*Battery Pack USB charger*
PDA's, iPods, PSP's, etc, they all can be recharged through their USB cable. If you look closely, the USB port charges devices at 5vdc. Well, that's a piece of cake! Just take 4 AA batteries (1.5v each * 4=5v) and solder the wires of the battery case to a USB female plug. A little hot glue to keep everything in place, and DONE!
I bought all my parts from Radio Shack, but you could do just as well if you make your own battery holder from some bit of plastic box or whatever, and cut a female USB plug off of a bit of dead hardware. I had neither around, so I resorted to buying the stuff: it ran about $8.00
This is the "USB plug extender" You are going to cut it in half and use the female end.
This is the USB plug cut open. You just need a sharp pocket knife. Separate the two ends, carve out the block of hot glue that's in the middle (be careful not to damage the two outer wires of the plug. Save the black plastic covering. It makes things look a lot more professional when you are finished.
This is the female end of the plug you are going to use. Snip off the two wires/connections in the middle, leaving connections 1 and 4. You will solder the red and black wires from the battery holder to these.
WOW, what a cruddy soldering job! You can tell I haven't done this since high school. It works though. BE CAREFUL to get the wires lined up correctly. Red goes to the left wire, black goes to the right one (as you are looking at the back of the plug). If you get these wrong, you could fry your device!!!!!
That was the hard part! Now you just have to slip the black plastic cover over the top, fill the cavity with hot glue, and hot glue the plug onto the side of the battery pack. DONE!
I have had trouble getting this device to work properly with rechargeable batteries. The Nm-Hi AA's I was using are 1.2v each, (4.8v all together) so that may explain it. There is no harm done, the battery pack just does no good. Using it with standard 1.5v alkaline batteries works great.
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