Abstract:
A method and apparatus for coupling a battery charger and/or a battery tester to a battery is provided. A clamp can be selectively removed from a cable. This allows replacement of the clamp as desired as well as fixedly or removably coupling the cable to the battery tester or charger.

Description:
BACKGROUND OF THE INVENTION  
       [0001]     The present invention relates to electronic battery testers and chargers of the type used to electrically test and charge storage batteries. More specifically, the present invention relates to clamps which are used to electrically couple such electronic battery testers and chargers to terminals of storage batteries.  
         [0002]     Storage batteries are used in many applications as sources of power. For example, storage batteries are used in automotive vehicles, both electrical vehicles and vehicles with internal combustion engines, as well as power supplies such as backup power systems. It is often desirable to measure the condition of such storage batteries. For example, it can be useful to determine the amount of charge a storage battery can hold (i.e. the capacity of the battery) or the state of health of a storage battery.  
         [0003]     A number of battery testing techniques are known in the art. These techniques include measuring the specific gravity of acid contained in a storage battery. Measuring a battery voltage and performing a load test on a battery in which a large load is placed on the battery and the response observed. More recently, a technique has been pioneered by Dr. Keith S. Champlin and Midtronics, Inc. of Willowbrook, Illinois for testing storage batteries by measuring the conductance of the batteries. This technique is described in a number of United States patents, for example, U.S. Pat. No. 3,873,911, issued Mar. 25, 1975, to Champlin, entitled ELECTRONIC BATTERY TESTING DEVICE; U.S. Pat. No. 3,909,708, issued Sep. 30, 1975, to Champlin, entitled ELECTRONIC BATTERY TESTING DEVICE; U.S. Pat. No. 4,816,768, issued Mar. 28, 1989, to Champlin, entitled ELECTRONIC BATTERY TESTING DEVICE; U.S. Pat. No. 4,825,170, issued Apr. 25, 1989, to Champlin, entitled ELECTRONIC BATTERY TESTING DEVICE WITH AUTOMATIC VOLTAGE SCALING; U.S. Pat. No. 4,881,038, issued Nov. 14, 1989, to Champlin, entitled ELECTRONIC BATTERY TESTING DEVICE WITH AUTOMATIC VOLTAGE SCALING TO DETERMINE DYNAMIC CONDUCTANCE; U.S. Pat. No. 4,912,416, issued Mar. 27, 1990, to Champlin, entitled ELECTRONIC BATTERY TESTING DEVICE WITH STATE-OF-CHARGE COMPENSATION; U.S. Pat. No. 5,140,269, issued Aug. 18, 1992, to Champlin, entitled ELECTRONIC TESTER FOR ASSESSING BATTERY/CELL CAPACITY; U.S. Pat. No. 5,343,380, issued Aug. 30, 1994, entitled METHOD AND APPARATUS FOR SUPPRESSING TIME-VARYING SIGNALS IN BATTERIES UNDERGOING CHARGING OR DISCHARGING; U.S. Pat. No. 5,572,136, issued Nov. 5, 1996, entitled ELECTRONIC BATTERY TESTER DEVICE; U.S. Pat. No. 5,574,355, issued Nov. 12, 1996, entitled METHOD AND APPARATUS FOR DETECTION AND CONTROL OF THERMAL RUNAWAY IN A BATTERY UNDER CHARGE; U.S. Pat. No. 5,585,416, issued Dec. 10, 1996, entitled APPARATUS AND METHOD FOR STEP-CHARGING BATTERIES TO OPTIMIZE CHARGE ACCEPTANCE; U.S. Pat. No. 5,585,728, issued Dec. 17, 1996, entitled ELECTRONIC BATTERY TESTER WITH AUTOMATIC COMPENSATION FOR LOW STATE-OF-CHARGE; U.S. Pat. No. 5,589,757, issued Dec. 31, 1996, entitled APPARATUS AND METHOD FOR STEP-CHARGING BATTERIES TO OPTIMIZE CHARGE ACCEPTANCE; U.S. Pat. No. 5,592,093, issued Jan. 7, 1997, entitled ELECTRONIC BATTERY TESTING DEVICE LOOSE TERMINAL CONNECTION DETECTION VIA A COMPARISON CIRCUIT; U.S. Pat. No. 5,598,098, issued Jan. 28, 1997, entitled ELECTRONIC BATTERY TESTER WITH VERY HIGH NOISE IMMUNITY; U.S. Pat. No. 5,656,920, issued Aug. 12, 1997, entitled METHOD FOR OPTIMIZING THE CHARGING LEAD-ACID BATTERIES AND AN INTERACTIVE CHARGER; U.S. Pat. No. 5,757,192, issued May 26, 1998, entitled METHOD AND APPARATUS FOR DETECTING A BAD CELL IN A STORAGE BATTERY; U.S. Pat. No. 5,821,756, issued Oct. 13, 1998, entitled ELECTRONIC BATTERY TESTER WITH TAILORED COMPENSATION FOR LOW STATE-OF CHARGE; U.S. Pat. No. 5,831,435, issued Nov. 3, 1998, entitled BATTERY TESTER FOR JIS STANDARD; U.S. Pat. No. 5,914,605, issued Jun. 22, 1999, entitled ELECTRONIC BATTERY TESTER; U.S. Pat. No. 5,945,829, issued Aug. 31, 1999, entitled MIDPOINT BATTERY MONITORING; U.S. Pat. No. 6,002,238, issued Dec. 14, 1999, entitled METHOD AND APPARATUS FOR MEASURING COMPLEX IMPEDANCE OF CELLS AND BATTERIES; U.S. Pat. No. 6,037,751, issued Mar. 14, 2000, entitled APPARATUS FOR CHARGING BATTERIES; U.S. Pat. No. 6,037,777, issued Mar. 14, 2000, entitled METHOD AND APPARATUS FOR DETERMINING BATTERY PROPERTIES FROM COMPLEX IMPEDANCE/ADMITTANCE; U.S. Pat. No. 6,051,976, issued Apr. 18, 2000, entitled METHOD AND APPARATUS FOR AUDITING A BATTERY TEST; U.S. Pat. No. 6,081,098, issued Jun. 27, 2000, entitled METHOD AND APPARATUS FOR CHARGING A BATTERY; U.S. Pat. No. 6,091,245, issued Jul. 18, 2000, entitled METHOD AND APPARATUS FOR AUDITING A BATTERY TEST; U.S. Pat. No. 6,104,167, issued Aug. 15, 2000, entitled METHOD AND APPARATUS FOR CHARGING A BATTERY; U.S. Pat. No. 6,137,269, issued Oct. 24, 2000, entitled METHOD AND APPARATUS FOR ELECTRONICALLY EVALUATING THE INTERNAL TEMPERATURE OF AN ELECTROCHEMICAL CELL OR BATTERY; U.S. Pat. No. 6,163,156, issued Dec. 19, 2000, entitled ELECTRICAL CONNECTION FOR ELECTRONIC BATTERY TESTER; U.S. Pat. No. 6,172,483, issued Jan. 9, 2001, entitled METHOD AND APPARATUS FOR MEASURING COMPLEX IMPEDANCE OF CELLS AND BATTERIES; U.S. Pat. No. 6,172,505, issued Jan. 9, 2001, entitled ELECTRONIC BATTERY TESTER; U.S. Pat. No. 6,222,369, issued Apr. 24, 2001, entitled METHOD AND APPARATUS FOR DETERMINING BATTERY PROPERTIES FROM COMPLEX IMPEDANCE/ADMITTANCE; U.S. Pat. No. 6,225,808, issued May 1, 2001, entitled TEST COUNTER FOR ELECTRONIC BATTERY TESTER; U.S. Pat. No. 6,249,124, issued Jun. 19, 2001, entitled ELECTRONIC BATTERY TESTER WITH INTERNAL BATTERY; U.S. Pat. No. 6,259,254, issued Jul. 10, 2001, entitled APPARATUS AND METHOD FOR CARRYING OUT DIAGNOSTIC TESTS ON BATTERIES AND FOR RAPIDLY CHARGING BATTERIES; U.S. Pat. No. 6,262,563, issued Jul. 17, 2001, entitled METHOD AND APPARATUS FOR MEASURING COMPLEX ADMITTANCE OF CELLS AND BATTERIES; U.S. Pat. No. 6,294,896, issued Sep. 25, 2001; entitled METHOD AND APPARATUS FOR MEASURING COMPLEX SELF-IMMITANCE OF A GENERAL ELECTRICAL ELEMENT; U.S. Pat. No. 6,294,897, issued Sep. 25, 2001, entitled METHOD AND APPARATUS FOR ELECTRONICALLY EVALUATING THE INTERNAL TEMPERATURE OF AN ELECTROCHEMICAL CELL OR BATTERY; U.S. Pat. No. 6,304,087, issued Oct. 16, 2001, entitled APPARATUS FOR CALIBRATING ELECTRONIC BATTERY TESTER; U.S. Pat. No. 6,310,481, issued Oct. 30, 2001, entitled ELECTRONIC BATTERY TESTER; U.S. Pat. No. 6,313,607, issued Nov. 6, 2001, entitled METHOD AND APPARATUS FOR EVALUATING STORED CHARGE IN AN ELECTROCHEMICAL CELL OR BATTERY; U.S. Pat. No. 6,313,608, issued Nov. 6, 2001, entitled METHOD AND APPARATUS FOR CHARGING A BATTERY; U.S. Pat. No. 6,316,914, issued Nov. 13, 2001, entitled TESTING PARALLEL STRINGS OF STORAGE BATTERIES; U.S. Pat. No. 6,323,650, issued Nov. 27, 2001, entitled ELECTRONIC BATTERY TESTER; U.S. Pat. No. 6,329,793, issued Dec. 11, 2001, entitled METHOD AND APPARATUS FOR CHARGING A BATTERY; U.S. Pat. No. 6,331,762, issued Dec. 18, 2001, entitled ENERGY MANAGEMENT SYSTEM FOR AUTOMOTIVE VEHICLE; U.S. Pat. No. 6,332,113, issued Dec. 18, 2001, entitled ELECTRONIC BATTERY TESTER; U.S. Pat. No. 6,351,102, issued Feb. 26, 2002, entitled AUTOMOTIVE BATTERY CHARGING SYSTEM TESTER; U.S. Pat. No. 6,359,441, issued Mar. 19, 2002, entitled ELECTRONIC BATTERY TESTER; U.S. Pat. No. 6,363,303, issued Mar. 26, 2002, entitled ALTERNATOR DIAGNOSTIC SYSTEM; U.S. Pat. No. 6,392,414, issued May 21, 2002, entitled ELECTRONIC BATTERY TESTER; U.S. Pat. No. 6,417,669, issued Jul. 9, 2002, entitled SUPPRESSING INTERFERENCE IN AC MEASUREMENTS OF CELLS, BATTERIES AND OTHER ELECTRICAL ELEMENTS; U.S. Pat. No. 6,424,158, issued Jul. 23, 2002, entitled APPARATUS AND METHOD FOR CARRYING OUT DIAGNOSTIC TESTS ON BATTERIES AND FOR RAPIDLY CHARGING BATTERIES; U.S. Pat. No. 6,441,585, issued Aug. 17, 2002, entitled APPARATUS AND METHOD FOR TESTING RECHARGEABLE ENERGY STORAGE BATTERIES; U.S. Pat. No. 6,445,158, issued Sep. 3, 2002, entitled VEHICLE ELECTRICAL SYSTEM TESTER WITH ENCODED OUTPUT; U.S. Pat. No. 6,456,045, issued Sep. 24, 2002, entitled INTEGRATED CONDUCTANCE AND LOAD TEST BASED ELECTRONIC BATTERY TESTER; U.S. Pat. No. 6,466,025, issued Oct. 15, 2002, entitled ALTERNATOR TESTER; U.S. Pat. No. 6,466,026, issued Oct. 15, 2002, entitled PROGRAMMABLE CURRENT EXCITER FOR MEASURING AC IMMITTANCE OF CELLS AND BATTERIES; U.S. Pat. No. 6,534,993, issued Mar. 18, 2003, entitled ELECTRONIC BATTERY TESTER; U.S. Pat. No. 6,544,078, issued Apr. 8, 2003, entitled BATTERY CLAMP WITH INTEGRATED CURRENT SENSOR; U.S. Pat. No. 6,556,019, issued Apr. 29, 2003, entitled ELECTRONIC BATTERY TESTER; U.S. Pat. No. 6,566,883, issued May 20, 2003, entitled ELECTRONIC BATTERY TESTER; U.S. Pat. No. 6,586,941, issued Jul. 1, 2003, entitled BATTERY TESTER WITH DATABUS; U.S. Pat. No. 6,597,150, issued Jul. 22, 2003, entitled METHOD OF DISTRIBUTING JUMP-START BOOSTER PACKS; U.S. Pat. No. 6,621,272, issued Sep. 16, 2003, entitled PROGRAMMABLE CURRENT EXCITER FOR MEASURING AC IMMITTANCE OF CELLS AND BATTERIES; U.S. Pat. No. 6,623,314, issued Sep. 23, 2003, entitled KELVIN CLAMP FOR ELECTRICALLY COUPLING TO A BATTERY CONTACT; U.S. Pat. No. 6,633,165, issued Oct. 14, 2003, entitled IN-VEHICLE BATTERY MONITOR; U.S. Pat. No. 6,635,974, issued Oct. 21, 2003, entitled SELF-LEARNING POWER MANAGEMENT SYSTEM AND METHOD; U.S. Ser. No. 09/780,146, filed Feb. 9, 2001, entitled STORAGE BATTERY WITH INTEGRAL BATTERY TESTER; U.S. Ser. No. 09/756,638, filed Jan. 8, 2001, entitled METHOD AND APPARATUS FOR DETERMINING BATTERY PROPERTIES FROM COMPLEX IMPEDANCE/ADMITTANCE; U.S. Ser. No. 09/862,783, filed May 21, 2001, entitled METHOD AND APPARATUS FOR TESTING CELLS AND BATTERIES EMBEDDED IN SERIES/PARALLEL SYSTEMS; U.S. Pat. No. 6,469,511, issued Nov. 22, 2002, entitled BATTERY CLAMP WITH EMBEDDED ENVIRONMENT SENSOR; U.S. Ser. No. 09/880,473, filed Jun. 13, 2001; entitled BATTERY TEST MODULE; U.S. Pat. No. 6,495,990, issued Dec. 17, 2002, entitled METHOD AND APPARATUS FOR EVALUATING STORED CHARGE IN AN ELECTROCHEMICAL CELL OR BATTERY; U.S. Ser. No. 60/348,479, filed Oct. 29, 2001, entitled CONCEPT FOR TESTING HIGH POWER VRLA BATTERIES; U.S. Ser. No. 10/046,659, filed Oct. 29, 2001, entitled ENERGY MANAGEMENT SYSTEM FOR AUTOMOTIVE VEHICLE; U.S. Ser. No. 09/993,468, filed Nov. 14, 2001, entitled KELVIN CONNECTOR FOR A BATTERY POST; U.S. Ser. No. 09/992,350, filed Nov. 26, 2001, entitled ELECTRONIC BATTERY TESTER; U.S. Ser. No. 10/042,451, filed Jan. 8, 2002, entitled BATTERY CHARGE CONTROL DEVICE; U.S. Ser. No. 10/073,378, filed Feb. 8, 2002, entitled METHOD AND APPARATUS USING A CIRCUIT MODEL TO EVALUATE CELL/BATTERY PARAMETERS; U.S. Ser. No. 10/093,853, filed Mar. 7, 2002, entitled ELECTRONIC BATTERY TESTER WITH NETWORK COMMUNICATION; U.S. Ser. No. 10/098,741, filed Mar. 14, 2002, entitled METHOD AND APPARATUS FOR AUDITING A BATTERY TEST; U.S. Ser. No. 10/112,114, filed Mar. 28, 2002, entitled BOOSTER PACK WITH STORAGE CAPACITOR; U.S. Ser. No. 10/109,734, filed Mar. 28, 2002, entitled APPARATUS AND METHOD FOR COUNTERACTING SELF DISCHARGE IN A STORAGE BATTERY; U.S. Ser. No. 10/112,105, filed Mar. 28, 2002, entitled CHARGE CONTROL SYSTEM FOR A VEHICLE BATTERY; U.S. Ser. No. 10/112,998, filed Mar. 29, 2002, entitled BATTERY TESTER WITH BATTERY REPLACEMENT OUTPUT; U.S. Ser. No. 10/119,297, filed Apr. 9, 2002, entitled METHOD AND APPARATUS FOR TESTING CELLS AND BATTERIES EMBEDDED IN SERIES/PARALLEL SYSTEMS; U.S. Ser. No. 60/387,046, filed Jun. 7, 2002, entitled METHOD AND APPARATUS FOR INCREASING THE LIFE OF A STORAGE BATTERY; U.S. Ser. No. 10/177,635, filed Jun. 21, 2002, entitled BATTERY CHARGER WITH BOOSTER PACK; U.S. Ser. No. 10/200,041, filed Jul. 19, 2002, entitled AUTOMOTIVE VEHICLE ELECTRICAL SYSTEM DIAGNOSTIC DEVICE; U.S. Ser. No. 10/217,913, filed Aug. 13, 2002, entitled, BATTERY TEST MODULE; U.S. Ser. No. 10/246,439, filed Sep. 18, 2002, entitled BATTERY TESTER UPGRADE USING SOFTWARE KEY; U.S. Ser. No. 10/263,473, filed Oct. 2, 2002, entitled ELECTRONIC BATTERY TESTER WITH RELATIVE TEST OUTPUT; U.S. Ser. No. 10/271,342, filed Oct. 15, 2002, entitled IN-VEHICLE BATTERY MONITOR; U.S. Ser. No. 10/310,515, filed Dec. 5, 2002, entitled BATTERY TEST MODULE; U.S. Ser. No. 10/310,490, filed Dec. 5, 2002, entitled ELECTRONIC BATTERY TESTER; U.S. Ser. No. 10/310,385, filed Dec. 5, 2002, entitled BATTERY TEST MODULE; U.S. Ser. No. 60/437,255, filed Dec. 31, 2002, entitled REMAINING TIME PREDICTIONS; U.S. Ser. No. 60/437,224, filed Dec. 31, 2002, entitled DISCHARGE VOLTAGE PREDICTIONS; U.S. Ser. No. 60/437,611, filed Jan. 2, 2003, entitled REMAINING TIME PREDICTIONS; U.S. Ser. No. 10/349,053, filed Jan. 22, 2003, entitled APPARATUS AND METHOD FOR PROTECTING A BATTERY FROM OVERDISCHARGE; U.S. Ser. No. 10/388,855, filed Mar. 14, 2003, entitled ELECTRONIC BATTERY TESTER WITH BATTERY FAILURE TEMPERATURE DETERMINATION; U.S. Ser. No. 10/396,550, filed Mar. 25, 2003, entitled ELECTRONIC BATTERY TESTER; U.S. Ser. No. 60/467,872, filed May 5, 2003, entitled METHOD FOR DETERMINING BATTERY STATE OF CHARGE; U.S. Ser. No. 60/477,082, filed Jun. 9, 2003, entitled ALTERNATOR TESTER; U.S. Ser. No. 10/460,749, filed Jun. 12, 2003, entitled MODULAR BATTERY TESTER FOR SCAN TOOL; U.S. Ser. No. 10/462,323, filed Jun. 16, 2003, entitled ELECTRONIC BATTERY TESTER HAVING A USER INTERFACE TO CONFIGURE A PRINTER; U.S. Ser. No. 10/601,608, filed Jun. 23, 2003, entitled CABLE FOR ELECTRONIC BATTERY TESTER; U.S. Ser. No. 10/601,432, filed Jun. 23, 2003, entitled BATTERY TESTER CABLE WITH MEMORY; U.S. Ser. No. 60/490,153, filed Jul. 25, 2003, entitled SHUNT CONNECTION TO A PCB FOR AN ENERGY MANAGEMENT SYSTEM EMPLOYED IN AN AUTOMOTIVE VEHICLE; U.S. Ser. No. 10/653,342, filed Sep. 2, 2003, entitled ELECTRONIC BATTERY TESTER CONFIGURED TO PREDICT A LOAD TEST RESULT; U.S. Ser. No. 10/654,098, filed Sep. 3, 2003, entitled BATTERY TEST OUTPUTS ADJUSTED BASED UPON BATTERY TEMPERATURE AND THE STATE OF DISCHARGE OF THE BATTERY; U.S. Ser. No. 10/656,526, filed Sep. 5, 2003, entitled METHOD AND APPARATUS FOR MEASURING A PARAMETER OF A VEHICLE ELECTRICAL SYSTEM; U.S. Ser. No. 10/656,538, filed Sep. 5, 2003, entitled ALTERNATOR TESTER WITH ENCODED OUTPUT; U.S. Ser. No. 10/675,933, filed Sep. 30, 2003, entitled QUERY BASED ELECTRONIC BATTERY TESTER; U.S. Ser. No. 10/678,629, filed Oct. 3, 2003, entitled ELECTRONIC BATTERY TESTER/CHARGER WITH INTEGRATED BATTERY CELL TEMPERATURE MEASUREMENT DEVICE; U.S. Ser. No. 10/441,271, filed May 19, 2003, entitled ELECTRONIC BATTERY TESTER; U.S. Ser. No. 09/653,963, filed Sep. 1, 2000, entitled SYSTEM AND METHOD FOR CONTROLLING POWER GENERATION AND STORAGE; U.S. Ser. No. 09/654,217, filed Sep. 1, 2000, entitled SYSTEM AND METHOD FOR PROVIDING STEP-DOWN POWER CONVERSION USING INTELLIGENT SWITCH; U.S. Pat. No. 6,465,908, issued Oct. 15, 2002, entitled INTELLIGENT POWER MANAGEMENT SYSTEM; U.S. Pat. No. 6,497,209, issued Dec. 24, 2002, entitled SYSTEM AND METHOD FOR PROTECTING A CRANKING SUBSYSTEM; U.S. Pat. No. 6,437,957, issued Aug. 20, 2002, entitled SYSTEM AND METHOD FOR PROVIDING SURGE, SHORT, AND REVERSE POLARITY CONNECTION PROTECTION; U.S. Pat. No. 6,377,031, issued Apr. 23, 2002, entitled INTELLIGENT SWITCH FOR POWER MANAGEMENT; U.S. Ser. No. 10/174,110, filed Jun. 18, 2002, entitled DAYTIME RUNNING LIGHT CONTROL USING AN INTELLIGENT POWER MANAGEMENT SYSTEM; U.S. Ser. No. 60/488,775, filed Jul. 21, 2003, entitled ULTRASONICALLY ASSISTED CHARGING; U.S. Ser. No. 10/258,441, filed Apr. 9, 2003, entitled CURRENT MEASURING CIRCUIT SUITED FOR BATTERIES; U.S. Pat. No. 6,507,196, issued Jan. 14, 2003; entitled BATTERY HAVING DISCHARGE STATE INDICATION; U.S. Pat. No. 5,871,858, issued Feb. 16, 1999, entitled ANTI-THEFT BATTERY; U.S. Ser. No. 10/705,020, filed Nov. 11, 2003, entitled APPARATUS AND METHOD FOR SIMULATING A BATTERY TESTER WITH A FIXED RESISTANCE LOAD; U.S. Ser. No. 10/280,186, filed Oct. 25, 2002, entitled BATTERY TESTER CONFIGURED TO RECEIVE A REMOVABLE DIGITAL MODULE; and U.S. Ser. No. 10/681,666, filed Oct. 8, 2003, entitled ELECTRONIC BATTERY TESTER WITH PROBE LIGHT; which are incorporated herein in their entirety.  
         [0004]     Electronic battery testers and chargers are often used in harsh environments and are expected to function properly over an extended period of time. One source of failure in electronic battery testers and chargers are the clamps which are used to electrically couple the battery tester to terminals of storage batteries.  
       SUMMARY OF THE INVENTION  
       [0005]     A method and apparatus for coupling a battery charger and/or a battery tester to a battery is provided. In one aspect of the present invention, a clamp can be selectively removed from a cable. This allows replacement of the clamp as desired. The cable can be fixedly or removably coupled to the battery tester or charger. 
     
    
     BRIEF DESCRIPTION OF THE DRAWINGS  
       [0006]      FIG. 1  is a side view of a clamp in accordance with the prior art.  
         [0007]      FIG. 2-1  is a perspective view of a replaceable clamp electrically coupled with a cable in accordance with an embodiment of the present invention.  
         [0008]      FIG. 2-2  is a perspective view of a replaceable clamp partially cutaway and electrically coupled with a cable in accordance with an embodiment of the present invention.  
         [0009]      FIG. 2-3  is a perspective view of a replaceable clamp disconnected from a cable in accordance with an embodiment of the present invention.  
         [0010]      FIG. 3  is a simplified block diagram of a battery tester with which the present invention is useful.  
         [0011]      FIG. 4  is a simplified block diagram of a battery charger with which the present invention is useful. 
     
    
     DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS  
       [0012]     In the discussion below, the term “battery contact” is used to define a portion of the battery onto which the replaceable clamp of the present invention can be applied. The actual contact is an electrical contact and can be placed some distance from the battery.  
         [0013]      FIG. 1  is a side view of a Kelvin clamp  100  in accordance with the prior art. Clamp  100  includes first elongate clamp member  102  having a first jaw  106  and first hand grip  110  separated by a first coupling (hidden from view). Clamp  100  also includes second elongate clamp member  104  having a second jaw  108  and a second hand grip  112  separated by second coupling  116 . Second elongate clamp member  104  is pivotally joined with first elongate clamp member  102  by second coupling  116  and the first coupling.  
         [0014]     First elongate clamp member  102  is coupled to cable  124 . Cable  124  includes a first electrical conductor (hidden from view) and a second electrical conductor (hidden from view), which are electrically isolated from each other. The first electrical conductor is electrically coupled to first jaw  106  and conductive piece  136 , which grips a battery contact. Rivet  111  couples conductive piece  136  to jaw  106  and is insulated from first elongate clamp member  102  by an insulator  115 . The second electrical conductor can be electrically coupled to second jaw  108  or electrically coupled to first jaw  108 . The first electrical conductor and the second electrical conductor provide Kelvin connections to the battery contacts.  
         [0015]     Clamp  100  is used in harsh environments to test and charge lead acid or other batteries. Gases will attack metal and corrode terminals on the clamp causing clamp  100  to easily wear out. The present invention provides a replaceable clamp for quickly and efficiently replacing a corroded clamp with a non-corroded clamp in the field by a user.  
         [0016]      FIGS. 2-1  through  2 - 3  are perspective views of replaceable clamp  200  in accordance with an embodiment of the present invention. Clamp  200  is designed to electrically connect cable  224  from a battery tester and/or charger (not shown) to a battery contact. Clamp  200  can either connect to a negative or positive battery contact.  FIGS. 2-1  through  2 - 3  illustrate this electrical connection as a Kelvin connection, a sensor lead connection, and a connection capable of carrying a high current for charging a battery. Other types of connections that electrically connect the battery tester or charger to the battery contacts are within the scope of the present invention.  
         [0017]      FIG. 2-1  illustrates clamp  200  electrically connected with cable  224  and configured in a closed position. Clamp  200  includes a first elongate clamp member  202  which has first jaw end  206  and first hand grip end  210  separated by first pivot coupling  214 . Replaceable clamp  200  also includes second elongate clamp member  204  which has second jaw end  208  and second hand grip end  212  separated by a second pivot coupling (hidden from view). Second elongate clamp member  204  is pivotally joined to first elongate clamp member  202  by first pivot coupling  214  and the second pivot coupling. Pivotally joining first elongate clamp member  202  to second elongate clamp member  204  causes first jaw end  206  to be aligned with second jaw end  208 . First jaw end  206  and second jaw end  208  are in a closed position.  
         [0018]      FIG. 2-2  illustrates clamp  200  partially cutaway and electrically connected with cable  224 . Clamp  200  includes a spring  215  coupled to first elongate clamp member  202  and second elongate clamp member  204 . The spring is configured to urge first jaw end  206  and second jaw end  208  together in a closed position. First elongate clamp member  202  also includes electrically conductive piece  236 , which is mechanically coupled to second jaw end  208  by rivet  234 . An insulator  217  isolates rivet  234  from conductive piece  236 .  
         [0019]     Referring to both  FIGS. 2-1  and  2 - 2 , cable  224  includes a main electrical connector  221 , a first electrical connector  229  and a second electrical connector  235 . Those skilled in the art will recognized that multiple electrical connectors can be housed in cable  224  to electrically connect to a clamp, such as clamp  200 .  
         [0020]     The main electrical connector  221  is capable of carrying a high current such that the high current can charge a battery. Terminal  218  is electrically coupled to the main electrical connector. Terminal  218  includes terminal hole  220  which aligns with first hole (not shown in  FIGS. 2-1  or  2 - 2 ) of first hand grip  210 . Removable fastener  222  (shown fastened in  FIG. 2-1  and shown unfastened in  FIG. 2-2 ) couples terminal  218  to first hand grip  210  through the first hole and terminal hole  220  such that fastener  222  can disconnect clamp  200  from cable  224 .  
         [0021]     First electrical conductor  229  includes first portion  230  and second portion  232 . Second electrical conductor  235  includes first portion  231  and second portion  233 . First portion  230  of first electrical conductor  229  is electrically coupled to conductive piece  236  at one end and coupled to first electrical plug  226  at the other end. First portion  231  of second electrical conductor  235  is electrically coupled to second jaw  208  through rivet  234  at one end and coupled to first electrical plug  226  at the other end. Second portions  232  and  233  are coupled to cable  224  at one end and coupled to second electrical plug  228  at the other end. First electrical plug  226  is removably electrically connected with second electrical plug  228 .  
         [0022]     In one embodiment of the present invention, first electrical conductor  229  and second electrical conductor  235  together provide a Kelvin connection capable of injecting a forcing function into a battery as well as measuring a voltage across the battery. In another embodiment of the present invention, first electrical conductor  229  includes two electrically isolated contacts which provide a Kelvin connection and second electrical conductor  235  provides a sensor lead that is capable of sensing a physical property of the battery, such as temperature as discussed in  FIG. 3 . Those skilled in the art will recognize that electrical conductors  229  and  235  can be electrically coupled anywhere along first and second elongate clamp members  202  and  204  as long as at least one of first and second electrical conductors  229  and  235  electrically couple with a battery contact to provide a Kelvin connection or a sensor lead.  
         [0023]      FIG. 2-3  illustrates replaceable clamp  200  with removable fastener (not shown in  FIG. 2-3 ) removed from terminal  218  and first electrical plug  226  electrically disconnected from second electrical plug  228 .  FIG. 2-3  also illustrates first hole  217  formed in first hand grip  210  such that terminal hole  220  will align with first hole  217  when the fastener is connecting cable  224  to clamp  200 . Electrical plugs  226  and  228  and the removable fastener electrically disconnect clamp  200  from cable  224 . Thus, clamp  200  can be entirely replaced with a second clamp having a similar configuration. In general, first jaw  206 , second jaw  208  and the electrically conductive piece (not shown in  FIG. 2-3 ) can be formed of an electrically conductive material such as copper. In addition, insulating grips can be provided on first and second hand grips ( 210 ,  212 ) for user protection.  
         [0024]      FIG. 3  is a simplified block diagram of an example electronic battery tester circuitry  300  with which the present invention is useful. The present invention is not restricted in application to the battery test circuitry  300  of  FIG. 3 . Other types of battery test circuitry are within the scope of the present invention. Illustrated in  FIG. 3  is a four point (or Kelvin connection) technique used to couple system  300  to battery  302 . Connections  308  and  310  are used to couple to battery contacts  304  and  306 , respectively, of battery  302 . Connection  308  includes two individual connections  308 A and  308 B. Similarly, connection  310  includes two individual connections  310 A and  310 B. Clamps  200  of the present invention grasp battery contacts  304  and  306  and couple them to electrical connections  308  and  310 .  
         [0025]     Circuitry  300  includes a current source  312  and a differential amplifier  314 . Current source  312  is coupled to connections  308 B and  310 B of connections  308  and  310 , respectively. Differential amplifier  314  is coupled to connection  308 A and connections  310 A of connections  308  and  310 , respectively. An output from differential amplifier  314  is provided to analog to digital converter  318  which itself provides a digitized output to microprocessor  320 . Microprocessor  320  is connected to a system clock  322 , a memory  324  and analog to digital converter  318 . Microprocessor  320  is also capable of receiving an input from an input device  326  and providing an output of output device  328 . The input can be, for example, a rating for the battery  302 . Input device can comprise any of the following multiple types of input devices. The result of a battery test, either qualitative or quantitative, can be an output device  328 . Device  328  can be a display or other output. The invention can operate with any technique for determining a voltage across battery  302  and a current through battery  302  and is not limited to the specific techniques set forth herein. The forcing function source or current source  312  can provide any signal having a time varying component, including a stepped pulse or a periodic signal, having any shape, applied to battery  302 . The current source can be an active source in which the current source signal is injected into battery  302 , or can be a passive source, such as a load, which is switched on under the control of microprocessor  320 .  
         [0026]     In operation, microprocessor  320  determines a dynamic parameter, such as dynamic conductance, of battery  302  as a function of sensed voltage and current. The change in these sensed values is used to determine the dynamic parameter. A temperature sensor  330  can be thermally coupled to battery  302  and used to compensate battery measurements. Temperature readings can be stored in memory  324  for later retrieval.  
         [0027]      FIG. 4  is a simplified block diagram of a battery charging system  400  with which the present invention is useful. The present invention is not restricted in application to the battery charging system  400  of  FIG. 4 . Other types of battery charging systems are within the scope of the present invention. System  400  is shown coupled to battery  402 . System  400  includes battery charging and testing circuitry  404  and microprocessor  406 . System  400  couples to battery contacts  408  and  410  through Kelvin electrical connections  412  and  414  respectively. Electrical connection  412  includes a first connection  412 A and second connection  412 B and connection  414  includes a first connection  414 A and a second connection  414 B. Clamps  200  of the present invention provide coupling between battery contacts  408  and  410  and electrical connections  412  and  414 . Battery charger  400  operates in a manner similar to 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.  
         [0028]     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.