There's a deal over at StackSocial you might want to take advantage of, but you'll have to hurry. The ZeroLemon SolarJuice 10000mAh Battery is on sale for $26, down from a regular price of $50. The deal on this solar-powered battery is only good for the rest of the day, though.
The ZeroLemon SolarJuice has a large solar panel on the top surface that can suck in the sun's rays to provide power for your gadgets. However, it takes a few days of direct sunlight to fill up the entire 10,000mAh battery. Of course, you can plug it into a wall to charge it up faster, then get a little spare juice casually throughout the day.
There are three USB ports, two of which can output 2A and a third for 1A. In addition, you get an LED flashlight built-into the battery. It's water-resistant too.
The StackSocial deal includes free shipping, but you have to act fast.