I have a small cabin on the northern CA coast that has intermittent power from the utility. I have looked at Will's videos on Growatt systems and it looks like what I might need. But need some help confirming this. When utility power goes down, I want to be sure, mainly that the fridge/ freezer has power. We are not there at times when the power quits. It would be nice to power a few other things like lights at those times as well. As I understand it, the Growatt units have a transfer switch that will switch between utility, solar and battery. I am thinking of using 2 100 watt lithium batteries with the system and having them charged by the utility or solar ( 2-100 watt panels) controlled by the transfer switch. Am I on the right track here? And what Growatt units would work for my needs?Thanks for the help in advance.