Don't you just hate it when you're taking photos with your camera then your battery just dies on you and there isn't anywhere to charge your camera! Well I have come up with a solution! It's to build a Portable USB Power Supply and I will show you how you build one in this Instructable. Here are the specs for Portable USB Power supply
battery life=over 3 hours
Step 1: Gather Materials
Here is a list of things you need to build the Portable USB Power Supply
1-5v voltage regulator
1-female usb port
philip screw driver
16/64" drill bit
hot glue gun
Step 2: Solder the Components on the Printed Circuit Board
Now solder the components listed below on the pcb board according to the photo below
U1=5v voltage regulator
D2= rectifying Diode
Female usb port
Step 3: Cut the Printed Circuit Board
To cut the pcb you must clamp the pcb in the vice with the top of the vice in line with the spot where you want to cut the pcb. Then run the knife along the top of the vice 20 times with pressure on the pcb. Flip the board over and do the same with the other side. Next squeeze the sides of the board. Then bend the board and it should just snap off cleanly if you ran the knife along the top of the vice the right number of times.
Step 4: Modify the Case
Now cut a notch in the case with a hand saw or dremel so the USB plug can fit in nicely. After that you need to drill a 16/64" hole in the case to put the led in. Then using a dremel cut out an opening so the switch can fit in the case.
Step 5: Put Everything in the Case
Screw the pcb to the case or glue it. Next hot glue the led in the hole you made earlier. Then hot glue the usb plug in the slot. Now put the Battery in the case it should fit tightly.
Step 6: Put the Top on and Try It Out
Now screw the lid on. Then try it out by plugging something in the usb slot and turning your Portable USB Power Supply on.