engadget:New features like a quad-core processor and high-res display are fantastic additions to Windows Phone, but what kind of impact does it have on battery life? Runtime on the 1520's battery is about what we expected; this battery is one of the largest in a phone of its size, so our preconceived notions of its performance were admittedly pretty high. On our first full day of regular use, which included taking quite a few pictures, downloading a few apps, checking email and social media and a few other standard smartphone activities, the phone yielded around 12 hours of juice. This would be pretty good for most phones, but a power-efficient platform like Windows Phone should be able to squeeze even more life out of a 3,400mAh battery. On the second full day of regular use, however, its life appeared to bounce back after conducting countless photo sessions and other activities. By the end of that 13-hour day, we still had roughly 30 percent left. Because of the inconsistencies, we're conducting some additional tests. We'll continue to update this review as those results come in. (Update: the WPBench battery drain test merited a time of 3:30. This is just shy of the Lumia 925's time and significantly better than the 1020.)