The GoPro Battery BacPac is a high capacity battery which allows longer recording time for the GoPro. Battery BacPac works well and easily doubles the time recording capacity of the camera. We use this regularly to record information, such as road conditions, while travelling in the car on our trip around Australia.
The GoPro Battery BacPac comes with an enlarged enclosure backing case so that it can be mounted inside the waterproof container. It also has a protective carry case to avoid damage when not in the camera.
The GoPro Battery BacPac can be charged separately via a USB cable. If you charge the Battery BacPac when it is fixed to the camera it automatically charges the camera battery before it charges itself - giving you maximum camera usage. A great feature.