Here's how I explain it to people. Imagine you have a piece of pipe with water flowing through it. Voltage is the pressure of the water, Amperage is the amount of water flowing thru the pipe. Let's say you double the pressure of water, or voltage. You would in fact cut in half the amount of amperage for the same amount of water flowing thru the pipe. Or if you'd drop the voltage in half, you'd have to have double the size of pipe to get the amount of water flowing thru it to be the same. If you look on units that can run on 120/240, you'll see something like 120 volts, 10 amp or 240 volts, 5 amp. With LED lights, yours are 5 volt, but they draw milliamp. You only need a very small wire to get them powered up, unless you're running across long distances, then you'd need a bigger gauge wire because of voltage drop and amperage increases.