I am adding an Orion 121230 dcdc charger to my set up. I currently have 165w solar panel on a 100/20 controller and that runs to a 100ah lithium. It cannot get to 14.4 with the panel alone. Under the hood of the truck I have a factory battery.... Flooded I believe, and that is connected to a optima lead acid (48ah) through a blue sea ML-ACR (Automatic Charging Relay) that it not connected to the lithium. I wan to keep the ACR in case I need to connect the starter battery and it together via a switch in case I need a jump start. How or should I do this? Can I connect the engine connection wire directly to the positive terminal on the optima? Will that work?
Thanks