Could use some advice. I started with a small solar offgrid system and have expanded to charging my car and running my AC with it to cut back electric bill. However when I don't drive a lot power is wasted. Eventually I would like to upgrade to use more of my solar more efficiently. I was thinking of having an inverter where the grid comes into it. When my batteries get to %50 have it switch automatically to grid power as a backup till solar recharges batteries. I know the Sol Arc supports this. But it's also $8k just for the inverter. I have a 100A breaker box and a small electric stove (not used much). Furnace and water are gas. AC is a 450 watts window unit. Charging car can be done from 2k to 8k watts (adjustable). I have 20+kWh of LiFePo4 batteries and 3.4k watts of solar (will expand next year). Any good more affordable options to set this up or is Sol Arc it?