If the generator is not large enough to power the heat pump and the lighting, what's the point? I'm leaving.

You'd better ask your insurance company if they will even insure you if you put batteries of this magnitude in your garage. Same as an electric vehicle. Fire risk if over charged or short.

My batteries are outside on an open air porch. On a slab with concrete board walls and metal cover. Any fire will be localized and should be contained. Each cell I have is individually monitored and sensed for over or under conditions.