POWER SUPPLY UNIT INCLUDING SECONDARY BATTERY

摘要

A power supply unit includes: a plurality of secondary batteries connected in series; limiting resistors connected to individual electrodes of the plurality of secondary batteries; a voltage detection circuit detecting inter-terminal voltages of each of the plurality of secondary batteries based on potentials obtained from the plurality of secondary batteries through the limiting resistors; a control circuit specifying one of the secondary batteries to be discharged based on the inter-terminal voltages of the plurality of secondary batteries detected by the voltage detection circuit and sending a discharge instruction; and a discharge circuit allowing the specified secondary battery to discharge through the limiting resistors in response to the instruction from the control circuit.