Nissin's NDP300C Power Pack Pro 300 Battery is an external power source for Nissin Di866 flashes and Canon 580EX II, 580EX, 550EX, MR-14EX Speedlights. The Power Pack Pro 300 consists of a heavy aluminum housing with a leatherette covering. It contains a rechargeable 7.2VAC, 3300mAh NiMH battery cluster (NBC300) that outputs DC 315V. The battery cluster is good for over 300 shots of full power flashes and can be recharged more than 200 times. Replacement battery clusters are available (extra purchase required) and are interchangeable with the included unit to keep your shooting going when continuous power to flash is required.
The Power Pack Pro 300 has a remarkable recycling time of 0.5 seconds for shoe-mount flashes and 1.2 ~ 1.5 seconds for handle-mount flashes. It connects to the flash via a dedicated power cord (included). At the top of the unit is a power indicator lamp, and 2 power cord connectors for powering 2 flash units at the same time.