Well, I guess that's the difference between "chassis wiring" and "power transmission" in the table at https://www.powerstream.com/Wire_Size.htm https://www.powe

Well, I guess that's the difference between "chassis wiring" and "power transmission" in the table at https://www.powerstream.com/Wire_Size.htm https://www.powerstream.com/Wire_Size.htm It's about how long your wires are going to be, and a desktop electronic project has at least orders of magnitude smaller cable than a van, I'd say.