The present invention relates to an apparatus for forming battery cells (18) by a formation end or a formation electronic unit (10) including a power electronic device (11). The formation end or formation electronic unit (10) provides a controlled output voltage or controlled output current for the formation in a serial connection state or parallel formation (19) of battery cells (18) to be formed. The battery cells include an integrated power electronic device having power semiconductors, and at least one among the power semiconductors influences a formation current of the battery cells (18) to be formed, including the integrated power electronic device.