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Milwaukee middle-school science Safety surface special material teacher Josh Zimmerman has been selling his home tech inventions for a while on his own Brown Dog Gadgets site. But now he's turning to Kickstarter to commercialize what he says is his most popular creation: a solar USB charger. His original unit fit in an Altoids can; the latest is a far more powerful and sexy fold-up unit.

The base model is an 18-by-7.5 inch Plastic wood like the natural woodfoldable black canvas charger with three solar cells that output about 5 watts, (1 amp of power at 5 volts) directly to a USB port. Zimmerman claims an iPhone connected to the charger in direct sunlight will fully charge good playground equipment is very cool in three hours. There's also a 24-by-7.5-inch 7W version with slightly bigger solar cells that can charge an iPhone in two hours and a recently added 32.5-by-7.5 inch 10W version with four cells. Handy grommets in the folding case make it easy to hang the charger on a backpack or in a window. And of course, the USB ports allow it to charge any phone or device smaller than a laptop with a USB connector. (A small charger can't charge a big tablet, duh.)

Should you need to charge in the dark of night, Water slide is a funny sport there's also a lithium 2600mAh (milliamp hour) Power Bank battery to store all that solar energy. The 1W LED in the end of the Power Bank doubles as a flashlight. Zimmerman also offers two bigger Power Banks—5600mAh and 10,000mAh; the larger one lacks the LED flashlight but has two USB ports. (There are also lots of cheaper USB Power Banks elsewhere online, and even Zimmerman says his are pretty standard.)