A method for estimating lifespan of a battery, comprising steps of: fully discharging the battery; partially charging the fully discharged battery under a predetermined charging condition; acquiring pieces of voltage information at multiple specific points of measurement time while partially charging the battery; and calculating remaining capacity of the battery by using the acquired pieces of voltage information and reference data, wherein, at the step of acquiring pieces of voltage information, increments of voltage from a time of starting to charge the fully discharged battery to the specific points of measurement time are acquired as the pieces of voltage information, wherein the increments of voltage are differences between a battery voltage measured at the time of starting to charge the fully discharged battery and battery voltages measured at the multiple specific points of measurement time, wherein, at the step of calculating remaining capacity of the battery, particle filter is applied to the acquired pieces of voltage information, wherein the step of fully discharging is performed when load starts to be stabilized based on operation schedule or accumulated operation pattern of an ESS composed of the battery, wherein the step of fully discharging is performed if SOC of the battery is lower than a preset threshold when the load starts to be stabilized, and wherein, when the particle filter is applied to the acquired pieces of voltage information, the increment of voltage at the initial point of measurement time and the increment of voltage at the last point of measurement time are given higher reliability than those at the other points of measurement time, wherein the reference data is measured data during actual use of an already manufactured battery with the same specification as the battery, and wherein the step of calculating remaining capacity of the battery includes steps of: calculating battery capacity measured at one cycle of full discharge and charge by using the measured increments of voltage; and calculating a residual lifespan of the battery by applying battery capacities measured at multiple cycles of full discharge and charge to the particle filter. fully discharging the battery; partially charging the fully discharged battery under a predetermined charging condition; acquiring pieces of voltage information at multiple specific points of measurement time while partially charging the battery; and calculating remaining capacity of the battery by using the acquired pieces of voltage information and reference data, wherein, at the step of acquiring pieces of voltage information, increments of voltage from a time of starting to charge the fully discharged battery to the specific points of measurement time are acquired as the pieces of voltage information, wherein the increments of voltage are differences between a battery voltage measured at the time of starting to charge the fully discharged battery and battery voltages measured at the multiple specific points of measurement time, wherein, at the step of calculating remaining capacity of the battery, particle filter is applied to the acquired pieces of voltage information, wherein the step of fully discharging is performed when load starts to be stabilized based on operation schedule or accumulated operation pattern of an ESS composed of the battery, wherein the step of fully discharging is performed if SOC of the battery is lower than a preset threshold when the load starts to be stabilized, and wherein, when the particle filter is applied to the acquired pieces of voltage information, the increment of voltage at the initial point of measurement time and the increment of voltage at the last point of measurement time are given higher reliability than those at the other points of measurement time, wherein the reference data is measured data during actual use of an already manufactured battery with the same specification as the battery, and wherein the step of calculating remaining capacity of the battery includes steps of: calculating battery capacity measured at one cycle of full discharge and charge by using the measured increments of voltage; and calculating a residual lifespan of the battery by applying battery capacities measured at multiple cycles of full discharge and charge to the particle filter. calculating battery capacity measured at one cycle of full discharge and charge by using the measured increments of voltage; and calculating a residual lifespan of the battery by applying battery capacities measured at multiple cycles of full discharge and charge to the particle filter.