Development of Mechanical Design for Electric Vehicle Retrofit Kit

In today's world, electric vehicle (EV) production is increasing due to updated regulations, the fight against the climate crisis and governments' pressure on automotive manufacturers. In this context, it is not sustainable to consider currently produced cars with internal combustion engines as unusable in the future. The body design of a traditional internal combustion car differs from today's EVs. For this reason, when starting the electrical retrofitting of an existing design, the first step should be started with the flexible battery pack design for available spaces. This thesis introduces flexible-modular battery pack design and assembly of equipment such as traction assembly including gearbox, powerbox and 1.8kW charger in available spaces for the first generation Fiat Panda in Solidworks 2023 environment. The modules used in the designed custom battery pack use prismatic battery cells with 50Ah electricity storage capacity produced by BYD and licensed by Samsung. Two of the modules have 20 battery cells, while one has 16 cells, and the battery pack contains a total of 56 prismatic cells in 3 modules. As the beginning of the project, Flexible Bus Bars are introduced to provide power distribution between prismatic cells and between modules. In the next stage, electrical powertrain elements are introduced to the available spaces in the Fiat Panda chassis. The engine support part is designed to mount the SMAC 200 series electric motor to the Panda's chassis in accordance with the available space and reduction-differential gearbox. Static analyzes for the designed and developed engine support part are carried out using Solidworks, taking into account the weight of the gearbox as well as the own weight of the e-motor. Subsequently, the connection of the battery pack to the chassis was developed. A simple, lightweight and high-strength connection support part is required for the rear support element. For this purpose, a rear connection support assembly consisting of 7 parts in total is developed. A lightweight shield made of sheet metal was developed to protect the rear support assembly. While this rear shield was designed not to affect the performance of the cooling channels under the battery pack, it was also designed not to affect the driving dynamics of the car in the most compressed and extended state of the suspension. Power wiring is a must for the battery pack. In this process, electrical routing is performed on Solidworks according to the previously designed electrical schematic. In order to ensure the connection of each of the electrical components such as relays, current sensors and resistors, the necessary power wiring is completed by providing appropriate terminal lugs. At this point, the necessary equipment in terms of the mechanical parts and battery pack of the retrofit kit has been assembled in the available spaces on the vehicle chassis. The routing of the retrofit kit's power wiring on the Panda's chassis must be planned. In order to achieve this, the necessary male and female sockets are defined for elements such as powerbox and electric motor, and then they are completed in accordance with the architecture using appropriate routes. The main aim of this project is increasing the mechanical design properties in Solidworks environment.