Abstract: An apparatus and a method for managing the energy supplied to a low-voltage system of a motor vehicle that comprises an energy-recovery stage. The low-voltage system, operating at a first voltage, comprises a battery, a system for charging the battery, and motor-vehicle loads supplied by the battery and/or by the alternator. A high-voltage system operates at a second voltage higher than the first voltage. The high-voltage system includes the vehicle energy-recovery stage, which supplies the second voltage. The second voltage is supplied through an intermediate energy-storage system and a DC-DC converter, which converts the second voltage into the first voltage on the low-voltage bus. A module regulates the alternator, that activates at least one first operating mode in which the alternator regulates a voltage of the battery at a nominal operating value.