Rapidly charging a battery without overcharging
US6111389A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Jun 18, 1998 |
| Grant date | Aug 29, 2000 |
| Priority date | — |
| Expiry date | Jun 18, 2018 |
Classification
- Technology area (CPC Y)Emerging Cross-Sectional Technologies
- CPC primaryY02E60/10
- WIPO fieldElectrical machinery, apparatus, energy
- WIPO sectorElectrical engineering
Abstract
In the rapid charging of a Nickel Cadmium (NiCad) battery, the rapid charging is terminated and trickle charging is initiated when any of three conditions is satisfied: a first condition determined by comparing a sensed instantaneous battery voltage with a target voltage; a second condition which is determined by comparing the instantaneous battery temperature with minimum and maximum values; and a third condition determined by comparing an elapsed time of rapid charging with a maximum value. Because battery voltage versus rapid charging time is a function of ambient temperature, the target voltage is determined from an initial measurement of battery temperature, which is assumed to equal the ambient temperature. The target voltage, which is approximately a linearly declining function of ambient temperature, is determined by reading a stored lookup table using the sensed temperature as an index or address.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.