A battery system monitor for monitoring a battery system having a plurality of battery modules (104, 106) each including a pair of terminals, wherein terminals of the battery modules (104, 106) are interconnected such that the battery modules (104, 106) are coupled in series with each other between first and second terminals (101, 102) of the battery system, the battery system monitor comprising: a plurality of cell measurement circuits, CMCs, (108, 110) each configured to measure a voltage at or current through a pair of terminals of an associated battery module (104, 106); a plurality of wireless communication transceivers (112, 114) each associated with a different CMC of the plurality of CMCs (108, 110) and configured to transmit voltage or current measurement information of the associated CMC across a wireless communication link; and characterized by a controller (160, 260) configured to receive the voltage or current measurement information from the plurality of wireless communication transceivers (112, 114) and determine the relative positions of the battery modules (104, 106) associated with the CMCs (108, 110) in the series coupling between the first and second terminals (101, 102) of the battery system based on the voltage or current measurement information from the plurality of wireless communication transceivers (112, 114) by performing steps of: identifying an artifact in a time-series of voltage or current measurements received from a first wireless communication transceiver (112, 114); identifying the artifact in a time-series of voltage or current measurements received from a second wireless communication transceiver (112, 114); comparing timing of occurrence of the identified artifact in the time-series of voltage or current measurements received from the first and second wireless communication transceivers (112, 114); and determining the relative positions in the series coupling of the battery modules (104, 106) associated with the CMCs (108, 110) associated with the first and second wireless communication transceivers (112, 114) based on the compared timing of occurrence of the identified artifact in the time-series. a plurality of cell measurement circuits, CMCs, (108, 110) each configured to measure a voltage at or current through a pair of terminals of an associated battery module (104, 106); a plurality of wireless communication transceivers (112, 114) each associated with a different CMC of the plurality of CMCs (108, 110) and configured to transmit voltage or current measurement information of the associated CMC across a wireless communication link; and characterized by a controller (160, 260) configured to receive the voltage or current measurement information from the plurality of wireless communication transceivers (112, 114) and determine the relative positions of the battery modules (104, 106) associated with the CMCs (108, 110) in the series coupling between the first and second terminals (101, 102) of the battery system based on the voltage or current measurement information from the plurality of wireless communication transceivers (112, 114) by performing steps of: identifying an artifact in a time-series of voltage or current measurements received from a first wireless communication transceiver (112, 114); identifying the artifact in a time-series of voltage or current measurements received from a second wireless communication transceiver (112, 114); comparing timing of occurrence of the identified artifact in the time-series of voltage or current measurements received from the first and second wireless communication transceivers (112, 114); and determining the relative positions in the series coupling of the battery modules (104, 106) associated with the CMCs (108, 110) associated with the first and second wireless communication transceivers (112, 114) based on the compared timing of occurrence of the identified artifact in the time-series. identifying an artifact in a time-series of voltage or current measurements received from a first wireless communication transceiver (112, 114); identifying the artifact in a time-series of voltage or current measurements received from a second wireless communication transceiver (112, 114); comparing timing of occurrence of the identified artifact in the time-series of voltage or current measurements received from the first and second wireless communication transceivers (112, 114); and determining the relative positions in the series coupling of the battery modules (104, 106) associated with the CMCs (108, 110) associated with the first and second wireless communication transceivers (112, 114) based on the compared timing of occurrence of the identified artifact in the time-series.