Man has learned to make fire, and provided himself with warmth and hot food. A fire of coals, the user can add to that getting power. As a result, even while away from the grid you can charge your iPhone, iPad, laptop, browser or portable TV.
Video portal YouTube user under the name Kipkay shows that charge mobile devices in field conditions is possible by means of a small thermoelectric generator, which converts thermal energy into electrical energy.
To this end, he built a small "Dixieland", an aluminum can from under the coffee. The side of the bank secured thermoelectric generator that converts heat into electricity. To connect the cable with 30-pin connector that connects to the iPhone.
Now just put this pot on the fire (you can use an electric stove) and a few minutes begin charging mobile gadget.
Kipkay notes that the efficiency of such a generator is very low. And it is hardly to be expected that the energy received will last for more than charging the phone battery or work lights. But for tourists and enthusiasts enough.