HIGH-EFFICIENCY BATTERY CHARGER

• US 20140091754A1
• Filed: 09/26/2013
• Published: 04/03/2014
• Est. Priority Date: 09/28/2012
• Status: Active Grant

• Current Assignee: Vector Products Incorporated (Stanley Black & Decker, Inc.)
• Original Assignee: Henry Shum, Mathew Inskeep
• Inventors: Shum, Henry, Inskeep, Mathew
• Granted Patent: US 9,537,339 B2
• Time in Patent Office: Days
• US Class Current: 320/107
• CPC Class Codes: H02J 7/0069 Charging or discharging for charge maintenance, battery initiation or rejuvenation
• CPC Class Codes: H02J 7/007182 in response to battery voltage
• CPC Class Codes: H02J 7/04 Regulation of charging current or voltage
• CPC Class Codes: Y02B 40/00 Technologies aiming at improving the efficiency of home appliances, e.g. induction cooking or efficient technologies for refrigerators, freezers or dish washers

Abstract

A high efficiency battery charger. The high-efficiency battery charger can include a first transformer to produce a charging current, a second transformer to produce a maintenance current lower than the charging current, a power feed circuit having an input for connection to a power source, and control circuitry configured to detect a depleted battery to cause the power feed circuitry to feed power to the first transformer while disabling the second transformer, and to detect a charged battery to cause the power feed circuitry to feed power to the second transformer while disabling the first transformer.

Claims

1. A high efficiency battery charger, comprising:

a first transformer to produce a charging current and having a first output to couple the charging current to a depleted battery;

a second transformer to produce a maintenance current lower than the charging current, the second transformer having a second output to couple the maintenance current to a charged battery;

a power feed circuit having an input for connection to a power source and an output connected to respective ones of the first and second transformers; and

control circuitry having an input coupled to the first and second outputs and an output coupled to the power feed circuitry,

wherein the control circuitry is configured to detect a depleted battery to cause the power feed circuitry to feed power to the first transformer while disabling the second transformer and to detect a charged battery to cause the power feed circuitry to feed power to the second transformer while disabling the first transformer.

2. The high-efficiency battery charger of claim 1, wherein the first transformer provides the charging current in the range of about 1 ampere to about 100 amperes.

3. The high-efficiency battery charger of claim 2, wherein the first transformer provides a boost current in the range of about 50 amperes to about 400 amperes.

4. The high-efficiency battery charger of claim 1, wherein the second transformer provides the maintenance current in the range of about 0 amperes to about 2 amperes.

5. The high efficiency battery charger of claim 1, wherein at least one of the first transformer and the second transformer comprise at least one of an E-E type core shape or an E-I type core shape.

6. The high-efficiency battery charger of claim 5, wherein the first transformer has a core diameter in the range of about 28 millimeters to about 55 millimeters.

7. The high-efficiency battery charger of claim 5, wherein the second transformer has a core diameter in the range of about 12 millimeters to about 16 millimeters.

8. A high-efficiency battery charger, comprising:

a power source;

a plurality of transformers for providing power to a battery, wherein a first transformer is larger than a second transformer;

power feed circuitry, wherein the power feed circuitry is configured to selectively provide power from the power source to one of the plurality of transformers while disconnecting the rest of the plurality of transformers from the power source; and

control circuitry, wherein the control circuitry is configured to instruct the power feed circuitry to selectively provide power to the first transformer when high current is required, and to the second transformer when high current is not required.

9. The high-efficiency battery charger of claim 8, wherein the control circuitry is configured to instruct the power feed circuitry to selectively provide power to the first transformer when the battery is detected to be fully charged, and to the second transformer when the battery is detected to be less than fully charged.

10. The high-efficiency battery charger of claim 8, wherein the control circuitry is configured to instruct the power feed circuitry to selectively provide power to the first transformer when a voltage of the battery is detected to be below a specified voltage, and to the second transformer when a voltage of the battery is detected to be at or above the specified voltage.

11. The high-efficiency battery charger of claim 8, wherein the control circuitry is configured to instruct the power feed circuitry to selectively provide power to the first transformer for a first amount of time, and to the second transformer for a second amount of time.

12. The high-efficiency battery charger of claim 11, wherein the first amount of time and the second amount of time are determined according to a schedule.

13. A method for operating a high-efficiency battery charger, comprising:

charging the battery using a main transformer that is larger than an auxiliary transformer;

determining whether the battery is fully charged;

disconnecting the main transformer when the battery is determined to be fully charged; and

providing a maintenance charge using the auxiliary transformer while the main transformer is disconnected.