The Sandberg Outdoor Solar Powerbank 10000 allows you to charge your smartphone up to four times. Yet it is extremely small in size and does not add a lot of extra weight to the backpack. The powerbank is equipped with an efficient US-made solar cell that generates enough energy to charge your smartphone on a sunny day. The power bank is protected by a robust IP66 shell, which is safe in all weather conditions and can withstand being lost in the snow, stuck in the bottom of a backpack while crossing a river, or dropped in the desert sand.