US Patent 9975403 Transport refrigeration system and method for operating

A refrigeration system having a refrigeration unit (22) for providing temperature conditioned air to a temperature controlled space, an engine (26) and an electric generation device (24) driven by the engine, is provided with a battery system (28) for supplying electric power. A method of operating the transport refrigeration includes, during a high cooling demand mode, operating the engine (26) to drive the electric generation device (24) for supplying electric power and simultaneously employing the battery system (28) for supplying electric power to jointly power the plurality of power demand loads (50, 42, 46, 48) of the refrigerant unit.