Solar is confusing enough without having different standards for measuring the size of wire you need. I have a problem with my solar set up and through the trouble shooting process I was asked what size wire went from the batteries to the inverter. I checked and it was 2 ga SAE. I was then asked if that was the same size as AWG. After some research, I found that SAE is 3- 12 percent smaller than AWG. Therefore it cannot carry as much current. By the way, AWG stands for American Wire Gage. SAE stands for Society of Automotive Engineers.
Why do they do that to us? Isn’t it confusing enough for the smaller the gauge the bigger the wire!! Who would setup something so backwards? Then they add 2/0 and that wire is lots bigger!
It is actually good to know that there is a difference and in some applications it could really be important.
Google can really help you figure it out. I hope someone can understand why they have such a confusing standard.