Electric Vehicle PowerBox and electrical harness with Vehicle Management Unit: Widespread adoption of Electric and Hybrid Vehicles is often seen as a necessary step in the decarbonization process, because it enables relocating and concentrating carbon emission sources away from densely inhabited locations to energy production facilities, which are more efficient in terms of energy conversion and well equipped for flue gas treatement. Altough favourable for emission reduction, Electric Vehicles are not as popular yet, mainly due to their higher intial cost: one solution to this problem is the electrification of Internal Combustion Engine Vehicles through so called “Retrofit Kits”, which allows owners to convert the vehicle(s) they already own for a fraction of the cost.