Design of a Swappable Battery System for a Low Voltage Urban Battery Electric Vehicle

With the rapid development of urban low-voltage electric vehicles (EVs) in fields such as short-distance travelling and logistics and delivery, the issues of range and charging efficiency are becoming more and more evident. The traditional fixed charging method has limitations such as long charging time and high cost of infrastructure construction, which affects the user experience and market penetration. In this thesis, an innovative battery swap system is designed for the M1 class of urban passenger cars, represented by the Fiat 500e. The study transforms the original 400V high-voltage power architecture into a modular 48V low-voltage system, which improves safety while providing greater scenario compatibility for battery swap operations. The study firstly systematically sorted out the strategies and patent layouts of the world's mainstream power swap technologies, classified and analyzed them from the viewpoints of battery module form, swapping method and interface design, which provided theoretical support for this design. Then, based on the existing structural boundaries of the vehicle, a variety of design options for the swap path are proposed and modelled and optimized iteratively by SolidWorks. In the design stage of the module and transpallet, the design of the structure, electrical interface and fixing mechanism of the transpallet system is completed by taking into account the actual core parameters and packaging limitations, vehicle boundaries, material strength and power support conditions. Its mechanical reliability is verified by finite element method. Finally, a prototype of the system is realized, which is suitable for the parallel arrangement of two battery modules and has the ability of precise guidance and fast locking. The research results have certain reference value for improving the service efficiency and energy supply convenience of urban low-voltage electric vehicles and also provide a design paradigm for the engineering of low-cost power swap technology.