I don't think the camera features will drain battery, espesically if you factor in that you don't take shots all day long. If you look at the competition and say that there are Android phones out there with 3000 mAh, dont forget that a) Andorid is a Battery hog and b) none of these phones are nearly as optimized for Android as the Lumias are for WP. I think best would be to compare it to the iPhone, the rumored new one. About the same Processor, screen size, -quality and dpi. And both are optimized for there respective OSs. The iPhone has a 5,45Whr Battery with 3.8V wich calculates to 1430mAh. So my guess would be that the 2000mAh of the Lumia will suffice. At least that what i hope.