A bidirectional DC to DC converter having a first operational mode and a second operational mode includes a first terminal pair that has a positive terminal and a negative terminal and that connects the converter to a first electric circuit, a second terminal pair that has a positive terminal and a negative terminal and that connects the converter to a second electric circuit, an accumulation element for temporary accumulation of electric energy; and a switching circuit connected to the first terminal pair, the second terminal pair, and the accumulation element. Electric energy is transferred from the first electric circuit to the second electric circuit via the accumulation element in the first operational mode of the bidirectional DC to DC converter and, from the second electric circuit to the first electric circuit via the accumulation element in the second operational mode of the DC to DC converter.