not true, the amount of power has nothing to do with wattage, but instead ampheres.
And the guage depends on how long the wire is...
this is what my MECP book says about it
iasca's recomended MINIMUM wire gage size
first number is current in ampheres. Second number is wire guage to use..
Also, you're gonna have about 15ft of wire, you'll have a slight voltage drop using 4 guage if you go over 16ft, I did, got 2 guage and had full voltage traveling through, now I have more power and had to switch to 1/0 guage wire with a distro block
up to 4 feet total amp draw
0-20 is 14ga
20-35 is 12ga
35-50 is 10ga
50-65 is 8ga
65-85 is 6ga
85-105 is 6ga
105-125 is 4ga
125-150 is 2ga
4' to 7'
0-20 is 12ga
20-35 is 10ga
35-50 is 8ga
50-65 is 8ga
65-85 is 6 ga
85-105 is 6 ga
105-125 is 4ga
125-150 is 2ga
7' to 10'
0-20 is 12ga
20-35 is 8ga
35-50 is 8ga
50-65 is 6ga
65-85 is 4ga
85-105 is 4ga
105-125 is 4ga
125-150 is 2ga
10' to 13'
0-20 is 10ga
20-35 is 8ga
35-50 is 6ga
50-65 is 4ga
65-85 is 4ga
85-105 is 2ga
105-125 is 2ag
125-150 is 0ga
13' to 16'
0-20 is 10ga
20-35 is 6ga
35-50 is 4ga
50-65 is 4ga
65-85 is 2ga
85-105 is 2ga
105-125 is 0ga
125-150 is 0ga
16' to 19'
0-20 is 8ga
20-35 is 6ga
35-50 is 4ga
50-65 is 4ga
65-85 is 2 ga
85-105 is 2ga
105-125 is 0ga
125-150 is 0ga
19' to 22'
0-20 is 8ga
20-35 is 6ga
35-50 is 4ga
50-65 is 4ga
65-85 is 2ga
85-105 is 2ga
105-125 is 0ga
125-150 is 0ga
22' to 28'
0-20 is 8ga
20-35 is 4ga
35-50 is 4ga
50-65 is 2ga
65-85 is 0ga
85-105 is 0ga
105-125 is 0ga
125-150 is 00ga