The invention relates to a direct voltage capture device (8) for an energy storage device (1). The energy storage device (1) is provided with a plurality of energy supply branches (Z); and each of the energy supply branches (Z) is provided with a plurality of energy storage modules (3) so as to generate an alternating voltage on a plurality of output terminals (1a, 1b, 1c) of the energy storage device (1). The direct voltage capture device (8) is provided with a half-bridge circuit (9) with a plurality of collective terminals (8a, 8b, 8c); and each of the collective terminals (8a, 8b, 8c) is coupled to one of the output terminals (1a, 1b, 1c) of the energy storage device (1). The direct voltage capture device also comprises a reference terminal (8d) coupled with a reference potential bus (4). The direct voltage capture device also comprises a step-up converter (14) which is coupled between the half-bridge circuit (9) and the reference terminal (8d) and is designed to provide a direct voltage (UZK) for capture terminals (8e, 8f) of the direct voltage capture device (8) according to the potential between the the half-bridge circuit (9) and the reference terminal (8d).