... advantages of high quality sine wave AC output, microcomputer control, humanness design, and it is simple, stable, no ... accumulator.* With three stage charges for battery choice* Protect Inverter overload, under voltage, over voltage, over temperature, short ... 5%(Linear load) Inverter efficiency≥85%Work environmental temperature-10°C~60°CWork environmental elevation≤1000m 20KW off grid solar inverter