Hybrid proton exchange membrane fuel cell (PEMFC)/battery power system is regarded as one of the most potential alternative power solutions in vehicular application since its low or zero emission and long life comparing to conventional engine and stand-alone battery pack. As the hybridization may reduce the fuel efficiency and battery efficiency because of interconnected power distribution, elaborate power management is prerequisite. This study presents DC/DC power converters including unidirectional boost and bidirectional types by using time delay control (TDC) to implement power management for hybrid power system. The bidirectional DC/DC converter operation mode is automatically switched by power management rules with battery state-of-charge (SOC) constraint. MATLAB/Simulink model of full hybrid power system is constructed to simulate the efficacy of proposed algorithm. Proportional-integral control (PIC) is employed in order to compare the control performance. Experimental validation is also performed with commercial PEMFC Horizon H-100, lithium-ion battery pack, DC/DC unidirectional and bidirectional converter prototype with National Instrument (NI) LabVIEW. Copyright (C) 2015, Hydrogen Energy Publications, LLC. Published by Elsevier Ltd. All rights reserved.