Abstract:
A charging apparatus for charging a battery comprising a current source for providing current to the battery, a controller connected to the battery and to the current source for controlling charging of the battery, and a memory connected to the controller for storing information about the battery. The memory may also store information about the charging apparatus. Preferably, the memory is a nonvolatile memory, such as E 2 PROM. Also disclosed are a battery having a memory for storing information, a power tool having a memory for storing information about the tool, and a reading apparatus for reading the information stored in the memory of the charger, battery and/or power tool.

Description:
This is a request for filing a continuation application under 37 CFR §1.53(b), of prior application Ser. No. 09/292,165, filed on Apr. 15, 1999 now U.S. Pat. No. 6,218,806 entitled Method and Apparatus for Obtaining Product Use Information. 

   CROSS-REFERENCE TO RELATED APPLICATIONS  
   The present application is based upon and claims priority under 35 USC § 119 and 37 CFR § 1.78 of copending U.S. provisional applications Ser. No. 60/089,066, filed on Jun. 12, 1998, and Ser. No. 60/087,896, filed on Jun. 3, 1998. 
   FIELD OF THE INVENTION 
   This invention relates generally to a method and apparatus for obtaining product use information and more particularly, for obtaining use information of components included in a rechargeable battery system. 
   BACKGROUND OF THE INVENTION 
   Rechargeable battery systems include three main components: (1) a rechargeable battery or battery pack; (2) a charger for charging the battery; and (3) a device powered by the battery, such as portable power tools and certain kitchen and domestic appliances. Knowledge of how a user actually uses and interacts with each component can provide useful insights, which can in turn be implemented in future product designs. 
   Typically, such information is derived from actual interviews with users, either individually or in groups. However, the information derived from these interviews is usually information relating to the user&#39;s perception of his use patterns, which are often subjective and inaccurate. 
   It is thus an object of the invention to provide a method and apparatus for obtaining actual product use information. 
   SUMMARY OF THE INVENTION 
   In accordance with the present invention, a charging apparatus for charging a battery comprising a current source for providing current to the battery, a controller connected to the battery and to the current source for controlling charging of the battery, and a memory connected to the controller for storing information about the battery. The memory may also store information about the charging apparatus. Preferably, the memory is a non-volatile memory, such as E 2 PROM. 
   Additional features and benefits of the present invention are described, and will be apparent from, the accompanying drawings and the detailed description below. 

   
     BRIEF DESCRIPTION OF THE DRAWINGS 
     The accompanying drawings illustrate preferred embodiments of the invention according to the practical application of the principles thereof, and in which: 
       FIG. 1  is a circuit schematic diagram of a battery charger according to the present invention; 
       FIG. 2  is a circuit schematic diagram of a battery according to the present invention; 
       FIG. 3  is a circuit schematic diagram of a cordless tool according to the present invention; and 
       FIG. 4  is a block diagram of a data reader according to the present invention. 
   

   DETAILED DESCRIPTION 
   The invention is now described with reference to the accompanying figures, wherein like numerals designate like parts. All the teachings of the Saar U.S. Pat. Nos. 4,388,582 and 4,392,101 are hereby incorporated by reference into this specification. 
   Referring to  FIG. 1 , a battery  10  is connected to a charger  20 . Battery  10  comprises a plurality of battery cells  11  connected in series, which dictate the voltage and storage capacity for battery  10 . Battery  10  includes three battery contacts: first battery contact  12 , second battery contact  13 , and third battery contact  14 . Battery contact  12  is the B+ (positive) terminal for battery  10 . Battery contact  14  is the B− or negative/common terminal. Battery contact  13  is the S or sensing terminal. Battery contacts  12  and  14  receive the charging current sent from the charger  20  (preferably from current source  22 , as discussed below) for charging the battery  10 . 
   As shown in  FIG. 1 , the battery cells  11  are connected between the battery contacts  12  and  14 . In addition, preferably connected between battery contacts  13  and  14  is a temperature sensing device  15 , such as a negative temperature co-efficient (NTC) resistor, or thermistor, R T . The temperature sensing device is preferably in closer proximity to the cells  11  for monitoring of the battery temperature. Persons skilled in the art will recognize that other components, such as capacitors, etc., or circuits can be used to provide a signal representative of the battery temperature. 
   Battery  10  may also comprise an identifier as known in the prior art, so that charger  20  can identify the type and capacity of the battery, and charge accordingly. 
   The charger  20  preferably comprises a controller  21 , which in turn includes positive terminal (B+)  16  and negative (B−) terminal  17 , which are coupled to battery  10  via battery contacts  12  and  14 , respectively. The positive terminal may also act as an input, preferably an analog/digital input, in order for the controller  21  to detect the battery voltage. In addition, the controller  21  may include another input TC, preferably an analog/digital input, which is coupled to the temperature sensing device  15  via the third battery contact  13  (S). This allows the controller  21  to monitor the battery temperature. Controller  21  may include a microprocessor  23  for controlling the charging and monitoring operations. Controller  21  may control a current source  22  that provides current to battery  10 . This current may be a fast charging current and/or an equalization current. Current source  22  may be integrated within controller  21 . 
   A switch SW1 may be connected to controller  21  to manually select charging processes or modes, such as a fast charging mode and a refresh mode. 
   A memory  25  is preferably connected to the controller  21 . Preferably, the memory  25  is a non-volatile memory such as E 2 PROM. Accordingly, controller  21  may read and/or write in memory  25 . Controller  21  may store in memory  25  information related to the battery, such as type, capacity, charging process, etc. Similarly, controller  21  may store in memory  25  information related to the charger. For example, controller  21  may store information such as number of NiCd batteries charged, number of NiMH batteries charged, number of times switch SW1 was on or activated (i.e., the number of times the refresh mode was selected), number of times the charging process was delayed to allow cooling of the battery, etc. 
   Preferably controller  21  can designate a string of memory slots, or “buckets,” for storing related information. For example, in order to save information on initial battery temperature, a string of memory slots of memory  25  may be organized into buckets, each bucket representing a range of initial battery temperatures. Accordingly, a bucket may be designated for initial temperatures below 20° C. A second bucket may be designated for initial temperatures between 20° and 30°, and so on. Accordingly, for example, if a battery  10  with an initial temperature of 43° C. is inserted into charger  20 , controller  23  would read the bucket corresponding for initial temperatures between 40° and 45°, increase the read value and store the new value in the bucket. 
   Similar buckets may be established for other information, such as charge termination process, i.e., number of times minus-delta-V was used to terminate charging, number of times temperature change rate was used to terminate charging, etc. 
   Persons skilled in the art will recognize that controller  21  may store in memory  25  any type of desired information, provided the controller  21  receives the proper input. For example, a signal  24  originating from the power supply representative of the voltage received from an outlet or generator, i.e., the mains voltage, may be received by controller  21 . Controller  21  can then determine and store, for example, the number of times the mains voltage was below 90 volts or above 130 volts. 
   Similarly, controller  21  may also store into memory  25  the amount of time a battery  10  is connected to charger  20 . Such information is useful to determine actual conditions of use, which can then be trusted in designing future chargers. 
   Persons skilled in the art will recognize that any information related to the battery charging process and/or charger may be stored in memory  25  so long as controller  21  receives the proper input and a large enough memory is provided. 
   In order to analyze the information, it must be downloaded from charger  20 . Referring now to  FIGS. 1 and 4 , such operation may be accomplished by connecting the charger  20  to a reader  50  and/or a computer  53 , which has memory  53 M. Reader  50  may have contacts  54 ,  55  and  56  which connect to the different terminals of charger  20 . Reader  50  may also have a microprocessor  51  for controlling the communications between charger  20  and reader  50 . A memory  52  may also be provided in reader  50  for storing the contents of memory  25 , if so desired. This allows the analyst to download the information from charger  20 , without carrying a separate computer  53 , and then later downloading the contents of memory  52  into memory  53 M of computer  53 . Reader  50  may also contain enough memory to store the information downloaded from several chargers  20 . Reader  50  may be connected tote serial or parallel ports of computer  53 , for example. 
   Controller  21  has at least one line for transmitting the contents of memory  25 . Preferably, this line is the TC line. Controller  21  preferably conducts a “data dump” operation, where the information of memory  25  is directly transmitted without further intervention from controller  21 . Controller  21  may send the information to reader  50  after a hand-shaking routine between reader  50  and controller  21  is conducted. Preferably, controller  21  sends the information via the TC line according to a serial communication scheme. Reader  50  then receives the information, stores it into memory  52  and/or sends it to computer  53  for analysis. 
     FIG. 2  illustrates a battery  30  according to the present invention, where like numerals represent like parts. The main difference between battery  10  and battery  30  is that battery  30  has been equipped with a controller  31 , preferably connected to terminals  12 ,  13  and  14 . Controller  31  may include a microprocessor  32  for controlling the sensing and memory operations, as discussed below. 
   A memory  33  is preferably connected to the controller  31 . Preferably, the memory  33  is a non-volatile memory such as E 2 PROM. Accordingly, controller  31  may read and/or write in memory  33 . Controller  31  may store in memory  33  information related to the battery, such as temperature, length of charging process, etc., in a manner similar to that explained above. 
   A bias pull-down resistor  34  may be disposed between terminals  13  and  14 . 
   Referring now to  FIGS. 2 and 4 , the information from memory  33  may be downloaded by connecting the battery  30  to a reader  50  and/or a computer  53 . Reader  50  may have contacts  54 ,  55  and  56  which connect to the terminals  12 ,  13  and  14  of battery  30 . 
   Reader  50  and controller  31  may conduct a hand-shaking routine to induce controller  31  into transmitting the information stored in memory  33 . Such a routine could be as simple as pulling up the bias on the line connected to the sensing terminal  13 . Controller  31  would sense the bias pull-up and proceed to transmit the information. Preferably, controller  31  conducts a data dump operation, where the information of memory  33  is directly transmitted without further intervention from controller  31 . Controller  31  may send the information to reader  50  according to a serial communication scheme. Reader  50  then receives the information, stores it into memory  52  and/or sends it to computer  53  for analysis. Reader  50  may also contain enough memory to store the information downloaded from several batteries  30 . 
     FIG. 3  illustrates a tool  40  according to the present invention. Tool  40  comprises terminals  46  and  48  for receiving power from a battery connected thereto, and tool circuits  41  connected to terminals  46  and  48 . Tool circuits  41  may include power regulation circuits, motor circuits, etc. A controller  42  is preferably connected to terminals  46  and  48 . Controller  42  may include a microprocessor  43  for controlling the sensing and memory operations, as discussed below. Controller  42  may also be connected to a terminal  47  to be used for transmitting information, as discussed below. A bias pull-down resistor  45  may be disposed between terminals  47  and  48 . 
   A memory  44  is preferably connected to the controller  42 . Preferably, the memory  44  is a non-volatile memory such as E 2 PROM. Accordingly, controller  42  may read and/or write in memory  44 . Controller  42  may store in memory  44  information related to the tool  40 , such as tool temperature, length of use, number of times the tool has been turned on, etc., in a manner similar to that explained above. Controller  42  receives the desired information from the tool circuits  41 . 
   Referring now to  FIGS. 3 and 4 , the information from memory  33  may be downloaded by connecting the tool  40  to a reader  50  and/or a computer  53 . Reader  50  may have contacts  54 ,  55  and  56  which connect to the terminals  46 ,  47  and  48  of battery  30 . 
   Reader  50  and controller  42  may conduct a hand-shaking routine to induce controller  42  into transmitting the information stored in memory  44 . Such a routine could be as simple as pulling up the bias on the line connected to the terminal  47 . Controller  42  would sense the bias pull-up and proceed to transmit the information. Preferably, controller  42  conducts a data dump operation, where the information of memory  44  is directly transmitted without further intervention from controller  42 . Controller  42  may send the information to reader  50  according to a serial communication scheme. Reader  50  then receives the information, stores it into memory  52  and/or sends it to computer  53  for analysis. Reader  50  may also contain enough memory to store the information downloaded from several tools  40 . 
   In order to provide more accurate use information, it is preferable that memories  25 ,  33  and  44  are pre-programmed with identification codes or serial numbers that are downloaded by reader  50 . Using the pre-programmed identification code, computer  53  can then better analyze the downloaded information by disregarding old information, comparing use between downloads, etc. 
   Persons skilled in the art will recognize that the use information can also be used to detect instances of abuse. 
   Persons skilled in the art may recognize other alternatives or additions to the means or steps disclosed herein. However, all these additions and/or alterations are considered to be equivalents of the present invention.