The Solio Xcellerator USB Battery Bundle is powered by AA batteries rechargeable by USB. It can deliver a rapid charge to a Solio charger even if there’s no sunlight and the light is low. The batteries can be charged from the sun, or through a USB charging cable or from a wall outlet. When you do have the sun, the kickstand acts as base pivot so that the solar charger can track the sun’s path. The bottomline here is that you don’t have to suffer slow charging speeds just because you have a desire to be environment-friendly. The Solio Xcellerator USB Battery Bundle will store the power and juice up your device quickly whenever you need. It’s a portable arrangement that you can break down into separate pieces and easily stow away in a backpack while you’re traveling.