In this instructable I will show you how to make a solar powered USB charger for your phone or mp3 player. This is item is great because it doesn't always have to be sunny for you to charge you phone or other USB device. The way the circuit is designed lets the solar panel be constantly charging the batteries and by flipping the switch the batteries start to charge your USB powered device.
Hope you like it.
Step 1: Supplies
To make the Solar USB Phone Charger with Battery Backup you will need:
6 volt Solar Panel
4 AA Battery holder
4 AA Rechargeable Batteries
2 diodes (I used 1n4007 but any will work)
Solder and soldering iron (optional)
2 100 Ohm resistors (only for apple devices)
Heat Shrink (optional)
You can find all of these parts at your local Radio shack. Lets start making it.
Step 2: Making It
To make it just follow the circuit diagram as shown. Make sure all of your wires have good electrical connection. If you don't have a soldering iron than you can twist the wires together and cover it with tape. The first circuit shown charges all USB devices except apple devices. To charge all devices including apple products add 2 100 ohm resistors connected to the two data pins on the female USB as shown in the second picture.
If you have any questions then post it in the comments.