ELECTRIC POWER STORAGE DEVICE

PROBLEM TO BE SOLVED: To remove overcharging if an overcharging state is entered.SOLUTION: Current path opening/closing means 22 capable of switching a current path capable of electrically connecting a positive electrode terminal 17 and a negative electrode terminal 18 between a current non-cutoff state and a current cutoff state comprises: a spring 31 made of a conductive material; a conductor 32 energized by the spring 31 in a direction in which the current path is closed; and a rotation member 33 which rotates the conductor 32 between an open state holding position for opening the current path and a movement allowed position where the conductor is allowed to move to a closed state position for closing the current position. A circuit of a diode and a circuit part of a motor are connected in series between the positive electrode terminal 17 and negative electrode terminal 18. When an overcharging state is entered, the rotation member 33 is rotated by the motor to switch the current path opening/closing means 22 into the current non-cutoff state, a current flows from the positive electrode terminal 17 to the negative electrode terminal 18 through the current path, and electric power of a secondary battery is consumed as Joule heat by the spring 31 and conductor 32 constituting the current path.SELECTED DRAWING: Figure 4 【課題】過充電状態になった場合、過充電を解消する。【解決手段】正極端子１７と負極端子１８とを電気的に接続可能な電流経路を、電流非遮断状態と電流遮断状態とに切り換え可能な電流経路開閉手段２２は、導電材製のばね３１と、ばね３１により電流経路を閉じる方向へ付勢された導電体３２と、導電体３２を、電流経路を開いた開状態保持位置と、電流経路を閉じる閉状態位置への移動を許容する移動許容位置とに回動する回動部材３３とを備えている。正極端子１７と負極端子１８との間にダイオードの回路と、モータの回路部とが直列に接続されている。過充電状態になると、モータにより回動部材３３が回動され、電流経路開閉手段２２は電流非遮断状態に切り換えられ、正極端子１７から電流経路を経て負極端子１８へと電流が流れ、二次電池の電力は、電流経路を構成するばね３１及び導電体３２でジュール熱として消費される。【選択図】図４