in a preferred embodiment , a thermostatically - controlled variable air - circulation mechanism and a thermostatically - controlled coolant - pump circulatable of coolant from a coolant vessel to the fan - containing cooling - coils air - space enclosure cyclically , and a coolant vessel - thermostat and freezing coils connected with an electrical freezer mechanism , are powered by dual batteries in electrical parallel when in use , and the freezer mechanism by solely one thereof when ignition is off for an automobile by virtue of solenoid switch , the fans being run in electrical series at predetermined lower temperatures and in parallel at predetermined higher temperatures by virtue of circuitry and thermostatically - controlled other solenoid switches , maximum ice - production being controlled thermostatically .