A battery control device, comprising: a first charging state amount calculation unit that calculates a first charging state amount (SOCi) of the battery on the basis of an integrated value of a current of the battery; a second charging state amount calculation unit that calculates a second charging state amount (SOCv) of the battery on the basis of an open circuit voltage of the battery; characterised in that it further comprises a feature amount calculation unit that calculates a feature amount indicating a charging/discharging pattern of a battery; a third charging state amount calculation unit that calculates a third charging state amount of the battery on the basis of the feature amount, the first charging state amount (SOCi), and the second charging state amount (SOCv), wherein the feature amount calculation unit calculates, as the feature amount, a discharging count rate which is a ratio of the number of times of discharging of the battery to a sum of the number of times of charging and discharging of the battery in a predetermined time width, wherein the third charging state amount calculation unit calculates a weighting coefficient (w) on the basis of the discharging count rate, and calculates the third charging state amount by performing weighted combination of the first charging state amount (SOCi) and the second charging state amount (SOCv) on the basis of the weighting coefficient, wherein the third charging state amount calculation unit calculates the third charging state amount by combining a value multiplied the first charging state amount (SOCi) by the weighting coefficient and a value multiplied the second charging state amount (SOCv) by a value subtracted the weighting coefficient from 1, and wherein the third charging state amount calculation unit: sets the weighting coefficient to 0 when the discharging count rate is 0.5; increases the weighting coefficient as the discharging count rate becomes smaller when the discharging count rate is equal to or larger than 0 and smaller than 0.5; and increases the weighting coefficient as the discharging count rate becomes larger when the discharging count rate is larger than 0.5 and smaller than or equal to 1. a first charging state amount calculation unit that calculates a first charging state amount (SOCi) of the battery on the basis of an integrated value of a current of the battery; a second charging state amount calculation unit that calculates a second charging state amount (SOCv) of the battery on the basis of an open circuit voltage of the battery; characterised in that it further comprises a feature amount calculation unit that calculates a feature amount indicating a charging/discharging pattern of a battery; a third charging state amount calculation unit that calculates a third charging state amount of the battery on the basis of the feature amount, the first charging state amount (SOCi), and the second charging state amount (SOCv), wherein the feature amount calculation unit calculates, as the feature amount, a discharging count rate which is a ratio of the number of times of discharging of the battery to a sum of the number of times of charging and discharging of the battery in a predetermined time width, wherein the third charging state amount calculation unit calculates a weighting coefficient (w) on the basis of the discharging count rate, and calculates the third charging state amount by performing weighted combination of the first charging state amount (SOCi) and the second charging state amount (SOCv) on the basis of the weighting coefficient, wherein the third charging state amount calculation unit calculates the third charging state amount by combining a value multiplied the first charging state amount (SOCi) by the weighting coefficient and a value multiplied the second charging state amount (SOCv) by a value subtracted the weighting coefficient from 1, and wherein the third charging state amount calculation unit: sets the weighting coefficient to 0 when the discharging count rate is 0.5; increases the weighting coefficient as the discharging count rate becomes smaller when the discharging count rate is equal to or larger than 0 and smaller than 0.5; and increases the weighting coefficient as the discharging count rate becomes larger when the discharging count rate is larger than 0.5 and smaller than or equal to 1. sets the weighting coefficient to 0 when the discharging count rate is 0.5; increases the weighting coefficient as the discharging count rate becomes smaller when the discharging count rate is equal to or larger than 0 and smaller than 0.5; and increases the weighting coefficient as the discharging count rate becomes larger when the discharging count rate is larger than 0.5 and smaller than or equal to 1.