Cool find This is going to be the on-going problem with Samsung's drive for ever-thinner devices. Battery storage technology has not advanced sufficiently to allow such cosmetic changes without there being a direct and tangible consequence. Hope is on the horizon with some of the in-lab technologies. If they can just commercialise these then we will see dramatic improvements to the capacity of a given size of battery. One such that springs to mind is nanotech - where they managed to incorporate the surface area of a football field into a single AA sized cell. Industralise that and we'll see the 600% capacity increase realised.