Hybrid inverter

Ok thanks all I had a mobile rv service come to do the connections for it and he kept saying you can't do it. And he also instaled a sup panel in front compartment, I am not great with el but coud not understand why it coud not be connected in main panel as it had at least 2 emty spaces for breakers, anyway in the end he moved all but HW and converter out in sub panel so it will run of inverter. It started and ran ouer 15000 btu air conditioner for about 5 minutes befor we shut it down. Then connected to mains and charger charged batteries at 90 + A
Now I am a happy camper.
Frank.