Abstract: An energy storage device includes an electrode assembly having a negative electrode plate and a separator wound around a tubular core material. The core material has a first line part and a second line part extending along a first imaginary line and a second imaginary line parallel to a long side surface of a case, respectively. At least one of the first line part and the second line part has a curved portion that protrudes toward the other beyond the first imaginary line or the second imaginary line. An inner peripheral edge of the negative electrode plate is located at a position other than the curved portion in at least one of the first line part and the second line part.

Abstract: A temperature estimation device includes: a charge-discharge data acquisition unit that acquires charge-discharge data relating to charge-discharge of an energy storage device; an environmental temperature data acquisition unit that acquires temperature data relating to an environmental temperature of a battery board accommodating a plurality of the energy storage devices; and a temperature estimation unit that calculates an ambient temperature of the energy storage device in the battery board using the charge-discharge data and the temperature data, and estimates a temperature of the energy storage device using the calculated ambient temperature and the charge-discharge data.

Abstract: The estimation device 4 is provided with: a first acquisition unit 41 for acquiring SOC values obtained at the start and end of charging, discharging, or float-charging of a power storage element 3; a storage unit 42 storing multiple deterioration coefficients corresponding to multiple SOC ranges; an identification unit 41 for identifying, on the basis of the start and end SOC values acquired by the first acquisition unit 41, a corresponding deterioration coefficient from among the multiple deterioration coefficients stored in the storage unit 42; and an estimation unit 41 for estimating the deterioration of the power storage element 3 on the basis of the deterioration coefficient identified by the identification unit 41.

Abstract: An energy storage device includes an electrode assembly formed by winding a negative electrode plate, a separator and the like. An innermost periphery of the negative electrode plate, the separator and the like which are wound together has a flattened shape having a pair of bent portions disposed on opposite sides in a first direction as viewed in a direction of the winding axis, and an end edge of the negative electrode plate on an innermost periphery side is disposed at one bent portion out of the pair of bent portions or a position in the vicinity of the one bent portion.

Abstract: An energy storage device includes an electrode assembly having a negative electrode plate and a separator wound around a tubular core material. The core material has a first line part and a second line part extending along a first imaginary line and a second imaginary line parallel to a long side surface of a case, respectively. At least one of the first line part and the second line part has a curved portion that protrudes toward the other beyond the first imaginary line or the second imaginary line. An inner peripheral edge of the negative electrode plate is located at a position other than the curved portion in at least one of the first line part and the second line part.

Abstract: An energy storage device includes an electrode assembly formed by winding a negative electrode plate, a separator and the like. An innermost periphery of the negative electrode plate, the separator and the like which are wound together has a flattened shape having a pair of bent portions disposed on opposite sides in a first direction as viewed in a direction of the winding axis, and an end edge of the negative electrode plate on an innermost periphery side is disposed at one bent portion out of the pair of bent portions or a position in the vicinity of the one bent portion.