Patent Publication Number: US-2013250466-A1

Title: Short circuit apparatus and method

Description:
RELATED APPLICATION 
     This application claims the benefit of U.S. Provisional Application Ser. No. 61/613,184, filed Mar. 20, 2012, titled SHORT CIRCUIT APPARATUS AND METHOD, docket ENERD-P12-001-01-US, the description of which is expressly incorporated by reference herein. 
    
    
     FIELD 
     The disclosure relates in general to methods and systems for storing and providing energy with a serviceable unit and, more particularly, to methods and systems for storing and providing energy with an assembly including a serviceable unit and a current limiting device. 
     BACKGROUND 
     Energy storage systems are known. Exemplary energy storage systems are disclosed in PCT Published Application No. WO2012/167269, application number PCT/US2012/040776, filed Jun. 4, 2012, titled ENERGY STORAGE SYSTEM and in PCT Published Application No. WO2012/158185, application number PCT/US2011/052169, filed Sep. 19, 2011, titled ENERGY STORAGE SYSTEM, the disclosures of which are expressly incorporated by reference herein. 
     SUMMARY 
     In an exemplary embodiment of the present disclosure, an assembly is provided. The assembly including a serviceable unit and a current limiting device. 
     In another exemplary embodiment of the present disclosure, an assembly is provided. The assembly comprising a serviceable unit including a positive electrical terminal connection, a negative electrical terminal connection, and a plurality of energy storage devices operatively coupled to the positive electrical terminal connection and the negative electrical terminal connection to form an electrical path of the serviceable unit; and a current limiting device coupled to the serviceable unit and including a current limiting component. The current limiting component being included in the electrical path of the serviceable unit. 
     In an example of the another exemplary embodiment, the current limiting component is selected from the group of a resistor and a fuse. 
     In another example of the another exemplary embodiment, the current limiting device is removably coupled to one of the positive electrical terminal connection and the negative electrical terminal connection. In a variation thereof, the current limiting component is selected from the group of a resistor and a fuse. In another variation thereof, the plurality of energy storage devices includes a plurality of prismatic cells electrically coupled together, the plurality of electrical storage devices having a fully charged open circuit voltage of between about 12 volts and about 192 volts. In yet another variation thereof, the plurality of energy storage devices includes a plurality of prismatic cells electrically coupled together, the plurality of electrical storage devices having a fully charged open circuit voltage of between about 24 volts and about 48 volts. In a further variation thereof, the current limiting device is press fit onto one of the positive electrical terminal connection and the negative electrical terminal connection. In yet a further variation thereof, the current limiting device provides a terminal that is electrically connected to the one of the positive electrical terminal connection and the negative electrical terminal connection that the current limiting device is coupled to through the current limiting component. In a refinement of the yet a further variation, the current limiting device includes a terminal connector having a cavity which receives the one of the positive electrical terminal connection and the negative electrical terminal connection and a base which is coupled to the terminal connector and the current limiting component. In a further refinement thereof, the terminal is supported by the base. 
     In yet another example of the another exemplary embodiment, the current limiting device is coupled to the serviceable unit in place of an electrical component of the electrical path. In a variation thereof, the current limiting component is selected from the group of a resistor and a fuse. In another variation thereof, the plurality of energy storage devices includes a plurality of prismatic cells electrically coupled together, the plurality of electrical storage devices having a fully charged open circuit voltage of between about 12 volts and about 192 volts. In a further variation thereof, the plurality of energy storage devices includes a plurality of prismatic cells electrically coupled together, the plurality of electrical storage devices having a fully charged open circuit voltage of between about 24 volts and about 48 volts. 
     In still another example of the another embodiment, the current limiting device is positioned in a first configuration relative to the serviceable unit to place the current limiting component in the electrical path and in a second configuration relative to the serviceable unit to remove the current limiting component from the electrical path. In a variation thereof, the current limiting device includes a carrier which supports current limiting component, the carrier being moveable relative to a housing of the serviceable unit, the carrier being in a first position relative to the housing in the first configuration and in a second position relative to the housing in the second configuration. In another variation thereof, the current limiting component is selected from the group of a resistor and a fuse. In still another variation thereof, the plurality of energy storage devices includes a plurality of prismatic cells electrically coupled together, the plurality of electrical storage devices having a fully charged open circuit voltage of between about 12 volts and about 192 volts. In yet still another variation thereof, the plurality of energy storage devices includes a plurality of prismatic cells electrically coupled together, the plurality of electrical storage devices having a fully charged open circuit voltage of between about 24 volts and about 48 volts. 
     In a further exemplary embodiment of the present disclosure, a method of testing a serviceable unit is provided. The serviceable unit including a positive electrical terminal connection, a negative electrical terminal connection, and a plurality of energy storage devices operatively coupled to the positive electrical terminal connection and the negative electrical terminal connection to form an electrical path of the serviceable unit. The method comprising the steps of sequentially: (a) placing a current limiting device in the electrical path of the serviceable unit, the current limiting device including a current limiting component; (b) subjecting the serviceable unit with the current limiting device to a vibration testing; (c) measuring a voltage of the serviceable unit, the voltage generally corresponding to the voltage difference between the positive electrical terminal connection and the negative electrical terminal connection; (d) shorting the positive electrical terminal connection to the negative electrical terminal connection; and (e) removing the current limiting device from the electrical path of the serviceable unit. 
     In one example of the further exemplary embodiment, the step of placing the current limiting device in the electrical path of the serviceable unit includes the step of coupling the current limiting device to one of the positive terminal electrical connection and the negative terminal electrical connection, the current limiting device providing a terminal, the current limiting component being in an electrical path between the one of the positive terminal electrical connection and the negative terminal electrical connection and the terminal. In a variation thereof, the step of measuring a voltage of the serviceable unit, the voltage generally corresponding to the voltage difference between the positive electrical terminal connection and the negative electrical terminal connection is performed by measuring a voltage between the terminal of the current limiting device and the other of the positive electrical terminal connection and the negative electrical terminal connection. In another variation thereof, the step of shorting the positive electrical terminal connection to the negative electrical terminal connection includes the step of establishing an external electrical connection between the terminal of the current limiting device and the other of the positive electrical terminal connection and the negative electrical terminal connection. In a refinement of the another variation, the external electrical connection between the terminal of the current limiting device and the other of the positive electrical terminal connection and the negative electrical terminal connection includes a circuit resistance of less than 0.1 ohms. In still another variation, the method further comprises the steps of: maintaining the external electrical connection for at least one hour; and monitoring an external temperature of the serviceable unit. In still a further variation thereof, the step of coupling the current limiting device to one of the positive terminal electrical connection and the negative terminal electrical connection includes the step of receiving the one of the positive terminal electrical connection and the negative terminal electrical connection within a cavity of the current limiting device. 
     In another example of the further exemplary embodiment, the step of placing the current limiting device in the electrical path of the serviceable unit includes the step of replacing an electrical conductor of the serviceable unit with the current limiting device. 
     In another example of the further exemplary embodiment, the electrical conductor of the serviceable unit and the current limiting device are supported by a carrier and the step of replacing the electrical conductor of the serviceable unit with the current limiting device includes the step of rotating the carrier which removes the electrical conductor of the serviceable unit from the electrical path of the serviceable unit and includes the current limiting device in the electrical path of the serviceable unit. 
     In any of the preceding examples of the further exemplary embodiment, the method further includes at least one of the following steps that are performed in any order between step (a) and step (d): subjecting the serviceable unit with the current limiting device to an altitude testing; subjecting the serviceable unit with the current limiting device to a thermal cycling testing; and subjecting the serviceable unit with the current limiting device to a shock testing. 
     In any of the preceding examples of the further exemplary embodiment, the method further includes at least two of the following steps that are performed in any order between step (a) and step (d): subjecting the serviceable unit with the current limiting device to an altitude testing; subjecting the serviceable unit with the current limiting device to a thermal cycling testing; and subjecting the serviceable unit with the current limiting device to a shock testing. 
     In any of the preceding examples of the further exemplary embodiment, the method further includes at least all of the following steps that are performed in any order between step (a) and step (d): subjecting the serviceable unit with the current limiting device to an altitude testing; subjecting the serviceable unit with the current limiting device to a thermal cycling testing; and subjecting the serviceable unit with the current limiting device to a shock testing. 
     The above and other features of the present disclosure, which alone or in any combination may comprise patentable subject matter, will become apparent from the following description and the attached drawings. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
       The aspects and many of the attendant advantages of this invention will become more readily appreciated as the same become better understood by reference to the following detailed description when taken in conjunction with the accompanying drawings. 
         FIG. 1  illustrates an exemplary serviceable unit; 
         FIG. 1A  illustrates a representative view of the exemplary serviceable unit of  FIG. 1 ; 
         FIG. 2  illustrates an exemplary serviceable unit and an exemplary current limiting device adapted to be coupled to a terminal connection of the serviceable unit; 
         FIG. 2A  illustrates a representative view of the exemplary serviceable unit and current limiting device of  FIG. 2 ; 
         FIG. 3  illustrates an exemplary serviceable unit and an exemplary current limiting device adapted to be coupled in an electrical connection between two series battery units of the serviceable unit, the current limiting device being actuatable from an exterior of the serviceable unit; 
         FIG. 3A  illustrates a representative view of the exemplary serviceable unit and current limiting device of  FIG. 3 ; 
         FIG. 4  illustrates an exemplary serviceable unit and an exemplary current limiting device adapted to be coupled in an electrical connection between two series battery units of the serviceable unit; 
         FIG. 4A  illustrates a representative view of the exemplary serviceable unit and current limiting device of  FIG. 4 ; 
         FIG. 5  illustrates an exemplary embodiment of the current limiting device of  FIG. 2 ; 
         FIG. 6  illustrates the current limiting device of  FIG. 5  coupled to a terminal connection of an exemplary serviceable unit; 
         FIG. 7  is a sectional view along lines  7 - 7  in  FIG. 6 ; 
         FIG. 8  illustrates a top view of a main body member of the current limiting device of  FIG. 5 ; 
         FIG. 9  is a sectional view along lines  9 - 9  in  FIG. 8 ; 
         FIG. 10  is a sectional view along lines  10 - 10  in  FIG. 8 ; 
         FIG. 11  is a sectional view along lines  11 - 11  in  FIG. 8 ; 
         FIG. 12  illustrates an exemplary embodiment of the current limiting device of  FIG. 4 ; 
         FIG. 12A  illustrates an exemplary installation site for the current limiting device of  FIG. 12 ; 
         FIG. 13  is a sectional view along lines  13 - 13  in  FIG. 12 ; 
         FIG. 14  illustrates an exploded assembly view of an exemplary embodiment of the current limiting device of  FIG. 3 ; 
         FIG. 15  illustrates a perspective, assembled view of the current limiting device of  FIG. 14 ; 
         FIG. 16  illustrates the current limiting device of  FIG. 14  assembled to an exterior wall of the serviceable unit and positioned in a shipping configuration; 
         FIG. 17  illustrates the current limiting device of  FIG. 14  assembled to an exterior wall of the serviceable unit and positioned in an operation configuration; 
         FIG. 18  illustrates a portion of the exterior wall of the serviceable unit adapted to couple the current limiting device of  FIG. 15 ; and 
         FIG. 19  illustrates an exemplary embodiment of the current limiting device of  FIG. 2 ; 
         FIG. 20  illustrates a bottom view of the current limiting device of  FIG. 19 ; and 
         FIG. 21  is an exemplary sequence of use of the disclosed current limiting devices. 
     
    
    
     Corresponding reference characters indicate corresponding parts throughout the several views. Although the drawings represent embodiments of various features and components according to the present disclosure, the drawings are not necessarily to scale and certain features may be exaggerated in order to better illustrate and explain the present disclosure. The exemplification set out herein illustrates embodiments of the invention, and such exemplifications are not to be construed as limiting the scope of the invention in any manner. 
     DETAILED DESCRIPTION OF THE DRAWINGS 
     For the purposes of promoting an understanding of the principles of the invention, reference will now be made to the embodiments illustrated in the drawings, which are described below. The embodiments disclosed below are not intended to be exhaustive or limit the invention to the precise form disclosed in the following detailed description. Rather, the embodiments are chosen and described so that others skilled in the art may utilize their teachings. It will be understood that no limitation of the scope of the invention is thereby intended. The invention includes any alterations and further modifications in the illustrated devices and described methods and further applications of the principles of the invention which would normally occur to one skilled in the art to which the invention relates. 
     As used herein, the term “serviceable unit” is defined to mean a device including a positive electrical terminal connection, a negative electrical terminal connection and a plurality of energy storage devices electrically coupled to the positive electrical terminal connection and the negative electrical terminal connection. Referring to  FIGS. 1 and 1A , an exemplary serviceable unit  100  is shown. Serviceable unit  100  includes a housing  101  which supports a plurality of energy storage units  102 , illustratively energy storage unit  102 A and  102 B are shown. Exemplary energy storage units include batteries. Exemplary batteries include lithium ion batteries. Exemplary energy storage units include prismatic battery cells. Exemplary serviceable units  100  are disclosed in PCT Published Application No. WO2012/167269, application number PCT/US2012/040776, filed Jun. 4, 2012, titled ENERGY STORAGE SYSTEM and in PCT Published Application No. WO2012/158185, application number PCT/US2011/052169, filed Sep. 19, 2011, titled ENERGY STORAGE SYSTEM, the disclosures of which are expressly incorporated by reference herein. 
     In one embodiment, a fully charged open circuit voltage of the serviceable unit is about 192 volts (“V”). In one embodiment, a fully charged open circuit voltage of the serviceable unit is about 48 V. In one embodiment, a fully charged open circuit voltage of the serviceable unit is about 96 V. In one embodiment, a fully charged open circuit voltage of the serviceable unit is between about 12 V and about 192 V. In one embodiment, a fully charged open circuit voltage of the serviceable unit is between about 24 V and about 192 V. In one embodiment, a fully charged open circuit voltage of the serviceable unit is between about 48 V and about 192 V. In one embodiment, a fully charged open circuit voltage of the serviceable unit is between about 12 V and about 96 V. In one embodiment, a fully charged open circuit voltage of the serviceable unit is between about 12 V and about 48 V. In one embodiment, a fully charged open circuit voltage of the serviceable unit is between about 24 V and about 48 V. In one embodiment, the serviceable units disclosed in PCT Published Application No. WO2012/167269, application number PCT/US2012/040776, filed Jun. 4, 2012, titled ENERGY STORAGE SYSTEM and in PCT Published Application No. WO2012/158185, application number PCT/US2011/052169, filed Sep. 19, 2011, titled ENERGY STORAGE SYSTEM provide fully charged open circuit voltages in these ranges. 
     Although two energy storage units  102  are illustrated, serviceable unit  100  may include any number of energy storage units. Further, the illustrated energy storage units are shown electrically connected in series through connection  104 . The energy storage units of serviceable unit  100  may be electrically coupled together in series, in parallel, and in combinations of series and parallel. 
     Serviceable unit  100  includes a positive electrical terminal connection  108  electrically coupled to the energy storage units  102  through connection  110  and a negative electrical terminal connection  112  electrically coupled to the energy storage units  102  through connection  114 . 
     Referring to  FIGS. 2 and 2A , an exemplary current limiting device  150  is illustrated. Current limiting device  150  includes a recess  152  which receives positive electrical terminal connection  108  of serviceable unit  100 . Current limiting device  150  includes at least one current limiting component which limits the amount of current that may inrush into energy storage units  102 . Exemplary current limiting components include resistors, fuses, and other suitable devices for limiting the current through the electrical path of positive electrical terminal connection  108 , the energy storage devices  102 , and negative electrical terminal connection  112 . An exemplary embodiment of current limiting device  150  is illustrated and described herein in connection with  FIGS. 5-11 . Another exemplary embodiment of current limiting device  150  is illustrated and described herein in connection with  FIGS. 19 and 20 . 
     Referring to  FIGS. 3 and 3A , an exemplary current limiting device  160  is illustrated. Current limiting device  160  is provided in the electrical connection  104  between energy storage device  102 A and energy storage device  102 B. Current limiting device  160  includes at least one current limiting component which is included in electrical connection  104  to limit the amount of current that may inrush into energy storage units  102 . Exemplary current limiting components include resistors, fuses, and other suitable devices for limiting the current through the electrical path of positive electrical terminal connection  108 , the energy storage devices  102 , and negative electrical terminal connection  112 . Although current limiting device  160  is illustrated as being provided in the electrical connection  104 , alternatively it may be provided in electrical connection  110  or in electrical connection  114 . 
     In the illustrated embodiment, current limiting device  160  extends out from a wall  103  of housing  101  and is actuatable by an operator. The operator may manipulate current limiting device  160  to a first configuration wherein the current limiting component is included in the electrical connection  104  to limit the amount of current and a second configuration wherein the current limiting component is not included in the electrical connection 1-4 and current is still able to flow between energy storage device  102 A and energy storage device  102 B. An exemplary embodiment of current limiting device  160  is illustrated and described herein in connection with  FIGS. 14-18 . 
     Referring to  FIGS. 4 and 4A , an exemplary current limiting device  170  is illustrated. Current limiting device  170  is provided in the electrical connection  104  between energy storage device  102 A and energy storage device  102 B. Current limiting device  170  includes at least one current limiting component which is included in electrical connection  104  to limit the amount of current that may inrush into energy storage units  102 . Exemplary current limiting components include resistors, fuses, and other suitable devices for limiting the current through the electrical path of positive electrical terminal connection  108 , the energy storage devices  102 , and negative electrical terminal connection  112 . Although current limiting device  170  is illustrated as being provided in the electrical connection  104 , alternatively it may be provided in electrical connection  110  or in electrical connection  114 . An exemplary embodiment of current limiting device  170  is illustrated and described herein in connection with  FIGS. 12 and 13 . 
     In one embodiment, a 0.25 W current limiting component is to be used for current limiting device  150 , current limiting device  160 , and current limiting device  170 . A first exemplary current limiting component is a 20 kilo-ohm, 0.25 W resistor. A second exemplary current limiting component is a PICO II brand form factor, fast 1 A, 125V axial fuse (part no. 0251001.MXL available from Little Fuse). 
     In one embodiment, wherein the current limiting component is a resistor, the resistance value is determined based on equation 1: 
     
       
         
           
             
               
                 
                   W 
                   = 
                   
                     
                       V 
                       2 
                     
                     R 
                   
                 
               
               
                 
                   ( 
                   1 
                   ) 
                 
               
             
           
         
       
     
     wherein W is the derated power value of the component in Watts (for a 0.25 W resistor, a derated value of 50% is used in one example), V is the voltage of the serviceable unit in Volts, and R is the resistance of the current limiting component in ohms. As an example, with a derated power of 0.125 W and a voltage of 100V, the resistance value should be about 80 kilo-ohms. 
     Referring to  FIG. 5 , an exemplary current limiting device  200  is shown. Current limiting device  200  includes a cover  202 , a current limiting component  204 , a foam adhesive component  206 , a terminal lock component  208 , and a retainer  210 . Cover  202  includes a cavity  212  which receives positive electrical terminal connection  108  (see  FIG. 7 ) and terminal lock component  208 . Terminal lock component  208  causes current limiting device  200  to be coupled to positive electrical terminal connection  108  through a friction fit. Other methods of coupling current limiting device  200  to positive electrical terminal connection  108  may be used. 
     Cover  202  includes a recess  214  which receives current limiting component  204 . Foam adhesive component  206  generally maintains the position of current limiting component  204  in recess  214 . In one embodiment, current limiting device  200  is assembled as follows. Current limiting component  204  is placed in recess  214 . Foam adhesive component  206  and terminal lock component  208  are received in cavity  212 . Retainer  210  (illustratively a screw) is threaded into a threaded opening  224  of cover  202 . 
     Current limiting device  200  is then press fit onto positive electrical terminal connection  108 . As shown in  FIG. 7 , a first lead wire  220  of current limiting component  204  is held in contact with positive electrical terminal connection  108 . A second lead wire  222  of current limiting component  204  is held in contact with retainer  210 . As such, retainer  210  is electrically coupled to positive electrical terminal connection  108 . An operator may cause a short circuit of serviceable unit  100  by placing an electrical conductor on negative electrical terminal connection  112  and on retainer  210 . The current limiting component  204  will limit the inrush of current to energy storage devices  102  due to the short circuit. In the case of a fuse, the fuse will blow creating an open circuit once a current threshold of the fuse is reached. Once the fuse blows, the voltage difference between positive electrical terminal connection  108  and negative electrical terminal connection  112  cannot be measured until current limiting device  200  removed. In the case of a resistor, the resistor limits the amount of current that will flow through energy storage devices  102 . The use of the resistor permits the voltage difference between positive electrical terminal connection  108  and negative electrical terminal connection  112  to continue to be measured. However, if the short circuit condition is allowed to continue, over time the voltage of the energy storage units  102  will be drained to about 0 volts. 
     In one embodiment, terminal lock component  208  is made from an electrically conductive material having a known resistance. In this embodiment, a separate current limiting component  204  is not needed. Rather, terminal lock component  208  forms the contact with positive electrical terminal connection  108  and provides a contact surface  230 . An operator may cause a short circuit of serviceable unit  100  by placing an electrical conductor on negative electrical terminal connection  112  and on contact surface  230  of terminal lock component  208 . 
     Referring to  FIGS. 19 and 20 , an exemplary current limiting device  600  is shown. Current limiting device  600  includes a base or cover  602 , a terminal connector  604 , a terminal  610 , and a current limiting component  612 . Terminal connector  604  is electrically coupled to one side of current limiting component  612  and terminal  610  is electrically coupled to another side of the current limiting component  612  resulting in the current limiting component  612  being in the electrical path between the terminal connector  604  and terminal  610 . 
     Terminal connector  604 , current limiting component  612 , and terminal  610  are assembled and are received in a pocket in base  602 . The pocket is filled with an epoxy potting material  614  to secure the components. Terminal connector  604  includes a cavity  607  which receives positive electrical terminal connection  108  or negative terminal connection  112 . Terminal connector  604  further includes a plurality of slots  608  which permit the end of terminal connector  604  to expand as the respective one of the positive electrical terminal connection  108  or negative terminal connection  112  is received. Further, the walls of the terminal connector  604  include rib features  606  which extend inward and grip the respective one of the positive electrical terminal connection  108  or negative terminal connection  112  when received in cavity  607 . As such, terminal connector  604  causes current limiting device  600  to be coupled to the respective one of positive electrical terminal connection  108  and negative terminal connection  112  through a friction fit. Other methods of coupling current limiting device  600  to the respective one of positive electrical terminal connection  108  and negative terminal connection  112  may be used. 
     Terminal  610  extends from a side of base  602 . Terminal  610  is illustratively shown as a lug, but may be a stud or other suitable shapes. Terminal  610  includes an aperture  616 . 
     In operation, current limiting device  600  is press fit onto positive electrical terminal connection  108  placing terminal  610  in electrical connection with positive electrical terminal connection  108 . An operator may cause a short circuit of serviceable unit  100  by placing an electrical conductor on negative electrical terminal connection  112  and on terminal  610 . The current limiting component  204  will limit the inrush of current to energy storage devices  102  due to the short circuit. In the case of a fuse, the fuse will blow creating an open circuit once a current threshold of the fuse is reached. Once the fuse blows, the voltage difference between positive electrical terminal connection  108  and negative electrical terminal connection  112  cannot be measured until current limiting device  200  removed. In the case of a resistor, the resistor limits the amount of current that will flow through energy storage devices  102 . The use of the resistor permits the voltage difference between positive electrical terminal connection  108  and negative electrical terminal connection  112  to continue to be measured. However, if the short circuit condition is allowed to continue, over time the voltage of the energy storage units  102  will be drained to about 0 volts. 
     Referring to  FIG. 12 , an exemplary current limiting device  300  is shown. Current limiting device  300  includes a cover  302 , a current limiting component  304 , an adhesive component  306 , and a pair of retainers  310 . Cover  302  includes a pocket  320  which receives current limiting component  304 . Adhesive component  306  holds current limiting component  304  in pocket  320 . Ramp surfaces  322  and  324  lead into pocket  320  and retain lead wires  326  and  328 , respectively. The ramp surfaces  322  and  324  result in lead wires  326  and  328  extending above surface  330  of cover  302 . 
     Referring to  FIG. 12A , an exemplary installation for current limiting device  300  is shown. Prior to installation, current limiting component  304  is received in pocket  320  and adhesive component  306  secures current limiting component  304  in place. The ends of lead wires  326  and  328  are trimmed to the appropriate lengths. 
     Referring to  FIG. 12A , a circuit board  190  of serviceable unit  100  is shown. Circuit board  190  includes a contact pad  192  and a contact pad  194 . Contact pad  192  is positioned to generally make contact with lead wire  326  of current limiting component  304 . Contact pad  194  is positioned to make contact with lead wire  328  of current limiting device  300 . Retainers  310  are then threaded into threaded openings  196  and  198  to secure current limiting device  300  in place. 
     At this point, energy storage unit  102 A is electrically coupled to energy storage unit  102 B. An operator may cause a short circuit of serviceable unit  100  by placing an electrical conductor on negative electrical terminal connection  112  and on negative electrical terminal connection  112 . The current limiting component  304  will limit the inrush of current to energy storage devices  102  due to the short circuit. In the case of a fuse, the fuse will blow creating an open circuit once a current threshold of the fuse is reached. Once the fuse blows, the voltage difference between positive electrical terminal connection  108  and negative electrical terminal connection  112  cannot be measured until current limiting device  300  removed and replaced with an electrical conductor. In the case of a resistor, the resistor limits the amount of current that will flow through energy storage devices  102 . The use of the resistor permits the voltage difference between positive electrical terminal connection  108  and negative electrical terminal connection  112  to continue to be measured. However, if the short circuit condition is allowed to continue, over time the voltage of the energy storage units  102  will be drained to about 0 volts. 
     Referring to  FIG. 14 , an exemplary current limiting device  400  is shown. Current limiting device  400  includes a carrier  402 , an insulator  404 , and a buss bar  406 . Carrier  402  includes a body  407  having coupled thereto a first copper pad  408  and a second copper pad  410 . The first copper pad  408  and the second copper pad  410  are electrically coupled together through a current limiting component  412  carried by body  407 . 
     Referring to  FIG. 15 , buss bar  406  includes a first end  420  and a second end  422 . When carrier  402 , insulator  404 , and buss bar  406  are assembled together, first end  420 , second end  422 , buss bar  406 , and first copper pad  408  all generally have the same radial extent. As such, current limiting device  400  may be coupled to wall  103  in a recess  176  of wall  103 . Wall  103  may include electrical contacts positioned generally 180 degrees apart relative to a central axis of the recess. By rotating current limiting device  400  relative to wall  103  cover  302 , either first end  420  and second end  422  may be placed in electrical communication with energy storage device  102 A and energy storage device  102 B (see  FIG. 17 ) or buss bar  406  and first copper pad  408  may be placed in electrical communication with energy storage device  102 A and energy storage device  102 B (see  FIG. 16 ). 
     Referring to  FIG. 18 , recess  176  may include tabs  184  to press the respective electrical contacts of current limiting device  400  into contact with the electrical contacts of serviceable unit  100 . Further, recess  176  may include detents  182  which lock current limiting device  400  in either the orientation shown in  FIG. 16  or the orientation shown in  FIG. 17 . 
     Since in the orientation shown in  FIG. 16 , current limiting component  412  is in electrical communication with energy storage devices  102 A and  102 B, current limiting component  412  limits the amount of current during a short circuit condition. This configuration is referred to as a shipping configuration. In the orientation shown in  FIG. 17 , current limiting component  412  is not in electrical communication with energy storage devices  102 A and  102 B, current limiting component  412  does not limit the amount of current. Rather, the current flows through buss bar  406 . This configuration is referred to as a use configuration. 
     Referring to  FIG. 21 , an exemplary method of use of the current limiting devices disclosed herein is shown. The current limiting device is placed in the electrical path of the serviceable unit, as represented by block  500 . In the case of current limiting device  200 , current limiting device  200  is assembled to either positive electrical terminal connection  108  or negative electrical terminal connection  112 . In the case of current limiting device  300 , current limiting device  300  replaces an electrical conductor and contacts contact pads  192  and  194 . In the case of current limiting device  400 , current limiting device  400  is turned to the orientation shown in  FIG. 16 . 
     The assembly of serviceable unit  100  and the respective current limiting device is subjected to altitude testing, as represented by block  502 . An exemplary altitude test is that the assembly of serviceable unit  100  and the respective current limiting device are stored for a minimum of 6 hours at a pressure of 11.6 kPa and a temperature of 20° C. After the altitude test is complete, characteristics of the assembly are measured, as represented by block  504  In one embodiment, the assembly passes the altitude test if no mass loss is recorded, a post test voltage between positive electrical terminal connection  108  and negative electrical terminal connection  112  is not less than 90% of a pre test voltage between positive electrical terminal connection  108  and negative electrical terminal connection  112  and a thermal event has not occurred. Exemplary thermal events include disassembly, rupture, or fire. 
     The assembly of serviceable unit  100  and the respective current limiting device is subjected to thermal cycling testing, as represented by block  506 . An exemplary thermal cycling test is that the assembly of serviceable unit  100  and the respective current limiting device are stored for a minimum of 6 hours at +75° C. followed by 6 hours at −40° C. with a 30 minute transition between temperature extremes. This cycle is repeated 10 times. After the thermal cycling test is complete, characteristics of the assembly are measured, as represented by block  508 . In one embodiment, the assembly passes the thermal cycling test if no mass loss is recorded, a post test voltage between positive electrical terminal connection  108  and negative electrical terminal connection  112  is not less than 90% of a pre test voltage between positive electrical terminal connection  108  and negative electrical terminal connection  112  and a thermal event has not occurred. Exemplary thermal events include disassembly, rupture, or fire. 
     The assembly of serviceable unit  100  and the respective current limiting device is subjected to vibration testing, as represented by block  510 . An exemplary vibration test is that the assembly of serviceable unit  100  and the respective current limiting device are mounted in a vibration test fixture and vibrated according to a logarithmic sweep between 7 Hz and 200 Hz and back to 7 Hz in 15 minutes. This cycle is repeated 12 times for a total of 3 hours for each of 3 mutually perpendicular mounting positions. Peak acceleration is 8 gn. After the vibration test is complete, characteristics of the assembly are measured, as represented by block  512 . In one embodiment, the assembly passes the vibration test if no mass loss is recorded, a post test voltage between positive electrical terminal connection  108  and negative electrical terminal connection  112  is not less than 90% of a pre test voltage between positive electrical terminal connection  108  and negative electrical terminal connection  112  and a thermal event has not occurred. Exemplary thermal events include disassembly, rupture, or fire. 
     The assembly of serviceable unit  100  and the respective current limiting device is subjected to shock testing, as represented by block  514 . An exemplary shock test is that the assembly of serviceable unit  100  and the respective current limiting device are mounted in a shock test fixture and experience three shocks per direction (positive and negative) in each axis, for a total of 18 shocks. (cell level: 150 g for 6 ms, pack level (multiple cells housed together) 50 g for 6 ms) After the shock test is complete, characteristics of the assembly are measured, as represented by block  516 . In one embodiment, the assembly passes the shock test if no mass loss is recorded, a post test voltage between positive electrical terminal connection  108  and negative electrical terminal connection  112  is not less than 90% of a pre test voltage between positive electrical terminal connection  108  and negative electrical terminal connection  112  and a thermal event has not occurred. Exemplary thermal events include disassembly, rupture, or fire. 
     The assembly of serviceable unit  100  and the respective current limiting device is subjected to short circuit testing, as represented by block  518 . An exemplary short circuit test is that the assembly of serviceable unit  100  and the respective current limiting device are conditioned at 55° C. is subjected to a short circuit condition with an external circuit resistance of less than 0.1 ohm for at least one hour after the external case temperature has returned to 55° C. Observation continues for six hours. After the short circuit test is complete, characteristics of the assembly are measured, as represented by block  520 . In one embodiment, the assembly passes the short circuit test if a temperature of the exterior of the assembly remains less than 170 degrees C. and a thermal event has not occurred. Exemplary thermal events include disassembly, rupture, or fire. 
     Once testing is complete, the current limiting device is removed from the electrical path of the serviceable unit, as represented by block  522 . In the case of current limiting device  200 , current limiting device  200  is disassembled from either positive electrical terminal connection  108  or negative electrical terminal connection  112 . In the case of current limiting device  300 , current limiting device  300  is removed and replaced with an electrical conductor which contacts contact pads  192  and  194 . In the case of current limiting device  400 , current limiting device  400  is turned to the orientation shown in  FIG. 17 . 
     While this invention has been described as having an exemplary design, the present invention may be further modified within the spirit and scope of this disclosure. This application is therefore intended to cover any variations, uses, or adaptations of the invention using its general principles. Further, this application is intended to cover such departures from the present disclosure as come within known or customary practice in the art to which this invention pertains.