Ordered just the inverter and one battery. My goal was to power the house during occasional power outages that the TVA likes to use to manage anomalies. I do NOT have solar. I have a 50 amp generator inlet box on the outside of the house, so I ordered a cable to go from the 30 amp twist lock to the 50 amp twist lock. After charging the battery and switching the manual interlock, the house did indeed come to life. I was able to use one of the medium size burners on the induction cooktop on high. One big question I had, and had gotten conflicting answers on, was whether I could plug my small generator into the 120 V charging inlet, and get 240 V out to the house at the same time. It worked! That way if the outage should last for an extended time, I would be able to keep the battery charged with the generator, while still getting some power to the house. You could see on the panel that 1800 watts were going in, almost 4000 watts were going out. Over time, I would expect that as long as my average draw was 1800 watts or less, I would have power as long as I could keep the generator gassed. I was NOT able to run my 2-1/2 ton central air, but honestly I was not expecting to be able to. Even on utility power the lights noticeably dim when the unit kicks on. Possiblly a soft start might do the trick. So for me, it solved the problem I was concerned with. One nice bonus is that I plugged the tankless water into one of the front AC plugs. That way the water heater won’t shut off in the middle of a shower if the power blips. When that happens the water goes cold really fast and makes for an exciting day.