Typical residential direct grid-tied inverters cannot be used to charge battery banks; they only convert incoming DC power into outgoing AC power. However, “multimode” inverters can send and receive grid power and receive power from a backup battery bank, operating in off-grid mode. “Stand-alone” inverters can’t interface with the grid and operate in off-grid mode only; these are generally less expensive than multimode inverters.
Desirable inverter features for off-grid cabins include:
• Built-in 120 VAC battery charger for use with a portable generator
• Sine instead of modified square waveform for better load efficiency and compatibility
• “Search” mode to reduce power consumption when no loads are running
• Remote display so the inverter can be controlled and monitored from the living area