5 V Smartphone Solar/Battery Charger




parts u'll need :

-USB extention cable

-plastic casing

-battery holder for 4 AA batteries

8V Solar panel with less then 200 mA

2 5V (or higher) diods

some wire

tools u'll need:

soldering iron


electronic pliers

hot glue gun

Step 1:

cut the USB extension cable in two and isolate the wires from each other

Step 2:

solder one diod to the red wire so no electricity can pass from the USB side of the cable

solder the green and white wire together and isolate em with some tape

Step 3:

solder the negativ side of the battery pack to the black USB wire and the red one to the positiv side

solder the second diod to the red wire so no electricity can pass from the battery to the solar panel

Step 4:

make a knot in the Usb wire and cut a hole in the side of the plastic cable, and another one in the top of the casing.

solder the negativ side of the solar panel to the black wire and the positiv to the diod on the red cable

glue the solar panel on top odf the box and lead the cables through the hole u cut before

and ur done :)



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    5 Discussions


    3 years ago

    Just wondering what your doing with regulating the output voltage?

    2 replies

    Reply 3 years ago

    I thought you would be better over shooting on the voltage and then regulating it down so when you have drained it a bit you would still be able to output full 5v. You've measured the voltage? Just thinking here that fully charged nimh cells can be up to 1.5v each or more, which could put you over 6v total. would hate for you to fry your phone if you didn't check


    Reply 3 years ago on Introduction

    solar panel is put on top of the box, i'll put up a picture of the hole thing finished :D