NOVELTY - The module (100) has a disconnection detection circuit (10) including a set of m-1 switches (SWa-1-SWa-m) including a set of terminals connected to few of multiple input terminals (V-1-v-m+1) counted from a high potential side, where m is an integer equal to or greater than 2. Another set of terminals outputs a set of signals. A set of control terminals is connected to another few of the input terminals counted from the side. The switches are turned on when a voltage applied to the control terminals is smaller than a preset value. A memory unit is connected to each of the latter terminals.    USE - Voltage monitoring module for use in a voltage monitoring system (claimed) for monitoring an output voltage of a battery cell of an assembled battery supplying power to an electric vehicle. Can also be used for a hybrid car and a petrol car.    ADVANTAGE - The module simultaneously determines presence or absence of a set of disconnections of battery cells in a disconnection detection operation period with respect to a voltage measurement period of the battery cells, thus drastically shortening a disconnection detection operation period as compared with a voltage measurement period of the battery cells, and hence increasing a frequency of voltage measurement of each battery cell. The module allows an engine control unit (ECU) to display activation of an emergency stop operation on a display device provided at a driver's seat, thus reliably preventing occurrence of an over discharge of each battery cell. The module detects presence or absence of a low-level signal to be input to a register in a self-diagnosis operation, when a current that originally allows a set of p-channel metal oxide semiconductor (PMOS) transistors to be turned on is supplied, thus enabling detection of presence or absence of a leakage failure in the disconnection detection circuit, and hence achieving better failure detection ability of the nodule.    DETAILED DESCRIPTION - An INDEPENDENT CLAIM is also included for a voltage monitoring system comprising a cell monitoring unit.    DESCRIPTION OF DRAWING(S) - The drawing shows a circuit block diagram of a voltage monitoring system for monitoring an output voltage of an assembled battery supplying power to an electric vehicle.    Switches (SWa-1-SWa-m)    Input terminals (V-1-v-m+1)    Disconnection detection circuit (10)    Activation circuit (13)    Voltage monitoring module (100)