The Truth About The Surface Pro's Battery Life

The Surface Pro has 4 hours of battery life. People seem to be parroting this all over the tech industry based on a comment from the Surface teams's twitter feed. But the twitter feed said it would have about half the battery life of the Surface RT. Specifically:

"Hey Shahroom, #Surface pro will have approximately half the batter life of Surface RT."

Well the Surface RT has 8 hours of battery life which means the Pro will have 4 right? No.

First to dispell the notion that the Surface has 8 hours of battery life. That's the number Microsoft quoted. That isn't the number we're seeing though. If you look at The Verge's reviews most manufacturers estimated battery life is higher, sometimes a lot higher, than the actual battery life. Here's two quotes from some of The Verge's reviewed laptops:

Vizio 14 inch - Another major issue with the 15.6-inch model is its poor battery life — at 3.5 hours it falls far short of Vizio’s 5.5 hour estimate. The 14-inch doesn’t live up to Vizio’s claim of 7 hours either; it died after four hours and nine minutes in our Verge Battery Test, which cycles through a series of popular websites and high-res images with the screen set to 65 percent brightness.

Dell XPS 14 inch - Dell advertises up to ten hours for this particular configuration, and as always, those numbers aren't grounded in the real world... but I actually managed over five and a half hours of real-world use before I felt compelled to connect a charger. In fact, the XPS 14 ran 6 hours, 59 minutes on our Verge Battery Test, which cycles through a series of 100 popular websites and high-res images with the laptop's display set to 65 percent brightness.

You get the picture. Manufacturers aren't the best when it comes to giving accurate battery life signs. That isn't surprising. Even more so everyone uses a their devices differently so the only thing you can use to get a sign of battery life is a particular review method (The Verge's battery test consists of emulating real world use by running a script that goes through 100 web pages at 65% brightness). So Microsoft's 8 hour battery life? Its just an estimate.

If you actually read a few reviews of the Surface RT that becomes apparent. The Verge said in their review:

Battery life, on the other hand, was consistent and impressive on the Surface. Microsoft claims that users can nab somewhere in the vicinity of eight hours on a single charge in mixed use. My experience bore those numbers out, and then some. I was able to put the Surface through a full day of relatively heavy use (video playback and streaming, document editing, lots of web browsing, app downloads, game playing, email, Twitter, and more) and still had some charge left that evening... and into the next morning, without having plugged it in overnight. Battery life on the Surface seemed more akin to an iPad than a laptop — which makes sense given the ARM architecture. In the same way I never worry about whether I've charged the iPad recently, I found myself carelessly leaving the Surface off of the charger for extended periods. And I think that's a good thing.

Engadget reviewed the Surface differently but also found positive results:

You caught the part earlier where we said this thing has robust battery life, right? How does nearly 10 hours sound? In our standard battery rundown test for tablets, which involves looping a locally stored video with WiFi on and brightness fixed at 50 percent, the Surface's 31.5 watt-hour battery held out nine hours and 36 minutes, which puts it just short of the new iPad (9:52) and just ahead of ASUS' high-end Transformer Pad Infinity (9:25).

AnandTech reviewed the Surface and it was competitive with similar tablets:



So clearly depending where you go you'll get a different story but it is clear that 8 hours is not the definitive number for battery life using the Surface. Its an estimate. Its better to low ball estimates like these. Lying to your customer is idiotic and when someone buys something with less battery than advertised it doesn't reflect well on the company. Apple is a pretty good example of this. Usually their battery estimates are on point (for example they list their battery life for the 11 inch Air at 5 hours and The Verge got about 30 minutes more than that).

I think you understand my point so I won't harp on. The reality is we won't know the battery life of the Surface Pro until its released. I'll leave you with 1 last thought though. 1 last argument. If the Surface Pro ships with an average battery life of 4 hours that would be lower than almost every single tablet and laptop that The Verge has reviewed recently. Do you really think that Microsoft would release their first laptop class device with the worst battery life we've seen all year?