With the Sandberg Outdoor Solar Powerbank 10000, you can charge your smartphone up to four times. It is super compact and adds very little extra weight to your backpack. The power bank is equipped with an efficient solar panel made in the USA, which generates enough power for an additional charge of your smartphone on a sunny day. The power bank is securely enclosed in an IP66 casing, making it safe in any weather and capable of being lost in the snow, sitting in your backpack while hiking through a river, or being dropped in desert sand.