"Yeah, I love the idea of stuff like this.  I own a portable solar panel and it's the greatest thing since sliced bread for mobile stuff when camping.  I live in Colorado and a little wind generator would be the business.  However, they make a big deal about how many times you can charge a device off the battery, but seem to dance around how long it takes that battery to charge.  I understand results may vary, and free energy is free energy, but are talking hours or days?"