DIAGNOSING RAPIDLY DEGRADING LITHIUM ION BATTERY CELLS USING DIRECT CURRENT INTERNAL RESISTANCE

Systems and methods for diagnosing rapidly degrading battery cells are disclosed. A direct current (DC) pulse is applied to a battery cell during at least one of a charging process or a discharging process. The change in voltage over time in response to the applied DC pulse is measured to determine direct current internal resistance (DCIR). A charge transfer resistance (R) component of the DCIR is isolated by excluding an ohmic resistance (R) component from the DCIR. The battery cell is diagnosed as rapidly degrading by predicting at least one state of health (SOH) of the battery cell indicative of rapid cell degradation.