This solar-powered backup battery pack features a rechargeable 5000mAh lithium battery for long-lasting reliable power - wherever and whenever you need it. You can also charge this bad boy up from the wall using the micro USB DC-in port, just like most smartphones use. When the Boost Solar is all charged up, you???ll have enough backup power to fully charge most smartphones twice. With the 5V=2.1A output you can also charge your tablet.