A battery sensor data transmission unit is described as including a connection state ascertainment unit for ascertaining a series connection state in which a battery cell is connected in series to one other battery cell with the aid of a power transmission line and/or for determining a bypassing state in which at least one pole of the battery cell is decoupled from at least one other battery cell. Furthermore, the battery sensor data transmission unit includes a data transmission unit designed for outputting a sensor signal, which represents a physical variable in or at the battery cell, in the series connection state to an evaluation device using the power transmission line and/or outputting the sensor signal in the bypassing state to the evaluation device using a battery housing wall as the transmission medium.