A few months ago I was in a campsite and saw some guy in the next site feeding little twigs into some tiny little burner for maybe an hour and a half, just constantly looking around for twigs. I thought it odd since there was a prohibition on campfires there, it was a National Park. And, I could not figure out why he did not put the kettle on the fire and get supper started, but instead he just kept trying to stoke the fire. Now I know what he was doing for an hour and a half.

Since it usually takes hours to charge up a phone, I really can't imagine why anyone would want one of those.

And, I wonder which is heavier, a solar power charger capable of powering a USB port or that thing?