The invention relates to a battery cell unit (10) which comprises a rechargeable electrochemical battery cell (11), a monitoring-and-control unit (12) connected in parallel to said battery cell (11), and a coupling unit in the form of a half bridge (14) comprising a first power semi-conductor (15) and a second power semi-conductor (16). Said battery cell unit (10) is equipped with an integrated circuit (20) that has a noise source (21). A switch-on delay can be achieved by means of said noise source (21). The invention also relates to a switching method for a battery system which comprises a plurality of intrinsically-safe battery cell units (10).