chrisbh17, That's exactly what went thru my mind. I see the power and ground that came with the USB are 14ga or maybe even 12ga, yet they are supposed to be fused at 10 amps. So looking at the power outlet with 18ga and 20 amps, your mind takes a large step backwards and goes... this can't be right. Maybe I shouldn't use those wires for this USB. But as I look around trying to sort it out, I see that depending on the drop % (I'm guessing it means percentage voltage drop), the charts we typically see are 1 or 2% drop and those show 12 or 14 ga for 20amp circuits. But I saw a reference that auto makers use a 5% or higher drop... and in those charts an 18ga can hold 20 amps of current, just not for the length of wire I estimate to be... but close. I don't understand when to use that sort of drop... perhaps it's the type of wire itself, because I do see different wire type references in the charts too and maybe the wire type determines how much voltage will be lost over x amount of distance. I guess I'm hoping to "get schooled" a bit, as I've got tons of mechanical and computer background, but almost no electrical knowledge.