Hi everyone newbie here with a question. I have a 12v solar panel, battery, fan and temperature sensor. Okay so I ran into the problem with the charging system were you cannot charge and discharge at the same time. Solution add another battery right ? Well problem with adding another battery I do not know how to switch between both batteries. Let me explain so if I have one battery charging by solar then I can use the charged battery to power the system. That’s my problem I do not know have to switch between both batteries to use one at a time. Anyone have any idea how how can make this work without having to go unplug the discharged battery and re-hook up the charged battery? Thanks again.