... high tech 3.CE, RoHS 4.solar energy system Features1. High efficiency up to 92% for grid ... 3. Inverter input voltage range: DC22~60V4. This system don't use solar charge controller. low cost.5 ... voltage, Frequency, Protection functions(short circuit, overload, over temperature, low battery,.) and so on.WarrantyWe provide 1 year warranty ... or by Air. 4KW Grid Tie Solar System, AC110V Solar System On Grid