Charged state estimating device and charged state estimating method of secondary battery
US8274291B2 · kind B2 · utility
Assignee
Inventor
Key dates
| Filing date | Nov 30, 2006 |
| Grant date | Sep 25, 2012 |
| Priority date | — |
| Expiry date | Feb 19, 2029 |
Classification
- Technology area (CPC Y)Emerging Cross-Sectional Technologies
- CPC primaryY02E60/10
- WIPO fieldMeasurement
- WIPO sectorInstruments
Abstract
When a battery current is not larger than a limit current set depending on the battery temperature and is flowing continuously for a predetermined time set depending on the battery temperature or longer, a decision is made that a secondary battery is in stable state. When the secondary battery is in stabilized state, the battery voltage is considered to be equal to the open circuit voltage and SOC estimation is performed based on the open circuit voltage-SOC characteristics. When the product of the internal resistance of the secondary battery and the limit current is made substantially constant (constant voltage) by setting the limit current in association with temperature dependence of the internal resistance, estimation error can be kept within a predetermined range in the stabilized state even if SOC estimation is performed while the battery voltage is assumed as the open circuit voltage. Consequently, SOC can be estimated with high precision within a predetermined error by a simple and reliable system under stabilized state.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.