This is a simple step-by-step guide to making a USB bare wire power cord to be used in various Arduino projects. I needed it for a water quality sampling project I'm working on and I thought it might be of general interest.

This is an old Blackberry USB power cord discarded from a previous life.

Simply cut the cord to the desired length (from the USB end). I don't know how long a cord I need so this may actually be a bit long. This cable is older and has a relatively thick foil shield.

The only wires of interest are the black and red wires. Trim everything else away.

It will be convenient to solder two solid pieces of wire onto the red and black twisted wires.

I put shrink wrap around the individual wires (didn't seem to have any small black shrink wrap so blue is the new black) and then shrink wrap around these and then shrink wrap around the whole thing.

Finished! The wires can now be used easily connect directly to a project or to a connector such as a barrel connector. Note: The rechargeable Li-ion battery happens to be a bit less than 1" diameter so I'm hoping all my electronics and battery will fit inside a standard PVC tube.