Abstract: An estimation device includes an acquisition unit that acquires current, voltage, and temperature of a lead-acid battery, a data accumulation unit that accumulates an integrated value or a calculated value of the current, voltage, and temperature that are acquired, an identification unit that identifies specific gravity of an electrolyte solution of the lead-acid battery based on history data accumulated in the data accumulation unit, an estimation unit that estimates a freezing risk of the lead-acid battery based on identified specific gravity of an electrolyte solution, and an output unit that outputs an estimation result of the estimation unit.

Abstract: An estimation device includes: an acquisition unit that acquires a voltage, a current, and a temperature of a lead-acid battery; a first deriving unit that derives a first SOC and a second SOC that are SOCs of a start point and an end point of an estimation period; a second deriving unit that derives a total amount of an overcharge amount in the estimation period; a third deriving unit that derives an actual measurement error based on a difference between the first SOC and the second SOC and the total amount of the overcharge amount; a first specification unit that specifies an estimation error based on the first SOC, the second SOC, and the temperature, and a relationship between the first SOC, the second SOC, and the temperature of the lead-acid battery, and the estimation error; a second specification unit that specifies an abnormality degree of the actual measurement error based on the derived actual measurement error and the specified estimation error; and an estimation unit that estimates generation of

Abstract: In a projection material for mechanical plating, a steel particle is used as a core, and the surrounding surface thereof is coated with a zinc alloy in which the content of Al is more than 5% by mass but equal to or less than 16% by mass, the content of Mg is equal to or more than 5.5% by mass but equal to or less than 15% by mass and the remaining portion is Zn and an impurity, and the content of Fe is equal to or more than 3% by mass but equal to or less than 80% by mass. In this way, the corrosion resistance of a zinc-based coating itself formed in mechanical plating is remarkably enhanced without dependence on protective coating formation treatment such as chromate treatment.

Abstract: In a projection material for mechanical plating, a steel particle is used as a core, and the surrounding surface thereof is coated with a zinc alloy in which the content of Al is more than 5% by mass but equal to or less than 16% by mass, the content of Mg is equal to or more than 5.5% by mass but equal to or less than 15% by mass and the remaining portion is Zn and an impurity, and the content of Fe is equal to or more than 3% by mass but equal to or less than 80% by mass. In this way, the corrosion resistance of a zinc-based coating itself formed in mechanical plating is remarkably enhanced without dependence on protective coating formation treatment such as chromate treatment.

Abstract: A flooded lead-acid battery includes a negative active material, a positive active material having lead dioxide as a main component, and an electrolyte solution that contains sulfuric acid and is flowable. The negative active material of the flooded lead-acid battery contains carbon, a water-soluble polymer formed of a bisphenol condensation product having a sulfonic acid group, and a cellulose ether. The flooded lead-acid battery has low turbidity of the electrolyte solution and is excellent in high rate discharge performance at low temperature, regenerative charge accepting performance, and endurance performance in a partially charged state.