Switronix's PocketBase Battery Holder with Battery and Charger Kit for Blackmagic Design Pocket Cinema Camera allows you to power the camera up to 5 hours with two LP-E6 type batteries, while simultaneously charging the removable internal battery. By keeping the internal battery inside the camera during operation, you can hotswap the attached LP-E6 batteries within the PocketBase for continuous camera operation.
The PocketBase mounts easily under the camera with an included 1/4-20" thumbscrew which allows a seamless integration. By attaching the included grips, it allows for comfortable hold without need of a rig.
The PocketBase is an all-metal enclosure designed to last through all facets of production. The camera power cable tucks in nicely for camera mounted application, but will also extend up to 24" for rail mounting. With the ability to hotswap batteries you can continue production without interruptions.
The PocketBase also includes a 1/4-20 mounting thread, to easily mount on rails if you were to put it on a rig.