A vehicle battery-pack equalization system that equalizes a voltage or a remaining capacity of each of a plurality of cells connected in series in a battery pack mounted on a vehicle by discharging each of the plurality of cells, wherein the vehicle battery-pack equalization system comprises an equalization controller with an equalization time setting unit for setting an equalization processing time of each of the cells to a time period which is obtained by multiplying a discharge time period of the battery pack immediately before an equalization process by a ratio of difference of an electric current discharged from the respective cell with respect to an equalization discharge electric current, the vehicle battery-pack equalization system being characterized in that: when the equalization process is interrupted during the equalization process, the equalization processing time of each of the cells for a next equalization process is set to a time period which is obtained by adding a discharge time period of the battery pack immediately before the next equalization process multiplied by a ratio of difference of an electric current discharged from the respective cell with respect to the equalization discharge electric current and a difference between an actual equalization processing time at a previous equalization process and a setting of the equalization processing time for the previous equalization process. wherein the vehicle battery-pack equalization system comprises an equalization controller with an equalization time setting unit for setting an equalization processing time of each of the cells to a time period which is obtained by multiplying a discharge time period of the battery pack immediately before an equalization process by a ratio of difference of an electric current discharged from the respective cell with respect to an equalization discharge electric current, the vehicle battery-pack equalization system being characterized in that: when the equalization process is interrupted during the equalization process, the equalization processing time of each of the cells for a next equalization process is set to a time period which is obtained by adding a discharge time period of the battery pack immediately before the next equalization process multiplied by a ratio of difference of an electric current discharged from the respective cell with respect to the equalization discharge electric current and a difference between an actual equalization processing time at a previous equalization process and a setting of the equalization processing time for the previous equalization process. when the equalization process is interrupted during the equalization process, the equalization processing time of each of the cells for a next equalization process is set to a time period which is obtained by adding a discharge time period of the battery pack immediately before the next equalization process multiplied by a ratio of difference of an electric current discharged from the respective cell with respect to the equalization discharge electric current and a difference between an actual equalization processing time at a previous equalization process and a setting of the equalization processing time for the previous equalization process. a discharge time period of the battery pack immediately before the next equalization process multiplied by a ratio of difference of an electric current discharged from the respective cell with respect to the equalization discharge electric current and a difference between an actual equalization processing time at a previous equalization process and a setting of the equalization processing time for the previous equalization process.