(via MAKEzine blog)
I’ve seen a lot of 9V battery based USB chargers. Most seem built around an Altoids mint container. This one is far smaller, and doesn’t have room to actually hold the 9V battery. Basically, you plug the battery in on one side and the USB device which needs charged in the other. I’ve skipped all the other 9V USB guides, but I may try to put one of these together just for those occasions when I have something which charges or runs off a USB connection. It even has a cool little LED so you can tell when it’s working.
One of the really cool things about this is the charger itself is built from the shell of a 9V battery. Instructions and images are given for disassembling one battery to build the charger. Obviously, then, you need a non-disassembled battery to hook up and provide power for the USB port.
[tags]9V USB charger, YAN9VUSBC (Yet another 9 volt USB charger)[/tags]