Abstract: An electrical storage system includes: an electrical storage device (10) including serially connected electrical storage blocks; a relay (SMR-B, SMR-G) switching a connection state between the electrical storage device and a load; a controller (30, 34) controlling the relay; and a current interruption circuit (60) interrupting energization of the electrical storage device. The current interruption circuit (60) includes an alarm circuit (63) outputting an alarm signal indicating that any one electrical storage block is overcharged or overdischarged by comparing a voltage value of each electrical storage block with a threshold; a latch circuit (64) retaining the alarm signal; and a transistor (68) causing the relay to switch from an on state to an off state upon reception of a latch circuit output signal. The controller determines an energization state of the electrical storage device after executing control for causing the alarm circuit to output the alarm signal by changing the voltage value or the threshold.

Abstract: An electrical storage system includes a relay switching between an on state where an electrical storage device (10) is connected to a load and an off state where connection of the electrical storage device with the load is interrupted; a controller controlling an on-off state of the relay; and a current interruption circuit (60) interrupting energization of the electrical storage device. The current interruption circuit includes an alarm circuit (63) outputting an alarm signal indicating that any one electrical storage block is in an overcharged state by comparing a voltage value of each electrical storage block with a threshold; a latch circuit (64) retaining the alarm signal; a transistor (66) causing the relay to switch from the on state to the off state upon reception of an output signal of the latch circuit; and a power supply circuit (63d) generating electric power for operating the latch circuit using electric power of the electrical storage device.

Abstract: A first electrical storage stack is connected in series with a second electrical storage stack. A current interrupter is configured to interrupt a current path by being removed from the current path. First and second detection line are respectively connected to first and second terminals of the first electrical storage stack. The second electrical storage stack is connected to the second terminal of the first electrical storage stack via the current interrupter. A third detection line is connected to a portion of the current path, located on the second electrical storage stack side of the current interrupter. A controller is configured to control charging and discharging operations of each of the first and second electrical storage stacks on the basis of the voltage of the first electrical storage stack, the voltage being detected via the first detection line and the third detection line.

Abstract: A plurality of detection units are connected respectively in parallel with a plurality of battery cells connected in series. The detection units each include an inductor and a zener diode connected in series. A battery checker includes a plurality of detection inductors and a single voltmeter that form a closed circuit. A plurality of detection inductors are arranged so that they are magnetically coupled respectively with the inductors of the plurality of detection units. Each zener diode is connected with the polarity to be reverse biased by the output voltage of the battery cell. Respective breakdown voltages of the zener diodes are set higher than the output voltage of each battery cell in normal use and different in a stepwise manner from each other.

Abstract: A relay that is electrically connected/disconnected to/from a battery in parallel with a smoothing capacitor on an inverter side with respect to a system main relay is provided. Thus, when the system is turned off, the battery and electrode buses are electrically disconnected from each other by the system main relay, and the positive electrode bus is thereby connected to the negative electrode bus by the relay. As a result, electric power accumulated in the smoothing capacitor is more reliably and more swiftly discharged.