A convenient invention that allows a person to charge their phone after exhausting all the battery power. By letting the solar panel to charge in the sun which is then moved to the power bank where it can be stored for later use. And with the solar panel glued on top of the backpack it can be charge as you go but just make sure it has natural light. However the drawback is that the solar panel require sunlight which can only be found outside and most of the time people stay inside buildings. But for example if you are playing football or so you can set the back pack outside and while you play the battery will fill up.
for more information: http://www.instructables.com/id/SOLAR-BAG/
