Disclosed herein is a medium- or large-sized battery module having a plurality of battery cells (unit cells), wherein the battery module is constructed in a structure in which detection units for detecting physical operation state of the battery cells are mounted to the respective battery cells, the detection units are connected to a control unit of the battery module while the detection units are connected in series with each other, and signals (detected signals) detected from the respective battery cells are transmitted to the control unit while the detected signals are included in signals detected from the entire battery cells. The detection units are mounted to the respective battery cells, and therefore, the accuracy of information on the physical operation state of the battery cells is improved, and the circuit for transmitting the detected signals to the control unit is simple although the number of the detection units is large. Consequently, it is possible to construct a battery module having a simple structure. In addition, the volume change measurement sensors formed in a specific shape are used for a battery module using lithium secondary batteries as unit cells, and therefore, it is possible to accomplish the simple structure of the battery module with reduced costs and to secure the safety of the battery module with high accuracy.