A method is provided for monitoring the status of a plurality of battery cells in a battery pack the method including: arranging the battery cells in at least two groups of cells; connecting the groups of cells to a sensor unit; and obtaining, by means of the sensor unit, at least one sensor measurement for each group which is indicative of the state of operation of the battery pack. The method according to the invention further includes: determining a cell measurement for each battery cell by means of an over-determined equation system which defines the cell measurement as a function of the sensor measurement; and evaluating any residual terms resulting from the equation system in order to identify any battery cell having a cell measurement which deviates from an expected value based on the remaining battery cells. A battery management system for monitoring the status of a plurality of connected battery cells as mentioned above is also provided.