Battery state of charge indicator
US5119011A · kind A · utility
Assignee
Inventor
Key dates
| Filing date | Aug 8, 1990 |
| Grant date | Jun 2, 1992 |
| Priority date | — |
| Expiry date | Aug 8, 2010 |
Classification
- Technology area (CPC Y)Emerging Cross-Sectional Technologies
- CPC primaryY10S320/18
- WIPO fieldElectrical machinery, apparatus, energy
- WIPO sectorElectrical engineering
Abstract
A method for measuring and storing the state of charge of batteries, such as used in electric vehicles. The stored charge value is initially derived from the value of battery terminal voltage measured prior to connection of the battery to the load, e.g. the traction motor. While the battery is connected to the load, approximated state of charge values are periodically derived by adding a correction voltage, comprising the product of measured load current and of a predetermined value of internal resistance, to the measured terminal voltage of the battery. The stored and approximated state of charge values are periodically compared and the stored state of charge value is decremented by a predetermined increment in response to the stored charge value having exceeded the approximated state of charge value during each of a predetermined plurality consecutive comparisons.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.