Patent Publication Number: US-2023142500-A1

Title: Battery modules with anti-arcing, hot swapping, and/or self-disabling features

Description:
TECHNICAL FIELD 
     The present disclosure relates to battery modules for powering equipment, and in particular relates to battery modules with anti-arcing, hot swapping, and/or self-disabling features. 
     BACKGROUND 
     Batteries have become increasingly important, with a variety of industrial, commercial, and consumer applications. Interest and research in batteries has resulted in a variety of battery chemistries, with differing benefits and drawbacks. For example, “flooded” lead-acid batteries tend to be more economical, but may require periodic maintenance such as replenishment of an electrolyte, which can spill. “Sealed” lead-acid batteries may require periodic maintenance via charging or “overcharging” of the battery to prevent stratification. Alternative lead-acid batteries may use a gelled electrolyte, which cannot spill and avoid acid liberation problems, but have their own drawbacks in that the internal resistance may be higher, limiting the ability of such batteries to deliver high currents. 
     Lithium-ion batteries are another kind of battery chemistry, which have been consistently gaining market share in an ever-growing list of applications. This growth has been spurred by many advantages that lithium-ion technology offers, such as a lower total cost of ownership, an increased power density, a lighter weight, an increased energy density, and a higher specific energy. One particular area of growth for the deployment of lithium-ion batteries has been in battery backup and energy storage systems for communication sites (e.g., telecommunications base stations) and data centers. Integration of lithium-ion technology presents new challenges, especially as global reliance on power for telecommunications, data centers, and energy storage continues to rise. 
     SUMMARY 
     Some aspects of the present disclosure provide an electrical power system configured to provide backup electrical power to a load. The electrical power system may include a battery rack having a bus configured to provide power. The system may include a battery module configured to couple with the bus and receive power therefrom, the battery module may include battery cells coupled to a pre-charge electrical path and a main electrical path, and a module controller configured to: detect that the battery module has been inserted into the battery rack, and pre-charge the battery cells of the battery module via the pre-charge electrical path until a voltage level of the battery cells may be synchronized with a voltage level of the bus. Methods and devices according to the electrical power system are also provided. 
     Some aspects of the present disclosure provide an electrical power system configured to provide backup electrical power to a load. The electrical power system may include a battery rack having a bus configured to provide power. The system may include a battery module configured to couple with the bus and receive power therefrom, the battery module may include battery cells coupled to a main electrical path, and a module controller configured to: detect a disconnect action indicating a future removal of the battery module from the battery rack, and open at least one switch along the main electrical path in response to the detection of the disconnect action and prior to the removal of the battery module from the battery rack. Methods and devices according to the electrical power system are also provided. 
     Some aspects of the present disclosure provide an electrical power system configured to provide backup electrical power to a load. The electrical power system may include a battery rack having a bus configured to provide power. The system may include a battery module configured to couple with the bus and receive power therefrom, the battery module may include battery cells coupled to a main electrical path, and a module controller configured to: detect that the battery module has been removed from the battery rack in a potentially unauthorized manner, and open at least one switch along the main electrical path in response to the detection of the removal of the battery module from the battery rack. Methods and devices according to the electrical power system are also provided. 
     The present disclosure is not limited to the aspects explicitly recited above, and others will be disclosed or be apparent to those of skill in the art. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         FIG.  1    is a block diagram of an energy storage/battery backup system. 
         FIG.  2 A  is a perspective view of one of the battery modules of  FIG.  1   . 
         FIG.  2 B  is a block diagram of one of the battery modules of  FIG.  1   . 
         FIG.  3 A  is a block diagram of the battery module of  FIGS.  2 A-B  during an initialization and/or pre-charging operation. 
         FIG.  3 B  is a block diagram of the battery module of  FIGS.  2 A-B  in a state of operation subsequent to the initialization and/or pre-charging operation of  FIG.  3 A . 
         FIG.  4    is a block diagram of the battery module of  FIGS.  2 A-B  illustrating aspects of an unexpected and/or unauthorized removal of the battery module from a battery rack. 
         FIG.  5    is a schematic diagram of a balancing circuit of the battery cells of  FIG.  4   . 
         FIGS.  6 - 8    are flowcharts illustrating aspects of various methods of controlling and/or operating the system of  FIG.  1    and/or the battery module of  FIGS.  2 A- 5   . 
         FIG.  9    is a block diagram of a microcontroller that may be used in the system of  FIG.  1    and/or the battery module of  FIGS.  2 A- 5   . 
     
    
    
     Herein, like reference numerals refer to corresponding parts throughout the drawings. Moreover, multiple instances of the same part may be designated by a common prefix separated from an instance number by a dash. 
     DETAILED DESCRIPTION 
     The present disclosure is based on the recognition that the adoption of new storage systems of electrical energy by customers in various applications may in some cases be slowed or halted by marketplace and design considerations. For example, uptime for telecommunications equipment is increasingly important. Service interruptions to install, upgrade, and/or perform maintenance on components of a cellular base station or a network operations center can be highly costly and/or frustrating to affected customers. It is therefore increasingly important that downtime be minimized. Present-day systems do not adequately address this need. 
     For example, state of the art backup battery systems are typically not hot swappable, and trained personnel and strict policies/procedures are deployed in order to perform commissioning and installation tasks of the battery systems. Such tasks typically consist of preconditioning batteries before connecting them to the electrical distribution system. This preconditioning can take significant time, resulting in high labor costs and/or loss of revenue from downtime. 
     In more detail, energy storage for telecommunications equipment often includes at least one rack, each having one or more battery modules and a rack controller (which may be integrated into one of the battery modules). It can be a lengthy process to install battery modules in a rack and/or to perform maintenance on the battery modules of the rack. For example, the rack may have a rack voltage, and a battery module to be installed or re-installed may have a different battery module voltage (that may be much lower than the rack voltage). When the battery module is installed or re-installed, an imbalance in voltage between the rack (i.e., the rack voltage) and the battery module (i.e., the battery module voltage) may result in an inrush of current into the battery module, potentially resulting in a dangerous electrical arc or damage to the rack or newly installed battery module. 
     To address the above and other problems, as well as other technical problems, the present disclosure provides battery modules and electrical power systems that include the battery modules. The battery modules have a design that addresses the need for installation, maintenance, upgrades, and removal of battery modules without service interruption through the inclusion of anti-arcing and/or “hot swappable” features. 
     Within battery systems, scheduled maintenance periods are only one source of downtime. Unfortunately, another source of downtime stems from the theft of battery modules, in part because the lithium-ion batteries therein have a high value. Battery modules according to the present disclosure, in being easier and/or safer to install and remove from a battery rack, may be actually more susceptible to theft. To address such problems, as well as other technical problems, in some embodiments battery modules according to the present disclosure may include (or may also include) a self-disabling anti-theft feature that results in a battery module being incapable of providing power if removed from the electrical power system in an unauthorized manner. 
     An example embodiment of an electrical power system  100  is provided in  FIG.  1   . The electrical power system  100  may include a battery rack  110  that may be configured to provide backup electrical power to a load  160 , which may be e.g., telecommunications equipment (e.g., a telecommunications station). The electrical power system  100  may be coupled to a grid or main power source  150 . In some embodiments, the electrical power system  100  may include a converter (or rectifier)  140  to convert an alternating current (AC) power signal received from the grid or main power source  150  into a direct current (DC) signal that is supplied to the load  160  and to the battery rack  110 . In some embodiments, the battery rack  110  may be in series between the grid or main power source  150  and the load  160  and as such may include the rectifier  140  therein. 
     The battery rack  110  may include one or more (and preferably, two or more) battery modules  120 . The battery modules  120  may be connected in series or in parallel to a bus or power line  113  within the battery rack  110 . The battery rack  110  may also include at least one rack controller  130  that controls operations of the battery rack  110 . For example, the rack controller  130  may include a microprocessor controller that monitors and/or controls system parameters of the battery rack  110  and/or the battery modules  120  thereof, such as voltages (input and/or output voltages), currents (input and/or output currents), temperatures (internal and external to the battery modules  120 ), and so on. In some embodiments, the rack controller  130  may be connected to an external network (not shown) to provide remote monitoring and/or control of the battery rack  110  to an operator at a remote location from the installation site of the battery rack  110 . 
     An example of one of the one or more battery modules  120  is shown in  FIG.  2 A , a perspective view of the exterior of the battery module  120 , and  FIG.  2 B , a block diagram of the battery module  120 . 
     The battery module  120  may include a housing  211  that is configured to mount within the battery rack  110 . 
     Within the housing  211 , the battery module  120  may include one or more battery cells  210 , which may be lithium-ion battery cells in some embodiments. The battery cells  210  may be in any of a combination of series and parallel configurations, and may provide collectively a total voltage and/or capacity for the battery module  120 . Different battery modules  120  in a battery rack  110  may have different capacities and/or voltages. 
     The battery module  120  may also include within the housing  211  a module controller  220 , which in some embodiments may be controlled via a control panel  212  available on an exterior of the housing  211 . The module controller  220  may be coupled to temperature, current, and/or voltage sensing circuits (not shown) within the battery module  120  and may be configured to control operations of the battery module. In some embodiments the module controller  220  may be or may include a battery management system (BMS). According to the present disclosure, the module controller  220  may be configured to control the opening and closing of first and second main switches  221  and  222  within the housing  211 . 
     Each of the first and second main switches  221  and  222  may be or may include a contactor, solid state switch, or other mechanisms that may be opened or closed responsive to a signal from the module controller  220 . In some embodiments, commands to close or open the switches can also be initiated remotely via a communication port (e.g., communication port  229  discussed in greater detail below), and/or via a wireless interface of the module controller  220 . 
     When the first and second main switches  221  and  222  are closed, each may couple a respective contacts or terminals of the connector  228  at the exterior of the housing  211  to the battery cells  210 . More specifically, the first main switch  221 , when closed, may connect a first contact terminal  226  (e.g., a negative terminal) with the battery cells  210 , and the second main switch  222 , when closed, may connect a second contact or terminal  227  (e.g., a positive terminal) to the battery cells  210 . The first and second terminals  226  and  227  may be configured to couple to corresponding contacts of the battery rack  110  that provide an electrical path to the bus  113  within the battery rack  110 . Thus, when the first and second main switches  221  and  222  are closed, the battery cells  210  may be charged or discharged via an electrical path having the first contact or terminal  226 , the first main switch  221 , the battery cells  210 , the second main switch  222 , and the second contact or terminal  227 . 
     The battery module  120  may also include within the housing  211  a pre-charge circuit  223  that includes a pre-charge switch  224  and a variable resistor  225 , such as a rheostat. The battery module  120  may control the opening and closing of the pre-charge switch  224  and the variable resistance of the variable resistor  225 . 
     The pre-charge circuit  223  may be configured to prevent an in rush of current, such as that which would exceed a specified amount of current that may be input into the battery module  120  or the cells  210  thereof. Stated differently, the pre-charge circuit  223 , in coordination with the module controller  220 , may be configured to increase gradually incoming current to the battery module  120  from a pre-determined minimum value to a pre-determined maximum value and/or until the battery module voltage is synchronized with the bus voltage of the battery rack  110 . 
     Reference is now made to  FIGS.  3 A and  3 B , which are block diagram of the battery module of  FIGS.  2 A-B  during various states of operation, with  FIG.  3 A  illustrating a state of operation during an initialization and/or pre-charging operation, and  FIG.  3 B  illustrating a state of operation subsequent to the initialization and/or pre-charging operation of  FIG.  3 A . 
     Prior to the state of operation illustrated in  FIG.  3 A , an operator or technician present at the installation site may insert a battery module  120  into the battery rack  110 . The module controller  220  may detect the main bus voltage present on the first and second terminals  226  and  227 . The module controller  220  may be configured to cause the variable resistance of the variable resistor  225  to be set to a maximum resistance value, if not previously performed. 
     Then, the operator or technician may indicate that an initialization and/or pre-charging operation of the battery module  120  is to be performed. This may occur responsive to a user input at the rack controller  130  (which may be received from a remote source). As seen in  FIG.  3 A , the module controller  220  may then signal the second main switch  222  and the pre-charge switch  224  to close, thereby exposing the battery cells  210  and the pre-charge circuit  223  to the bus voltage of the battery rack  110 . Due to the presence of the variable resistor  225  set to the maximum resistance value, the amount of current passed to the battery cells  210  may be initially limited. 
     The module controller  220  may then gradually decrease or change the resistance of the variable resistor  225  thereby resulting in a gradual increase of the current through the battery cells  210 . The module controller  220  may periodically measure the voltage across the battery cells  210  and/or the current through the battery cells  210  and perform periodic comparisons between the bus voltage of the battery rack  110  and the voltage across the battery cells  210 . 
     As a result of the periodic comparisons, the module controller  220  may determine or decide that the bus voltage of the battery rack  110  is equal to the voltage across the battery cells  210 , and/or that the difference between the voltage across the battery cells  210  and the bus voltage is such that a damaging inrush of current would not occur if the battery cells  210  were exposed to the bus voltage. The initialization and/or pre-charging operation may thus be completed. As seen in  FIG.  3 B , the module controller  220  may then signal the first main switch  221  to close. In some embodiments, optionally the module controller  220  may signal the pre-charge switch  224  to open after the first main switch  221  is closed. 
     Accordingly, subsequent to the states of operation illustrated in  FIGS.  3 A and  3 B , the battery module  120  may be coupled to the bus  113  of the battery rack  110 , and the battery module  120  may have a voltage that is synchronized to the voltage of the bus  113 . 
     The presence and configuration of the pre-charge circuit  223  and the module controller  220  may enable a “hot swappable” insertion feature that may limit (e.g., may initially limit) the current flowing into a battery module  120  inserted into a battery rack  110 . This may allow for an initial mismatch to exist between the bus voltage of the battery rack  110  and the voltage across the battery cells  210 . 
     Returning to  FIG.  2 B , the module controller  220  may communicate with the rack controller  130  via a communication path, which may be a wired path coupled to a communication port  229  as shown in  FIG.  2 B , or may be a wireless path. 
     Referring to  FIGS.  2 A-B  and  3 A-B, it may be seen that there are two paths from the first terminal  226  to the battery cells  210 : a main path that includes the first main switch  221  and a pre-charge path that includes the pre-charge circuit  223 . In some embodiments, the main path and the first main switch  221  thereof may be optional, provided that the presence of the variable resistor  225  along the path from the first terminal  226  to the battery cells  210  is acceptable. 
     In some embodiments, the second main switch  222  may be optional. 
       FIGS.  2 A-B  and  3 A-B show the first terminal  226 , second terminal  227 , and the communication port  229  as components of the single common connector  228 , but in some embodiments the first terminal  226 , the second terminal  227 , and the communication port  229  may be integrated into two or three separate connectors. In some embodiments where a wireless data path between the battery module  120  and the rack controller  130  is used, the communication port  229  may be omitted. 
     In some embodiments, the battery module  120  and the module controller  220  thereof may be configured a “hot swappable” removal feature that may prevent or reduce a rate of occurrence of an electrical arc. For example, when removing a battery module  120  that is connected to an active bus  113  via closed first and second main switches  221  and  222 , and/or a closed pre-charge switch  224 , there may be a risk of arcing due to a breaking of the electrical current flow between the battery module  120  and the bus  113 . According to the present disclosure, the connectors for the battery can provide advanced warning to the module controller  220  a disconnect action has been requested, which may enable the module controller  220  to transmit a signal to the first and second main switches  221  and  222 , and/or the pre-charge switch  224  to open (if closed), and thereby enter into an anti-arcing or disconnected state. 
     Therefore, in some embodiments, the module controller  220  may be configured to open the first main switch  221 , the second main switch  222 , and/or the pre-charge switch  224  based on a disconnect signal received from the rack controller  130  (e.g., via a data path such as the wired path coupled to the communication port  229 ). The rack controller  130  may be configured to transmit the disconnect signal responsive to a command to disconnect the battery module  120  from the battery rack  110 . As a first example, a technician (or other individual) may input a command to the rack controller  130  indicating that the battery module  120  is to be removed from the battery rack  110 . In response, the module controller  220  may transmit the signal to the first and second main switches  221  and  222 , and/or the pre-charge switch  224  to open (if closed), and thereby enter into an anti-arcing or disconnected state. 
     As a second example, a technician (or other individual) may unlock or open a locking mechanism (not shown in the figures but present on either or both of the battery module  120  and the battery rack  110 ) that is configured to secure the battery module  120  within the battery rack  110 . The unlocking or opening of the locking mechanism may indicate an imminent removal of the battery module  120  from the battery rack  110 . In response to a sensing of the unlocking or opening of the locking mechanism, the module controller  220  may transmit the signal to the first and second main switches  221  and  222 , and/or the pre-charge switch  224  to open (if closed), and thereby enter into an anti-arcing or disconnected state. 
     In some embodiments, a component within the battery module  120  may be configured to generate and transmit the disconnect signal without the involvement of the rack controller  130 . For example, when the locking mechanism configured to secure the battery module  120  within the battery rack  110  is present on a housing  211  of the battery module  120 , the sensing of the unlocking or opening of the locking mechanism may be performed by the module controller  220 . As another example, the technician (or other individual) may input a command via the control panel  212  of the battery module  120  indicating that the battery module  120  is to be removed from the battery rack  110 . 
     In response to a disconnect action or disconnect signal, examples of which are provided above, the module controller  220  may be able to enter into an anti-arcing or disconnected state, preventing or reducing a rate of occurrence of electrical arcs that may arise from disconnecting the battery module  120  from an active bus of the battery rack  110 , especially when such removals are unexpected (e.g., a technician inadvertently unlocks and attempts to remove a second battery module  120 - 2  instead of an intended first battery module  120 - 1 ). 
     As discussed above, not all removals of the battery module  120  from the battery rack  110  may be authorized removals. According to some embodiments of the present disclosure, and referring to  FIGS.  4  and  5   , the battery module  120  may be equipped with an anti-theft disabling feature. 
     The battery module  120  may be configured to detect an unauthorized removal, for example, by the sensing of the unlocking or opening of the locking mechanism in an unexpected manner (e.g., without entry of a command by an authorized technician or other individual indicating that the battery module  120  is to be removed). In response, as discussed above, the module controller  220  may enter the battery module  120  into the disconnected state by transmitting the signal to the first and second main switches  221  and  222 , and/or the pre-charge switch  224  to open (if closed). 
     In some embodiments, the battery module  120  may include a position or location sensor S (e.g., a Global Positioning System (GPS) sensor) that provides position or location information to the module controller  220 . The module controller  220  may store in memory thereof expected geographic position or location information that indicates an expected location of the battery module  120  (for example, a latitude and longitude). In some embodiments, the module controller  220  may also store radius information indicating a radius corresponding to a circle centered on the expected location of the battery module  120  that may be considered as equivalent to the expected location of the battery module  120 . In some embodiments, data associated with a geometric fence may be stored. The geometric fence, which may be non-circular, may be defined by a sequence of GPS locations, and may bound an area equivalent to the expected geographic position or location of the battery module  120 . If the position or location sensor S provides to the module controller  220  position or location information that is not the expected location of the battery module  120  or is not equivalent to the expected location of the battery module  120  (e.g., the position or location information is outside the circle centered on the expected location of the battery module  120  or outside the geometric fence), then the module controller  220  may determine that the battery module  120  has been removed in an unauthorized fashion. As such, some false positives that may stem from an unexpected but authorized removal may be avoided. 
     Based on the detecting of the unauthorized removal, the module controller  220  may instantiate a timer that corresponds to a predetermined and/or configurable time window. 
     During the time window, the module controller  220  may be configured to receive user input from an authorized user or technician indicating an authorization code. In some embodiments, the authorization code may be a pre-determined sequence of button pushes and/or other user inputs, or a data transmission transmitted from an external device to the module controller  220  via a data path. For example, the authorized user or technician may re-insert the battery module  120  into the battery rack  110  and enter input into the rack controller  130 . 
     Entry of the authorization code may indicate to the module controller  220  that the removal of the battery module  120  into the battery rack  110  was authorized, or that the battery module  120  has been recovered in a timely manner. 
     After the time window has elapsed (e.g., after the timer instantiated by the module controller  220  exceeds a threshold value), if the authentication code has not been entered or received, the module controller  220  may initiate a self-disabling function to remove charge from the battery cells  210 . For example, the module controller  220  may activate a balancing circuit  233  within each battery cell  210 . An example of a balancing circuit  233  having a transistor  235  and a resistor  237  is shown in  FIG.  5   . When the transistor  235  is enabled, the charge from the battery cell may be depleted as resistive losses via the resistor  237 . In some embodiments, the balancing circuit  233  may be activated for a period of time such that the charge in the battery cell  210  is depleted below a minimum level (e.g., below a minimum open-circuit voltage), such that internal safety circuitry of the battery module  120  or battery cells  210  will not permit recharging of the battery cells  210 , resulting in the battery module  120  and battery cells  210  being unavailable for use. 
     In addition to the above-described systems and apparatuses, the present disclosure provides methods that facilitate the installing, maintaining, upgrading, and/or removing of battery modules without service interruption, as well as methods that facilitate the disabling of a battery module if removed from an electrical power system in an unauthorized manner. Examples of flowcharts illustrating aspects of various methods of controlling and/or operating the system of  FIG.  1    and/or the battery module of  FIGS.  2 A- 5    are described with reference to  FIGS.  6 - 8   . 
       FIG.  6    is a flowchart of a method  600  of performing an initialization and/or pre-charging operation on a battery module  120  inserted into or coupled with a battery rack  110 . 
     Prior to the method of  FIG.  6   , an operator or technician present at the installation site may insert a battery module  120  into the battery rack  110 . The module controller  220  may detect the main bus voltage present on the first and second terminals  226  and  227  (block  610 ). The module controller  220  may be configured to set the variable resistance of the variable resistor  225  to a maximum resistance value, if not previously performed (block  620 ). 
     The module controller  220  may then signal the pre-charge switch  224  to close, thereby exposing the battery cells  210  and the pre-charge circuit  223  to the bus voltage of the battery rack  110  (block  630 ). In embodiments where the second main switch  222  is present, the second main switch  222  may also be closed. In some embodiments, the closing of the pre-charge switch  224  (and second main switch  222 ) may be performed responsive to a user input at the rack controller  130  or battery module  120  (which may be received from a remote source). 
     The module controller then may receive measurements of the voltage across the battery cells  210  and/or the current through the battery cells  210  and perform periodic comparisons between the bus voltage of the battery rack  110  and the voltage across the battery cells  210  to determine or decide that the voltage across the battery cells  210  is synchronized with the bus voltage of the battery rack  110  (block  640 ). If the voltage is not synchronized (e.g., the difference between the voltage across the battery cells  210  and the bus voltage is such that a damaging inrush of current may occur if the battery cells  210  were exposed to the bus voltage) (“N” branch from block  640 ) then the module controller  220  may gradually decrease or change the resistance of the variable resistor  225  thereby resulting in a gradual increase of the current through the battery cells  210  (block  650 ). 
     If the voltage is synchronized (e.g., the difference between the voltage across the battery cells  210  and the bus voltage is such that a damaging inrush of current would not occur if the battery cells  210  were exposed to the bus voltage) (“Y” branch from block  640 ) then the module controller  220  may then signal the first main switch  221  to close (block  660 ). In some embodiments, optionally the module controller  220  may signal the pre-charge switch  224  to open after the first main switch  221  is closed (block  670 ). 
       FIG.  7    is a flowchart of a method  700  of performing an arc prevention operation associated with removal of a battery module  120  from a battery rack  110 . 
     The battery module  120  may be configured to detect that a disconnect action has been performed (block  710 ). For example, the battery module  120  may receive a disconnect signal in response to a command to disconnect the battery module  120  from the battery rack  110 . One example of a disconnect action may be a technician inputting a command to the rack controller  130  indicating that the battery module  120  is to be removed from the battery rack  110 . Another example of a disconnect action may be a technician (or other individual) unlocking or opening a locking mechanism that is configured to secure the battery module  120  within the battery rack  110 . The battery module  120  may be configured to detect these (and other) disconnect actions. 
     In response to detecting that a disconnect action has been performed, the module controller  220  may transmit a signal to open (if closed) the first and second main switches  221  and  222  and/or the pre-charge switch  224  (block  720 ), and thereby enter into an anti-arcing or disconnected state. 
       FIG.  8    is a flowchart of a method  800  of detecting an unauthorized removal of a battery module  120  from a battery rack  110  and disabling the battery module  120  after a time window. 
     The battery module  120  may detect a potentially unauthorized removal (block  810 ). As a first example, the battery module  120  may sense the unlocking or opening of a locking mechanism in an unexpected manner (e.g., without entry of a command by an authorized technician or other individual indicating that the battery module  120  is to be removed). In response, as discussed above, the module controller  220  may enter the battery module  120  into the disconnected state by transmitting the signal to the first and second main switches  221  and  222 , and/or the pre-charge switch  224  to open (if closed) (block  820 ). 
     Based on the detecting of the potentially unauthorized removal, the module controller  220  may instantiate a timer that corresponds to a predetermined and/or configurable time window (block  830 ). 
     During the time window, the module controller  220  may be configured to receive user input from an authorized user or technician indicating an authorization code (block  840 ). Entry of the authorization code may indicate to the module controller  220  that the removal of the battery module  120  from the battery rack  110  was in fact authorized, or that the battery module  120  has been recovered from an unauthorized removal in a timely manner (“Y” branch from block  840 ). 
     If the authentication code has not been correctly entered or received (“N” branch from block  840 ), the module controller  220  may determine whether the time window has elapsed (e.g., after the timer instantiated by the module controller  220  exceeds a threshold value) (block  850 ). If the timer has not elapsed (“N” branch from block  850 ), the module controller may wait for input. Once the timer has elapsed (“Y” branch from block  850 ), and the authentication code has not been entered or received, the module controller  220  may initiate a self-disabling function to remove charge from the battery cells  210  (block  860 ). In some embodiments, as discussed above, balancing circuits of the battery module  120  may be activated for a period of time such that the charge in the battery cells  210  thereof is depleted below a minimum level, resulting in the battery module  120  and battery cells  210  being unavailable for use. 
       FIG.  9    illustrates various components of a microcontroller  1600  which may be a computing device used in the implementation of one or more of the devices herein, such as the module controller  220  or the rack controller  130 .  FIG.  9    illustrates hardware elements that can be used in implementing any of the various computing devices discussed herein. In some aspects, general hardware elements may be used to implement the various devices discussed herein, and those general hardware elements may be specially programmed with instructions that execute the algorithms discussed herein. In special aspects, hardware of a special and non-general design may be employed (e.g., ASIC or the like). Various algorithms and components provided herein may be implemented in hardware, software, firmware, or a combination of the same. 
     A microcontroller  1600  may include one or more processors  1601 , which may execute instructions of a computer program to perform any of the features described herein. The instructions may be stored in any type of computer-readable medium or memory, to configure the operation of the processor  1601 . For example, instructions may be stored in a non-volatile memory  1602 , which may be a read-only memory and/or in a volatile memory, such as random-access memory (RAM)  1603 . In some embodiments, a removable media, such as a hard disk, Universal Serial Bus (USB) drive, compact disk (CD) or digital versatile disk (DVD), floppy disk drive, or any other desired electronic storage medium may be used. The microcontroller  1600  may be configured to provide output to one or more output devices (not shown) such as printers, monitors, display devices, and so on, and receive inputs, including user inputs, via input devices (not shown), such as a remote control, keyboard, mouse, touch screen, microphone, or the like. The microcontroller  1600  may also include input/output interfaces  1607  which may include circuits and/or devices configured to enable the microcontroller  1600  to communicate with external input and/or output devices (such as computing devices on a network) on a unidirectional or bidirectional basis. The components illustrated in  FIG.  9    (e.g., processor  1601 , non-volatile memory  1602 ) may be implemented using basic computing devices and components, and the same or similar basic components may be used to implement any of the other computing devices and components described herein. For example, the various components herein may be implemented using computing devices having components such as a processor executing computer-executable instructions stored on a computer-readable medium, as illustrated in  FIG.  9   . 
     Aspects of the present disclosure have been described above with reference to the accompanying drawings, in which embodiments of the inventive concepts are shown. It will be appreciated, however, that the inventive concepts may, however, be embodied in many different forms and should not be construed as limited to the embodiments set forth above. Rather, these embodiments are provided so that this disclosure will be thorough and complete, and will fully convey the scope of the inventive concepts to those skilled in the art. Like numbers refer to like elements throughout. 
     It will be understood that, although the terms first, second, etc. are used throughout this specification to describe various elements, these elements should not be limited by these terms. These terms are only used to distinguish one element from another. For example, a first element could be termed a second element, and, similarly, a second element could be termed a first element, without departing from the scope of the present inventive concepts. The term “and/or” includes any and all combinations of one or more of the associated listed items. 
     The terminology used herein is for the purpose of describing particular embodiments only and is not intended to be limiting of the invention. As used herein, the singular forms “a”, “an” and “the” are intended to include the plural forms as well, unless the context clearly indicates otherwise. It will be further understood that the terms “comprises” “comprising,” “includes” and/or “including” when used herein, specify the presence of stated features, integers, steps, operations, elements, and/or components, but do not preclude the presence or addition of one or more other features, integers, steps, operations, elements, components, and/or groups thereof. 
     In the drawings and specification, there have been disclosed typical embodiments of the inventive concepts and, although specific terms are employed, they are used in a generic and descriptive sense only and not for purposes of limitation, the scope of the inventive concepts being set forth in the following claims.