Here is a multifunctional charger that you can use with your iPhone or iPod or many other devices. The main feature is solar charging using a 4.5V/100mA solar cell but it can also accept voltage input varying from 3.7V to 7V from a wall wart for example. Having a 3.7V 2000mAh Lithium Polymer battery inside it can also be used as a power reserve in your travels.
To build this you will need a Minty Boost Kit which is a USB charger and to this USB port you will connect the device who’s internal battery is depleted. You will also need a charger for the LiPo battery. The Minty Boost will be connected to this LiPo charger along with the solar cell.
Depending on the solar cell you will be using, you might need to put a diode between the cell and the charger to prevent the draining of the LiPo battery when the light is low. All it needs now is a case. All parts used are very compact, the solar cell is 3.7″x2.4″. Using a bigger one however will decrease the charging time.
It can’t take more than one hour to build it and considering the usability of this charger i wish you all good luck with your build.