Chapter 6 Engine Types and Classifi cations 143 Copyright by Goodheart-Willcox Co., Inc. Battery Hydrogen tanks Fuel cell module System module Electric motor Power distribution unit (PDU) Figure 6-38. This is a modern design for a fuel cell–powered vehicle. Note the parts of the system. (Mercedes-Benz) motor-generator converts the movement of its armature into electricity. Since it takes considerable energy to turn the armature, the car is slowed, assisting the braking of the vehicle. Fuel Cell A fuel cell can serve as a power plant by converting chemicals into electricity. See Figure 6-38. In a fuel cell,