Abstract: A refrigerated truck has a power management system for optimally distributing power between one or more energy sources, energy sinks, or energy storage components on the refrigerated truck. One such power consuming component includes a refrigeration unit that cools a refrigerated compartment of the refrigerated truck. Particularly with regard to this refrigeration unit, the power management system is operative to direct power from multiple power sources to the refrigeration unit so as to efficiently use available power. To do so, the power management system dynamically determines the availability of certain power sources and selects a preferred power source based on availability and a defined order of power source preference.