Voltage measurement method for battery

A voltage measurement method comprising:

• sequentially connecting m channels, for which n battery cells are divided, in a battery cell unit, in which then battery cells are connected in series, to a capacitor via a connection circuit and measuring a channel voltage per the channel, m being an integer equal to or smaller than n, and n being an integer equal to or larger than two;
• and
• comparing a deviation of a measured channel voltage from a reference voltage with a permissible deviation value, wherein
• for an abnormal channel whose deviation of the measured channel voltage from the reference voltage is larger than the permissible deviation value, measurement is performed by extending a charging time for charging the capacitor, and for a normal channel whose deviation is equal to or smaller than the permissible deviation value, the measurement is performed by shortening the charging time for charging the capacitor so as to maintain a measurement cycle, in which the measurement on all of the channels is performed, to be constant.