Battery state of charge evaluator system
US4433278A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Nov 18, 1980 |
| Grant date | Feb 21, 1984 |
| Priority date | — |
| Expiry date | Nov 18, 2000 |
Classification
- Technology area (CPC Y)Emerging Cross-Sectional Technologies
- CPC primaryY10S320/34
- WIPO fieldMeasurement
- WIPO sectorInstruments
Abstract
A microprocessor based electric vehicle traction battery monitoring system evaluates the state of charge, interfaces with a traction motor control system, and controls recharging. The state of charge is evaluated during the first part of discharge by integrating the current after compensating it for rate of discharge and during the last part of discharge by dividing the battery into sub-packs and evaluating the state of charge from the lowest sub-pack voltage compensated for polarization voltage. The charge storage capacity is also calculated from the lowest sub-pack voltage. The maximum traction motor current is progressively limited during the last part of discharge. During charging, the charge withdrawn is replaced while progressively reducing the charging current and the battery is then charged at a constant current until the rate of rise of the lowest sub-pack voltage falls below a fixed level.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.