Study on Aging Characteristics of Power Battery in Actual On-Board Environment Based on Data-driven

To study the aging characteristics of the power battery in actual on-board environment, the charging characteristics, the attenuation of internal resistance and voltage consistency of a three-stage constant-current charging power battery are studied with data-driven method. Results show that in the actual charging process, the charging current fluctuation is within 7A with the highest value of 114A, and the charging voltage fluctuation is within 5V, with the highest value of about 380V. At different mileage, the internal resistance of the power battery presents a discrete distribution. When the operating mileage increases from 160,000km to 200,000km, the internal resistance of the battery increases from 44.54mΩ to 56.10mΩ. The peak voltage difference of each battery unit increases gradually with the increase of the operating mileage. For SOC of 90%, the peak voltage difference increases from 0.021V to 0.030V. The linear fitting function between the internal resistance, peak voltage difference and the operating mileage can effectively evaluate the aging characteristics of batteries.