I'd be all over this
. A super-extended battery for those camera models. As I write this, there are still a few rewards available which will get you one of these batteries for $1 + $6 shipping! Once those are gone, you'll have to donate $35 to get one of the batteries.
This is a Kickstarter campaign
and it has far exceeded its goal.
I found this video to be a little confusing. The Limefuel Epic is a battery backpack. The Limefuel Epic on its own is said to be able to power your GoPro for 7 to ...