The GoodWe BT series is an AC-coupled retrofitting inverter that can upgrade existing three-phase on-grid photovoltaic systems to energy storage systems. The AC-coupled solution can convert any three-phase on-grid photovoltaic system into a battery energy storage system, enhancing independence from the grid and self-consumption. It is compatible with high-voltage Li-Ion batteries ranging from 180 to 600V and also features UPS-level transition for a stable and reliable power supply.