A transfer device for energy in a motor vehicle is designed for connection to a first vehicle electrical distribution system and a second vehicle electrical distribution system, which each comprise an associated energy store. In this case, the transfer device comprises a first sampling device for determining that the two energy stores have been filled sufficiently, a second sampling device for detecting an energy withdrawal from one of the vehicle electrical distribution systems, and a DC-to-DC converter for transferring energy between the vehicle electrical distribution systems. In addition, a control device is provided which is designed, in an automatic mode to control a transfer of energy from one of the vehicle electrical distribution systems into the other vehicle electrical distribution system on the basis of the signals of the sampling devices when energy is withdrawn from the other vehicle electrical distribution system.