Cell capacity testing methods, equipment, software products, and media based on lithium iron phosphate system

Abstract

This application provides a method, equipment, program product, and medium for testing the capacity of lithium iron phosphate (LFP) battery cells. The method includes: constantly charging the battery cell under test to full charge at a series of decreasing charging rates; constantly discharging the fully charged battery cell under test at a series of decreasing discharging rates; and determining the test capacity of the battery cell under test based on the multiple discharging rates and the discharge time corresponding to each of the multiple discharging rates. By performing a stepped charge-discharge cycle on the LFP cell, the capacity testing efficiency can be improved, the testing time can be greatly reduced, and the stepped charging method can eliminate cell polarization. By charging the LFP cell to full charge and then allowing it to start discharging from full charge, the accuracy of the capacity test can be improved. Furthermore, the constant current charge-discharge strategy can effectively reduce the risk of lithium plating at corners.

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