Backup System for an Electronic Parking Brake and a Method for Providing a Backup Power

A backup system for an electronic parking brake, EPB, of a commercial vehicle ensures a safe state even during electric power failure of a power supply unit of the EPB. The backup system includes a detection unit for detecting the power failure, a storage device for storing sufficient electric power to perform a switch into the safe state, a boost circuit configured to charge the storage device during standstill of the vehicle and to discharge the storage device during motion of the vehicle, and a switch device configured to supply the electric power of the storage device to the EPB if the power failure is detected by the detection unit.