Access control device, access control system, door portion having an access control device, and method for opening a door

An access control device for a door of a vehicle, the access control device comprising:

• an actuation element comprising an actuator, the actuation element being controllably configured to be brought from a blocking state into a release state and vice-versa;
• a power supply interface, which is configured to supply the access control device with power;
• a controller, which is configured to carry out open-loop and/or closed-loop control of a state of the actuation element;
• and
• a near-field communication interface, which is configured to read out a digital access authorisation and to transmit the digital access authorisation to the controller;
• wherein:
• the controller is configured to carry out the open-loop and/or closed-loop control of the state of the actuation element in accordance with a validity of the digital access authorisation,
• the power supply interface is configured such that a portable energy store is connectable without the use of tools,
• the power supply interface comprises an additional near-field communication interface, which is configured to read out an additional digital access authorisation and to transmit the additional digital access authorisation to the controller, and
• the controller is configured to generate a control signal that causes the actuation element to move into the release state or into the blocking state based on a determination that each of the following conditions are met:
• the power supply interface is supplied with power by the portable energy store,
• the digital access authorisation read via the near-field communication interface is valid, and
• the additional digital access authorisation read via the additional near-field communication interface is valid.