A computer implemented method, a control unit and a computer program for determining a configuration of a battery pack having one or more battery modules configured to be operationally connected as a string of battery modules, wherein a battery module includes a radio frequency identification, RFID, reader configured to read a radio frequency identification, RFID, tag of an adjacent battery module, by receiving first data from a first battery module (BM1), wherein the first data includes a module identifier of the first battery module (BM1) associated with second data of a second battery module (BM2) adjacent to the first battery module (BM1), the second data including at least a module identifier of the second battery module (BM2); and determining the configuration of the battery pack based on the first and second data.