A switch failure detection device includes a switch, a rectifier, a switch voltage detection circuit, and a controller. The switch is connected in a path in which a charging current to and a discharging current flow. The rectifier passes a discharging current by bypassing the switch when the switch is turned off. The detection circuit detects a voltage between an input and an output of the switch. The controller is configured to: determine whether the electric storage device is in a discharging state; send an off-command signal to the switch if the electric storage device is in the discharging state; receive the voltage; determine an input-output voltage of the switch based on the voltage; determine whether the input-output voltage is lower than a first reference voltage; and determine the switch has a turn-off problem if the input-output voltage is lower than the first reference voltage.
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