Gomadic High Capacity Rechargeable External Battery Pack suitable for the Raspberry Pi Board - Portable Charger with TipExchange Technology Very easy to operate. Simply connect Raspberry Pi Board, press activation button on pack, and charging begins. Quick start guide included. Integrated circuitry tailors output voltage and charging current to exact specification of the Raspberry Pi Board (accurate to 0.1v). Specification: Internal Battery (5200mAh lithium polymer), Input port (microUSB), Output Port (Standard USB), Onboard Circuit Design (Raspberry Pi Board Specific), Dimensions (2.8 X 2.1 X 0.75 inches), TipExchange enabled (Yes) Charging kit includes: Rechargeable Lithium Battery Pack, Coiled input/output cable (expandable to 24), Raspberry Pi Board Charging Connection, and Battery Pack input connection. Continue to use your Raspberry Pi Board for hours OR recharge it on the go without being tethered to a wall outlet