Abstract: This disclosure provides a new high-efficiency air conditioning system for cooling a motor vehicle control cabin. Various components of the system have been optimized (including the motor, the drive train and the condenser) in a way that minimizes battery draw-down, and allows long-term operation on battery power alone. The main engine of the vehicle can be shut down during loading or when the driver is resting overnight, and does not need to be restarted for 8 hours or more. The air conditioning system of this invention enhances the driver's comfort and alertness after resting, decreases vehicle weight, and substantially reduces air pollution and noise. The invention has the added benefits of reducing fuel consumption and wear and tear on the truck's engine, thereby sustaining considerable cost benefit for the fleet operator.