The Voltaic Portable Solar Charger Backpack is a versatile bag which provides some serious power to your smartphone, tablet, and other USB devices with great storage. The rugged monocrystalline solar panel with 3.69W total peak output at 6V will quickly charge all your handheld electronics. The system includes a removable and portable V15 backup battery pack that can be used to store power and charge your devices. The battery can also be charged from any standard USB port with the included micro USB adapter and USB cable.