The Switronix Powerbase-70 Battery Pack & Charger for Blackmagic Camera Kit from B&H -- the battery can be attached right underneath the camera or to a V-mount plate and will provide up to 4-6 hours of power. The charger delivers a full charge in 4-5 hours using a P-Tap connector.
The battery pack is a combination of a 70Wh 14.8V lithium-ion V-mount battery and a regulator block with a 12 inch DC cable. The battery attaches underneath the camera via an included mini quick release plate that has a 1/4"-20 screw extending from it. The plate snaps into the battery and enables mounting most any support gear with a 1/4"-20 thread. If you'll be attaching underneath the camera, you'll need to plug the 12 inch DC cable into the camera. If you'll be attaching to a V-mount plate, you won't need to use the cable as the battery is a standard V-mount battery and accordingly will make electrical contact with the plate. The battery has 1/4"-20 threads on the sides for attaching accessories.
Via an optional XP power regulation cable, the battery can also power two additional 12V and lower-voltage devices at the same time as powering the camera.
Switronix PowerBase 70 Battery for Blackmagic Cinema Camera (12" Cable)
The Switronix PowerBase 70 Battery for Blackmagic Cinema Camera (12" Cable) attaches on the bottom of the camera as a battery grip using an included mini quick release plate, and connects to the camera via a DC connector. It consists of a 14.8V, 77Wh lithium ion battery and a regulator block with a DC connector. The regulator block attaches on the side of the battery when the battery is mounted as a grip.
Two P-Tap outputs are available for powering 12V accessories and can also be used for lower voltage accessories if you incorporate optional XP power regulation cables. A V-mount adapter on the back of the battery allows direct connection to V-mount plates.
14.8V, 77Wh lithium ion battery
Attaches on the bottom of the camera as a battery grip using a mini QR plate
Connects to the camera via a DC connector
The DC connector is part of a regulator block that attaches to the side of the battery
Two P-Tap outputs for powering 12V accessories
Lower voltage accessories supported via optional XP power regulation cables
V-mount adapter on the back allows direct connection to V-mount plates
1/4"-20 accessory mounting threads on the sides
4-LED power indicator
Switronix PB70C PowerBase Charger
The Switronix PB70C PowerBase Charger is a compact, 90-240VAC battery charger for selected Switronix batteries. Using a P-tap connector, the PB70C delivers a full charge in 4-5 hours. A 2-color LED light on the front of the unit indicates the battery's status.