Characterization of a Fuel Cell/Battery Hybrid System for Electric Vehicle (EV) Applications

A fuel cell/battery hybrid system for an electric vehicle was characterized under simulated driving conditions. The fuel cell is a 72 cell stack with 270 cm² per cell of active electrode area. It has a continuous output of 1500 Watts and a peak power of 3000 Watts operating on hydrogen and atmospheric pressure air. The batteries are a tubular flooded lead-acid type. Seven 6 volt modules were connected in series with each module having a normal capacity of 205 Ahr. The fuel cell battery hybrid system was laboratory tested using a variable load battery cycler to simulate electric vehicle operation over a Modified Simplified Federal Urban Driving Schedule (MSFUDS). The fuel cell/battery hybrid operated successfully under steady state and dynamic conditions with the performance of the fuel cell only slightly degraded under the dynamic conditions of MSFUDS compared to steady state operation. For a hybrid system the electric motor, controller and auxiliary electronics could be designed to run more efficiently than with the fuel cell stack alone.