Current measuring apparatus for battery

• US 6,573,723 B2
• Filed: 04/04/2001
• Issued: 06/03/2003
• Est. Priority Date: 04/04/2000
• Status: Expired due to Term

• Current Assignee: Microchip Technology Incorporated
• Original Assignee: Microchip Technology Incorporated
• Inventors: Baston, David C.
• Primary Examiner(s): Riley, Shawn
• Assistant Examiner(s): LUK, LAWRENCE W
• Application Number:
  US09/826,261
• Publication Number:
  US 20010033171A1
• Time in Patent Office: 790 Days
• Field of Search: 324/426, 324/428, 324/430, 320/107, 320/104, 428/90, 428/96, 428/97, 428/98, 428/178, 428/179, 428/180
• US Class Current: 324/426
• CPC Class Codes: G01R 1/203 Resistors used for electric measuring, e.g. decade resistors standards, resistors for comparators, series resistors, shunts resistors in general H01C; microwave or radiowave terminations H01P1/26; coupling devices H01R
• CPC Class Codes: G01R 19/0092 measuring current only all subgroups of G01R19/00 take precedence
• CPC Class Codes: G01R 31/2607 Circuits therefor G01R31/2642 takes precedence
• CPC Class Codes: G01R 31/364 Battery terminal connectors with integrated measuring arrangements
• CPC Class Codes: G01R 31/3648 comprising digital calculation means, e.g. for performing an algorithm
• CPC Class Codes: G01R 31/379 for lead-acid batteries
• CPC Class Codes: G01R 31/382 Arrangements for monitoring battery or accumulator variables, e.g. SoC
• CPC Class Codes: G01R 31/3835 involving only voltage measurements

Abstract

An apparatus for measuring electrical energy passing to and from a battery post. The apparatus includes a resistor having a known resistance, a first conducting surface and a second conducting surface. The conducting surfaces are arranged such that current flow from a battery post will travel through the resistor from the first conducting surface to the second conducting surface, and current flow to the post travels through the resistor from the second to the first conducting surfaces. The energy measuring apparatus further includes a first lead electrically connected to the first conducting surface of the resistor, and a second lead electrically connected to the second conducting surface of the resistor.

Claims

1. An apparatus for measuring electrical current passing to and from a battery post, comprising:

a resistor, the resistor being in the shape of a sleeve so as to be coaxially received on a battery post and to provide an electrical connection to the battery post, the resistor having a known resistance and a first conducting surface and a second conducting surface, wherein current flow from the battery post travels through the resistor from the first conducting surface to the second conducting surface of the resistor and current flow to the battery post travels through the resistor from the second conducting surface to the first conducting surface of the resistor;

a first lead electrically connected to the first conducting surface of the resistor; and

a second lead electrically connected to the second conducting surface of the resistor.

2. An apparatus according to claim 1, further comprising a volt meter connected between the first and the second leads for measuring the voltage drop across the resistor.

3. An apparatus according to claim 2, further comprising a computer including:

memory for storing the known resistance of the resistor; and

a processor programmed to,

receive the measured voltage drop for 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.

4. An apparatus according to claim 1, wherein the known claim resistance of the resistor is between about 50 microOhm and about 200 microOhm.

5. An apparatus according to claim 1, wherein the resistor includes at least one channel between the first and the second conducting surfaces.

6. An apparatus according to claim 1, wherein the resistor is made from a material at least including lead.

7. A battery including the apparatus of claim 1, and further including:

a case;

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

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

wherein the first conducting surface of the resistor is positioned on a portion of the post extending out of the case.

8. A battery according to claim 7, wherein the storage cell includes lead and lead-oxide plates immersed in an acid electrolyte.

9. A battery according to claim 7, further comprising a volt meter connected between the first and the second leads for measuring the voltage drop across the resistor.

10. A battery according to claim 9, further comprising a computer including:

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.

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

12. A battery according to claim 7, wherein the resistor is provided in the shape of a sleeve and the first conducting surface of the resistor is coaxially received on the battery post.

13. A battery according to claim 12, wherein the first conducting surface of the resistor includes at least one channel.

14. A battery according to claim 12, further comprising a sleeve-like terminal coaxially received on the second conducting surface of the resistor.

15. A battery according to claim 7, wherein the resistor includes at least one channel between the first and the second conducting surfaces.

16. A battery according to claim 7, wherein the resistor is made from a material at least including lead.

17. An apparatus for measuring electrical current passing to and from a battery post, comprising:

a resistor being integrally formed as part of a battery post and providing an electrical connection to the battery post, the resistor having a known resistance and a first conducting surface and a second conducting surface, wherein current flow from the battery post travels through the resistor from the first conducting surface to the second conducting surface of the resistor and current flow to the battery post travels through the resistor from the second conducting surface to the first conducting surface of the resistor;

a first lead electrically connected to the first conducting surface of the resistor; and

a second lead electrically connected to the second conducting surface of the resistor.

18. An apparatus according to claim 17, wherein the second conducting surface of the resistor includes at least one channel.

19. A battery including the apparatus of claim 17, and further including:

a case;

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

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

wherein the first conducting surface of the resistor is positioned on a portion of the post extending out of the case.

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

21. A battery according to claim 19, further comprising a volt meter connected between the first and the second leads for measuring the voltage drop across the resistor.

22. A battery according to claim 21, further comprising a computer including:

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.

23. A battery according to claim 19, wherein the known resistance of the resistor is between about 50 microOhm and about 200 microOhm.

24. A battery according to claim 19, wherein the resistor is integrally formed as part of the battery post.

25. A battery according to claim 24, wherein the first conducting surface of the resistor includes at least one channel.

26. A battery according to claim 19, wherein the resistor includes at least one channel between the first and the second conducting surfaces.

27. A battery according to claim 19, wherein the resistor is made from a material at least including lead.

28. A resistor for use in measuring electrical current passing to and from a battery post, comprising:

a resistor in the shape of a sleeve for being coaxially received on a battery post;

the resistor having a first conducting surface for contacting the battery post, and a second conducting surface, wherein current flow from the battery post travels through the resistor from the first conducting surface to the second conducting surface and current flow to the battery post travels through the resistor from the second conducting surface to the first conducting surface;

wherein the resistor has a known resistance, whereby current flow through the resistor can be determined based on a measured change in voltage between the first and the second conducting surfaces and the known resistance.

29. A resistor according to claim 28, wherein the known resistance is between about 50 microOhm and about 200 microOhm.

30. A resistor according to claim 28, wherein the known resistance is about 150 microOhm.

31. A resistor according to claim 28, wherein the second conducting surface includes at least one channel for dissipating heat.

32. A resistor according to claim 28, further including at least one channel between the first and the second conducting surfaces for dissipating heat.

33. A resistor according to claim 28, made from a material at least including lead.

34. A resistor according to claim 28, including an inner portion defining the first conducting surface and an outer portion received on the inner portion and defining the second conducting surface, and each portion includes bores for receiving leads for measuring a voltage change between the first and the second conducting surfaces.

35. A resistor according to claim 28, further including a lead secured to the first conducting surface and a lead secured to the second conducting surface, the leads for measuring a voltage change between the first and the second conducting surfaces.

36. A resistor for use in measuring electrical current passing to and from a battery post, comprising:

a resistor in the shape of a head of a battery post;

the resistor having a first conducting surface for contacting the battery post and a second conducting surface, wherein current flow from the battery post travels through the resistor from the first conducting surface to the second conducting surface and current flow to the battery post travels through the resistor from the second conducting surface to the first conducting surface;

wherein the resistor has a known resistance, whereby current flow through the resistor can be determined based on a measured change in voltage between the first and the second conducting surfaces and the known resistance.

37. A resistor according to claim 36, wherein the known resistance is between about 50 microOhm and about 200 microOhm.

38. A resistor according to claim 36, wherein the known resistance is about 150 micro Ohm.

39. A resistor according to claim 36, wherein the second conducting surface includes at least one channel for dissipating heat.

40. A resistor according to claim 36, further including at least one channel between the first and the second conducting surfaces for dissipating heat.

41. A resistor according to claim 36, made from a material at least including lead.

42. A resistor according to claim 36, including an inner portion defining the first conducting surface and an outer portion received on the inner portion and defining the second conducting surface, and each portion includes bores for receiving leads for measuring a voltage change between the first and the second conducting surfaces.

43. A resistor according to claim 36, further including a lead secured to the first conducting surface and a lead secured to the second conducting surface, the leads for measuring a voltage change between the first and the second conducting surfaces.