Wireless battery monitor

[0001] The present application claims the benefit of U.S. provisional patent application Ser. No. 60/548,513, filed Feb. 27, 2004 and U.S. provisional patent application Ser. No. 60/587,232, filed Jul. 12, 2004 and is a Continuation-In-Part of U.S. Ser. No. 10/914,304, filed Aug. 9, 2004, which is a Divisional of U.S. Ser. No. 10/093,853, filed Mar. 7, 2002 which is a Continuation-In-Part of and claims priority of U.S. Ser. No. 10/046,659, filed Oct. 29, 2001, which is a Divisional of Ser. No. 09/564,740, filed May 4, 2000, now U.S. Pat. No. 6,331,762, which is a Continuation-In-Part of application Ser. No. 08/962,754, filed Nov. 3, 1997, now U.S. Pat. No. 6,081,098 and also a Continuation-In-Part of application Ser. No. 09/575,627, filed May 22, 2000, which is a Continuation-In-Part of application Ser. No. 08/962,754, filed Nov. 3, 1997, now U.S. Pat. No. 6,081,098 and also claims priority to Provisional Application Ser. No. 60/132,622, filed May 5, 1999, U.S. Provisional Application No. 60/165,208, filed Nov. 12, 1999, and Provisional Application Ser. No. 60/175,762, filed Jan. 12, 2000, and entitled ENERGY MANAGEMENT SYSTEM FOR AUTOMOTIVE VEHICLE, the contents of which are hereby incorporated by reference in their entirety.

[0002] The present invention relates to storage batteries. More specifically, the present invention relates to battery monitors of the type used to monitor individual storage batteries or banks of storage batteries.

[0003] Individual storage batteries, and banks of storage batteries, are used in various applications including backup power supply applications. For example, remote cellular stations, electrical switching stations, hospitals, and many other installations require a source of backup power. In many such installations, it is important to ensure that the battery or batteries have not degraded and are capable of maintaining a desired amount of charge.

[0004] In the past, a technician has been typically required to perform battery tests on each of the batteries at the installation. This can be by manually connecting a battery tester to each of the batteries and taking measurements of the batteries. In another example configuration, test connections are run out to each of the batteries and connected to a central location. This allows the testing procedure to be automated.

[0005] These prior art techniques are cumbersome and are difficult to implement.

[0006] An electronic battery tester and method for testing a storage battery includes generating battery test data from an electronic battery test. The battery test data is transmitted over a wireless communication medium. In another aspect, a method and apparatus is provided for receiving battery test data from a wireless communication medium.

[0015] In the embodiments described below, an electronic battery tester provides battery test data, over a wireless communication medium, to a receiving station. Thus, when employed in a battery installation, the present invention reduces the large amount of wiring required for coupling individual cells and battery packs together to a controller. A battery installation that utilizes an embodiment of the present invention is described below in connection with FIG. 1. More detailed embodiments and method embodiments of the present invention are described further below in connection with FIGS. 2 through 8.

[0016] FIG. 1 is a simplified block diagram of a battery installation 100 including a plurality of batteries 102A, 102B . . . 102N. Each battery 102A . . . 102N is electrically coupled to a respective battery tester 104A, 104B . . . 104N. Each battery tester communicates with a data receiving station 106 over a wireless communication medium 108A, 108B . . . 108N, respectively. Receiving station 106 can be a single station or can comprise multiple stations.

[0017] During operation, each battery tester 104A-N performs a battery test on its respective battery 102A-N. The data is then transmitted along the communication medium 108A-N to the receiving station 106. The receiving station 106 can then act as appropriate, for example, by indicating which battery needs replacing, or may need replacing, prior to its ultimate failure.

[0018] FIG. 2 is a simplified block diagram showing the primary components of an example embodiment of battery tester 104 and receiving station 106. As can be seen in FIG. 2, battery tester 104 includes measurement circuitry 120, processor 122, communication circuitry 124 and memory 126. Measurement circuitry 120 and processor 122 together form battery test circuitry 121. Measurement circuitry 120 is configured to electrically couple to terminals of a battery 102 (shown in FIG. 1) and to measure, under the control of microprocessor 122, different parameters related to battery 102 (for example, battery voltage, battery temperature, etc.). The measured battery parameters are provided to microprocessor 122, which, in turn, generates a battery test result that is provided to battery communication circuitry 124. Communication circuitry 124, which comprises a transmitter/transceiver, transmits the battery test result over wireless communication link 108. The transmission can include identification information which uniquely identifies the battery tester that performed the test or battery from which the battery test information was obtained. This battery identification information can be stored in memory 126. Program instructions, for execution by processor 122, can also be stored in memory 126.

[0019] Receiving station 106, which is also shown in FIG. 2, includes a receiver (or transceiver) 130 and a computing device 132. Computing device 132 is coupled to receiver 130 via a connector 131 so that it can receive the battery test data. Computing device 132 includes a memory 134, which can store the received battery test data. Detailed embodiments of the present invention are described further below in connection with FIGS. 3 through 6.

[0020] As mentioned above, the configuration of the present invention reduces the large amount of wiring required for coupling individual cells and battery packs together to a controller. The particular measurement circuitry can perform any type of battery test including tests which are based upon impedance, conductance, voltage, resistive loading, etc. Wireless communication link 108 can be any type of communication link including a radio frequency (RF) link, an infrared (IR) link, or any other linking technique which does not require additional wiring to link a central location to the battery tester. A battery tester (such as 104) is installed on each cell, cell group, or monoblock (such as 102) and couples to the cell or group of cells through Kelvin connections (discussed further below in connection with FIG. 7). On a periodic basis, or as desired, battery tester 104 transmits data back to central receiving station 106. The transmission can be periodic, or can be based upon polling of receivers, which can be a part of communication circuitry 124. When used in a periodic basis, battery tester 104 can be maintained in a sleep mode and wake up, as desired, to obtain a battery test data reading, and broadcast the results. As mentioned above, the transmission can include identification information (such as a unique identification code for each tester or a serial number of the battery), which uniquely identifies the battery tester that performed the test or battery from which the battery test information was obtained. In some embodiments, this information is not necessary, for example, if battery tester 104 is responding to being polled.

[0021] In embodiments of the present invention, a copy of the identification information for each battery/tester is stored in memory 134 of computing device 132 included in receiving station 106. The identification information for each battery/tester can be input into computing device 132 using any suitable means. When transmitted information from testers 104A-N is received at station 106, computing device 132 carries out a verification process which includes a comparison between the transmitted identification information and the corresponding identification information stored in memory 134.

[0022] Communication medium 108 can operate in either a half or full duplex mode. In half duplex mode, battery tester 104 must either periodically, or randomly, transmit data. Preferably a technique should be used in which collisions with other data can be either avoided or otherwise problems associated with such collisions reduced. In a full duplex configuration, battery tester 104 can respond to being polled or to receiving other instructions. The data transmitted by battery tester 104 can include additional test data such as particular parameters used in the testing, or other information.

[0023] In one specific embodiment, the battery (such as 102) can be tested at a known interval, for example once per day and provide multiple transmissions, for example hourly, of the test data. An additional randomizing element can be introduced to help reduce the chance of collisions with transmissions from other battery testers.

[0024] Additional techniques can be used to aid in installation. For example, a reset signal can be transmitted during initialization of the battery tester 104 to provide a audible output, or other type of output, at receiving station 106, to indicate that data has been properly received and the link is operational. The receiving station output is designated by reference numeral 133. Once all of the units are installed, a synchronization button/input (such as 127) on each unit 104A-N can be used and pressed sequentially, to initiate transmission of data. This allows each transmitter 124 a different time slot which can be identified by receiver 130 and correlated by a particular battery or group of batteries being tested. This can also be used to correlate any identification data sent in the transmission with a particular battery or battery tester.

[0025] As mentioned above, receiving station 106 can be implemented as desired. For example, computing device 132 can be a PC connected to a RF receiver 130 so that it can receive the battery test data. Connector 131 can be an RS-232 connection, for example, provided between the RF receiver and the PC. The collected data can be used as desired. In one implementation, the receiving station 106 can be configured to couple into, for example, the Internet or an Intranet (internal or private Internet) and serve as a web server which contains the battery test data. This allows the batteries to be monitored by using any web browser coupled to receiving station 106 through a data network. Details regarding the storage and viewing of battery test data are provided below in connection with FIGS. 3, 4 and 5.

[0026] FIG. 3 illustrates an example battery information database 136, which is stored in memory 134. When computing device 132 receives new battery information from receiver 130, it executes program instructions, which may also be stored in memory 134 along with database 136, for updating database 136 with the newly received battery test data. Database 136 may be any type of hierarchical or relational database that is known in the industry or developed in the future. Similarly, the database update software may be any software that is suitable for updating the particular type of database 136. Database 136 can include one or more tables that, in turn, include several test data fields. As can be seen in FIG. 3, the test data fields can include a battery identification number field 138, a battery temperature field 140, a battery voltage filed 142, a battery conductance field 144, a battery condition field 146 and a measurement date and time filed 148. Within database 136, separate tables can be used for current and historical information. Database 136 can also include an additional table that stores battery maintenance and replacement information. Each maintenance/replacement record in the database can include a username, or other identification means, for the user that carried out the battery maintenance/replacement. In some embodiments, the username of a currently logged-in user is included in the database record each time an update is carried out.

[0027] FIG. 4 illustrates an example battery monitoring and test activation screen 150, which is utilized to display battery test data from database 136 (FIG. 3) and to remotely activate individual battery testers 104A-N (FIG. 1). Screen 150 can operate in an automatic refresh/display mode or in a manual mode. Enabling/disabling of the automatic display mode can be carried out by pointing and clicking on button 152 using a mouse, for example. In the automatic refresh/display mode, software triggers can be executed each time database 136 is updated. These triggers can be configured select current information from database 136 and populate a test detail section 154 of screen 150. In manual mode, query criteria (for example, a specific battery identification number) can be entered in field 156 and the query can be executed by pointing and clicking, on an execute-query button 158, using a mouse. Upon execution of the query, the corresponding results are displayed in detail section 154 of screen 150. Detail section 154, of screen 150, also includes a scrolling feature 160.

[0028] Screen 150 can also be used to remotely activate a specific battery tester to carry out a test on the respective battery that it is coupled to. This can be carried out by entering a battery identification number (or tester identification number) in field 162 and pointing and clicking, on an activate-test button 164, using a mouse. Activation of a specific battery tester can also be carried out by double clicking using a mouse, for example, on the specific battery tester's (or battery's) identification number, if the identification number is displayed in detail section 152 of screen 150.

[0029] Screen 150 also includes a message field 166, which is used to display errors associated with incorrect query (or identification) information. Field 166 can also be used to display confirmation information related to a particular battery tester that has just been successfully activated, for example.

[0030] In embodiments of the present invention, a user authorization process is carried out prior to allowing a user access to screen 150. An example user authorization screen 170 is shown in FIG. 5. A username and password has to be entered and, upon proper verification, the user is allowed access to screen 150. A login message field is also included in screen 170 to display messages related to the login process. A list of valid usernames and passwords may be stored in database 136 to provide the necessary verification. Screens 150 and 170 constitute an example user interface for receiving station 106.

[0031] As mentioned above, receiving station 106 can be configured to couple into, for example, the Internet or an Intranet and serve as a web server that contains the battery test data. In embodiments in which receiving station 106 couples into the Internet, the identification information, which uniquely identifies the battery tester 104 that performed the test, or battery 102 from which the battery test information was obtained, can be an Internet Protocol (IP) address. Here, each tester 104A-N (or battery 102A-N) has an associated unique IP address. FIGS. 6-1 and 6-2 show receiving station 106 coupled to the Internet 180 (via Internet connection 182) and to Intranet 186 (via connection 188), respectively. An Internet user can view and operate screens 150 and 170 form a computer 183, connected to the Internet 180, with the help of web browser 184. Similarly, screens 150 and 170 can be accessed from a client computer 190, which is connected to Intranet 186. In some embodiments, cellular phone or paging networks can be used for transferring certain information between testers 104A-N and receiving station 106.

[0032] As mentioned above, measurement circuitry can be implemented using any appropriate technique. Various techniques related to battery testing are shown and described in 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. 5,871,858, issued Feb. 16, 1999, entitled ANTI-THEFT BATTERY; 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

[0033] 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

[0034] 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. 6,377,031, issued Apr. 23, 2002, entitled INTELLIGENT SWITCH FOR POWER MANAGEMENT; 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. 6,437,957, issued Aug. 20, 2002, entitled SYSTEM AND METHOD FOR PROVIDING SURGE, SHORT, AND REVERSE POLARITY CONNECTION PROTECTION; 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. 6,465,908, issued Oct. 15, 2002, entitled INTELLIGENT POWER MANAGEMENT SYSTEM; 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. 6,469,511, issued Nov. 22, 2002, entitled BATTERY CLAMP WITH EMBEDDED ENVIRONMENT SENSOR; U.S. Pat. No. 6,495,990, issued Dec. 17, 2002, entitled METHOD AND APPARATUS FOR EVALUATING STORED CHARGE IN AN

[0035] ELECTROCHEMICAL CELL OR BATTERY; U.S. Pat. No. 6,497,209, issued Dec. 24, 2002, entitled SYSTEM AND METHOD FOR PROTECTING A CRANKING SUBSYSTEM; U.S. Pat. No. 6,507,196, issued Jan. 14, 2003; entitled BATTERY HAVING DISCHARGE STATE INDICATION; 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. Pat. No. 6,707,303, issued Mar. 16, 2004, entitled ELECTRONIC BATTERY TESTER; U.S. Pat. No. 6,737,831, issued May 18, 2004, entitled METHOD AND APPARATUS USING A CIRCUIT MODEL TO EVALUATE CELL/BATTERY PARAMETERS; U.S. Pat. No. 6,744,149, issued Jun. 1, 2004, entitled SYSTEM AND METHOD FOR PROVIDING STEP-DOWN POWER CONVERSION USING AN INTELLIGENT SWITCH; U.S. Pat. No. 6,759,849, issued Jul. 6, 2004, entitled BATTERY TESTER CONFIGURED TO RECEIVE A REMOVABLE DIGITAL MODULE; 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. Ser. No. 09/880,473, filed Jun. 13, 2001; entitled BATTERY TEST MODULE; 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. 10/042,451, filed Jan. 8, 2002, entitled BATTERY CHARGE CONTROL DEVICE; 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. 60/437,224, filed Dec. 31, 2002, entitled DISCHARGE VOLTAGE 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. 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. 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. 10/681,666, filed Oct. 8, 2003, entitled ELECTRONIC BATTERY TESTER WITH PROBE LIGHT; U.S. Ser. No. 10/748,792, filed Dec. 30, 2003, entitled APPARATUS AND METHOD FOR PREDICTING THE REMAINING DISCHARGE TIME OF A BATTERY; U.S. Ser. No. 10/767,945, filed Jan. 29, 2004, entitled ELECTRONIC BATTERY TESTER; U.S. Ser. No. 10/783,682, filed Feb. 20, 2004, entitled REPLACEABLE CLAMP FOR ELECTRONIC BATTERY TESTER; U.S. Ser. No. 60/548,513, filed Feb. 27, 2004, entitled WIRELESS BATTERY MONITOR; U.S. Ser. No. 10/791,141, filed Mar. 2, 2004, entitled METHOD AND APPARATUS FOR AUDITING A BATTERY TEST; U.S. Ser. No. 60/557,366, filed Mar. 29, 2004, entitled BATTERY MONITORING SYSTEM WITHOUT CURRENT MEASUREMENT; U.S. Ser. No. 10/823,140, filed Apr. 13, 2004, entitled THEFT PREVENTION DEVICE FOR AUTOMOTIVE VEHICLE SERVICE CENTERS; U.S. Ser. No. 60/575,945, filed Jun. 1, 2004, entitled BATTERY TESTER CAPABLE OF IDENTIFYING FAULTY BATTERY POST ADAPTERS; U.S. Ser. No. 60/577,345, filed Jun. 4, 2004, entitled NEW METHOD FOR AUTOMATICALLY TESTING A BATTERY AND TRANSMITTING DATA TO ANOTHER MODULE IN A VEHICLE; U.S. Ser. No. 10/864,904, filed Jun. 9, 2004, entitled ALTERNATOR TESTER; U.S. Ser. No. 10/867,385, filed Jun. 14, 2004, entitled ENERGY MANAGEMENT SYSTEM FOR AUTOMOTIVE VEHICLE; U.S. Ser. No. 10/870,680, filed Jun. 17, 2004, entitled ELECTRONIC BATTERY TESTER WITH RELATIVE TEST OUTPUT; U.S. Ser. No. 60/582,925, filed Jun. 25, 2004, entitled BATTERY TESTER WITH BATTERY POTENTIAL FOR RECOVERY OUTPUT; U.S. Ser. No. 10/883,019, filed Jul. 1, 2004, entitled MODULAR ELECTRONIC BATTERY TESTER; U.S. Ser. No. 60/585,700, filed Jul. 6, 2004, entitled TEST STATION; U.S. Ser. No. 60/587,232, filed Jul. 12, 2004, entitled WIRELESS BATTERY TESTER; which are incorporated herein in their entirety.

[0036] FIG. 7 is a block diagram of battery tester 104 in accordance with a specific embodiment of the present invention. Tester 104 is shown coupled to battery 102, which includes a positive battery terminal 202 and a negative battery terminal 204. Tester 104 includes current source 210, differential amplifier 212, analog-to-digital converter 214 and microprocessor 122. Amplifier 212 is capacitively coupled to battery 102 through capacitors C₁ and C₂. Amplifier 212 has an output connected to an input of analog-to-digital converter 214. Microprocessor 122 is connected to system clock 216, memory 126 and analog-to-digital converter 214. Microprocessor 122 is also capable of receiving an input from input device 127. Microprocessor 122 also connects to communication circuitry 124 and output device 218.

[0037] In operation, current source 210 is controlled by microprocessor 122 and provides current I in the direction shown by the arrow in FIG. 7. In one embodiment, this is a square wave or a pulse. Differential amplifier 212 is connected to terminals 202 and 204 of battery 102 through capacitors C₁ and C₂, respectively, and provides an output related to the voltage potential difference between terminals 202 and 204. In a preferred embodiment, amplifier 212 has a high input impedance. Circuitry 104 includes differential amplifier 222 having inverting and noninverting inputs connected to terminals 202 and 204, respectively. Amplifier 222 is connected to measure the open circuit potential voltage (VBAT) of battery 102 between terminals 202 and 204. The output of amplifier 212 is provided to analog-to-digital converter 214 such that the voltage across terminals 202 and 204 can be measured by microprocessor 122.

[0038] Circuitry 104 is connected to battery 102 through a four-point connection technique known as a Kelvin connection. This Kelvin connection allows current I to be injected into battery 102 through a first pair of terminals (206A and 208A) while the voltage V across the terminals 202 and 204 is measured by a second pair of connections (206B and 208B). Because very little current flows through amplifier 212, the voltage drop across the inputs to amplifier 212 is substantially identical to the voltage drop across terminals 202 and 204 of battery 102. The output of differential amplifier 212 is converted to a digital format and is provided to microprocessor 122. Microprocessor 122 operates at a frequency determined by system clock 216 and in accordance with programming instructions stored in memory 126.

[0039] Microprocessor 122 determines the conductance of battery 102 by applying a current pulse I using current source 210. The microprocessor determines the change in battery voltage due to the current pulse I using amplifier 212 and analog-to-digital converter 214. The value of current I is generated by current source 210 is known and is stored in memory 126. In one embodiment, current I is obtained by applying a load to battery 102. Microprocessor 122 calculates the conductance of battery 102 using the following equation:

[0040] $\begin{array}{cc}\mathrm{Conductance}=G_{\mathrm{BAT}}=\frac{\Delta I}{\Delta V}& \mathrm{Equation}1\end{array}$
where ΔI is the change in current flowing through battery 102 due to current source 210 and ΔV is the change in battery voltage due to applied current ΔI.

[0041] Based upon the battery conductance GBAT and the battery voltage, the battery tester 104 determines the condition of battery 102. A temperature sensor 220 can be thermally coupled to battery 102 and used to compensate battery measurements. Temperature readings can be stored in memory 126 and transmitted with the help of communication circuitry 124.

[0042] Battery test circuitry 104 is programmed with information which can be used with the determined battery conductance and voltage as taught in the above patents to Dr. Champlin and Midtronics, Inc. For example, if the battery conductance G_BAT is lower than a predetermined threshold for a particular battery at a particular voltage, microprocessor 122 determines that battery 102 has failed the battery test. For example, as explained in the Champlin patents, the tester can compare the measured CCA (Cold Cranking Amp) with the rated CCA for that particular battery. Microprocessor 122 can also use information input from input device 127 provided by, for example, an operator. This information may consist of the particular type of battery, location, etc. Tester 104 can also receive software updates through input device 127.

[0043] Input device 127 can comprise one or more sensors, for example, or other elements which provide information such as time, date, humidity, barometric pressure, noise amplitude or characteristics of noise in the battery or in the test result, or any other information or data which may be sensed or otherwise recovered which relates to the conditions of the test how the battery test was performed, or intermediate results obtained in conducting the test. All this information can be stored in memory 126. As mentioned above, battery test results and other information stored in memory 126 can be transmitted by communication circuitry 124, which operates under the control of microprocessor 122.

[0044] FIG. 8 is a flowchart 250 of a method of monitoring batteries in accordance with an embodiment of the present invention. At step 252, a battery test is performed on each of a plurality of batteries and corresponding test data is generated. At step 254, the test data is transmitted over the wireless communication medium. At step 256, the transmitted test data is received over the wireless communication medium. Different techniques, some of which are set forth above, can be employed to carry out the steps shown in the flowchart of FIG. 8 while maintaining substantially the same functionality without departing from the scope and spirit of the present invention.

[0045] 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. In Equation 1, a calculated battery dynamic parameter is battery conductance. However, other battery dynamic parameters can be used without departing from the spirit and scope of the invention. Examples of other dynamic parameters include dynamic resistance, admittance, impedance or their combinations.