Forgot to charge your phone? Your dog is waiting for his walk, you have lots of calls to make and you have to check on your investments. No problem. Just grab your charger, plug it into your phone with your USB cable, put it in your pocket and off you go. The dog's happy, your phone has power, and you're in touch with the world.
Shockproof, Dustproof, Water Resistant - Charge it by USB input: Micro USB or iPhone lighting port. Keep it charged by sunlight when offgrid. More power to charge larger smartphones whose batteries are 2750 mAh or more. Power when and where you need it.
With 4 solar panels your battery will charge in the field using the sun in 1/4 the time of a single panel unit.