Battery voltage tester for end of cell

• US 5,418,085 A
• Filed: 07/12/1993
• Issued: 05/23/1995
• Est. Priority Date: 01/31/1991
• Status: Expired due to Fees

• Current Assignee: Eveready Battery Company Incorporated (Energizer Holdings, Inc.)
• Original Assignee: Eveready Battery Company Incorporated (Energizer Holdings, Inc.)
• Inventors: Bailey, John C., Huhndorff, Harry R.
• Primary Examiner(s): LANGEL, WAYNE A
• Application Number:
  US08/090,805
• Time in Patent Office: 680 Days
• Field of Search: 429/91, 429/92, 429/93
• US Class Current: 429/91
• CPC Class Codes: G01D 7/005 Indication of measured value by colour change
• CPC Class Codes: G01R 31/364 Battery terminal connectors with integrated measuring arrangements
• 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 10/488 Cells or batteries combined with indicating means for external visualization of the condition, e.g. by change of colour or of light density
• CPC Class Codes: H01M 6/505 Cells combined with indicating means for external visualization of the condition, e.g. by change of colour or of light intensity
• CPC Class Codes: Y02E 60/10 Energy storage using batteries
• CPC Class Codes: Y10T 29/49115 including coating or impregnating

Abstract

A battery is provided with an end-of-cell voltage indicating device which can be used to indicate the state-of-charge of the battery. The indicating device has a flexible substrate of the same peripheral configuration as the battery. The substrate has an indicating coating on one surface which is in thermal or electrical contact with a conductive circuit pattern which can be temporarily connected between the terminals of the battery on application of pressure to an indicated spot on the surface of the substrate. The conductive circuit means causes the indicating coating to undergo a visible change which is representative of the state-of-charge or voltage of the battery. A dual end-switched, integral battery and state-of-charge indicating device having two switches disposed on one end of the battery is also disclosed.

Claims

1. An integral battery and state-of-charge indicating device comprising:

a battery having a first end and a second end, and a first and a second external terminal of opposite polarity;

a state-of-charge indicating device affixed to and disposed substantially in its entirety upon one of said first end and said second end, said device comprising;

a flexible member covering a portion of each of said first and second terminal;

an indicating material on one surface of said flexible member; and

conductive means on said flexible member in association with said indicating material and positioned for electrical contact with said first and second external terminals such that pressure on said flexible member will cause said conductive means to complete an electrical circuit between said first and second external terminals on said battery causing said indicating material to change optical absorption to an extent depending on the state-of-charge of said battery.

2. An integral state-of-charge indicating device and battery as set forth in claim 1, wherein:

said indicating material is a thermochromic material; and

said conductive means is a shaped conductive pattern in thermal contact with said indicating material.

3. An integral state-of-charge indicating device and battery as set forth in claim 1, wherein:

said indicating material is a liquid crystal material.

4. An integral state-of-charge indicating device and battery as set forth in claim 1, wherein:

said indicating material is an electrochromic material which undergoes a color change or change in optical absorption as part of an oxidation/reduction reaction caused by the direct application of a DC electrical potential to said material, and said conductive means are spaced electrical contacts for contacting said first and second external terminals on said battery and for directly applying the DC potential from said battery to said electrochromic material.

5. An integral state-of-charge indicating device and battery as set forth in claim 1, wherein:

said indicating material comprises spaced discrete areas of indicating material, the number of said areas which change color indicating the state-of-charge of said battery.

6. An integral state-of-charge indicating device and battery as set forth in claim 1, wherein said indicating material is a combination of layers of thermochromic materials that are activated at different temperatures.

7. An integral state-of-charge indicating device and battery as set forth in claim 1, wherein:

said flexible member is a washer-like member of substantially the same peripheral dimensions as said battery and said indicating material and conductive means are on the same side of said washer-like member.

8. An integral state-of-charge indicating device and battery as set forth in claim 1, including an electrical insulating coating on said conductive means except in the area where said conductive means is positioned for electrical contact with said first and second external terminals on said battery.

9. An integral state-of-charge indicating device and battery as set forth in claim 6, wherein the first terminal of the battery is an end cover for the battery, and the second terminal is in contact with the housing for the battery;

the flexible member has a first end for contacting the first terminal of the battery and a second end for contacting the second terminal of the battery, and the flexible member is disposed on the end cover of the battery.

10. An integral battery and state-of-charge indicating device in accordance with claim 1 wherein said flexible member conforms generally in shape to the end to which it is affixed.

11. A battery having an integral state-of-charge indicating device comprising:

a conductive housing containing the active components of said battery;

a first conductive cover attached to one end of said housing, said first conductive cover being electrically connected to said housing and forming the positive terminal for said battery;

a second conductive cover for closing the opposite end of said housing, said second conductive cover being electrically insulated from said housing, said second conductive cover forming the negative terminal for said battery;

a state-of-charge indicating device disposed substantially in its entirety upon and affixed to said second conductive cover, said indicating device having a circular form, said indicating device comprising;

a flexible member shaped to conform to said second conductive cover;

a layer of thermochromic material on one surface of said member;

a shaped conductive pattern on the surface of said thermochromic material, said conductive pattern having first and second end portions;

a layer of electrical insulating material on said conductive pattern, said insulating material having an opening so as to leave exposed at least one of said first and second end portions of said conductive pattern so that when pressure is applied to the surface of said flexible member above said first and second end portions of said conductive pattern one of said end portions will contact said positive terminal while the other end portion contacts said negative terminal causing said conductive pattern to heat and change the color of said thermochromic material thereby indicating the state-of-charge of said battery.

12. A battery as set forth in claim 11, wherein said battery has a label covering the surface of said housing with the ends of said label rolled over the edge of said first and second conductive covers, said state-of-charge indicating device being held in contact with said second conductive cover by said rolled edge of said label.

13. A battery having an integral state-of-charge indicating device comprising:

a housing containing the active components of said battery, said housing defining a first battery end and a second battery end opposite said first battery end;

a first conductive member on said housing forming a first external terminal for said battery;

a second conductive member on said housing forming a second external terminal for said battery;

a state-of-charge indicating device having a generally circular form, said indicating device secured to and overlying substantially in its entirety one of said first battery end and said second battery end, said device disposed adjacent said first and second conductive members, said device comprising;

a flexible member disposed on said housing in contact with a portion of one of said first and second conductive members and over a part of the other conductive member;

an indicating coating on one surface of said flexible member;

a conductive pattern in thermal contact with said indicating coating, said conductive pattern having a first end adjacent said first conductive member and a second end adjacent said second conductive member;

a layer of insulation covering all but the first and second ends of said conductive pattern so that pressure applied to the surface of said flexible member above said first and second ends of said conductive pattern will cause said conductive pattern to be electrically connected between the external terminals of said battery causing said conductive pattern to heat and said indicating coating to exhibit a visual change which can be related to the state-of-charge of said battery.

15. A battery as set forth in claim 13, wherein said electrochromic material takes part in an oxidation/reduction reaction on application of a DC electrical potential producing a visual change in said electrochromic material.

17. A combination battery and state-of-charge indicating device as set forth in claim 15, wherein at least one layer of said plurality of layers of thermochromic material exhibits an indicia indicative of the state-of-charge of said battery.

14. A battery having a integral state-of-charge indicating device comprising:

a housing for containing the active components of said battery, said housing defining a first battery end and a second battery end opposite said first battery end;

a first conductive portion of said housing forming a first external terminal for said battery;

a second conductive portion of said housing forming a second external terminal for said battery;

a generally circular, flexible substrate affixed to and overlying substantially in its entirety one of said first battery end and said second battery end, said substrate disposed on said housing such that said substrate covers a portion of said first and second external terminals;

a layer of electrochromic material covering a portion of said substrate;

a first electrically conductive means in electrical contact with said electrochromic material;

a second electrically conductive means in electrical contact with said electrochromic material;

a layer of electrical insulating material covering said first end and second electrically conductive means with the exception of the end portions thereof, so that pressure on said flexible substrate will cause at least one of said end portions of said first and second electrically conductive means to come into electrical contact with at least one of said first and second external terminals thereby applying a DC potential to said electrochromic material causing it to change color or optical absorption to an extent indicative of the state-of-charge of said battery.

16. A combination battery and a state-of-charge indicating device comprising:

a battery having a first end and a second end and first and second conductive portions forming external terminals of opposite polarity;

a state-of-charge indicating device having a circular form, affixed to and overlying substantially in its entirety one of said first end and said second end, said device comprising;

a flexible layer forming a substrate;

a plurality of layers of thermochromic material on said substrate, said thermochromic layers exhibiting a change in color or change in optical absorption at different temperatures;

a conductive pattern in thermal contact with said plurality of thermochromic layers, said conductive pattern having a first and a second end portion which on application of pressure to said substrate will complete an electrical circuit between said conductive pattern and said external terminals on said battery thereby causing said conductive pattern to heat and in turn cause said plurality of thermochromic layers to change color or optical absorption in relation to the state-of-charge of said battery.

18. A combination battery and state-of-charge indicating device as set forth in claim 16, wherein said indicia indicative of the state-of-charge of said battery is a word.

19. In a battery having a first end and a second end and a first external terminal and a second external terminal of opposite polarity, an integral battery state-of-charge indicator comprising:

a flexible member disposed upon and affixed to one of said first end and said second end, substantially the entirety of said flexible member overlying said one of said first end and said second end, said member conforming generally in shape to the end upon which it is disposed;

thermochromic indicating material on one surface of said flexible member; and

conductive means on said flexible member in association and in thermal contact with said indicating material and positioned for electrical contact with said first and said second external terminals, such that pressure on said flexible member will cause said conductive means to complete an electrical circuit between said first and said second external terminals on said battery causing said indicating material to change optical absorption to an extent depending on the state-of-charge of said battery.

20. An integral battery state-of-charge indicator in accordance with claim 19, wherein said flexible member is a washer-like member of substantially the same peripheral dimensions as said battery and said indicating material and conductive means are on the same side of said washer-like member.

21. An integral battery state-of-charge indicator in accordance with claim 19 including an electrical insulating coating on said conductive means except in the area where said conductive means is positioned for electrical contact with said first and second external terminals on said battery.

22. An integral battery state-of-charge indicator in accordance with claim 19 wherein said indicating material is a combination of layers of thermochromic materials that are activated at different temperatures.

23. An integral battery and state-of-charge indicating device comprising:

a battery having a first and a second end, and a first and a second external terminal of opposite polarity;

a state-of-charge indicating device affixed to said battery, said device comprising;

a first switch disposed upon one of said first end and said second end, said first switch for establishing electrical connection with one of said first and said second external terminals;

a voltage indicator disposed upon and affixed to said battery;

a first electrical conductor providing electrical connection between said first switch and said voltage indicator, said first electrical conductor extending from said first switch on one end of said battery to said indicator disposed on said battery;

a second switch disposed upon the same end of said battery that said first switch is disposed upon, said second switch for establishing electrical connection with the other of said first and said second external terminals; and

a second electrical conductor providing electrical connection between said second switch and said voltage indicator, said second electrical conductor extending from said second switch on said one end of said battery to said indicator disposed on said battery.

24. An integral battery and state-of-charge indicating device in accordance with claim 23 further comprising a wafer structure disposed upon a negative end cover of said battery and further disposed over a portion of the battery can, said wafer structure having:

a top substrate layer overlying portions of said first and said second electrical conductors in a region of said one end of said battery;

an insulative layer disposed underneath said portions of said first and said second electrical conductors extending along said one end of said battery, said insulative layer defining a first opening located directly over said negative end cover such that said portion of said first electrical conductor is exposed to said negative end cover, said insulative layer further defining a second opening located directly over and providing access to said battery can such that said portion of said second electrical conductor is exposed to said battery can.

25. An integral battery and state-of-charge indicating device in accordance with claim 23 wherein said voltage indicator is a thermochromic indicator.

26. An integral battery and state-of-charge indicating device in accordance with claim 23 wherein said voltage indicator is an electrochromic indicator.

27. An integral battery and state-of-charge indicating device in accordance with claim 23 wherein said voltage indicator is disposed substantially in its entirety upon the side of said battery.

28. An integral battery and state-of-charge indicating device comprising:

a battery having a first end and a second end, and a first and a second external terminal of opposite polarity;

a state-of-charge indicating device affixed to and disposed substantially in its entirety upon one of said first end and said second end, said device comprising;

a flexible member disposed proximate to a portion of each of said first and second terminals;

an indicating material on one surface of said flexible member; and

conductive means on said flexible member in association with said indicating material, said conductive means comprising a first end portion and a second end portion wherein said first end portion is in electrical contact with said first external terminal of said battery and said second end portion is positioned for electrical contact with said second external terminal such that pressure on said flexible member will cause said conductive means to complete an electrical circuit between said first and second external terminals on said battery causing said indicating material to change optical absorption to an extent depending on the state-of-charge of said battery.