The off-grid solar PV system generally consists of a photovoltaic array composed of solar cell modules, solar charge and discharge controller, battery pack, off-grid inverter, DC load and AC load. The photovoltaic array converts solar energy into electric energy when there is light, and then supplies power to the load through the solar charge and discharge controller while charging the battery pack. When there is no light, the battery pack supplies power to the DC load through the solar charge and discharge controller. Meanwhile, the battery also supplies power directly to the independent inverter, which inverts into AC power and supplies power to the AC load.