Road vehicle provided with an electronic dc-dc power converter and corresponding control method

10) A method to control a road vehicle (1) comprising:

• an internal combustion engine (5);
• an electric starter motor (20), which is coupled to the internal combustion engine (5) and can be operated to start the internal combustion engine (5);
• a high-voltage electric circuit (16) provided with a first storage system (14);
• a low-voltage electric circuit (17) provided with a second storage system (24), which has the same nominal voltage as the electric starter motor (20) and is directly connected to the electric starter motor (20) to directly supply power to the electric starter motor (20) without the interposition of any conversion device;
• and
• an electronic DC-DC power converter (23), which connects the low-voltage electric circuit (17) and the high-voltage electric circuit (16) to one another in order to transfer power from the high-voltage electric circuit (16) to the low-voltage electric circuit (17);
• wherein the control method comprises the steps of:
• detecting a turned-on condition of the road vehicle (1);
• detecting a cold-start condition of the internal combustion engine (5);
• and
• activating, in the presence of a turned-on condition of the road vehicle (1) and when the internal combustion engine (5) is off, the electronic DC-DC power converter (23) so as to transfer power to be at least partially supplied to the electric starter motor (20) from the high-voltage electric circuit (16) to the low-voltage electric circuit (17) only in case of the cold-start condition of the internal combustion engine (5);
• wherein, in the absence of the cold-start condition of the internal combustion engine (5), the power to be supplied to the electric starter motor (20) is only and exclusively provided by the second storage system (24).