Just last month, GoPro introduced the long-awaited LCD screen module for its viewfinder-less HERO HD actioncam. At the time, the company stated that the module was the first in a series of BacPac accessories, designed to extend the capabilities of the 1080p high-def camera. Now, the next of those accessories has been released, in the form of the Battery BacPac. It allows an included 1100mAh lithium-ion battery to be mounted onto the back of the camera (which already has its own identical battery), potentially doubling its run time.

As is the case with the LCD BacPac, this new one makes the total camera package thicker when attached. This means that the HERO's existing waterproof housing will no longer be big enough to hold everything, so the module comes with a replacement deeper back door for the housing. Actually, it comes with two – a solid waterproof model, and a lower-weight non-waterproof "skeleton" model.

Once in operation, three LEDs on the back of the module indicate the level of remaining battery life.

As with any of the BacPac modules, it will only work with the 1080p HERO HD, and not the 960p version. It can serve as an off-camera battery charger for either model, however – in this scenario, users could shoot without the extra weight and bulk of the module, instead leaving it hooked up to the USB port of their computer to recharge one battery while the other is in use.

The Battery BacPac is available now via the GoPro website, for US$49.99.