The COOLER 0 DEGREE refrigerator operates in different modes based on the cold requirements of the 0 degree and refrigerator compartments. It has three normal operation modes: cold request only from the 0 degree compartment, cold request from both compartments, or cold request only from the refrigerator compartment. Additionally, it features a defrosting cycle for the battery evaporator that occurs every 3 hours of compressor operation and is managed by the evaporator sensor. An acoustic alarm activates if the appliance door remains open for more than 3 minutes.