Charge a wide range of devices such as the TetherBoost Core Controller, Case Relay, tablets, smartphones, iPods, the CamRanger, and more with the Tether Tools Rock Solid 10000 mAh External Battery Pack. It features dual output ports that enable you to power up to two devices at the same time. The battery pack is capable of providing up to 50 hours and 20 hours of power to the iPhone 6 and the iPad Air 2 respectively. This lithium-polymer battery pack works in conjunction with the internal microchip that controls the voltage based on the device being charged. Whenever the battery pack runs out of power, you can charge it with the USB charging cable included.