This pack contains 2 XR FLEXVOLT 18 V - 54 V batteries, 3 Ah - 9 Ah Li-Ion, and a dual charger. "Flexvolt" battery system: The "flexvolt" batteries can be used on both 18 V and 54 V tools. The runtime varies depending on the voltage of the tool used: for example, the DCB547 provides a runtime of 3Ah on a 54 V tool but increases to 9 Ah when used on an 18 V tool. Technical specifications: XR FLEXVOLT 18V - 54V 9AH - 3AH LI-ION DCB547: This battery is compatible and fits all XR 18 V and 54 V XR FLEXVOLT tools. Voltage: 18 / 54 V Capacity: 3 / 9 Ah Length: 125 mm Width: 85 mm Height: 90 mm Dual charger DCB132: This charger features a dual port with a simultaneous output current of 4 Ah on each port. LED indicator Voltage: 18 V Battery type: XR Li-Ion Charging current: 2 x 4 Ah (dual port) Charging time: 90 min (6 Ah) Weight: 1.2 kg.