Patent ID: 11860233
Assignee: HONDA MOTOR CO., LTD.
Field: Electrical machinery, apparatus, energy (Electrical engineering)
Classification: CPC G  H  Y | IPC G  H

Claim 0:
1. A battery unit comprising:
a battery module including a battery cell;
a voltage detector configured to detect an open circuit voltage or a closed circuit voltage of the battery cell;
a current detector configured to detect a current of the battery cell;
a battery heat flow detector configured to detect a heat flow of the battery cell;
a storage configured to store (A1) and (A2) below,, (A1): a table map of open circuit voltage OCV vs. state of charge SOC characteristics of the battery cell, and, (A2): heat flow HF vs. SOC initial characteristics of the battery cell, and states of charges at peaks of differential characteristics of the HF vs. SOC initial characteristics; and
a battery state estimator configured to estimate a SOC of the battery cell corresponding to a detected open circuit voltage of the battery cell, based on (A1) above, wherein
at a start of charge of the battery cell, the battery state estimator estimates, as a start SOC, a SOC of the battery cell corresponding to the open circuit voltage of the battery cell detected by the voltage detector, based on (A1) above,
during the charge of the battery cell, the battery state estimator measures HF vs. SOC present characteristics of the battery cell, based on the heat flow of the battery cell detected by the battery heat flow detector, detects a peak of differential characteristics of the measured HF vs. SOC present characteristics, and determines a SOC at the detected peak as a SOC(HF), based on (A2) above,
the battery state estimator calculates a charge capacity from the start of the charge to detection of the peak, based on a charge current detected by the current detector and a charge time, and calculates a SOC (OCV) based on the calculated charge capacity and the start SOC estimated at the start of the charge, and
in a case where the SOC(OCV) deviates with respect to the SOC(HF) by an amount of deviation equal to or greater than a predetermined value, the battery state estimator corrects (A1) above based on the amount of deviation.