KELVIN CONNECTOR ADAPTER FOR STORAGE BATTERY

Abstract

A Kelvin connector adapter for use in connecting a Kelvin connection to a storage battery includes a conducting threaded portion adapted to be received in a threaded connector of the storage battery. A side pad contact is adapted to electrically connect to a side pad of the threaded connector. A first Kelvin connection pad is electrically coupled to the threaded portion and a second Kelvin connection pad is electrically coupled to the side pad contact.

Claims

1. A Kelvin connector adapter for use in connecting a Kelvin connection to a storage battery, comprising: a conducting threaded portion adapted to be received in a threaded connector of the storage battery; a side pad contact adapted to electrically connect to a side pad of the threaded connector; a first Kelvin connection pad electrically coupled to the threaded portion and adapted to connect to a first connector of a Kelvin clamp; and a second Kelvin connection pad electrically coupled to the side pad contact and adapted to connect to a second connector of the Kelvin clamp.

2. The Kelvin connector adapter of claim 1 including an insulating layer covering at least a portion of the adapter.

3. The Kelvin connector adapter of claim 1 wherein the first Kelvin connection pad and the threaded portion are formed by a single metal piece.

4. The Kelvin connector adapter of claim 1 wherein the second Kelvin connection pad and the side pad contact are formed by a single metal piece.

5. The Kelvin connector adapter of claim 1 including an insulating layer between the first Kelvin connection pad and the second Kelvin connection pad.

6. The Kelvin connector adapter of claim 1 wherein the first Kelvin connection pad and the second Kelvin connection pad have opposed faces.

7. The Kelvin connector adapter of claim 1 wherein the first Kelvin connection pad and the second Kelvin connection pad have ridged surfaces adapted for electrically connecting to a Kelvin clamp.

8. An electronic battery tester configured to electrically connect to a storage battery through a Kelvin connection made using the Kelvin connector adapter of claim 1.

9. A battery charger configured to electrically connect to a storage battery through a Kelvin connection made using the Kelvin connector adapter of claim 1.

10. A method of electrically connecting to a storage battery using a Kelvin connector, comprising: providing a conducted threaded portion adapted to be received in a threaded connector in a storage battery; providing a side pad contact adapted to be electrically connected to a side pad of the threaded connector; providing a first Kelvin connection pad electrically coupled to the threaded portion; providing a second Kelvin connection pad electrically coupled to side pad contact; and connecting to the first Kelvin connection pad and the second Kelvin connection pad using a Kelvin clamp.

11. The method of claim 10 including providing an insulating layer covering at least a portion of the adapter.

12. The method of claim 10 including forming the first Kelvin connection pad and the threaded portion with a single metal piece.

13. The method of claim 10 including forming the second Kelvin connection pad and the side pad contact with by a single metal piece.

14. The method of claim 10 including providing an insulating layer between the first Kelvin connection pad and the second Kelvin connection pad.

15. The method of claim 10 wherein the first Kelvin connection pad and the second Kelvin connection pad have opposed faces.

16. The method of claim 10 wherein the first Kelvin connection pad and the second Kelvin connection pad have ridged surfaces adapted for electrically connecting to a Kelvin clamp.

17. A method of testing a storage battery using an electronic battery tester configured to electrically connect to the storage battery through a Kelvin connection made using the Kelvin connector adapter of claim 1.

18. A method of charging a storage battery using a battery charger connected to the storage battery through a Kelvin connection made using this Kelvin connector adapter of claim 1.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

[0007] FIG. 1 shows a battery having different types of battery contacts.

[0008] FIG. 2 is a side plan view of a prior art Kelvin clamp.

[0009] FIG. 3 is exploded perspective view showing a Kelvin connector adapter in accordance with one configuration being inserted into a battery contact of a storage battery.

[0010] FIG. 4A is a side cross-sectional view and 4B is a perspective view with an insulating body removed of the Kelvin connector adapter of FIG. 3.

[0011] FIG. 5 is a simplified diagram of a prior art configuration showing metal posts used to couple to a storage battery.

[0012] FIG. 6 is a simplified diagram illustrating the electrical connections of Kelvin connectors when connecting to a storage battery using the Kelvin connector adapter illustrated in FIG. 3.

[0013] FIG. 7 is a simplified schematic diagram of an electronic battery tester coupled to a storage battery through the Kelvin connector adapter of FIG. 3.

[0014] FIG. 8 is a simplified schematic diagram of a battery charger coupled to a storage battery through the Kelvin connector adapter of FIG. 3.

DETAILED DESCRIPTION OF ILLUSTRATIVE EMBODIMENTS

[0015] A Kelvin connector adapter for a storage battery is provided. Some types of storage batteries include screw in terminals for providing a connection. One typical such battery uses side terminal connectors. In such a storage battery configuration, it may be difficult to provide a Kelvin connector for use in performing a battery test. In the past, screw in metal lugs have been used whereby Kelvin connector clamps are then physically coupled to the screw in lugs.

[0016] In one configuration, a Kelvin connector adapter is providing for connecting Kelvin clamps to such a storage battery. The Kelvin connector adapter includes a connecting threaded portion which is screwed into a side terminal of a battery. A side pad contact is configured to electrically connect to a side pad of the threaded connector. First and second Kelvin connector pads are provided and used to electrically connect to a Kelvin clamp.

[0017] In the discussion below, the term battery contact is used to define a portion of the battery onto which clamps of the present embodiments can be applied. FIG. 1 shows a battery 100 having different types of battery contacts to which a clamp in accordance with the present embodiments can couple. Battery contacts 106 and 108 are side screw terminals. In side terminals can be positioned anywhere on the battery housing. In battery 100 of FIG. 1, each of side screw terminals 106 and 108 includes a lead ring 110 with an embedded threaded feature 112 (for example, a stainless steel Helicoil thread), which is in contact with the lead ring 110.

[0018] It is relatively easy to properly connect to battery posts using any suitable clamp such as the example Kelvin clamp 198 shown in FIG. 2 that directly attaches to a post. However, proper electrical connection to side screw terminals 106 and 108 with a clamp such as Kelvin clamp 198 can usually be carried out only by screwing in lead terminal adapters (not shown) that effectively change side screw terminals such as 106 and 108 to battery posts. Thus, a clamp such as Kelvin clamp 198 cannot be directly attached to side screw terminals or, in general, to female receptacle terminals.

[0019] FIG. 3 is an exploded perspective view showing Kelvin connector adapter 200 with respect to battery contact 106 of battery 100. As illustrated in FIG. 3, a threaded tip 202 of adapter 200 is configured to be threaded (screwed) into threaded feature 112 of contact 106. As discussed below in more detail adapter 200 includes opposed Kelvin contact pads 210 and 212 configured to be clamped using a Kelvin connector clamp such as clamp 198 shown in FIG. 2.

[0020] FIG. 4A is a side cross-sectional view of adapter 200. As illustrated in FIG. 4A, the threaded tip 202 and Kelvin contact pad 210 are formed of a single piece. Preferably, this piece is conductive metal. One example material is brass. Although the components are illustrated as being farmed of a single metal piece. Any configuration which provides an electrical connection therebetween may be employed. Similarly, as illustrated in FIG. 4, a side post contact pad 220 is illustrated for contacting the lead ring 112 of battery contact 106. The side post contact pad is electrically connected to Kelvin contact pad 212. In the configuration illustrated in FIG. 4A, these components are fabricated from a single metal piece, for example, of brass. However, separate components may also be used so long as there is an electrical connector therebetween.

[0021] FIG. 4A also illustrates an insulating body 222 which is molded around components 202, 210, 212 and 220 to form the shape illustrated in FIG. 3. The insulating body 220 can comprise, for example, a molded plastic and can be configured to fill the space between opposed contact pads 210, 212. The insulating material should not cover the outer surface of pads 210, 212 such that electrical contact can be made thereon.

[0022] FIG. 4B is a perspective view showing the Kelvin connector adapter 200 with its insulating body 220 removed to thereby more clearly illustrate the metal components which form threaded tip 202, opposed Kelvin contact pads 210, 212 and side post contact pad 220.

[0023] FIG. 5 is a simplified diagram of a prior art configuration for providing posts 230 for electrically coupling to battery contacts 106 and 108 of battery 100 using Kelvin connector clamps. FIG. 5 illustrates resistors 232 and 234 through which all voltage and current measurements are made when employing connectors 230. This introduces an error in measurements made using Kelvin connectors because a portion of the electrical path to the battery is shared by each connector such that the current flowing through resistors 232, 234 will introduce an error in the voltage measurement.

[0024] In contrast, FIG. 6 is a simplified diagram showing the electrical connection to the battery contacts 108, 106 when employing Kelvin contact adapter 200 in accordance with the invention. As illustrated in FIG. 6, each Kelvin contact pad 212 provides separate electrical connections through resistors 240, 242 or 244, 246 to the battery contacts 108 and 106, respectively. This reduces error in measurements made using the Kelvin connectors in comparison to the prior art configuration illustrated in FIG. 5.

[0025] FIG. 7 is a simplified block diagram of electronic battery tester circuitry 500 with which the present embodiments are useful. A four point (or Kelvin connection) technique is used to couple system 500 to battery 502 through adapter 200. Kelvin connections 508 and 510 are used to couple to battery contacts 504 and 506, respectively, of battery 502. Kelvin connection 508 includes two individual connections 508A and 508B. Similarly, Kelvin connection 510 includes two individual connections, 510A and 510B. Kelvin clamps 198 attach to battery contacts 504 and 506 using adapters 200 and couple them to electrical connections 508, 510.

[0026] Circuitry 500 includes a current source 512 and a differential amplifier 514. Current source 512 is coupled to connections 508B and 510B of Kelvin connections 508 and 510, respectively. Differential amplifier 514 is coupled to connection 508A and connection 510A of Kelvin connections 508 and 510, respectively. An output from differential amplifier 514 is provided to analog to digital converter 518 which itself provides a digitized output to microprocessor 520. Microprocessor 520 is connected to a system clock 522, a memory 524, and analog to digital converter 518. Microprocessor 520 is also capable of receiving an input from an input device 526 and providing an output of output device 528. The input can be, for example, a rating for the battery 502. Input device 526 can comprise any or multiple types of input devices. The result of a battery test, either qualitative or quantitative, can be an output device 528. Device 528 can be a display or other output. The embodiments can operate with any technique for determining a voltage across battery 502 and a current through battery 502 and is not limited to the specific techniques set forth herein. The forcing function source or current source 512 can provide any signal having a time varying component, including a stepped pulse or a periodic signal, having any shape, applied to battery 502. The current source can be an active source in which the current source signal is injected into battery 502, or can be a passive source, such as a load, which is switched on under the control of microprocessor 520.

[0027] In operation, microprocessor 520 can receive an input through input 526, such as a rating for battery 502. Microprocessor 520 determines a dynamic parameter, such as dynamic conductance, of battery 502 as a function of sensed voltage and current. The change in these sensed values is used to determine the dynamic parameter. For example, the dynamic conductance (G) is determined as:

G=I/V EQ. 1

where I is the change in current flowing through battery 502 due to current source 512 and V is the change in battery voltage due to applied current I. A temperature sensor 530 can be thermally coupled to battery 502 and used to compensate battery measurements. Temperature readings can be stored in memory 524 for later retrieval.

[0028] FIG. 8 is a simplified block diagram of a battery charging system 600 using one of the present embodiments. System 600 is shown coupled to battery 602. System 600 includes battery charging and testing circuitry 604 and microprocessor 606. System 600 couples to battery contacts 608 and 610 through Kelvin electrical connections 612 and 614 respectively. Electrical connection 612 includes a first connection 612A and second connection 612B and connection 614 includes a first connection 614A and a second connection 614B. Kelvin clamps 300 (FIGS. 3-1, 3-2 and 3-3) provide coupling between battery contacts 608 and 610 and electrical connections 612 and 614. Battery charger 600 operates in any appropriate manner. One example is the battery charger set forth in U.S. Pat. No. 6,104,167, issued Aug. 15, 2000, and entitled METHOD AND APPARATUS FOR CHARGING A BATTERY, which is incorporated herein by reference.

[0029] As illustrated in the figures and discussed above, a configuration is provided in which a screw in lug provides two electrical connections to the threaded connector of a storage battery. This provides an adapter whereby a Kelvin connection is provided to the screw in terminals. In the specific illustration, one side of the Kelvin connector electrically and physically couples to the threads of the screw in terminal while a second connection is provided to contact to a side pad of the connector.

[0030] This configuration removes or substantially eliminates any effects of the electrical resistance in the adapter. The individual Kelvin leads connect directly to the battery post rather than through a lug.

[0031] As illustrated in the figures, the adapter includes two opposed electrically conducting side panels. These side panels can be clipped on to using Kelvin connector alligator clips such as those described in some of the references cited in the Background section.

[0032] Although the figures illustrate one of the connectors coupling to the side pad of the battery connector. In another configuration, the second connection also connects to the threaded portion of the connector.

[0033] An insulating material can be used to surround portions of the adapter leaving the contact pads exposed.

[0034] Although the present invention has been described with reference to preferred embodiments, workers skilled in the art will recognize that changes may be made in form and detail without departing from the spirit and scope of the invention. Although specific references are made herein to testing of a storage battery, the connector adapter may also be used for charging a battery. One such example includes an intelligent battery charger which performs a battery test for use in the charging procedure. As illustrated, the connector pads may have ridged surfaces to facilitate electrical connection with a Kelvin clamp.