Battery pack for supplying an electrically driven treatment apparatus with an electric driving power, the battery pack comprising: - a plurality of accumulator cells, wherein the accumulator cells have cell contacts, - at least one circuit board (52, 53, 54), wherein the at least one circuit board (52, 53, 54) is electrically connected to the cell contacts, and - a battery pack housing, wherein the battery pack housing has a first battery pack housing part and a second battery pack housing part, wherein the first battery pack housing part and the second battery pack housing part are closed by each other, - wherein the accumulator cells are disposed within the battery pack housing, characterized - in that the cell contacts and the at least one circuit board (52, 53, 54) are disposed within the second battery pack housing part, wherein the second battery pack housing part is configured as a mold for a casting compound, and wherein the cell contacts and the at least one circuit board (52, 53, 54) are enclosed by the casting compound, and/or - in that the at least one circuit board (52, 53, 54) is disposed within the battery pack housing, wherein the one battery pack housing part has at least one thread, wherein the other battery pack housing part has at least one head abutment surface, wherein the head abutment surface is disposed on an end adjacent to the one battery pack housing part of the other battery pack housing part, wherein the battery pack has at least one screw, wherein the screw is screwed into the thread for mechanical connection of the one battery pack housing part and the other battery pack housing part to each other, and a screw head bears on the head abutment surface. - a plurality of accumulator cells, wherein the accumulator cells have cell contacts, - at least one circuit board (52, 53, 54), wherein the at least one circuit board (52, 53, 54) is electrically connected to the cell contacts, and - a battery pack housing, wherein the battery pack housing has a first battery pack housing part and a second battery pack housing part, wherein the first battery pack housing part and the second battery pack housing part are closed by each other, - wherein the accumulator cells are disposed within the battery pack housing, characterized - in that the cell contacts and the at least one circuit board (52, 53, 54) are disposed within the second battery pack housing part, wherein the second battery pack housing part is configured as a mold for a casting compound, and wherein the cell contacts and the at least one circuit board (52, 53, 54) are enclosed by the casting compound, and/or - in that the at least one circuit board (52, 53, 54) is disposed within the battery pack housing, wherein the one battery pack housing part has at least one thread, wherein the other battery pack housing part has at least one head abutment surface, wherein the head abutment surface is disposed on an end adjacent to the one battery pack housing part of the other battery pack housing part, wherein the battery pack has at least one screw, wherein the screw is screwed into the thread for mechanical connection of the one battery pack housing part and the other battery pack housing part to each other, and a screw head bears on the head abutment surface.