An Energy Management System for fuel cell/battery vehicles was developed to minimize fuel consumption and extend the lifespan of powertrain components. The system uses a multi-objective online optimization technique to balance actual fuel usage, stress on the fuel cell and battery, and battery state of charge. This approach does not require prior knowledge of driving patterns. By splitting power demand among available sources, the system effectively reduces strain on components. Simulation results demonstrate the system's efficiency, achieving near-optimal results compared to traditional methods.