System and method of estimating state of charge of battery using coulomb counting estimation with periodic calibration using artificial intelligence based estimation

Abstract

A battery management system for tracking a state of charge of a battery including multiple cells including a coulomb counter (CC) estimator and an artificial intelligence (AI) estimator. The CC estimator determines a charge difference over time for tracking changes of a state of charge of each cell and updates a corresponding state of charge value. The AI estimator converts a set of sample values of a cell into an estimated state of charge for calibrating the cell. A controller may periodically invoke the AI estimator to calibrate the state of charge of each cell and to update a corresponding state of charge value. Processing by the AI estimator may be minimized by being used only to calibrate each cell before combined error of the CC estimator reaches a predetermined threshold. AI based calibration may use Long Short-Term Memories and may further incorporate voltage mean and voltage variance over time.