The exchange of the energy storage unit from an electric vehicle is considered an alternative to in-vehicle battery charging. If the exchange process is mechanically assisted or automated, the exchange can potentially be accomplished in much less time than that required for in-vehicle charging. Many means for accomplishing battery exchange have been proposed or attempted, with various degrees of success, from the late 1800's through the present. In recent years, battery exchange methods have not been embraced by the electric vehicle industry, in deference to fast in-vehicle battery charging. Only a small number of semi-automated mechanizations have actually been demonstrated.
The history of electric vehicle battery exchange is reviewed, focusing on innovations and technical lessons learned. Design and deployment considerations are identified for battery exchange in general, and specific embodiments thereof. A technical comparison with fast charging is presented. Possible configurations for automated or assisted battery replacement are reviewed, with advantages and limitations of each discussed. Safety and regulatory considerations, and institutional and technical impediments are cited. The need for battery interface standards is briefly discussed.