Patent Publication Number: US-11664539-B2

Title: Dual sided reusable battery indicator

Description:
RELATED APPLICTIONS 
     This application is a continuation of U.S. patent application No. 16/834,827, filed Mar. 30, 2020, which is a continuation of U.S. patent application No. 15/340,757, filed Nov. 1, 2016, the entirety of both U.S. patent application Nos. 16/834,827 and 15/340,757 is hereby incorporated by reference herein. 
    
    
     FIELD OF THE INVENTION 
     The disclosure relates generally to battery indicators and, more specifically, relates to a two sided reusable battery characteristic indicator. 
     BACKGROUND OF THE INVENTION 
     Electrochemical cells, or batteries, are commonly used as electrical energy sources. A battery contains a negative electrode, typically called the anode, and a positive electrode, typically called the cathode. The anode contains an electrochemically active anode material that can be oxidized. The cathode contains an electrochemically active cathode material that can be reduced. The electrochemically active anode material is capable of reducing the electrochemically active cathode material. A separator is disposed between the anode and the cathode. The battery components are disposed in a can, or housing, that is typically made from metal. 
     When a battery is used as an electrical energy source in an electronic device, electrical contact is made to the anode and the cathode, thereby completing a circuit that allows electrons to flow through the device, and which results in respective oxidation and reduction reactions that produce electrical power to the electronic device. An electrolyte is in contact with the anode, the cathode, and the separator. The electrolyte contains ions that flow through the separator between the anode and cathode to maintain charge balance throughout the battery during discharge. 
     There is a growing need for portable power for electronic devices such as toys; remote controls; audio devices; flashlights; digital cameras and peripheral photography equipment; electronic games; toothbrushes; radios; clocks, and other portable electronic devices. Consumers need to have power readily available for these electronic devices. Because batteries necessarily become depleted of power over time as they are used, consumers need to have access to spare batteries (and/or access to fully recharged rechargeable batteries). It is helpful for a consumer to know the power state of a battery currently in use so that the consumer can have quick access to the needed number of replacement batteries. Batteries come in common sizes, such as the AA, AAA, AAAA, C, and D battery sizes, that have fixed external dimensions and constrained internal volumes per ANSI standard. 
     Currently, some batteries include on-cell battery charge indicators to help a consumer determine when a battery is nearly depleted and in need of replacement. However, these current on-cell battery charge indicators are single use (i.e., attached to a single battery cell) and cumbersome (because typically two contact buttons must be simultaneously depressed to activate the indicator). Additionally, these on-cell battery indicators require removal of the battery from an electronic device (or package) in order to use the indicator. 
     SUMMARY OF THE INVENTION 
     According to some aspects, a reusable battery indicator comprises a voltage sensor configured to convert sensed analog characteristics of a battery to digital information; a communication circuit communicatively connected to the voltage sensor; an antenna operatively coupled to the communication circuit; and a connection mechanism having at least a first connector and a second connector that are electrically connected to the voltage sensor. The first connector and the second connector are adapted to be removably connected to a first battery terminal and to a second battery terminal, respectively, thereby completing an electrical circuit between the voltage sensor and the first and second battery terminals when the connection mechanism is coupled to the first battery terminal and to the second battery terminal. 
     According to another aspect, a remote battery indication system comprises a battery; and a reusable battery indicator, the battery indicator including a voltage sensor, a communication circuit communicatively connected to the voltage sensor, an antenna operatively coupled to the communication circuit, and a connection mechanism having at least a first connector and a second connector that are electrically connected to the voltage sensor. The first connector and the second connector are adapted to be removably connected to a first battery terminal and to a second battery terminal, respectively, thereby completing an electrical circuit between the voltage sensor and the first and second battery terminals when the connection mechanism is coupled to the first battery terminal and to the second battery terminal. The first connector and the second connector are electrically attached to a first battery terminal and a second battery terminal, respectively, so that the voltage sensor senses an electrical characteristic of the battery. 
     In accordance with the teachings of the disclosure, any one or more of the foregoing aspects of a reusable battery indicator or a remote battery indication system may further include any one or more of the following optional forms. 
     In some optional forms a voltage booster may be electrically connected to or incorporated in the voltage sensor. 
     In other preferred forms, at least one of the first connector and the second connector comprises at least one of a magnet, a cup, a sleeve, a tab, a socket, a pin, a washer, a spring connector, or any combination thereof. 
     In yet other preferred forms, at least one of the first connector and the second connector comprises at least one metal and at least one insulator. 
     In yet other preferred forms, at least one of the first connector and the second connector comprises at least one of a metal, a metal alloy, cold-rolled steel, carbon, or any combination thereof. 
     In yet other preferred forms, the communication circuit may comprise at least one of radio-frequency identification circuitry, Bluetooth® circuitry, Bluetooth® low energy circuitry, Wi-Fi circuitry, Zigbee® circuitry, LORA circuitry, and Z-wave circuitry. 
     In yet other preferred forms, the voltage sensor is capable of reading an open circuit voltage of less than 1.8 Volts. 
     In yet other preferred forms, the voltage sensor, and the communication circuit are formed on a printed circuit board that is adapted to be inserted between the first connector and the second connector. 
     In yet other preferred forms, the first connector and the second connector may comprise flexible wires with conductive magnets. 
     In yet other preferred forms, the voltage sensor, and the communication circuit are mounted within a housing, and the housing is sized and shaped to fit between two cylindrical batteries that are arranged longitudinally side-by-side. 
     In yet other preferred forms, the housing has a cross-section that is in the shape of a triangular prism. 
     In yet other preferred forms, the housing has one side that is concave or two sides that are concave. 
     In yet other preferred forms, the voltage sensor is disc-shaped and the voltage sensor is arranged to fit one end of a cylindrical battery cell. 
     In yet other preferred forms, the voltage sensor is one of a thin disc BLE, UHF, or RF module. 
     In yet other preferred forms, a housing of the reusable battery indicator is mounted within a battery receptacle of an electronic device. 
     In yet other preferred forms, a computing device is communicatively connected to the communication circuit, and the computing device receives information from the communication circuit through the antenna. 
     In yet other preferred forms, the computing device includes a processor and a memory, the memory storing a software routine that causes the processor to detect a wireless communication signal from the reusable battery indicator, to remotely control battery circuitry through the reusable battery indicator to determine battery characteristic data; and to send the battery characteristic data to a user interface. 
     In yet other preferred forms, the battery characteristic data comprises at least one of an electrical capacity, a voltage, an impedance, a temperature, a current, an age, a charge/discharge cycle count, and a coulomb count. 
     In yet other preferred forms, the software routine, when executed by the processor, causes the processor to determine at least one of a battery type, a physical location of the battery, and an electrical device that the battery is powering. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
       While the specification concludes with claims particularly pointing out and distinctly claiming the subject matter, which is regarded as forming the present invention, the invention will be better understood from the following description taken in conjunction with the accompanying drawings. 
         FIG.  1    is a top plan view of a battery cell and a reusable battery indicator constructed in accordance with the teachings of the disclosure, the battery cell and the reusable battery indicator being separated from one another. 
         FIG.  2    is a top plan view of the reusable battery indicator of  FIG.  1    connected to the battery cell. 
         FIG.  3    is a close-up plan view of a printed circuit board of the reusable battery indicator of  FIG.  1   . 
         FIG.  4    is an electronic circuit schematic diagram of the reusable battery indicator of  FIG.  1   . 
         FIGS.  5 A and  5 B  are top and bottom perspective views, respectively, of a second embodiment of a reusable battery indicator that is connected to a battery cell. 
         FIG.  6    is a top perspective view of a third embodiment of a reusable battery indicator that is connected to a battery cell. 
         FIGS.  7 A and  7 B  are top and bottom perspective views, respectively, of a fourth embodiment of a reusable battery indicator that is connected to a battery cell. 
         FIGS.  8 A and  8 B  are top and bottom perspective views, respectively, of a fifth embodiment of a reusable battery indicator that is connected to a battery cell. 
         FIG.  9    is a close-up cross-sectional view of a negative radial leaf at one end of the reusable battery indicator of  FIGS.  8 A and  8 B . 
         FIG.  10    is a bottom perspective view of a battery compartment of an electronic device including two battery cells and a sixth embodiment of a reusable battery indicator that is connected to one of the battery cells. 
         FIG.  11    is an end view of a seventh embodiment of a reusable battery indicator that is attached to one cell of a pair of battery cells. 
         FIG.  12    is a diagram of a eighth embodiment of a reusable battery indicator that is located between two adjacent battery cells. 
         FIG.  13    is a schematic diagram of a battery indication system including the reusable battery indicator of  FIG.  1   . 
         FIG.  14 A  is a perspective view of a ninth embodiment reusable battery indicator and a battery cell. 
         FIG.  14 B  is side cross-sectional view of the reusable battery indicator and battery cell of  FIG.  14 A . 
     
    
    
     DETAILED DESCRIPTION OF THE INVENTION 
     Electrochemical cells, or batteries, may be primary or secondary. Primary batteries are meant to be discharged, e.g., to exhaustion, only once and then discarded. Primary batteries (or disposable batteries) are described, for example, in David Linden,  Handbook of Batteries  (4 th  ed. 2011). Secondary batteries (or rechargeable batteries) are intended to be recharged and used over and over again. Secondary batteries may be discharged and recharged many times, e.g., more than fifty times, a hundred times, or more. Secondary batteries are described, for example, in David Linden,  Handbook of Batteries  (4 th  ed. 2011). Accordingly, batteries may include various electrochemical couples and electrolyte combinations. Although the description and examples provided herein are generally directed towards primary alkaline electrochemical cells, or batteries, it should be appreciated that the invention applies to both primary and secondary batteries of aqueous, nonaqueous, ionic liquid, and solid state systems. Primary and secondary batteries of the aforementioned systems are thus within the scope of this application and the invention is not limited to any particular embodiment. 
     Referring to  FIGS.  1  and  2   , a primary alkaline electrochemical cell, or battery cell  10 , is illustrated that includes a cathode  12 , an anode  14 , and a housing  18 . The battery cell  10  also includes an end cap  24 . The end cap  24  serves as a negative terminal of the battery cell  10 . A positive pip  26  is located at the opposite end of the battery cell  10  from the end cap  24 . The positive pip  26  serves as a positive terminal of the battery cell  10 . An electrolytic solution is dispersed throughout the battery cell  10 . The battery cell  10  can be, for example, a AA, AAA, AAAA, C, or D alkaline battery. Additionally, in other embodiments, the battery cell  10  can be a 9V battery, a camera battery, a watch battery, or any other type of primary or secondary battery. 
     The housing  18  can be made of any suitable type of housing base material, for example cold-rolled steel or nickel-plated cold-rolled steel. In the embodiment illustrated in  FIG.  1   , the housing  18  may have a cylindrical shape. In other embodiments, the housing  18  may have any other suitable, non-cylindrical shape. The housing  18 , for example, may have a shape comprising at least two parallel plates, such as a rectangular, square, or prismatic shape. The housing  18  may be, for example, deep-drawn from a sheet of the base material, such as cold-rolled steel or nickel-plated steel. The housing  18  may be, for example, drawn into a cylindrical shape. The housing  18  may have a sidewall. The interior surface of the sidewall of the housing  18  may be treated with a material that provides a low electrical-contact resistance between the interior surface of the sidewall of the housing  18  and an electrode, such as the cathode  12 . The interior surface of the sidewall of the housing  18  may be plated, e.g., with nickel, cobalt, and/or painted with a carbon-loaded paint to decrease contact resistance between, for example, the internal surface of the sidewall of the housing  18  and the cathode  12 . 
     Next to the battery cell  10  is one embodiment of a communication mechanism, such as a reusable battery indicator  40 . The reusable battery indicator  40  includes an integrated circuit, which may be incorporated into a printed circuit board (PCB)  42 , a first connector  44  that is electrically connected to the PCB  42 , and a second connector  46  that is electrically connected to the PCB  42 . The first connector  44  may be removably and electrically connected to the positive pip  26  to form a positive electrical connection and the second connector  46  may be removably and electrically connected to the end cap  24  to form a negative electrical connection, as illustrated in  FIG.  2   . The first connector  44  and the second connector  46  may take virtually any physical form that allows the first connector  44  and the second connector  46  to form electrical connections with the battery cell  10  and the PCB  42 . In some embodiments, the first connector  44  and the second connector  46  may take any one or more of the following forms, a magnet, a cup, a sleeve, a tab, a socket, a pin, a washer, a spring connector, a wire loop, or any combination thereof. Moreover, the first connector  44  and the second connector  46  may be formed from virtually any material that transmits analog information, such as electrical information, from the battery cell to the PCB  42 . For example, in some embodiments, the first connector  44  and the second connector  46  may be formed from one or more of the following materials, a metal, a metal alloy, cold-rolled steel, hard drawn ferrous and non-ferrous alloys, high and low carbon steel alloys, post or pre-plated ferrous and non-ferrous alloys, or any combination thereof. In some embodiments, at least one of the first connector  44  and the second connector  46  may comprise a metal and an insulator. More specifically, an inner surface of the first and second connectors  44 ,  46  may include a non-conductive coating (such as a polymer layer, epoxy, or passivate) or an additional insulator ring (e.g., paper, phenolic, or polymer) in areas other than contact areas for the terminals to guard against shorting to the battery housing or crimp. 
     Generally, the integrated circuit receives electrical information, such as amperes or volts from the first connector  44  and from the second connector  46 , and the electrical information is used by the integrated circuit to calculate battery characteristic information, such as power or charge level, and the integrated circuit then transmits the battery characteristic information to a receiver, such as a computer, a smart phone, or a personal digital assistant, for use by the consumer. In this way, the reusable battery indicator  40  allows a consumer to acquire the battery characteristic information without removing the battery cell from an electronic device (or from a package). The first connector  44  and the second connector  46  deliver the electrical information to the integrated circuit without interfering with electrical contacts between the battery cell and the electronic device. Furthermore, the reusable battery indicator  40  is movable from one battery cell to another battery cell so as to be reused over and over again, thereby reducing the overall cost to a consumer. 
     Turning now to  FIGS.  3  and  4   , formed on the PCB  42  is an integrated circuit  48 , that includes an embedded voltage sensor  50  within the integrated circuit  48  that is communicatively connected to the first connector  44  and to the second connector  46 . The embedded voltage sensor  50  senses analog characteristics of the battery cell, such as amperes and voltage and converts the sensed analog characteristics to digital information. The PCB  42  also includes a communication circuit  52 . An antenna  54  is operatively coupled to the communication circuit  52 . The communication circuit  52  may comprise one or more of a radio-frequency identification circuit, a Bluetooth® circuit, a Bluetooth® low energy circuit, a Wi-Fi circuit, a Zigbee® circuit, a LORA circuit, and a Z-wave circuit. In one embodiment, an integrated circuit, such as a wireless Bluetooth Low-Energy voltage sensor, may incorporate the analog to digital converter, a microcontroller, a Bluetooth radio, a memory device, and a DC/DC voltage converter. 
     A voltage booster  56  is electrically connected to the integrated circuit  48  and the embedded voltage sensor  50 . The embedded voltage sensor  50  and the voltage booster  56  are capable of reading the open circuit voltage of the battery that may be, for example, less than 1.8 volts. In some embodiments, the communication circuit  52  may comprise one or more of a thin disc BLE module, a UHF module, or a RF module. 
     In the embodiment illustrated in  FIGS.  3  and  4   , the integrated circuit  48 , the voltage sensor  50 , and the communication circuit  52  are all formed on the PCB  42 , which is connected to the first connector  44  and the second connector  46 . However, in other embodiments, the integrated circuit  48 , the voltage sensor  50 , and the communication circuit  52  may be formed as separate components that are communicatively and operatively connected to one another. 
     In the embodiment illustrated in  FIGS.  5 A and  5 B , similar elements are numbered exactly 100 greater than elements numbered in  FIGS.  1 - 4   . For example, the battery cell is numbered  10  in  FIGS.  1 - 4    and the battery cell is numbered  110  in  FIGS.  5 A and  5 B . Unless stated otherwise, any element from any illustrated embodiment may be incorporated into any other illustrated embodiment. 
     Turning now to  FIGS.  5 A and  5 B , a second embodiment of the reusable battery indicator  140  is attached to a battery cell  110 . The reusable battery indicator  140  includes a PCB  142 , a first connector  144 , and a second connector  146 . While the battery cell  110  in  FIGS.  5 A and  5 B  is illustrated as a AA size battery, the illustration is not intended to limit the reusable battery indicator  140  to the illustrated battery cell  110 . Rather, the reusable battery indicator  140  may be sized and shaped to fit virtually any battery cell, especially those battery cell sizes listed elsewhere in the specification. 
     In the embodiment illustrated in  FIGS.  5 A and  5 B , the first connector  144  and the second connector  146  comprise flexible wires  160 ,  162 , respectively. The flexible wires  160 ,  162  may be formed as spring wires (from hard drawn ferrous and non-ferrous spring alloys) that capture the positive battery terminal  126  and the negative battery terminal  124 , respectively, to transmit electrical characteristics, such as voltage and amperes, to the integrated circuit formed on the PCB  142 . In the illustrated embodiment, the flexible wires  160 ,  162  are formed of ASTM A228 music wire with pre or post nickel plating to enhance conductivity, to reduce contact resistance, and to provide corrosion resistance. 
     In the embodiment illustrated in  FIGS.  5 A and  5 B , the flexible wire  160  includes a first end  166 , which is connected to a positive terminal  168  on the PCB  142  and a second end  170 , which is also connected to the positive terminal  168  on the PCB  142 . The flexible wire  160  includes a first leg  172 , extending from the first end  166  and a second leg  174  extending from the second end  170 . The first leg  172  and the second leg  174  are oriented substantially parallel to a longitudinal axis A of the battery cell  110 . The first leg  172  and the second leg  174  are connected to one another at an end loop  176 . The end loop  176  lies in a plane that is substantially perpendicular to the longitudinal axis of the battery cell  110 . The end loop  176  is sized and shaped to fit around the positive terminal  126  of the battery cell  110 . As a result, the flexible wire  160  forms a positive electrical pathway from the positive battery terminal  126  to the positive terminal  168  on the PCB  142 . Moreover, the flexible wire  160  may be formed to produce a spring force that biases the flexible wire  160  into the attached position illustrated in  FIGS.  5 A and  5 B , while allowing the flexible wire  160  to be temporarily deformed by a user to remove the reusable battery indicator  140  from the battery cell  110  when desired. 
     Similar to the flexible wire  160 , the flexible wire  162  includes a first end  178 , which is connected to a negative terminal  180  on the PCB  142  and a second end  182 , which is also connected to the negative terminal  180  on the PCB  142 . The flexible wire  162  includes a first leg  184 , extending from the first end  178  and a second leg  186  extending from the second end  182 . The first leg  184  and the second leg  186  are oriented substantially parallel to the longitudinal axis A of the battery cell  110 . The first leg  184  and the second leg  186  are connected to one another at an end loop  188 . The end loop  188  lies in a plane that is substantially perpendicular to the longitudinal axis of the battery cell  110 . The end loop  186  is sized and shaped to fit around the negative terminal  124  of the battery cell  110 . As a result, the flexible wire  162  forms a negative electrical pathway from the negative battery terminal  124  to the negative terminal  180  on the PCB  142 . Moreover, the flexible wire  162  may be formed to produce a spring force that biases the flexible wire  162  into the attached position illustrated in  FIGS.  5 A and  5 B , while allowing the flexible wire  162  to be temporarily deformed by a user to remove the reusable battery indicator  140  from the battery cell  110  when desired. 
     The approximately 90° bends between the first and second legs  172 ,  174  of the first flexible wire  160  and the end loop  176  and between the first and second legs  184 ,  186  of the second flexible wire  162  and the end loop  188 , create an axial force, which maintains the reusable battery indicator  140  in electrical connection with the battery cell  110 . In other embodiments, the bends may be more than 90° to mate to a tapered positive terminal. 
     In some embodiments, one or more of the first flexible wire  160  and the second flexible wire  162  may include a conductive magnet, or the one or more of the first flexible wire  160  and the second flexible wire  162  may be formed from conductive magnetic material, to provide additional retention force between the first flexible wire  160  and the positive terminal  126  and between the second flexible wire  162  and the negative terminal  124 . 
     In other embodiments, one or more of the first flexible wire  160  and the second flexible wire  162  may be formed as a Kelvin connection, including separate power and sensing terminals, to measure impedance. Additionally, in alternate embodiments, the first flexible wire  160  and the second flexible wire  162  need not be formed as a single continuous wire, but may be formed as multiple wire pieces, for example, two wire pieces that are separated by a small distance in the end loop. 
     As in  FIGS.  5 A and  5 B , in the embodiment of  FIG.  6   , similar elements are numbered exactly 100 greater than elements numbered in  FIGS.  1 - 4   . For example, the battery cell is numbered  10  in  FIGS.  1 - 4    and the battery cell is numbered  110  in  FIG.  6   . Unless stated otherwise, any element from any illustrated embodiment may be incorporated into any other illustrated embodiment. 
     Turning now to  FIG.  6   , a third embodiment of the reusable battery indicator  140  is attached to a battery cell  110 . The reusable battery indicator  140  includes a PCB  142 , a first connector  144 , and a second connector  146 . While the battery cell  110  in  FIG.  6    is illustrated as a AA size battery, the illustration is not intended to limit the reusable battery indicator  140  to the illustrated battery cell  110 . Rather, the reusable battery indicator  140  may be sized and shaped to fit virtually any battery cell, especially those battery cell sizes listed elsewhere in the specification. 
     In the embodiment illustrated in  FIG.  6   , the first connector  144  and the second connector  146  comprise flexible wires  160 ,  162 , respectively. The flexible wires  160 ,  162  may be formed as spring wires that capture the positive battery terminal  126  and the negative battery terminal  124 , respectively, to transmit electrical characteristics, such as voltage and amperes, to the integrated circuit formed on the PCB  142 . 
     The flexible wires  160 ,  162  in  FIG.  6    are similar to the flexible wires of  FIGS.  5 A and  5 B , except that the flexible wires  160 ,  162  in  FIG.  6    have only a single leg. More specifically, the flexible wire  160  includes a first end  166 , which is connected to a positive terminal  168  on the PCB  142 . The flexible wire  160  includes a single leg  172 , extending from the first end  166 . The single leg  172  is oriented substantially parallel to a longitudinal axis A of the battery cell  110 . The single leg  172  forms an end loop  176  at a second end. The end loop  176  lies in a plane that is substantially perpendicular to the longitudinal axis of the battery cell  110 . The end loop also lies below the plane of the contact surface of the positive terminal  126 . In this manner, the end loop  176  does not interfere with an electronic device making contact with the positive terminal  126 . The end loop  176  is sized and shaped to fit around the positive terminal  126  of the battery cell  110 . As a result, the flexible wire  160  forms a positive electrical pathway from the positive battery terminal  126  to the positive terminal  168  on the PCB  142 . Moreover, the flexible wire  160  may be formed to produce a spring force that biases the flexible wire  160  into the attached position illustrated in  FIG.  6   , while allowing the flexible wire  160  to be temporarily deformed by a user to remove the reusable battery indicator  140  from the battery cell  110  when desired. 
     Similar to the flexible wire  160 , the flexible wire  162  includes a first end  178 , which is connected to a negative terminal  180  on the PCB  142 . The flexible wire  162  includes a single leg  184 , extending from the first end  178 . The single leg  184  is oriented substantially parallel to the longitudinal axis A of the battery cell  110 . The single leg  184  forms an end loop  188  at a second end. The end loop  188  lies in a plane that is substantially perpendicular to the longitudinal axis of the battery cell  110 . The end loop  188  also lies below the plane of the contact surface of the negative terminal  124 . In this manner, the end loop  188  does not interfere with an electronic device making contact with the negative terminal  124 . The end loop  188  is sized and shaped to fit around the negative terminal  124  of the battery cell  110 . As a result, the flexible wire  162  forms a negative electrical pathway from the negative battery terminal  124  to the negative terminal  180  on the PCB  142 . Moreover, the flexible wire  162  may be formed to produce a spring force that biases the flexible wire  162  into the attached position illustrated in  FIG.  6   , while allowing the flexible wire  162  to be temporarily deformed by a user to remove the reusable battery indicator  140  from the battery cell  110  when desired. 
     In some embodiments, one or more of the first flexible wire  160  and the second flexible wire  162  may include a conductive magnet, or the one or more of the first flexible wire  160  and the second flexible wire  162  may be formed from conductive magnetic material, to provide additional retention force between the first flexible wire  160  and the positive terminal  126  and between the second flexible wire  162  and the negative terminal  124 . 
     In other embodiments, one or more of the first flexible wire  160  and the second flexible wire  162  may be formed as a Kelvin connection, including separate power and sensing terminals, to measure impedance. 
     In the embodiment illustrated in  FIGS.  7 A and  7 B , similar elements are numbered exactly 200 greater than elements numbered in  FIGS.  1 - 4   . For example, the battery cell is numbered  10  in  FIGS.  1 - 4    and the battery cell is numbered  210  in  FIGS.  7 A and  7 B . Unless stated otherwise, any element from any illustrated embodiment may be incorporated into any other illustrated embodiment. 
     Turning now to  FIGS.  7 A and  7 B , a fourth embodiment of the reusable battery indicator  240  is attached to a battery cell  210 . The reusable battery indicator  240  includes a PCB  242 , a first connector  244 , and a second connector  246 . While the battery cell  210  in  FIGS.  6 A and  6 B  is illustrated as a AA size battery, the illustration is not intended to limit the reusable battery indicator  240  to the illustrated battery cell  210 . Rather, the reusable battery indicator  240  may be sized and shaped to fit virtually any battery cell, especially those battery cell sizes listed elsewhere in the specification. 
     In the embodiment illustrated in  FIGS.  7 A and  7 B , the first connector  244  and the second connector  246  comprise leaf springs  260 ,  262 , respectively. The leaf springs  260 ,  262  may be formed as planar legs that capture the positive battery terminal  226  and the negative battery terminal  224 , respectively, to transmit electrical characteristics, such as voltage and amperes, to the integrated circuit formed on the PCB  142 . 
     In the embodiment illustrated in  FIGS.  7 A and  7 B , the leaf spring  260  includes a first end  266 , which is connected to a positive terminal  268  on the PCB  242 . The leaf spring  260  includes a first leg  272 , extending from the first end  266 . The first leg  272  is substantially planar (or very slightly curved to mirror the curvature of the outer surface of the battery cell  210 ) and is oriented substantially parallel to the longitudinal axis of the battery cell  210 . The first leg  272  turns approximately 90° near a second end  273 , forming an end clip  276 . The end clip  276  lies in a plane that is substantially perpendicular to the longitudinal axis of the battery cell  210 . The end clip  276  includes a concave end that is curved to mirror an outer cylindrical surface of the positive terminal  226  of the battery cell  210 . As a result, the leaf spring  260  forms a positive electrical pathway from the positive battery terminal  226  to the positive terminal  268  on the PCB  242 . Moreover, the leaf spring  260  may be formed to produce a spring force that biases the leaf spring  260  into the attached position illustrated in  FIGS.  7 A and  7 B , while allowing the leaf spring  260  to be temporarily deformed by a user to remove the reusable battery indicator  240  from the battery cell  210  when desired. 
     Similar to the leaf spring  260 , the leaf spring  262  includes a first end  278 , which is connected to a negative terminal  280  on the PCB  242 . The leaf spring  262  includes a first leg  284 , extending from the first end  278 . The first leg  284  is substantially planar (or very slightly curved to mirror the curvature of the outer surface of the battery cell  210 ) and is oriented substantially parallel to a longitudinal axis of the battery cell  210 . The first leg  284  turns approximately 90° near a second end  285 , forming an end clip  288 . The end clip  288  lies in a plane that is substantially perpendicular to the longitudinal axis of the battery cell  210 . The end clip  288  includes a concave end that is curved to mirror an outer cylindrical surface of the negative terminal  224  of the battery cell  210 . As a result, the leaf spring  262  forms a negative electrical pathway from the negative battery terminal  224  to the negative terminal  280  on the PCB  242 . Moreover, the leaf spring  262  may be formed to produce a spring force that biases the leaf spring  262  into the attached position illustrated in  FIGS.  7 A and  7 B , while allowing the leaf spring  262  to be temporarily deformed by a user to remove the reusable battery indicator  240  from the battery cell  210  when desired. 
     The approximately 90° bends between the first leg  272  of the first leaf spring  260  and the end loop  276  and between the first leg  184  of the second leaf spring  262  and the end loop  288 , create an axial force, which maintains the reusable battery indicator  240  in electrical connection with the battery cell  210 . 
     In some embodiments, one or more of the first leaf spring  260  and the second leaf spring  262  may be integrated into the positive terminal  268  and the negative terminal  280 , respectively, of the PCB  242  as one layer of a multi-layered PCB  242 . 
     In some embodiments, the reusable battery indicator  240  may also include a retention clip  291  that extends from the reusable battery indicator  240  in a plane substantially perpendicular to the longitudinal axis of the battery cell  210 . The retention clip  291  may include two opposing legs that are curved to mirror the curvature of the outer surface of the battery cell  210 . The retention clip  291  provides additional retention force to retain the reusable battery indicator  240  on the battery cell  210 . 
     In the embodiment illustrated in  FIGS.  8 A,  8 B, and  9   , similar elements are numbered exactly 300 greater than elements numbered in  FIGS.  1 - 4   . For example, the battery cell is numbered  10  in  FIGS.  1 - 4    and the battery cell is numbered  310  in  FIGS.  8 A,  8 B, and  9   . Unless stated otherwise, any element from any illustrated embodiment may be incorporated into any other illustrated embodiment. 
     Turning now to  FIGS.  8 A,  8 B, and  9   , a fifth embodiment of the reusable battery indicator  340  is attached to a battery cell  310 . The reusable battery indicator  340  includes a PCB  342 , a first connector  344 , and a second connector  346 . While the battery cell  210  in  FIGS.  8 A and  8 B  is illustrated as a AA size battery, the illustration is not intended to limit the reusable battery indicator  340  to the illustrated battery cell  310 . Rather, the reusable battery indicator  340  may be sized and shaped to fit virtually any battery cell, especially those battery cell sizes listed elsewhere in the specification. 
     Similar to the previous embodiment, in the embodiment illustrated in  FIGS.  8 A,  8 B , and  9 , the first connector  344  and the second connector  346  comprise first and second leaf springs  360 ,  362 , respectively. The first and second leaf springs  360 ,  362  are similar to the first and second leaf springs  260 ,  262  of  FIGS.  7 A and  7 B , with the following exceptions. 
     In the embodiment illustrated in  FIGS.  8 A,  8 B, and  9   , the first leaf spring  360  includes a retention clip  391  that extends in a plane that is substantially perpendicular to the longitudinal axis of the battery cell  310 . In other embodiments, the second leaf spring  362  may include a similar retention clip. The retention clip  391  may include two opposing legs that are curved to mirror the curvature of the outer surface of the battery cell  310 . The retention clip  391  provides additional retention force to retain the reusable battery indicator  340  on the battery cell  310 . 
     Instead of including an end clip, the second leaf spring  346  includes an end loop  388 . The end loop  388  lies in a plane that is substantially perpendicular to the longitudinal axis of the battery cell  310 . The end loop  388  includes an inner opening  392  that is sized and shaped to mirror an outer cylindrical surface of the negative battery terminal  324 . As a result, the second leaf spring  362  forms a negative electrical pathway from the negative battery terminal  324  to the negative terminal on the PCB  342 . 
     In some embodiments, the end loop  388  may include a disc-shaped voltage sensor that is arranged to fit one end of the cylindrical battery cell  310 . 
     Turning specifically now to  FIG.  9   , the end loop  388  may include a radial collar  394  that extends away from the end loop  388 , towards the PCB  342 . The radial collar  394  is sized and shaped to fit within a negative cap recess  396 . The radial collar  394  provides negative terminal location and contact force, in addition to the end loop  388 . 
     In other embodiments, a similar end loop with a radial collar may be formed in the first leaf spring for contact at the positive battery terminal. In such embodiments, the radial collar may provide additional clearance at the positive battery terminal where a reverse polarity insertion guard exists. 
     The end loop  388  and radial collar  394  cooperate with battery cells having a negative cap/positive crimp groove. 
     Turning now to  FIG.  10   , a sixth embodiment of a reusable battery indicator  440  is illustrated. In the embodiment of  FIG.  10   , the reusable battery indicator includes a housing  498 , the integrated circuit, the voltage sensor, and the communication circuit being mounted within the housing  498 . In the embodiment of  FIG.  10   , the housing  498  is sized and shaped to fit between two cylindrical battery cells  410  that are arranged longitudinally side-by-side. In the embodiment illustrated in  FIG.  10   , the housing  498  has a cross-section that is in the shape of a triangular prism. More specifically, the housing  498  has a first side  497  that is concave and a second side  499  that is concave. In other embodiments, the housing  498  may have a shape such as rectangular, trapezoid, elliptical, semi-circular, and variable, that fits within the void described by the triangular prism. In the embodiment of  FIG.  10   , the reusable battery indicator  440  is mounted between the battery cells  410  and within a battery receptacle  495  of an electronic device  500 . 
     Turning now to  FIG.  11   , a seventh embodiment of a reusable battery indicator  540  is illustrated and located between two battery cells  510 . In the embodiment of  FIG.  11   , the reusable battery indicator  540  includes a housing  598  that has only a single concave side. 
       FIG.  12    illustrates an alternative housing shape. In this embodiment, the housing  698  is arranged to fit in the void formed by two cylindrical battery cells  610  that are arranged side by side and oriented such that the respective longitudinal axes of the battery cells  610  are parallel to one another. In the embodiment illustrated in  FIG.  12   , the housing  698  has a cross-sectional shape that is defined by the following equation:
 
 A   v =( D   B   2 −Π/4× D   B   2 )/2, where
 
     A v  is the cross-sectional area of the housing  698 ; and 
     D B  is a diameter of one battery cell  610 . 
     A housing having a cross-sectional shape defined by the preceding equation maximizes the usable space between the battery cells. For example, a housing having the cross-sectional shape defined above would result in the following housing volumes for the given battery sizes (assuming that the housing length was equal to the battery cell length). For a AAA battery, the housing would have a volume of 526 mm 3 ; and for a AA battery, the housing would have a volume of 1140 mm 3 . 
     Turning now to  FIG.  13   , a computing device  800  is communicatively connected to the communication circuit in the reusable battery indicator  740 . The computing device receives information from the communication circuit through wireless signals sent by the antenna in the reusable battery indicator  740 . For example, the wireless signal may be one or more of a wifi signal, a Bluetooth® signal, a RFID signal, or any other wireless signal. In other embodiments, the computing device  800  and the reusable battery indicator  740  may communicatively connected by a wired connection. 
     The computing device  800  includes a processor  802  and a memory  804 . The memory  804  may store processor executable instructions that when executed by the processor  802  cause the processor  802  to detect a wireless communication signal from the reusable battery indicator  740 . In some embodiments the memory  804  may comprise a non-transitory computer readable medium with the processor executable instructions embedded thereon as an article of manufacture. The processor executable instructions may also cause the processor  802  to send wireless signals back to the reusable battery indicator  740  to remotely control battery circuitry through the reusable battery indicator  740 . In this manner, the processor  802  may cause the reusable battery indicator  740  to determine battery characteristic data; and to send the battery characteristic data to a user interface, such as a display  806  on the computing device  800 . 
     In some embodiments, the battery characteristic data may comprise at least one of an electrical capacity; a voltage; an impedance, a temperature, a current; an age, a charge/discharge cycle count, and a coulomb count. 
     In other embodiments, the processor executable instructions, when executed by the processor  802 , causes the processor  802  to determine at least one of a battery type, a physical location of the battery, and an electrical device that the battery is powering by communicating with the reusable battery indicator  740 . 
     Turning now to  FIGS.  14 A and  14 B , yet another embodiment of a reusable battery indicator  940  is illustrated. The reusable battery indicator  940  includes a first connector  944  and a second connector  946 . The first connector  944  connects to the negative terminal  924  of the battery  910  and the second connector  946  connects to the positive terminal of the battery  910 . The first connector  944  includes an insulated leg  905  with an embedded wire  907 . The insulated leg  905  includes an inner portion  909  that prevents the embedded wirer  907  from making contact with the crimped wall  961  of the battery housing  918 . However, the embedded wire  907  is exposed at a radially inward end of the insulated leg  905  so that the embedded wire  907  may make electrical contact with the negative terminal  924 , thus completing the electrical connection. 
     The dimensions and values disclosed herein are not to be understood as being strictly limited to the exact numerical values recited. Instead, unless otherwise specified, each such dimension is intended to mean both the recited value and a functionally equivalent range surrounding that value. For example, a dimension disclosed as “40 mm” is intended to mean “about 40 mm.” 
     Every document cited herein, including any cross referenced or related patent or application and any patent application or patent to which this application claims priority or benefit thereof, is hereby incorporated herein by reference in its entirety unless expressly excluded or otherwise limited. The citation of any document is not an admission that it is prior art with respect to any invention disclosed or claimed herein or that it alone, or in any combination with any other reference or references, teaches, suggests or discloses any such invention. Further, to the extent that any meaning or definition of a term in this document conflicts with any meaning or definition of the same term in a document incorporated by reference, the meaning or definition assigned to that term in this document shall govern. 
     While particular embodiments of the present invention have been illustrated and described, it would be obvious to those skilled in the art that various other changes and modifications can be made without departing from the spirit and scope of the invention. It is therefore intended to cover in the appended claims all such changes and modifications that are within the scope of this invention.