Battery Cell Capacity Estimation Using SOC Voltage Error Minimization

The patent segments the battery pack into individual battery cells for separate monitoring and estimation. Instead of treating the battery pack as a uniform entity, each cell is individually characterized with its own SOC estimator, allowing accurate tracking of cell-specific variations and aging effects while maintaining manageable complexity through modular processing.

The patent applies local quality by assigning unique electrochemical parameters and SOC estimators to each battery cell based on its specific characteristics. Each cell receives customized estimation parameters adapted to its individual aging state and electrochemical properties, improving overall accuracy without requiring complete redesign of the entire estimation system.

The patent performs preliminary characterization of each battery cell's electrochemical properties during manufacturing or initial operation phases. These pre-determined parameters (capacity, impedance, voltage-SOC relationships) are stored and reused during operation, eliminating the need for repeated complex calculations while maintaining accurate SOC and capacity estimation during vehicle operation.

The patent employs computationally efficient approximation methods and simplified models that provide sufficiently accurate results for real-time operation. Instead of using heavy sophisticated algorithms continuously, the system uses lightweight estimation techniques that are computationally inexpensive and can be executed frequently without significant time penalty.