Small and Compact. All portable batteries are lightweight and small. Universal. Power Bank is compatible with portable players, iPods, video and photo cameras, cell phones, tablets, laptops and many other devices. Reliable. The output voltage of a Power Bank is controlled by a built-in microcomputer. The system is protected against overcharging, deep discharge, overheating or battery short circuit. High-capacity. A fully charged Power Bank can charge a smartphone or any other handheld device several times.