How to Solder a resistor to an LED
A basic instruction for electronic enthusiasts. I use an RGB LED and a 510 ohm resistor as I may change from 6 to 9 volts later, but with my LEDs i could go as low as 330 ohms. I sacrifice some brightness for the sake of longer life. To choose your resistor, the value in ohms = voltage of your batteries or power supply / (as in divided by) the amperage that your LED needs to run.