Patent ID: 8446123

Claim:
A state monitoring unit for monitoring a state of an assembled battery in which a plurality of unit cells are connected in series, the state monitoring unit comprising: a high voltage side including a plurality of voltage monitoring devices, each device corresponding to respective unit cells among the plurality of unit cells; and a low voltage side electrically isolated with the high voltage side, and including a controller which controls the respective voltage monitoring devices, wherein a common voltage measurement command for instructing a voltage measurement of the unit cells is transmitted from the controller to the respective voltage monitoring devices connected via a communication channel in a daisy-chain scheme, the controller comprises a storage for storing latency time determined based on a required time for each of the voltage monitoring devices elapsing from transmission of the common voltage measurement command with respect to the communication channel to voltage measurement of the unit cells performed by the each of the voltage monitoring devices which has received the common voltage measurement command, and the controller measures charging/discharging current of the assembled battery when the latency time has elapsed from the transmission of the common voltage measurement command with respect to the communication channel.