Battery cover assembly having integrated battery condition monitoring

• US 20040012396A1
• Filed: 04/21/2003
• Published: 01/22/2004
• Est. Priority Date: 04/06/2001
• Status: Active Grant

• Current Assignee: Microchip Technology Incorporated
• Original Assignee: Microchip Technology Incorporated
• Inventors: Batson, David C.
• Granted Patent: US 7,012,404 B2
• Time in Patent Office: Days
• US Class Current: 324/444
• CPC Class Codes: G01R 31/364 Battery terminal connectors with integrated measuring arrangements
• CPC Class Codes: H01M 10/12 Construction or manufacture
• CPC Class Codes: H01M 10/425 Structural combination with electronic components, e.g. electronic circuits integrated to the outside of the casing printed circuits H05K1/00
• CPC Class Codes: H01M 10/4257 Smart batteries, e.g. electronic circuits inside the housing of the cells or batteries
• CPC Class Codes: H01M 10/48 Accumulators combined with arrangements for measuring, testing or indicating the condition of cells, e.g. the level or density of the electrolyte constructional details of current conducting connections for detecting conditions inside cells or batteries, e.g. details of voltage sensing terminals, H01M50/569
• CPC Class Codes: H01M 10/486 for measuring temperature
• 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 50/561 Hollow metallic terminals, e.g. terminal bushings
• 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: H01M 50/581 in response to temperature
• CPC Class Codes: H02J 7/0048 Detection of remaining charge capacity or state of charge [SOC]
• 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
• CPC Class Codes: Y02T 10/70 Energy storage systems for electromobility, e.g. batteries

Abstract

A terminal assembly for measuring electrical current passing to and from a battery post, including an electrically conductive collar for connecting to a post of a battery, and an electrically conductive terminal for receiving a connector of a load. An electrically conductive resistor having a known resistance extends between outer surfaces of the collar and the terminal. The terminal assembly is incorporated into a battery, which also includes a volt meter connected between the outer surfaces of the collar and the terminal for measuring the voltage drop across the resistor, memory for storing the known resistance of the resistor, and a processor programmed to receive the measured voltage drop from the volt meter, retrieve the known resistance from the memory, and calculate current flow through the resistor based on the measured voltage drop and the known resistance, whereby current flow to and from the battery can be measured.

Claims

1. A terminal assembly for measuring electrical current passing to and from a battery post, comprising:

A. an electrically conductive collar having an inner surface for contacting a battery post;

B. an electrically conductive terminal for receiving a load connector; and

C. an electrically conductive resistor having a known resistance extending between outer surfaces of the collar and the terminal, wherein current flow from the battery post travels through the resistor from the collar to the terminal and current flow to the post travels through the resistor from the terminal to the collar.

2. A terminal assembly according to claim 1, further comprising a first lead electrically connected to the outer surface of the collar, and a second lead electrically connected to the outer surface of the terminal.

3. A terminal assembly according to claim 2, further comprising a volt meter connected between the first and the second leads for measuring the voltage drop across the resistor.

4. A terminal assembly according to claim 3, further comprising a computer including:

A. memory storing the known resistance of the resistor; and

B. a processor programmed to,

receive the measured voltage drop from the volt meter,

retrieve the known resistance from the memory, and

calculate current flow through the resistor based on the measured voltage drop and the known resistance.

5. A terminal assembly according to claim 4, further comprising:

A. a thermometer for measuring an actual temperature of the resistor;

B. the memory of the computer also stores a temperature coefficient of resistivity for the resistor; and

C. the processor of the computer is further programmed to,

receive the actual temperature from the thermometer,

retrieve the temperature coefficient of resistivity from the memory,

calculate an actual resistance of the resistor based on the known resistance, the temperature coefficient of resistivity, and the actual temperature, and

calculate actual current flow through the resistor based on the measured voltage drop and the actual resistance.

6. A terminal assembly according to claim 4, wherein the computer further comprises a clock and the processor is programmed to calculate a total charge based on the current flow and the charge time.

7. A terminal assembly according to claim 1, wherein the known resistance of the resistor is between about 50 microOhm and about 200 microOhm.

8. A terminal assembly according to claim 1, wherein the resistor is made from a material including lead.

9. A terminal assembly according to claim 1, wherein the resistor is made from a material including manganese.

10. A battery including the terminal assembly of claim 1, and further including:

A. a case;

B. a storage cell contained within the case for receiving and storing an electrical charge; and

C. an electrically conductive post connected to the storage cell and extending out of the case;

wherein the inner surface of the collar of the terminal assembly is positioned on a portion of the post extending out of the case.

11. A battery according to claim 10, wherein the storage cell includes lead and lead-oxide plates immersed in an acid electrolyte.

12. A battery post cover for receipt on a battery having at least one battery post extending therefrom, the cover including the terminal assembly of claim 1 and further comprising:

A. a first surface having a post port;

B. a second surface having a terminal port, and wherein the cover defines a substantially closed chamber; and

C. a circuit board received in the closed chamber; and

wherein the collar of the terminal assembly is positioned in the post port of the inner cover for receiving a battery post, the terminal extends through the terminal port of the outer cover, and leads extend from the outer surface of the collar and the outer surface of the terminal into the closed chamber of the covers and connect to the circuit board.

13. A battery post cover according to claim 12, wherein the resistor and the leads of the terminal assembly are contained within the cover.

14. A battery post cover according to claim 12, further comprising a volt meter mounted on the circuit board and connected between the first and the second leads of the terminal assembly for measuring the voltage drop across the resistor.

15. A battery post cover according to claim 14, further comprising a computer mounted on the circuit board and including:

A. memory storing the known resistance of the resistor; and

B. a processor programmed to,

receive the measured voltage drop from the volt meter, retrieve the known resistance from the memory, and

calculate current flow through the resistor based on the measured voltage drop and the known resistance.

16. A battery post cover according to claim 15, further comprising:

A. a thermometer mounted on the circuit board for measuring an actual temperature of the resistor;

B. the memory also stores a temperature coefficient of resistivity for the resistor; and

C. the processor is further programmed to,

receive the actual temperature from the thermometer,

retrieve the temperature coefficient of resistivity from the memory,

calculate an actual resistance of the resistor based on the known resistance, the temperature coefficient of resistivity, and the actual temperature, and

calculate actual current flow through the resistor based on the measured voltage drop and the actual resistance.

17. A battery post cover according to claim 15, wherein the computer further comprises a clock and the processor is programmed to calculate a total charge based on the current flow and the charge time.

18. A battery including the battery post cover of claim 12, and further including:

A. a case having an open top sealed by the first surface of the battery post cover;

B. a storage cell contained within the case for receiving and storing an electrical charge; and

C. an electrically conductive post connected to the storage cell and extending out of the case and through the post port of the cover, and wherein the inner surface of the collar of the terminal assembly is attached to the post.

19. A battery according to claim 18, wherein the storage cell includes lead and lead-oxide plates immersed in an acid electrolyte.