以上四種工作模式都是在光伏和市電都有的情況下可選擇，如果沒有市電互補，逆變器只有一種工作模式，那就是光伏獨充模式。

Battery charging also has four ways to choose, if you choose to use the mains to charge the battery, it should be noted that the efficiency will be reduced, because the mains to charge the battery after release, there will be a certain amount of power loss, usually off the grid inverter charging and discharging efficiency is about 90%, so there will be about 10% of the power loss.

1) Photovoltaic priority: photovoltaic priority to battery charging, only when there is no photovoltaic, the battery will be charged by the mains. This mode is suitable for the utility price is relatively expensive, and the power supply requirements are not particularly high.

2) Mains priority: Mains priority to charge the battery, only when there is no mains, photovoltaic power to charge the battery. This model is suitable for the scenario where the mains electricity price is cheaper but there are frequent power outages.

3) Simultaneous charging of mains and PV: This mode is suitable for users with low mains price and high power supply requirements.

4) Photovoltaic sole charge: with or without mains power, only photovoltaic charge is used. This mode is suitable for the utility price is particularly high, and the demand for power supply is not very high.

The above four working modes are optional in the case of photovoltaic and mains power. If there is no mains complementary inverter, there is only one working mode, that is, photovoltaic single-charge mode.