An apparatus for managing the energy supplied to a low-voltage system of a vehicle that comprises an energy-recovery stage, said low-voltage system, which operates at a first voltage (V bat), comprising: a battery, which supplies said first voltage (V bat) on a low-voltage bus; a system for charging the battery, which comprises an alternator for supplying a charging voltage (V ALT) to said battery; and vehicle loads, which are supplied by the battery and/or by the alternator, said vehicle comprising a high-voltage system, operating at a second voltage (V inDCDC) higher than said first voltage (V bat), said system comprising said vehicle energy-recovery stage, which supplies said second voltage (V inDCDC), said second voltage (V inDCDC, V DClink) being supplied through an intermediate energy-storage system to a DC-DC converter, which converts said second voltage (V inDCDC, V DClink) into said first voltage (V bat) on said low-voltage bus, including a module for regulating the alternator configured for activating at least one first operating mode in which the alternator regulates a voltage of the battery at a nominal operating value, said apparatus being characterized in that: it is configured for detecting information on the regulated voltage in order to detect the operating mode of the alternator; and upon detection of said first operating mode, it is configured for carrying out a procedure for regulation of the DC-DC converter, which comprises: - an operation, in which a current (I LS) required by the vehicle loads is estimated; - an operation, in which the value of current determined by the ratio between the power (P outINV) supplied by the energy-recovery stage and the battery voltage (V bat) is calculated; - an operation, in which a pre-set fixed current value (I F) that enables sizing of the DC-DC converter at a given value of desired average transferrable power is considered; - an operation of evaluating the lowest of said three values, namely, the estimated required current (I LS), the current value determined by the ratio (P in /V bat), and the pre-set fixed current value (I F); and - an operation of limitation, by means of the DC-DC converter, of the output current to the lowest of said three values, namely, the estimated required current (I LS), the current value determined by the ratio (P in /V bat), and the pre-set fixed current value (I F). a battery, which supplies said first voltage (V bat) on a low-voltage bus; a system for charging the battery, which comprises an alternator for supplying a charging voltage (V ALT) to said battery; and vehicle loads, which are supplied by the battery and/or by the alternator, it is configured for detecting information on the regulated voltage in order to detect the operating mode of the alternator; and upon detection of said first operating mode, it is configured for carrying out a procedure for regulation of the DC-DC converter, which comprises: - an operation, in which a current (I LS) required by the vehicle loads is estimated; - an operation, in which the value of current determined by the ratio between the power (P outINV) supplied by the energy-recovery stage and the battery voltage (V bat) is calculated; - an operation, in which a pre-set fixed current value (I F) that enables sizing of the DC-DC converter at a given value of desired average transferrable power is considered; - an operation of evaluating the lowest of said three values, namely, the estimated required current (I LS), the current value determined by the ratio (P in /V bat), and the pre-set fixed current value (I F); and - an operation of limitation, by means of the DC-DC converter, of the output current to the lowest of said three values, namely, the estimated required current (I LS), the current value determined by the ratio (P in /V bat), and the pre-set fixed current value (I F). - an operation, in which a current (I LS) required by the vehicle loads is estimated; - an operation, in which the value of current determined by the ratio between the power (P outINV) supplied by the energy-recovery stage and the battery voltage (V bat) is calculated; - an operation, in which a pre-set fixed current value (I F) that enables sizing of the DC-DC converter at a given value of desired average transferrable power is considered; - an operation of evaluating the lowest of said three values, namely, the estimated required current (I LS), the current value determined by the ratio (P in /V bat), and the pre-set fixed current value (I F); and - an operation of limitation, by means of the DC-DC converter, of the output current to the lowest of said three values, namely, the estimated required current (I LS), the current value determined by the ratio (P in /V bat), and the pre-set fixed current value (I F).