Kelty got the idea for the solar-powered charger from the Minty Boost, a $20 charger powered by two AA alkaline batteries. It’s called the Minty Boost because it is also housed in an Altoids breath mints tin. But it had its shortcomings.
“The problem is, with an iPod Touch or an iPhone, the battery in an iPhone is so big that it will deplete the batteries [in the Minty Boost] and you’ll only get half a charge,” he explained.
To improve upon the Minty Boost, Kelty replaced the AA batteries with a rechargeable lithium polymer battery and added a small solar panel. The solar panel recharges the internal battery, which in turn recharges the iPhone.
“The idea is that you can leave this out in the sun during the day while you’re using your phone, or whatever device, and at night time, plug your phone into it and you’re good to go,” Kelty said.