If you need more time than this you have several DIY options and several USB based options. I not a big fan of either. The folks at P&C came up with the Tehkron CagePro + GoPro cage.
Basically it is a cage like the one you’d use for DSLRs with two clever additions:
- You can power a GoPro of a regular LP-E6 Canon battery and
- You get a 62mm mounting thread for filters.
I can see how changing the battery on a GoPro can be a crappy task, especially if it is mounted in a hard to reach spot. The added power will let you record for over 4 hours per battery swap. (At the cost of about 60 USD per battery).
You can use the added filter thread for an ND filter or a CPL filter giving you better control over exposure.
The CagePro is compatible with both the Hero3 and the Hero3+ as long as you use the Hero3 skeleton housing.
Here is the description as written over at P&C:
“Our unique Patent Pending design solves several problems for filmmakers who use the GOPRO HERO3 / HERO3+in professional production and broadcast environments. First and foremost, our cage offers additional mounting points – an important feature to minimize vibrations when rigging the GOPRO to cars, motorcycles, planes, boats, and more.
The CagePro also incorporates a 62mm threaded filter ring to further improve the image quality from the GOPRO HERO3 / HERO3+ Cameras. By adding an ND Filter you can reduce shutter speeds on bright days which can help to reduce Jello and Rolling Shutter effects. Or slap on a CPL (circular polarizing) filter to reduce glare on reflective surfaces and enhance color saturation in skies, oceans, and trees.
Our most innovative feature pumps power to your Hero3 through a common LP-E6 battery (Canon DSLR Type)! A single Canon LP-E6 Battery can provide more than 5 hours of run time on a single charge. A perfect solution for long video takes, or a full day of Time Lapse projects.
Operating sounds simple – you slide the Gopro into its cage (the skeleton, non water proofed one) and slide that into the CagePro. The CagePro has an internal USB connection that charges the GoPro battery so the camera still runs of its original battery.
There are two versions: one with a handle for $180 and a more basic one for $150. Both have added mounting points, so I guess your choice mostly depends on if you are going to be hand holding the camera or mounting it to be stationary.