Prolific leakster @The_Malignant today republished a pair of claimed images of a purported battery pack believed to have been designed for a 42mm second-generation Apple Watch. Originally posted by an unnamed source on the Chinese social network Weibo, the tiny battery shows an increased capacity of 334 mAh. By comparison, the original Apple Watch is outfitted with a 245 mAh battery (42mm version) so it's entirely conceivable that the Apple Watch 2 could offer a few hours of additional battery life—assuming the leaked photo is genuine.
Apple Watch 2 could offer a few hours of additional run time via a stronger 334 mAh battery