NOVELTY - The device has a single converter (CO) comprising an execution unit for executing a control rule depending on a maximal electrical power of electrical energy sources (2, 3) to maintain a determined level of load of a battery (1). The converter has diodes (5, 6) with cathodes connected to the battery and anodes respectively connected to high potentials of the energy sources. The battery is chosen among central and specialized batteries such that the device functions even if a heat engine of a motor vehicle is stopped.    USE - Used for managing solar and thermoelectric energy sources such as a solar cell and a heat generator utilizing heat wasted by a heat engine of a motor vehicle such as a lorry.    ADVANTAGE - The management device ensures the maintenance of electricity generation without introduction of fuel and without any emissions, and the maintenance of the load of the battery during prolonged parking of the vehicle. The device allows the production of electrical energy from the combustion of the fuel and not from the heat engine or fuel cell in order to ensure fuel saving, and permits the utilization of electrical apparatuses/accessories or the recharging of their batteries when the heat engine is stopped. The device maintains certain electrical performances when the vehicle is at stop heat engine state or during prolonged parking, and ensures the maintenance of electronic equipments and multimedia resources in standby mode. The converter can be used as an interface in order to avoid the architectural and functional constraints of the energy sources to provide a voltage compatible with battery voltage, thus permitting to dimension the sources with optimum power or volume, and hence avoiding the limitation of the number of elementary elements in series in the generator at the time of arranging the elements in series or parallel. The device allows the utilization of a source independent of a main network of the vehicle in order to supply several apparatuses at the time of testing and developing periods, thus avoiding the malfunctioning of the apparatuses. The utilization of the single converter reduces the number of necessary components to simultaneously control the energy sources, and the management of the sources ensures the better availability of the energy in order to improve the useful power.    DESCRIPTION OF DRAWING(S) - The drawing shows a management device.    Converter (CO)    Battery (1)    Electrical energy sources (2, 3)    Diodes (5, 6)