Testing Solar Panel

Last Friday, I brought home a set of the solar panels along with charging equipment. I began cleaning the equipment and making visual checks for damages. A rough outline of the circuit diagram was drawn on paper. I noticed that wire size seems be chosen randomly for various connections according to the battery box. I made a note to check NEMA standards for wire size according to amperage when measured. I ordered a multimeter to test amperage at various locations. Currently, I am working on incorporating quick disconnects and measurement points in the wiring schematic.