Energy monitoring system for a vehicle

The present disclosure relates to an energy monitoring system for a vehicle, a vehicle comprising such an energy monitoring system and a method for manufacturing such an energy monitoring system. The energy monitoring system comprises an on-board battery charging system, a traction voltage system and a control unit. The traction voltage system is connected to the on-board battery charging system and the control unit is configured to transfer energy stored in the traction voltage system to the on-board battery charging system in case an energy level of the traction voltage system exceeds a defined threshold.