Patent ID: 6801017
Filing Date: 2004-10-05
Classification: H01M,H02J,Y02E

Abstract:
A four-stage charging technique for nickel-zinc cells and batteries, whereby a high cycle life is assured, without dendrite formation or harmful overcharge, with minimal shape change of the zinc electrode, and with minimal oxygen recombination;wherein, in a first stage, the nickel-zinc cell or battery is provided with an average current less than C/S for a period of less than five minutes, or until the terminal voltage of a cell reaches 1.75 volts to 1.79 volts; wherein a second stage provides a fast charge until the terminal voltage of a cell reaches between 1.88 volts and 1.92 volts; wherein a third stage provides a moderate charge until the terminal voltage of a cell reaches 1.90 volts to 1.94 volts; and wherein a fourth stage provides a slow charge period when the terminal voltage is greater than 1.94 volts.