Vehicle configured as urban bus, for road public transport, comprising an electrical power supply system which comprises: - an electrical power line configured to supply electric power to a plurality of electrical utilities of said vehicle; - a plurality of alternators that are actuated by a combustion engine of said vehicle to produce electrical energy which is supplied to said electrical power line for supplying power to a plurality of electrical utilities when the engine is running; - electric batteries for supplying power to a starter upon starting the combustion engine, said electric batteries also being provided for supplying power to said plurality of electrical utilities when the engine is not running, wherein said electrical power supply system comprises: - an electronic switch that is placed between the batteries and the electronic power line; - an electronic control unit of the electronic switch that receives signals representing the operational state of the engine and the decelerations of the vehicle; wherein: - said electronic control unit is configured such that it opens the electronic switch when the engine is running and no deceleration has been detected, in order to prevent the electrical energy in the power line from being supplied to the batteries, which otherwise would become users of the electrical energy; - said electronic control unit is configured such that it closes the electronic switch when the engine is not running so as to allow the engine to be started with the energy supplied by the batteries; and - said electronic control unit is further configured such that it closes the electronic switch when the detected deceleration is enough to recover the electrical energy produced by the alternators that act as electrical energy generators during braking of the vehicle, and wherein: - each alternator is provided with a controlled rectifier, which allows the output voltage of the rectifier to be adapted to the measured voltage on the terminals of the batteries; - any such controlled rectifier is designed to reduce said output voltage, when the electronic switch is opened, thus reducing the power consumed by the various utilities connected to the power supply line while each said controlled rectifier is designed to increase said output voltage when the electronic switch is closed, to increase the energy recovery, and wherein the electronic control unit is designed to measure the opening time of the electronic switch after starting the engine, the electronic control unit being designed to inform the vehicle driver of the need to charge the batteries with a charger when said opening time is greater than a certain threshold value. - an electrical power line configured to supply electric power to a plurality of electrical utilities of said vehicle; - a plurality of alternators that are actuated by a combustion engine of said vehicle to produce electrical energy which is supplied to said electrical power line for supplying power to a plurality of electrical utilities when the engine is running; - electric batteries for supplying power to a starter upon starting the combustion engine, said electric batteries also being provided for supplying power to said plurality of electrical utilities when the engine is not running, - an electronic switch that is placed between the batteries and the electronic power line; - an electronic control unit of the electronic switch that receives signals representing the operational state of the engine and the decelerations of the vehicle; - said electronic control unit is configured such that it opens the electronic switch when the engine is running and no deceleration has been detected, in order to prevent the electrical energy in the power line from being supplied to the batteries, which otherwise would become users of the electrical energy; - said electronic control unit is configured such that it closes the electronic switch when the engine is not running so as to allow the engine to be started with the energy supplied by the batteries; and - said electronic control unit is further configured such that it closes the electronic switch when the detected deceleration is enough to recover the electrical energy produced by the alternators that act as electrical energy generators during braking of the vehicle, - each alternator is provided with a controlled rectifier, which allows the output voltage of the rectifier to be adapted to the measured voltage on the terminals of the batteries; - any such controlled rectifier is designed to reduce said output voltage, when the electronic switch is opened, thus reducing the power consumed by the various utilities connected to the power supply line while each said controlled rectifier is designed to increase said output voltage when the electronic switch is closed, to increase the energy recovery,