What is the meaning of "Return To Utility Voltage/SOC" in my X3-NEO-LV inverter settings?

When the voltage/SOC is lower than the setted value, the battery stars to charge.
(For lead-acid battery) Default: 42 V, range:40-60 V; (For Lithium-ion battery) Default: 20%, range:10~40%.
Note: The priority of Alarm Voltage/Soc is higher than Return To Utility Voltage/SOC