The electric vehicles (EVs) industry is currently experiencing a rapid growth. The reasons can be attributed to a rise in environmental awareness, fueled by regulatory interventions that simultaneously encourage the adoption of EVs and strictly regulate the emissions of internal combustion engine (ICE) vehicles. In this expanding trend, retrofit kits are a valid solution that does not involve the production of new cars. The EVERGRIN project, which is the focus of this thesis, intends to develop an approved conversion kit able to turn a modern ICE vehicle into an electric one. The difference with respect to other projects is the existence of a Vehicle Management Unit (VMU), a control unit that allows to centralize into a single device the monitoring activities of the original electric and electronic elements of the converted car.