Battery electric flow test system and method

A method of testing electricity flow of a battery, the battery comprising a used battery, the method comprising:

• setting a type of the battery to be tested and a set value for each test item;
• operating an AC impedance meter according to a user's request, inputting a first input frequency to the battery, and identifying a first output frequency for the first input frequency;
• identifying a first phase difference between the first input frequency and the first output frequency;
• determining a resonant frequency by identifying whether the first phase difference is ‘0’;
• inputting a second input frequency to the battery by varying frequency and identifying a second output frequency for the second input frequency;
• sequentially varying the frequency up to a set frequency to input the varied frequency to the battery, identifying a phase difference between the input frequency input to the battery and the output frequency corresponding to the input frequency to determine a resonant frequency, and registering the resonant frequency;
• determining a frequency having a highest band from among the registered resonant frequencies as a high-frequency resonant frequency;
• calculating an AC impedance using a voltage and a current at the high-frequency resonant frequency;
• and
• comparing the calculated AC impedance with an electricity flow upper limit of the set value to diagnose that it is normal when the calculated AC impedance is lower than the electricity flow upper limit and diagnose that it is abnormal when the calculated AC impedance is higher than the electricity flow upper limit.