NOVELTY - A charge-discharge cycle potential determining method involves carrying out package to the capacitor monomer battery with seal of 20 mm longer, PP tube with 5 mm diameter, connecting liquid injection hole with vacuum pump, allowing to stand for 18 plus minus 4 hours to determine the reduction potential of the charge-discharge potential of the positive electrode and the negative electrode according to the oxidation, and using a stepped charge discharge cycles carried out using a current of different sizes, the same time the PP pipe connected vacuum pump to maintain the vacuum degree of -0.5MPa.    USE - Method for determining charge-discharge cycle potential of lithium ion capacitor battery.    ADVANTAGE - The method enables determining charge-discharge cycle potential in efficient and quick manner.    DETAILED DESCRIPTION - A charge-discharge cycle potential determining method involves carrying out package to the capacitor monomer battery with seal of 20 mm longer, PP tube with 5 mm diameter, connecting liquid injection hole with vacuum pump, allowing to stand for 18 plus minus 4 hours to determine the reduction potential of the charge-discharge potential of the positive electrode and the negative electrode according to the oxidation, and using a stepped charge discharge cycles carried out using a current of different sizes, the same time the PP pipe connected vacuum pump to maintain the vacuum degree of -0.5MPa, the different stages of specific voltage and current size, where the first stage: starting voltage of the initial voltage, cutoff voltage U1, current is 0. 02-0.05C, the second stage: starting voltage of the operating voltage lower limit, the cut-off voltage U2, the current is 0. 05-0.1C, third stage: starting voltage of the operating voltage lower limit cut-off voltage U3, current is 0.1-0.2C, fourth stage: starting voltage of the operating voltage lower limit, the cut-off voltage U4, current is 0.1-0.2C, fifth stage: starting voltage of the operating voltage lower limit cut-off voltage U5, current is 0.1-0.2C, and the U1 less than U2 less than U3 less than U4 less than U5 is operating voltage limit.