Control system for an internal combustion engine boosted with an electronically controlled pressure charging device

The present invention relates to an electronically driven pressure boosting system that is used to boost the torque output of an internal combustion engine. The system comprises an electrically driven supercharger (10), an electrical supply system for providing electrical power to drive the pressure charging device (10) including a battery (16) and an engine-driven battery recharger (27), a switch (53) to connect and disconnect the battery (16) and recharger (27) and an engine control system (32) for controlling the switch (53) and the operation of the pressure charging device (10). The engine control system (32) is used to determine a capacity utilization of the electrical supply system (16,27), and then to control the switch (53) to isolate at least partially the battery (16) from the engine-driven battery recharger and drive the pressure charging device (10) using the battery (16) when said capacity utilization is above a first threshold.