I'm having an electrician install a 6kw 240v split-chase inverter/battery charger, a 5.2kwh/48v battery, and a 110v to 48v 25amps battery charger. The inverter will have its input connected to the main panel and its output connected to our 6-group sub-panel, so as long as the main panel gets power from the grid, the inverter will provide pass-through to the sub-panel.
The battery charger will be connected to the battery, which gets connected to the 48v port of the inverter. The inverter will have its dip-switches set to never charge the battery, as that will be the job of the battery charger.
The idea is that when the power goes out, the inverter switches automatically to battery power. I'll need to connect the 110v output of the EV6 to the battery charger before the battery is exhausted and that will recharge the battery as long as the average power usage on the sub-panel is less than the power that the EV6 can provide. The battery supports peak loads of 100 amps output so that will handle peak loads when appliances or our well pump switches on, something the EV6 alone would not be able to handle.
I have no idea whether this will work but will find out soon enough