Electrical storage
system with: an electrical storage device (10); a load (20); a line (PL) configured to connect the electrical storage device (10) and the load (20); a
relay (SMR-G) that is provided in the line (PL); a
capacitor (C11) which has one end connected to the electrical storage device (10) and the other end connected to a ground; a
voltage sensor (21) configured to detect a
voltage value of the
capacitor (C11); a first
insulation resistance (RB) which is set up between the electrical storage device (10) and the ground; a second insulation
resistor (RL) which is installed between the load (20) and the ground; a first current path (L1) which includes the first
insulation resistance (RB); a second current path (L2) comprising the conductor (PL) and the second
insulation resistance (RL); and a
control unit (50) that is configured to (a) Controlling ON and OFF of the
relay (SMR-G), and (b) Determine that the
relay (SMR-G) is blocked in an ON state if the
voltage value is substantially equal to a second voltage value in a case where control to turn off the relay (SMR-G) is carried out, where a first resistance value is higher than a second resistance value, the second voltage value is higher than a first voltage value, the first resistance value is a resistance value of the first insulation resistance (RB), the second resistance value is a resistance value of the second insulation resistance (RL), the first voltage value is a voltage value when a
discharge current of the electrical storage device (10) flows to the
capacitor (C11) in the first current path (L1), the second voltage value is a voltage value when the
discharge current of the electrical storage device (10) flows to the capacitor (C11) in the second current path (L2).