Electric vehicles are gaining significant market share and will rapidly develop in the next few years. However, the optimization of the power train is still a topic requiring investigations to achieve an entire system optimization. Most of the literature on this topic is focused on single components of the power train, such as batteries, power converters, motors, etc. All these devices still require improvements, are worth investigation, and represent interesting fields of research. Moreover, the design of the overall system is still an issue, and it is the key to achieving optimization of costs, weights, and volumes also considering lifetime, safety, standards, and regulation requirements. Electric vehicles also represent an opportunity related to recyclability aspects such as the second life of batteries or material recycling, and this needs consideration and innovative solutions. This Special Issue aims to provide the current state-of-the-art technology in the design of the power train, updated status of this field, and to cover new aspects and new solutions. Topics of interests include (but are not limited to): Power electronic converters such as inverters, onboard chargers, and DC/DC converters; Reliability and lifetime estimation of powertrain subsystems and components; Thermal management solutions for the drive unit, onboard power electronics, and battery modules; System-level optimization considering performance, cost, efficiency, and reliability; Safety requirements and protection solutions; Design of motors; Design for wide-bandgap drives.