IEC 62864-1:2016 applies to series hybrid systems (electrically connected) with onboard energy storage (hereinafter referred as hybrid system). This standard specifies the following basic requirements, characteristics, functions and test methods for hybrid systems: - energy management to control the power flow among primary power source, energy storage system and power converters; - energy consumption, energy efficiency and regenerated energy; - vehicle characteristics achieved by energy storage system; - test methods of combined test; and - test methods of completed vehicles based on factory (stationary) and field (running) tests.