GP GPACC3C20000 3C20A 20000mAh Portable Powerbank - Black With the ever increasing use of Smartphones and other portable devices GP have bought out a range of portable power emergency chargers. Allowing you to charge any device that charges via USB (iPhone, iPod, iPad, Most Smartphones, etc) on the move without needing to find a fixed power point. Over-temperature cut-off during PowerBank recharging Complies with UN38.3 air transport safety standard Short circuit protection prevents from malfunction caused by short circuit Loopback protection auto cut-off when the same cable is plugged into input/output simultaneously. Protection in place for prolonged battery life Under-temperature Over-charging Over-discharging protection Overload