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 is configured to operate at a first voltage (V bat), including: a battery, which is configured to supply said first voltage (V bat) on a low-voltage bus; a system for charging the battery, comprising an alternator for supplying a charging voltage (V ALT) to said battery; and vehicle loads configured to be supplied by the battery and/or by the alternator, said vehicle comprising a high-voltage system, which is configured to operate at a second voltage (V inDCDC, V DClink) higher than said first voltage (V bat), said system comprising said vehicle energy-recovery stage, which is configured to supply said second voltage (V inDCDC, V DClink), said second voltage (V inDCDC, V DClink) configured to be supplied through an intermediate energy-storage system to a DC-DC converter, which is configured to convert said second voltage (V inDCDC, V DClink) into said first voltage (V bat) on said low-voltage bus, said apparatus comprising a control module configured for carrying out energy-management operations at least by the alternator, the second voltage (V inDCDC, V DClink) of said DC-DC converter configured to be regulated via a control procedure of a hysteretic type comprising an operation of threshold comparison with hysteresis of the value of said second voltage (V inDCDC, V DClink), and an operation of activation or deactivation of said DC-DC converter on the basis of the result of said comparison operation, said apparatus comprises an additional load (R ext), which is configured to be set in parallel with the input of the DC-DC converter and is configured to be selectively connected to the high-voltage bus; characterised in that, if the power supplied by the energy-recovery stage is higher than the power absorbed by the DC-DC converter, the apparatus is configured for keeping the DC-DC converter always activated, with a current limitation (200, 300, 400), and for selecting the connection of the additional load according to a further hysteretic control procedure, in particular based upon the second voltage (V inDCDC, V DClink) or upon the state of charge of the intermediate energy-storage system, said further hysteretic control procedure comprising respective thresholds for the additional load (S ext) and for the DC-DC converter (S DCDC) and envisages setting the threshold value (S ext) that controls selective connection of the additional load to the high-voltage bus at a voltage value higher than the threshold value (S DCDC) of activation of the DC-DC converter, so that, as the second voltage increases, first the DC-DC converter is activated and then, in the case where the voltage continues to rise, the additional load (R ext) is activated and, instead, as the second voltage decreases, first the additional load (R ext) is deactivated and, in the case where the second voltage continues to drop, the DC-DC converter is deactivated. a battery, which is configured to supply said first voltage (V bat) on a low-voltage bus; a system for charging the battery, comprising an alternator for supplying a charging voltage (V ALT) to said battery; and vehicle loads configured to be supplied by the battery and/or by the alternator,