In modern internal combustion engines a greater reduction of CO₂ emissions is required in order to significantly reduce fuel consumption and minimize the emissions of polluting gases, allowing them to fall within the strict limits set by current regulations. In a conventional engine control system, it is not possible to optimize the efficiency of the alternator in terms of emissions and fuel consumption, due to a constant voltage which is imposed and is not modifiable. On the contrary, in a system capable of controlling the voltage of the alternator, referring to such an alternator as "smart" hereafter, it would be possible to optimize its efficiency as a function of the vehicle/engine working points. This system requires first and foremost a communication protocol between the alternator and engine control unit, and a special sensor that gets data on the charging status of the battery.In this chapter a management strategy is proposed for regulating the alternator regulation voltage in order to maximize its efficiency on the basis of the engine and vehicle conditions. This is done by using an "Intelligent Alternator Module (IAM)" that communicates using the LIN protocol with the Engine Control Module (ECM), and an "Intelligent Battery Sensor (IBS)," which provides the information about the battery State-Of-Charge (SOC).These procedures are implemented for both gasoline and diesel engines and the expected improvement has been achieved: the average life of the vehicle battery has been increased, fuel consumption and emission have been reduced. In particular, measurements done have shown that consumption reduction due to the control system described above is about 2-3% on NEDC homologation cycle.