While Nokia’s release of six new devices stole all of the headlines this morning ahead of Apple’s expected iPad 5 unveil later today, Microsoft’s Surface Pro 2 tablets are quitely hitting the stores this same day, promising a host of improvements over the original, somewhat disappointing models. Extra computing power, less weight and more functionality is the order of the day, but there’s still one are where Microsoft falls flat on its face – and that’s its pathetically poor battery life in comparison to other devices that run anything but the Windows OS.

AnandTech’s Anand Lal Shimpi and CodingHorror’s Jeff Atwood today published the results of a series of tests done on the Surface Pro 2, revealing that it packs in around 6.68 hours of batter life whilst browing the internet. Admittedly that’s a decent, 41.5% improvement over the original Surface Pro’s battery life of just 4.72 hours, but it’s still some distance behind the likes of Apple’s iPad 4 (9.48 hours) and Google’s Nexus 7 (12.23 hours).

Given that the Surface Pro is basically a full PC running an Intel quad-core, 1.7Ghz Core i7 processor, few techies will be surprised that it falls short against Apple’s and Google’s ARM-based devices, but sadly for Microsoft that’s not the full story. As we all know, Microsoft also happens to offer its own ARM-based tablet, the Surface RT, and that fared little better, clocking in at just 6.81 hours of battery life, just a touch over what the Surface Pro 2 is now capable of. Moreover, even the newest Surface RT 2 only offers 8.08 hours, some distance behind the iPad and the Nexus’s best efforts.

To be fair to Microsoft, the Surface Pro 2 isn’t any old tablet – it is “practically a laptop,” as the company likes to point out. But in Atwood’s comparison of the Surface Pro 2 against laptops with similar specs, its battery life still leaves something to be desired. As an example, Atwood chose the 2013 MacBook Air, a machine that “spec-wise is about as close as we can get to the Surface Pro 2.”

During AnandTech’s tests, the 13-inch 2013 MacBook Air clocked up a massive 14.28 hours of battery life, a whole 113.8% better than what Microsoft’s machine could manage. Okay so the MacBook Air has a bigger, 54Wh battery (The Surface Pro 2 is just 42Wh), but even the 11-inch MacBook Air lasted far longer than Microsoft’s device.

As Atwood observed:

“That means the Air is somehow producing nearly two times the battery efficiency of the best hardware and software combination Microsoft can muster, for what I consider to be the most common usage pattern on a computer today.”

Following this, Atwood then looked at how an Apple Mac might perform whilst running Windows software. He dug into the archives at AnandTech and discovered a test comparing a 15-inch 2009 MacBook Pro running three different operating systems – OS X 10.5.7, Windows Vista x64 SP1, and Windows 7 RC1. The results were fairly eye-opening, with the 2009 MacBook Pro running OS X lasting for 8.13 hours, compared to just 6.02 hours on Vista and 5.48 hours with Windows 7.

Clearly then, there seems to be a problem with Windows itself. But what is it about Microsoft’s operating system that screws up the battery life? Unfortunately no one has an answer – Anandtech spoke to a number of hardware makers seeking close, but nobody seems to know.

Whatever the reason, as Atwood points out, this battery problem does little to help Microsoft’s efforts in selling Windows 8 as the best operating system for enterprise workers. Okay so it might be more productive, but when its battery barely scrapes through a single day at the office, its hard to see many people favoring over something ‘meatier’ running Android or iOS.

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