Here everything is found in the trash.
-1 usb boost DC 0.9v/5v (or disassemble a USB Car Cigarette Charger Lighter 5v,+ at the end and-on the side of the element)
-1 Battery case (child games)
-1 solar panel (here 12 V) but 5v is the best!
-1 GO-Pro Battery charge case, very important! (Here find in Dechetterie) charge indicator 5v !!! 5 euros for me
Step 1: New Usb or Recovery
-for 60 cents on amazon or recover an old 5v car charger sacrificed -_-
I filled it with hot glue gun (for wear)
Step 2: The GO-PRO Charger
5 euro or if you have the chance to find it like me, think to stick the interrupter inside that allows to activate the loading (small button)
Step 3: The Battery Case
-Just connect the son and drill 2 holes on the coter to pass the son when have firm.
Step 4: Final
and voila and the possibility to make all kinds of different connections in usb (4 wire in usb)