Does anyone make a pure sine inverter in the 4kw range that has an automatic transfer switch that would drop back to grid when battery power drops to a set level? Xantrex XW kinda mentions it but I could not find that in the manual. I am not going to grid tie so want to setup most of the house circuits to use inverter until battery voltage hits 50% SOC(48.81 volts by one chart I have).
Water heater and dryer would not be on the inverter panel but the bulk of the house could easily run that way.
Main loads would be chest freezers, TV/surround system, furnace. TV/surround use about 2.4kwh a day, chest freezer probably 1kwh(need to replace that one with a newer more energy efficient model), rest of the loads are a few lights and whatever furnace draws(I have to put it on a killa watt meter this fall).
Lighting is going towards all LED(have a couple fluorescent fixtures in the kitchen to swap out yet) so negligible draw.
Living alone I do not use that much electricity and once I get rid of that power pig of a water heater it will drop even further. Water heater is being replaced with an on demand natural gas unit.