The invention of automobiles with an internal combustion engine is one of the greatest achievements. Nowadays automobiles are the fundamental source of transportation. However, a large number of automobiles in use around the world caused and causing critical problems for society. Environmental pollution is one of the major problems in the current world. And conventional vehicles are one of the key reasons for environmental pollution. And fossil fuel crisis is another big problem in the current world. To reduce environmental pollution and fossil fuel crisis use of electric vehicles is the main solution. This book provides an approach for retrofitting of engine powered vehicle into an electric vehicle. It also deals with the fundamentals, theory, and design of electric vehicle battery pack and battery management system and electric vehicle powertrain. This book includes various subsystems like energy storage system, battery pack designing, battery management system designing, traction motors, gearbox, and electric vehicle chargers.