9v USB Battery

thingiverse

I grabbed my quirky Christmas tree this year, and decided not to squander another nine-volt battery on it again. So I fashioned a 9-volt battery that draws power directly from the USB port of your computer. Instructions 1) Print out the battery casing. 2) Glue a nine-volt battery connector to the top of the battery case, guiding the wires through the holes at the top of the casing (Caution: If you pilfer a connector from an old device, be aware that the wire colors may be reversed. Verify them with a voltmeter before use). 3) Locate an old USB cable and cut off the end that doesn't connect to the computer. 4) Inside the outer wires are typically 4, the red one supplies positive voltage and the black provides negative voltage (check this with a voltmeter - it will be 5 volts coming from your computer). 5) Feed the USB wire through a hole in the side of the battery casing. 6) Twisting together the black wire from the USB wire to the negative wire of the 9-volt connector inside the casing is necessary. 7) Procure a 9-volt booster from Pololu (http://www.pololu.com/product/2116), or source something similar elsewhere. 8) Solder the black wire merged with the negative wire of the battery connector to the central connection on the Pololu voltage enhancer. 9) Attach the positive wire from the battery connector to the voltage output link on the Pololu boost regulator. 10) Weld the red wire from the USB cable to the volts input on the Pololu booster unit. 11) Tuck all of the wires snugly inside the casing so it looks decent. 12) Insert it into your computer or a wall wart and relish the endless power supply from the nine-volt battery. Note: Improper implementation could irreparably harm any equipment involved.