The maximum discharge current of a battery is also determined by three factors: firstly, the maximum discharge current of the inverter itself, secondly, the load is too small, and thirdly, the maximum allowable discharge current of the battery. Under normal circumstances, the discharge current of a battery is determined by the load. The discharge current of the battery is equal to the load power/battery voltage * inverter efficiency. If the load power is 3kW, the battery voltage is 48V, and the inverter efficiency is 0.96, then the maximum charging current at this time is 3000/(48 * 0.96)=60A. It should be noted that the charging and discharging capacitance of the battery may be different. Some lead carbon batteries can have a discharge current of up to 1C. During the normal operation of the photovoltaic energy storage system, if there is light, the current of the battery may not be calculated according to the above formula, and the current of the battery should be less because it is possible that both the photovoltaic and battery supply power to the load.