Most offgrid inverters have a generator input to which they will switch when you start the generator. If you replace the generator with the grid (and you have b

Most offgrid inverters have a generator input to which they will switch when you start the generator. If you replace the generator with the grid (and you have batteries) and the grid goes down they switch seamlessly to the batteries - well, within a fraction of a second, some applainces "blink". I am actually using this system as a sort of UPS for our office