The larger display and higher resolution of the display are a significant impact on the battery life.
To dig in to this a bit more, additional testing was done to see just how much power the display draws. At maximum brightness, and with the system at idle, the display draws 7.65 W of power, while the rest of the system only consumes 1.43 W of power. On our 200 nit display brightness setting, that power requirement of the display drops to 4.1 W, which is still over double what the rest of the system is using at idle. The display is a significant factor, as expected.
When playing back a movie, the CPU can offload the task to fixed function hardware, so the overall power usage goes down even further than normal. The Surface Book 2 offers tremendous battery life at this task, coming in at close to 15 hours.
This would let you play The Avengers over six times on a single charge. That should be enough for almost any scenario.
With just the tablet, the battery life is still almost five hours of movie playback, which is certainly usable, although I doubt most people would use just the tablet to watch movies due to the size of it.
Despite the larger battery, the 100-Watt AC Adapter charges the battery quite quickly, and both batteries are full in under three hours.
Both batteries charge at the same time, and are almost in lock-step with each other in terms of charge, despite the difference in capacity.
For those interested, the bottom of the tablet features the same Surface Connect port, so you can charge the tablet away from the base if necessary, although most of the time it would be charged when docked.