Electricity: battery or capacitor charging or discharging – Battery or cell discharging – With charging
Reexamination Certificate
2001-08-15
2002-08-13
Toatley, Gregory (Department: 2838)
Electricity: battery or capacitor charging or discharging
Battery or cell discharging
With charging
Reexamination Certificate
active
06433511
ABSTRACT:
BACKGROUND
1. Technical Field
This invention relates generally to battery charging systems, and more specifically to systems that recondition batteries by discharging prior to charging.
2. Background Art
When a nickel-based rechargeable battery is placed in a charger before it is completely “dead”, it will lose some of its capacity due to the “memory effect”. In other words, if a battery is consistently partially discharged before recharging, the battery will “die” more and more quickly. In the worst case, a fully charged battery that originally lasted for four hours might die after only one hour.
This phenomenon is known as the memory effect, or voltage depression. It is particular to nickel chemistry batteries where the capacity, or in technical terms the “energy versus time curve”, changes based upon discharge patterns. The good news is that the memory effect can be nearly eliminated by fully discharging the battery at a nominal current. This type of full discharge is called “reconditioning”.
To keep a battery at original capacity, the battery needs to be reconditioned whenever the discharge time, i.e. the usable time of the battery, has become reduced. However, it is not always clear to the user when reconditioning is needed. Some chargers make the decision for the user. For example, U.S. Pat. No. 5,942,878, issued to Ito, entitled “Method and Device for Reducing Memory Effect of a Battery”, discloses one such charging system. The charger reconditions the battery every Nth charge depending upon usage.
The problem with these battery systems is that they sometime choose to recondition the battery when it is inconvenient for the user. For example, when the user is in a hurry and wants to charge the battery quickly for a special event, he will become frustrated when the charger starts a reconditioning cycle, thereby doubling the charge time. Likewise, if the user wants to recondition his battery right now, he may be frustrated when the charger does not think the time is appropriate.
Manufacturers have tried to overcome this problem by incorporating manual recondition switches in the chargers. For example, the 100-Watt 4 Station charger manufactured by ESI Technology includes a Mode Selector Switch that selects between charge and recondition modes.
The problem with mechanical switches is that they add cost to the end product. Additionally, they are mechanical parts that may fail after repeated use. There is thus a need for an improved method and apparatus for initiating reconditioning of batteries.
REFERENCES:
patent: 5826958 (1998-10-01), Avitan
patent: 5982146 (1999-11-01), Nguyen
patent: 6163131 (2000-12-01), Gartstein et al.
patent: 6239578 (2001-05-01), Schnell et al.
Burrus, IV Philip H.
Toatley Gregory
LandOfFree
Method and apparatus for manually reconditioning a battery... does not yet have a rating. At this time, there are no reviews or comments for this patent.
If you have personal experience with Method and apparatus for manually reconditioning a battery..., we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Method and apparatus for manually reconditioning a battery... will most certainly appreciate the feedback.
Profile ID: LFUS-PAI-O-2928673