Battery charge indicator

• US 7,876,068 B2
• Filed: 12/11/2003
• Issued: 01/25/2011
• Est. Priority Date: 10/24/2003
• Status: Expired due to Fees

• Current Assignee: ICC-Nexergy, Inc
• Original Assignee: International Components Corporation (ICC-Nexergy, Inc)
• Inventors: Faunce, Rita L., Laurx, Joseph A., Wentink, Robert F.
• Primary Examiner(s): Tso; Edward
• Assistant Examiner(s): Berhanu; Samuel
• Application Number:
  US10/732,942
• Publication Number:
  US 20050088146A1
• Time in Patent Office: 2,602 Days
• Field of Search: 320/132, 320/130, 320/128, 320/136, 320/137, 320/157, 320/166, 320/106, 320/107, 320/134, 320/1, 320/2, 320/5, 320/11, 320/14, 320/20, 320/30, 320/32, 320/39, 324/436, 324/437, 324/435, 307/66
• US Class Current: 320/132
• CPC Class Codes: H02J 7/0049 Detection of fully charged condition

Abstract

The resistors R1 and R2 are applied to terminals 1 and 8, respectively, of the switched-mode power supply 26. These resistors R1 and R2 are current-limiting resistors and function to control the output power and current. A standard buck regulator may be coupled to terminal 5 of the switched-mode power supply 26. The buck regulator includes a diode D7 and an inductor L1. The diode D7 and inductor L1 provide DC rectification and filtering of the high-frequency switch voltage from the switched-mode power supply 26.

Claims

1. A battery charge indicator for sensing and indicating various states of charge of a lithium ion battery, the battery charge indicator comprising:

a current sensing circuit for sensing charging current to said lithium ion battery during a constant current mode of operation and a constant voltage mode of operation and providing a first charge indication signal based upon comparing the magnitude of said charging current with a first predetermined value and generating a first charge indication signal solely as a function of said charging current when said charging current is less than or equal to said first predetermined value, wherein said first predetermined value is representative of a first predetermined charge state representative of an initial state of charge of said lithium ion battery, said current sensing circuit providing a second charge indication signal based upon comparing the magnitude of said charging current with a second predetermined value and generating a second charge indication signal solely as a function of said charging current when said charging current is less than or equal to said second predetermined value, said current sensing circuit providing a third charge indication signal based upon comparing the magnitude of said charging current with a third predetermined value and generating a third charge indication signal in said constant voltage mode of operation solely as a function of said charging current when said charging current is less than or equal to said third predetermined value;

a first indicator responsive to said first charge indication signal for providing an indication when said lithium ion battery is at an initial state of charge;

a second indicator responsive to said second charge indication signal for providing an indication when said lithium ion battery is at a transitional state of charge; and

a third indicator responsive to said third charge indication signal for providing an indication when said lithium ion battery is at a near full state of charge.

2. The battery charge indicator as recited in claim 1, wherein said first indicator includes a first visual indication.

3. The battery charge indicator as recited in claim 2, wherein said first visual indication is a first light emitting diode (LED).

4. The battery charge indicator as recited in claim 1, wherein said second indicator includes a second visual indication.

5. The battery charge indicator as recited in claim 1, wherein said first, second and third indicators comprise two LEDs.

6. The battery charge indicator as recited in claim 5, wherein one of said two LEDs is a red LED and the other of said two LEDs is a green LED and in a first state, said red LED is illuminated and in a second state both of said red and green LEDs are illuminated and in a third state, only said green LED is illuminated.

7. The battery charge indicator as recited in claim 1, wherein said third indicator includes a third visual indication.