STATE OF CHARGE INDICATOR FOR A BATTERY CHARGER

• US 20120081074A1
• Filed: 04/06/2011
• Published: 04/05/2012
• Est. Priority Date: 04/07/2010
• Status: Active Grant

• Current Assignee: Black & Decker Incorporated (Stanley Black & Decker, Inc.)
• Original Assignee: Black & Decker Incorporated (Stanley Black & Decker, Inc.)
• Inventors: Cunanan, Regina G.C., Wohltmann, Brian K., Lee, Dustin
• Granted Patent: US 8,796,995 B2
• Time in Patent Office: Days
• US Class Current: 320/112
• CPC Class Codes: B25F 5/00 Details or components of portable power-driven tools not particularly related to the operations performed and not otherwise provided for
• CPC Class Codes: B25F 5/02 Construction of casings, bodies or handles B25F5/006, B25F5/008 take precedence
• CPC Class Codes: B25F 5/021 with guiding devices guiding devices for hand tools on stands or supports B25H1/0078
• CPC Class Codes: G01R 31/3646 for indicating electrical conditions or variables, e.g. visual or audible indicators
• CPC Class Codes: G01R 31/374 with means for correcting the measurement for temperature or ageing
• CPC Class Codes: G01R 31/3835 involving only voltage measurements
• CPC Class Codes: G01R 31/385 Arrangements for measuring battery or accumulator variables for monitoring G01R31/382
• CPC Class Codes: H01H 2009/065 Battery operated hand tools in which the battery and the switch are directly connected
• CPC Class Codes: H01H 9/061 enclosing a continuously variable impedance
• CPC Class Codes: H01M 10/441 for several batteries or cells simultaneously or sequentially
• CPC Class Codes: H01M 10/448 End of discharge regulating measures
• CPC Class Codes: H01M 2010/4271 Battery management systems including electronic circuits, e.g. control of current or voltage to keep battery in healthy state, cell balancing
• CPC Class Codes: H01M 2010/4278 Systems for data transfer from batteries, e.g. transfer of battery parameters to a controller, data transferred between battery controller and main controller
• CPC Class Codes: H01M 2220/30 Batteries in portable systems, e.g. mobile phone, laptop
• CPC Class Codes: H01M 50/569 Constructional details of current conducting connections for detecting conditions inside cells or batteries, e.g. details of voltage sensing terminals battery terminal connectors with integrated measuring arrangements G01R31/364
• CPC Class Codes: H01R 12/7005 Guiding, mounting, polarizing or locking means; Extractors for printed circuit boards H05K
• CPC Class Codes: H01R 13/112 forked sockets having two legs
• CPC Class Codes: H02J 7/00034 Charger exchanging data with an electronic device, i.e. telephone, whose internal battery is under charge
• CPC Class Codes: H02J 7/00041 in response to measured battery parameters, e.g. voltage, current or temperature profile
• CPC Class Codes: H02J 7/0013 acting upon several batteries simultaneously or sequentially H02J7/1423 takes precedence
• CPC Class Codes: H02J 7/0019 : using switched or multiplexed charge circuits
• CPC Class Codes: H02J 7/0025 : Sequential battery discharge in systems with a plurality of batteries
• CPC Class Codes: H02J 7/0029 : with safety or protection devices or circuits
• CPC Class Codes: H02J 7/00306 : Overdischarge protection
• CPC Class Codes: H02J 7/0031 : using battery or load disconnect circuits H02J9/002 takes precedence
• CPC Class Codes: H02J 7/0045 : concerning the insertion or the connection of the batteries
• CPC Class Codes: H02J 7/0048 : Detection of remaining charge capacity or state of charge [SOC]
• CPC Class Codes: H02J 7/0063 : with circuits adapted for supplying loads from the battery
• CPC Class Codes: H02J 7/00714 : in response to battery charging or discharging current
• CPC Class Codes: H02J 7/007182 : in response to battery voltage
• CPC Class Codes: H02P 3/08 : for stopping or slowing a dc motor
• CPC Class Codes: H02P 31/00 : Arrangements for regulating or controlling electric motors not provided for in groups H02P1/00 - H02P5/00, H02P7/00 or H02P21/00 - H02P29/00
• CPC Class Codes: H02P 7/285 : controlling armature supply only
• CPC Class Codes: H02P 7/29 : using pulse modulation
• CPC Class Codes: Y02E 60/10 : Energy storage using batteries
• CPC Class Codes: Y02P 70/50 : Manufacturing or production processes characterised by the final manufactured product

Abstract

A method is provided for indicating state of charge of a battery being charged by a charger. The method includes: supplying a charging current from a battery charger to a battery pack; determining voltage of battery cells residing in the battery pack; and illuminating a visual indicator on the battery charger to indicate state of charge of the battery pack, where brightness of the visual indicator correlates to the voltage of the battery cells in the battery pack.

Claims

1. A method for indicating state of charge of a battery being charged by a charger, comprising:

supplying a charging current from a battery charger to a battery pack;

determining voltage of one of more battery cells residing in the battery pack; and

illuminating a visual indicator on the battery charger to indicate a state of charge of the battery pack, where brightness of the visual indicator correlates to the voltage of the battery cells in the battery pack.

2. The method of claim 1 further comprises alternating brightness of visual indicator between two illumination states, including a first illumination state indicating the state of charge of the battery pack and a second illumination state indicating a fully charged state of the battery pack.

3. The method of claim 1 further comprises implementing a light emitting diode as the visual indicator and controlling an amount of voltage applied the light emitting diode to be proportional to the voltage of the battery cells.

4. The method of claim 1 further comprises implementing a light emitting diode as the visual indicator, the light emitting diode arranged in series with a transistor;

and controlling illumination of the light emitting diode by applying a control signal to the transistor.

5. The method of claim 4 further comprises adjusting a duty cycle of a pulse width modulated control signal in accordance with the voltage of the battery cells.

6. The method of claim 1 wherein determining the voltage of the battery cells further comprises measuring a voltage of the battery cells across terminals coupling the battery pack to the battery charger.

7. The method of claim 1 further comprises determining the voltage of the battery cells further comprises receiving voltage measurements via a data link between the battery pack and the battery charger.

8. The method of claim 1 further comprises controlling a rate at which the visual indicator is illuminated in accordance with the voltage of the battery cells.

9. A battery charger that charges a battery pack coupled thereto, comprising:

a visual indicator;

a power supply module operable to supply a charging current from the battery charger to the battery pack;

a voltage monitoring module operable to determine voltage of one or more battery cells in the battery pack; and

a charge control module configured to receive the voltage of the battery cells from the voltage monitoring module and illuminate the visual indicator to indicate state of charge of the battery pack while the charging current is being delivered to the battery pack, where brightness of the visual indicator correlates to the voltage of the battery cells in the battery pack.

10. The battery charger of claim 9 wherein the charge control module alternates illuminating the visual indicator between two illumination states, including a first illumination mode indicating the state of charge of the battery pack when the battery pack is in a partially charged state and a second illumination mode indicating the state of charge of the battery pack when the battery pack is in a fully charged state.

11. The battery charger of claim 9 wherein the visual indicator is a light emitting diode and the charge control module controls an amount of voltage applied to the light emitting diode to be proportional to the voltage of the battery cells.

12. The battery charger of claim 11 wherein the light emitting diode is arranged in series with a source terminal or drain terminal of a transistor;

and the charge control module controls illumination of the light emitting diode by applying a control signal to a gate terminal of the transistor.

13. The battery charger of claim 12 wherein the control signal is pulse width modulated and the charge control module adjusts a duty cycle of the control signal in accordance with the voltage of the battery cells.

14. The battery charger of claim 9 wherein the voltage monitoring module measures a voltage of the battery cells across terminals coupling the battery pack to the battery charger.

15. The battery charger of claim 9 wherein the charge control module in data communication via a data link with a controller in the battery pack to receive voltage measurements for the battery cells in the battery pack.

16. The battery charger of claim 9 wherein the charge control module controls a rate at which the visual indicator is illuminated in accordance with the voltage of the battery cells.

17. A battery charger that charges a battery pack coupled thereto, comprising:

a visual indicator;

a power supply module operable to supply a charging current from the battery charger to the battery pack;

a voltage monitoring module operable to determine voltage of one or more battery cells in the battery pack; and

a charge control module configured to receive the voltage of the battery cells from the voltage monitoring module and illuminate the visual indicator to indicate state of charge of the battery pack while the charging current is being delivered to the battery pack, where a rate at which the visual indicator is illuminated in accordance with the voltage of the battery cells.

18. The battery charger of claim 17 wherein the visual indicator is a light emitting diode and arranged in series with a source terminal or drain terminal of a transistor;

and the charge control module controls illumination of the light emitting diode by applying a control signal to a gate terminal of the transistor.

19. The battery charger of claim 18 wherein the control signal is pulse width modulated and the charge control module adjusts a duty cycle of the control signal in accordance with the voltage of the battery cells.