Thinking about shooting with your GH2 camera longer than usual? Unfortunately Panasonic doesn't offer an OEM version battery grip to run dual batteries, but this GH2 External Battery Kit could help you out.
Christian writes in with positive news that this single battery lasted longer in a recent shoot, than several internal batteries from a previous shoot [Thanks Christian]. The kit comes with an 8500mAh rechargeable battery, GH2 Dummy battery, and necessary cables with DC 12V 6500mA, DC 9V 8500mA, and DC 5V 15000mA to power both the Panasonic GH2 camera, and 2/3" zoom professional video lenses. Check out the Panasonic GH2 Extended Battery Kit via eBay (Click Here).
Panasonic GH2 Extended External Battery Kit Power Zoom Lenses
If you happen to require more than one battery, you can stock up on more cheap CCTV type batteries found on eBay (Click Here).
CCTV Battery 5V 9V 12V DC Rechargeable