Powerful Lithium Polymer Rechargeable Gomadic Brand Battery Pack High Capacity Portable Charger Compatible with SkyGolf SkyCaddie SG5 with upgradeable TipExchange Technology Integrated circuitry tailors output voltage and charging current to exact specification of the SkyGolf SkyCaddie SG5 (accurate to 0.1v). Very easy to operate. Simply connect SkyGolf SkyCaddie SG5, press activation button on pack, and charging begins. Quick start guide included. Specification: Internal Battery (7800mAh lithium polymer), Input port (microUSB), Output Port (Standard USB), Onboard Circuit Design (SkyGolf SkyCaddie SG5 Specific), Dimensions (2.75 X 3.25 X 0.75 inches), TipExchange enabled (Yes) Internal circuit protects the SkyGolf SkyCaddie SG5 from various power ailments including surges, overcharging and short circuiting. Advanced logic maximizes charger efficiency Built with high capacity lithium polymer rechargeable battery technology (28 Wh / 7800 mAh) in a compact design.