Abstract: A method for manufacturing a nickel-metal hydride battery includes: a first step of preparing a first nickel-metal hydride battery having a positive electrode including nickel hydroxide (Ni(OH)2); and a second step of manufacturing the second nickel-metal hydride battery by performing 600% overcharging to the prepared first nickel-metal hydride battery. The 600% overcharging is a process for supplying the first nickel-metal hydride battery with an amount of electric power of 600% of the rated capacity of the first nickel-metal hydride battery.

Abstract: A method of recycling a battery pack includes first to third steps. The first step is a step of estimating an amount of generation of Ni2O3H in a positive electrode of the battery pack based on a voltage value and a temperature of the battery pack. The second step is a step of recycling the battery pack for a high-capacity application when the estimated amount of generation is equal to or smaller than a prescribed reference amount. The third step is a step of recycling the battery pack for a high input-and-output application when the estimated amount of generation is greater than the reference amount and not greater than a reference amount.

Abstract: A method for manufacturing a nickel-metal hydride battery includes: a first step of preparing a first nickel-metal hydride battery having a positive electrode including nickel hydroxide (Ni(OH)2); and a second step of manufacturing the second nickel-metal hydride battery by performing 600% overcharging to the prepared first nickel-metal hydride battery. The 600% overcharging is a process for supplying the first nickel-metal hydride battery with an amount of electric power of 600% of the rated capacity of the first nickel-metal hydride battery.

Abstract: A method of recycling a battery pack includes first to third steps. The first step is a step of estimating an amount of generation of Ni2O3H in a positive electrode of the battery pack based on a voltage value and a temperature of the battery pack. The second step is a step of recycling the battery pack for a high-capacity application when the estimated amount of generation is equal to or smaller than a prescribed reference amount. The third step is a step of recycling the battery pack for a high input-and-output application when the estimated amount of generation is greater than the reference amount and not greater than a reference amount.

Abstract: A battery system includes a chargeable and dischargeable secondary battery and a controller that estimates the deterioration state or the charge state of the secondary battery. When estimating the deterioration state or the charge state, the controller uses an average ion concentration between a positive electrode and a negative electrode. The average ion concentration varies depending on an electric current flowing through the secondary battery. The average ion concentration between the electrodes can be calculated with a computing expression that includes a surface pressure of the secondary battery as a variable. The surface pressure of the secondary battery can be detected by a pressure sensor. The surface pressure of the secondary battery can also be estimated from an electric current flowing through the secondary battery.

Abstract: [Task] To accurately estimate a distribution of concentration of lithium in an active material. [Means for Solution] A battery system has a lithium-ion secondary battery (1) and a controller (300). The lithium-ion secondary battery (1) employs a two-phase coexistence type positive electrode active material (141b). The controller (300) calculates a distribution of concentration of lithium in an active material (141b, 142b) of the lithium-ion secondary battery, through the use of a diffusion equation in which a boundary condition is set. The controller corrects a diffusion coefficient that is used in the diffusion equation, in accordance with history data indicating a charge/discharge state of the lithium-ion secondary battery to the present time.

Abstract: An electricity storage system includes an electricity storage block including an electricity storage element for performing charging and discharging; a relay switched between an ON state in which the electric storage block is connected to a load and an OFF state in which a connection between the electricity storage block and the load is cut off; a controller for controlling the ON state and the OFF state of the relay; and a current cutoff circuit so as to cut off energization of the electricity storage block. The current cutoff circuit has an alarm circuit to indicate that the electricity storage block is in an overcharged state by comparing a voltage value of the electricity storage block and a threshold; a latch circuit retains the alarm signal; and a transistor receives an output signal of the latch circuit and switches the relay from the ON state to the OFF state.

Abstract: A system for determining fixation of a relay has an electricity storage device, an electrical apparatus, a relay, a first insulation resistor, a second insulation resistor, a detection circuit, and a controller. When the relay is controlled to OFF, the controller determines, based on the voltage value detected by the detection circuit (the detected voltage value), whether or not the relay is fixed. When the detected voltage value is a voltage value that is obtained by dividing the reference voltage value by a combined resistance value and the reference resistance value, the controller determines that the relay is fixed. When the detected voltage value is a voltage value that is obtained by dividing the reference voltage value by the first resistance value and the reference resistance value, the controller determines that the relay is not fixed.

Abstract: An electric storage system includes electric storage blocks and a controller determining the state of each of the electric storage blocks. The plurality of electric storage blocks are connected in series, and each of the electric storage blocks has a plurality of electric storage elements connected in parallel. Each of the electric storage elements has a current breaker breaking a current path within the electric storage element. The controller acquires at least one parameter of an internal resistance and a full charge capacity of each of the electric storage blocks, and uses a change rate between the acquired parameter and a reference value to specify the number of current breakers in a broken state (the number of breaks) in each of the electric storage blocks. The reference value refers to the value of the parameter in the electric storage block not including the current breaker in the broken state.

Abstract: An electrical storage system includes a main battery, an auxiliary battery, a bidirectional DC-DC converter and a controller. The bidirectional DC-DC converter is provided between the auxiliary battery and a power supply path from the main battery to a driving motor. The bidirectional DC-DC converter steps down an output voltage from the power supply path to the auxiliary battery, and steps up an output voltage from the auxiliary battery to the power supply path. The controller controls charging and discharging of the auxiliary battery. The controller, when an allowable output power of the main battery decreases and an electric power becomes insufficient for a required vehicle output, supplies an electric power to the power supply path by discharging the auxiliary battery by using the bidirectional DC-DC converter.

Abstract: An electricity storage system includes an electricity storage device, a positive electrode line, a negative electrode line, a capacitor, at least two diodes, and a first intermediate line. The electricity storage device is able to supply power to a load. The electricity storage device includes at least two electricity storage groups connected in series. The electricity storage group includes at least two electricity storage elements connected in series. Each electricity storage element includes a current breaker. The capacitor is connected to the positive and negative electrode lines. At least two diodes are connected in series between the positive electrode line and the negative electrode line and are respectively connected in parallel to the electricity storage groups. The first intermediate line is connected between a first connection point at which the electricity storage groups are connected together and a second connection point at which the diodes are connected together.

Abstract: The state of a plurality of electric storage blocks connected in serial is determined. Each of the electric storage blocks includes a plurality of electric storage elements connected in parallel. Each of the electric storage elements includes a current breaker configured to break a current path in the electric storage element. When a first voltage characteristic is shifted from a second voltage characteristic, it is determined that the current breaker is operated. The first voltage characteristic is acquired from a voltage sensor acquiring an open circuit voltage of each electric storage block and indicates a change in the open circuit voltage with respect to a capacity of the electric storage block. The second voltage characteristic is calculated from a capacity retention rate and a variation of the capacity and indicates a change in the open circuit voltage with respect to the capacity of the electric storage block.

Abstract: An electrical storage system includes a main battery, an auxiliary battery, a bidirectional DC-DC converter and a controller. The bidirectional DC-DC converter is provided between the auxiliary battery and a power supply path from the main battery to a driving motor. The bidirectional DC-DC converter steps down an output voltage from the power supply path to the auxiliary battery, and steps up an output voltage from the auxiliary battery to the power supply path. The controller controls charging and discharging of the auxiliary battery. The controller, when an allowable output power of the main battery decreases and an electric power becomes insufficient for a required vehicle output, supplies an electric power to the power supply path by discharging the auxiliary battery by using the bidirectional DC-DC converter.

Abstract: A system for determining fixation of a relay has an electricity storage device, an electrical apparatus, a relay, a first insulation resistor, a second insulation resistor, a detection circuit, and a controller. When the relay is controlled to OFF, the controller determines, based on the voltage value detected by the detection circuit (the detected voltage value), whether or not the relay is fixed. When the detected voltage value is a voltage value that is obtained by dividing the reference voltage value by a combined resistance value and the reference resistance value, the controller determines that the relay is fixed. When the detected voltage value is a voltage value that is obtained by dividing the reference voltage value by the first resistance value and the reference resistance value, the controller determines that the relay is not fixed.

Abstract: [Task] To accurately estimate a distribution of concentration of lithium in an active material. [Means for Solution] A battery system has a lithium-ion secondary battery (1) and a controller (300). The lithium-ion secondary battery (1) employs a two-phase coexistence type positive electrode active material (141b). The controller (300) calculates a distribution of concentration of lithium in an active material (141b, 142b) of the lithium-ion secondary battery, through the use of a diffusion equation in which a boundary condition is set. The controller corrects a diffusion coefficient that is used in the diffusion equation, in accordance with history data indicating a charge/discharge state of the lithium-ion secondary battery to the present time.

Abstract: [Problem] To provide a configuration for cutting off energization of an electricity storage block without interposing a controller. [Solution] The electricity storage system has: an electricity storage block including an electricity storage element (11) for performing charging and discharging; a relay (SMR-B, SMR-G) switched between an ON state in which the electric storage block is connected to a load (22, 23) and an OFF state in which a connection between the electricity storage block and the load is cut off; a controller (34) for controlling the ON state and the OFF state of the relay; and a current cutoff circuit (60) for switching the relay from the ON state to the OFF state, so as to cut off energization of the electricity storage block.

Abstract: A battery system includes a chargeable and dischargeable secondary battery and a controller that estimates the deterioration state or the charge state of the secondary battery. When estimating the deterioration state or the charge state, the controller uses an average ion concentration between a positive electrode and a negative electrode. The average ion concentration varies depending on an electric current flowing through the secondary battery. The average ion concentration between the electrodes can be calculated with a computing expression that includes a surface pressure of the secondary battery as a variable. The surface pressure of the secondary battery can be detected by a pressure sensor. The surface pressure of the secondary battery can also be estimated from an electric current flowing through the secondary battery.

Abstract: The state of a plurality of electric storage blocks connected in serial is determined. Each of the electric storage blocks includes a plurality of electric storage elements connected in parallel. Each of the electric storage elements includes a current breaker configured to break a current path in the electric storage element. When a first voltage characteristic is shifted from a second voltage characteristic, it is determined that the current breaker is operated. The first voltage characteristic is acquired from a voltage sensor acquiring an open circuit voltage of each electric storage block and indicates a change in the open circuit voltage with respect to a capacity of the electric storage block. The second voltage characteristic is calculated from a capacity retention rate and a variation of the capacity and indicates a change in the open circuit voltage with respect to the capacity of the electric storage block.

Abstract: An electric storage system includes electric storage blocks and a controller determining the state of each of the electric storage blocks. The plurality of electric storage blocks are connected in series, and each of the electric storage blocks has a plurality of electric storage elements connected in parallel. Each of the electric storage elements has a current breaker breaking a current path within the electric storage element. The controller acquires at least one parameter of an internal resistance and a full charge capacity of each of the electric storage blocks, and uses a change rate between the acquired parameter and a reference value to specify the number of current breakers in a broken state (the number of breaks) in each of the electric storage blocks. The reference value refers to the value of the parameter in the electric storage block not including the current breaker in the broken state.