Method and apparatus for recharging batteries in the presence of a load current
US6459239B1 · kind B1 · utility
Assignee
Inventor
Key dates
| Filing date | Oct 31, 2001 |
| Grant date | Oct 1, 2002 |
| Priority date | — |
| Expiry date | Oct 31, 2021 |
Classification
- Technology area (CPC Y)Emerging Cross-Sectional Technologies
- CPC primaryY02E60/10
- WIPO fieldElectrical machinery, apparatus, energy
- WIPO sectorElectrical engineering
Abstract
A method and apparatus are disclosed for recharging a battery in the presence of a load. The present invention utilizes the battery itself as an averaging element to maintain the battery at the desired threshold voltage, VT (on average) as the current charging source is selectively turned on and off. Generally, the present invention measures the battery voltage at the end of each interval just before the current source is turned on or off. A calculation is performed for each charging cycle (current on and off) to determine the duty cycle for the subsequent cycle. The calculated duty cycle is the percentage of time that the current source should be applied for the next cycle. The calculated duty cycle is based on the difference between the actual battery voltage and the desired voltage. In this manner, the on and off times are modulated by the present invention such that the average battery voltage, Vbat, is the desired threshold voltage, VT.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.