Patent ID: 11876397
Assignee: LG ENERGY SOLUTION, LTD.
Field: Electrical machinery, apparatus, energy (Electrical engineering)
Classification: CPC H  G  Y | IPC G  H

Claim 8:
9. A method for controlling step charging of a secondary battery, comprising:
(a) measuring a voltage, a current and a temperature of the secondary battery while the secondary battery is in a discharging mode or a sleeping mode;
(b) estimating a state of charge (SOC) and an open circuit voltage (OCV) of the secondary battery based on the measured voltage value, the measured current value, and the measured temperature value before the start of charging of the secondary battery;
(c) determining a polarization voltage of the secondary battery from an internal resistance of the secondary battery, the measured current value, and the estimated OCV;
(d) determining an OCV deviation corresponding to a difference between the estimated OCV and a predefined minimum OCV value;
(e) determining a correction factor corresponding to the determined polarization voltage and the determined OCV deviation with reference to a predefined correlation between the polarization voltage and the correction factor and between the OCV deviation and the correction factor;
(f) determining a look-up SOC by correcting the estimated SOC according to the correction factor;
(g) determining a magnitude of a charging current corresponding to the look-up SOC and the measured temperature value with reference to a predefined correlation between the SOC and the magnitude of the charging current and between the temperature the magnitude of the charging current; and
(h) providing the determined charging current to a charging device so that a charging current corresponding to the determined magnitude of the charging current is applied to the secondary battery.