Emergency release of motor vehicles

Access device for a vehicle with - an authentication means for checking and administering an access authorization, - an unlocking means for unlocking a lock mechanism of the access device, - a first power supply device, which is designed to feed the authentication device irrespective of the on-board power supply of the vehicle with energy, and - a second power supply device, which is designed to supply the unlocking independently of the on-board power supply of the vehicle with energy, characterized, that the first power feeding device arranged separately from the second power supply means and is designed so that it is accessible from the outside of the vehicle and fed via they energy of the authentication device is supplied exclusively.