Some time ago I posted some details of the proposed Brunton All Day Power Pack for the GoPro 3+. The Brunton All Day bacpac is designed to add additional battery power to your GoPro. It will therefore in turn add additional filming time which can only be a good thing.
Compatible with GOPRO HERO3+
Input & Output with standard USB
Water and Shock-proof Case
Adventure armor has all the durability of your normal Gropro case
Provides 4X Runtime for GOPRO & 3X Smart Phone Charge
I have one on its way for test/review.