For almost as long as there have been Windows laptops, there has always been a giant squid in the room: Why is Windows' battery life so damn pitiful? The battery life discrepancy between Windows and other operating systems has never been clearer than with the Surface Pro 2 and the 2013 MacBook Air -- both have very similar specs (Haswell Core i5 CPU/GPU, battery size), and yet Apple's laptop has almost twice the battery life of Microsoft's tablet.