An imbalanced battery cell refers to the situation where different cells within a battery module or pack have differences in key parameters such as voltage, capacity, or internal resistance, leading to their inability to charge and discharge synchronously or achieve consistent performance.
The hazards of imbalance:
Reducing the available capacity of the system: The entire module is limited by the worst battery cell, and the early saturation or exhaustion limits the overall performance.
Accelerating aging: High-load battery cells or single cells frequently subjected to overcharge/overdischarge age faster, forming a vicious cycle.
Rising safety risks: Unbalanced battery cells may cause thermal runaway, swelling, and even fires, posing safety hazards.
Limited BMS control: Inaccurate SOC/SOH estimation affects the accuracy of battery management system strategies.
