A judicious study with regard to a more efficient energy management on board of an electric vehicle (EV) is discussed in this paper. This analysis follows the present trend in the field, knowing that the major drawback of the EV is the autonomy problem. Thus, by using a hybrid energy source (formed by ultracapacitors and battery) and with a proper current control (of polynomial type) one can get the proper energy management which will increase the lifetime of the battery. Through numerical simulations and tests at a reduced scale, the authors present a successfully energy management with regard to the DC/DC - battery and DC/AC - electrical machine subsystems operation, used on board of an EV.