The Solar USB Charger!

Have you ever been camping or driving and your phone runs out of battery?  These moments are very frustrating, and they led me to make my own solar phone charger.  Most retail solar chargers cost $40-$50, but by following this instructable, you can make your own for around $20!  Another great thing about this instructable is that is requires no soldering, so it is great for students or kids.  If for some reason something happens to your phone while charging with this device, I am not responsible.  Have fun!

You will need...

* A 9v 0.5 Watt Solar panel (Radioshack)
* A DPDT mini toggle switch (Radioshack)
* A USB extension cable- Male to Female (Dollar Store)
* 4 rechargeable AAA batteries (already had mine)
* 4 AAA battery holder
* Thin stranded wire
* Electric Tape
* A relatively small project enclosure (Radioshack)
* Optional- Labels
* A standard blocking diode


Tools
 
* Drill with drill bits
* Hot glue gun with glue
* Wire stripper

Step 1: Drill two holes on the lid of your project enclosure 2cm apart so the wires on your solar panel can enter the box.  Make sure the wires fit.  I made sure that my solar panel was all the way to one side of the enclosure so there was room for the switch to be installed.

Step 2: Drill a hole large enough for the top of your toggle switch to fit through on the opposite side of the solar panel.

Step 3: Fit your switch into the hole you drilled and hot glue it in place.

Step 4: Drill a hole in the side of the box as shown in the picture.  This will be for your USB cable.

Step 5: Put the solar panels wires through the holes you drilled, and hot glue the panel in place.  Attatch the blocking diode on the positive wire so electricity cant flow back into the solar panel.  This is extremely important, because the panel can be damaged if this is not done properly.  I found it easiest to not worry about that side's screws because the lid stays on fine without them, so feel free to put the panel on thop of them.

Step 6: Cut your USB extension cable in half, and save the Male side of the USB for other projects.  Strip the Female side of the USB's  wires, revealing  black, white, gray, and green wires.

Step 7: Twist together the white and green (data) wires, and put electric tapearound your connection.  This connection makes your phone understand that this is a charger.

Step 8: Feed the USB Cable through the hole in the side of the enclosure and hot glue it in place.  Make sure you leave some slack so if you mess up, you still have some wire to work with.

Step 9: Attatch the wires to your switch as shown in the diagram.  Make sure you keep positives on the same side as positives and negatives on the same side as negatives. 

Step 10: Hot Glue all of the wires onto the switch.  Put the lid on your project enclosure, switch the toggle switch so it is charging the AAAs, and let the solar panel charge up the batteries. 

Step 11: (optional) Put labels for "input" and "output" on either side of the switch so you know which side is which.

Plug your phone or USB cable into the Female USB cable, switch the toggle switch to "output", and let your phone charge.  Now you will never have to worry about getting stuck in the car with a dead phone, or even at the beach or a camping trip!  Enjoy!