I’m new and totally no electrical experience, I’m following Will’s 400 watts set up but with modification and that is no inverter because I want pure 12V only for simplicity and cost. What will be my drawing if the inverter will be removed in the picture? Do I need bus bar for negative wirings? Do I need main fuse immediately before my positive battery terminal? My loads are roof fan, food cooler, led light, cell phone, laptop and other gadgets. I have two battleborn 12V 100AH, TracerBN4215 MPPT 40amp, one 455watts solar panel (JA solar), fuse box for DC appliances, 50amp circuit breaker for my charge controller. So far, what I have done is installed my solar panel at the roof of my van and parallel connected the two batteries. I really appreciate your inputs, parts to be installed if I missed anything, and drawings if possible.