Charger for rechargeable nickel-zinc battery
US6801017B2 · kind B2 · utility
Assignee
Inventor
Key dates
| Filing date | May 6, 2003 |
| Grant date | Oct 5, 2004 |
| Priority date | — |
| Expiry date | May 6, 2023 |
Classification
- Technology area (CPC Y)Emerging Cross-Sectional Technologies
- CPC primaryY02E60/10
- WIPO fieldElectrical machinery, apparatus, energy
- WIPO sectorElectrical engineering
Abstract
A four-stage charging technique for nickel-zinc cells and batteries, is provided, whereby a high cycle life is assured, without dendrite formation or harmful overchange, with minimal shape change of the zinc electrode, and with minimal oxygen, recombination. In the first stage, the nickel-zinc cell or battery is charged with an average current less than C/5 for a period for less than five minutes, or until the terminal voltage of a cell reaches 1.75 volts to 1.79 volts. In the second stage, a fast charge is imposed, until the terminal voltage of a cells reaches between 1.88 volts and 1.92 volts. In the third stage, a moderate charge is imposed, until the terminal voltage of a cell reaches 1.90 volts to 1.94 volts. The forth stage gives a trickle charge when the terminal voltage is greater then 1.94 volts. Typically, each of the transitions between the Stages 1 and 2 and Stages 2 and 3 is determined by a temperature dependent voltage; the transition between Stages 3 and 4 is determined by a time dependent inflection point of the terminal voltage of the cell; and Stage 4 termination is determined when dV/dt=0.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.