Voltaic Systems 6W Solar Panel Kit with External Battery Pack (4,000mAh) - SILVER PANELS - 1 rugged monocrystalline solar panel with 6.15W total peak output at 6V. The panel is waterproof, lightweight, and coated in self-healing urethane to withstand abuse and resist scratches. BATTERY - The system includes a removable and portable V15 backup battery pack; a 4,000mAh, 15Wh universal battery 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. CHARGING - 3 hours direct sunlight fully charges a typical smartphone, 8 hours in direct sunlight charges most 7" tablets completely, and 11 hours in direct sunlight charges most 10" tablets completely. COMPATIBILITY - Voltaic's portable solar charger kit is designed to power and charge thousands of devices that charge from USB, including various handheld devices, USB cameras, and smartphones like the Apple iPhone, iPod, iPad, Samsung Galaxy, Sony, Nikon, Canon, Blackberry, and other Android devices. ALWAYS ON FEATURE - Voltaic's selectable "Always On" feature makes it easy and efficient to use the V15 battery with various sensor or time lapse applications (see below).