Charge state error online estimation method and system

The invention relates to the technical field of batteries, and discloses a state-of-charge error online estimation method and system, and the method comprises the steps: obtaining a state-of-charge error initial value corresponding to the power-on moment of a battery in a battery management system through an OCV table look-up algorithm; the real-time charge state error of the battery is calculated through an ampere-hour integral algorithm; the real-time calculation process of the ampere-hour integral algorithm is detected, and when the Rint model correction condition is triggered, the real-time charge state error is corrected through the Rint model algorithm; when a calibration algorithm is triggered, the real-time charge state error is calibrated; and storing and outputting the real-time state-of-charge error of the battery at the moment until the power-off moment of the battery management system is reached. A theoretical basis for SOC error estimation is provided, and SOC error online estimation is realized