To make your own FitBit charger, gather the necessary components: two different colors of electrical tape and a standard USB cable. Use a USB to wall socket adaptor with the USB cable once you have completed the device to provide the FitBit with a stronger charge. The Fitbit uses a Micro USB charging relay, and it has two connection points that can be hooked up with nonstandard chargers based on the correct wire configurations.
Begin by splitting a USB cable. Strip the cable carefully and you should see four smaller wires and cables within: a red power cable for the 5 V DC current, a black grounding cable, a green negative data cable and a white positive data cable. Connect the red cable to the positive connector on the FitBit and the grounding cable to the negative ground connector on the device. Make sure the two cables do not touch each other, and use the tape strips to space the cables evenly away from each other.
Use one color to signify the positive end and one color to signify the negative end, and tape the two with the appropriate connections so that they are evenly spaced for repeat applications. Because both chargers need to connect for the charge to work, tape the two carefully together, and apply them to the FitBit to begin charging.