Gomadic Portable AA Battery Pack designed for the Panasonic HC-V770 / HC-V777 - Powered by 4 X AA Batteries to provide Emergency charge. Built using TipExchange Technology Integrated circuitry regulates output voltage specific to the Panasonic HC-V770 / HC-V777. Advanced logic maximizes overall charger efficiency. Built using the unique Gomadic TipExchange Technology that protects your investment by providing the ability to upgrade charging ports by simply swapping physical connectors. Specification: Input Voltage (4 X AA Batteries), Cable length (6 inches), Dimensions (5.0 X 1.5 X 0.75 inches), Circuit Design (Panasonic HC-V770 / HC-V777 specific), TipExchange enabled (Yes) This Gomadic Battery Pack can be reused forever by simply inserting fresh batteries, providing instant power on demand. Internal circuit designed to protect your Panasonic HC-V770 / HC-V777 from power surges, overcharging and short circuiting.