Secondary battery state-of-charge estimating apparatus and method using polarization voltages, and recording medium usable thereby
US7154247B2 · kind B2 · utility
Assignee
Inventors
Key dates
| Filing date | Mar 9, 2004 |
| Grant date | Dec 26, 2006 |
| Priority date | — |
| Expiry date | Feb 15, 2025 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG01R31/374
- WIPO fieldMeasurement
- WIPO sectorInstruments
Abstract
When an ignition switch is turned ON, a CPU obtains a battery voltage detected by a voltage sensor and calculates a voltage difference between a battery voltage stored in ROM when the ignition switch was turned off and the obtained battery voltage. The CPU then compares the voltage difference with a determination value. If the voltage difference is less than the determination value, the CPU sets a polarization voltage stored in the ROM before a not-in-use period to a polarization voltage initial value. If the voltage difference is equal to, or greater than, the determination value, on the other hand, the CPU sets the polarization voltage initial value to 0. The CPU then calculates an open circuit voltage of a secondary battery using this polarization voltage initial value, and calculates a state-of-charge of the secondary battery from that calculated open circuit voltage.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.