The defrost cycle on LG refrigerators typically lasts for about 20 minutes. During this cycle, the refrigerator’s compressor is turned off, and the defrost heater is activated to melt any ice or frost that has accumulated on the evaporator coils. This helps to maintain optimal cooling efficiency and prevent ice buildup. It is important to note that the duration of the defrost cycle may vary depending on the model and specific settings of the refrigerator. For more detailed information, it is recommended to refer to the user manual or contact LG customer support.