Charging circuits for rechargeable batteries and cells
US5204611A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | May 2, 1991 |
| Grant date | Apr 20, 1993 |
| Priority date | — |
| Expiry date | May 2, 2011 |
Classification
- Technology area (CPC Y)Emerging Cross-Sectional Technologies
- CPC primaryY10S320/19
- WIPO fieldTransport
- WIPO sectorMechanical engineering
Abstract
Circuits are provided whereby rechargeable batteries and cells are charged very fast by a controlled current, and substantially at a rate never exceeding the ability of the battery or cell to accept current--i.e., to convert electrical current to stored chemical energy. The resistance free terminal voltage of the battery or cell is detected during an interval when the charging current is interrupted, and compared against an independent reference voltage to control the charging current when a difference between the reference voltage and the sensed resistance free terminal voltage exists. The reference voltage may be altered at any instant in time, as a function of the ambient temperature, or the internal temperature or pressure of the battery, as a function of the charging current when it is within a predetermined range, or if a particular change in the value of the charging current occurs over a predetermined period of time. Charging characteristics may also be controlled and altered either through the passage of time or as a consequence of predetermined conditions occurring. The various provisions preclude thermal runaway for example, and assure very rapid and complete charging op…
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.