Patent Publication Number: US-11664538-B2

Title: Battery module with smart electronic isolation systems

Description:
CROSS REFERENCE TO RELATED APPLICATIONS 
     This patent application claims priority to U.S. Provisional Patent Application No. 62/892,809, filed Aug. 28, 2019, and entitled Battery Interlock Smart Close-In System. The entire contents of the aforementioned application is hereby incorporated herein by reference. 
    
    
     TECHNICAL FIELD 
     The present disclosure relates to battery modules. More specifically, the disclosure relates to battery modules having smart electronic isolation systems. 
     BACKGROUND 
     A battery module system is a set of any number of battery modules, wherein each battery module includes a battery pack. Each battery pack includes one or more battery cells. The battery modules of the battery module system may be electrically configured in series, parallel or a mixture of both to deliver the desired voltage, capacity, or power density required for any number of applications. Battery module systems are used in energy dense battery applications such as charging an electric vehicle (“EV”), powering heavy duty power tools, or the like. 
     The risk of assembling the battery modules of a battery module system may be low as long as the battery packs are equally matched. Battery packs may be precisely measured, calibrated and matched at the initial manufacturer for such parameters as internal resistance, initial voltage and state of charge (SOC). The battery modules may then be discharged at the factory down to a SOC that is legal for shipping (for example, between 30% to 60% of full charge) and shipped to their final destination, where the battery modules can be assembled into the desired battery module systems. 
     Problematically however, battery modules may have their SOC, internal resistance and other internal parameters inadvertently changed during shipment. For example, conductive materials may come into contact with the power contacts of the battery modules during shipment. Additionally, the battery modules may have their internal parameters altered at different rates or to different degrees during use. If the difference in internal parameters between two battery modules are unacceptably high, the risk of arcing, fire or other hazards grow significantly. 
     Further, if two battery modules are at a significantly different SOC, the battery module with the greater SOC will discharge into the battery module with the lesser SOC, and the total power output will drop significantly. Moreover, significantly different SOCs between battery modules may cause back flow currents, which can damage a battery module. 
     Accordingly, there is a need for a battery module that can prevent or inhibit making electrical contact with other battery modules (or other similar electrical devices) if their internal parameters are significantly different. Further, there is a need for a battery module that can prevent or inhibit back flow. Additionally, there is a need for a battery module system wherein the individual battery modules of the battery module system may selectively connect with each other depending on the differences in internal parameters of each battery module. 
     BRIEF DESCRIPTION 
     The present disclosure offers advantages and alternatives over the prior art by providing a battery module with an electronic isolation system electrically connected between the battery pack and the power contacts of the battery module and an electronic control system controlling the electronic isolation system. The electronic isolation system, controlled by the electronic control system, prevents the battery pack from connecting to the power contacts if one or more parameters from either the battery module or a second electrical device that is to be connected to the battery module are at an unacceptable value. For example, the electronic control system may prevent electrical contact between the battery pack and power connectors of a first battery module that is to be connected to a second battery module, if the SOCs of the first and second battery modules are outside of an acceptable range of value. Further, the battery modules may be assembled into a battery module system wherein each of the battery modules may selectively connect to the other battery modules depending on differences in their internal parameters. Additionally, the control system prevents or inhibits current back flow from the power connectors to the battery pack of a battery module. 
     A battery module in accordance with one or more aspects of the present disclosure includes a first set of power contacts and a first set of signal contacts. A battery pack is operable to deliver electrical power to the set of power contacts. An electronic isolation system is operable to electrically disconnect and electrically connect the battery pack and the first set of power contacts. An electronic control system is electrically connected to the electronic isolation system and to one of the first set of signal contacts and/or the first set of power contacts. The electronic control system is operable to obtain a first comparison between a state of charge of the battery module and an electrical device, obtain a second comparison between a state of health of the battery module and the electrical device, obtain a third comparison between a temperature of the battery module and the electrical device and obtain a fourth comparison between a power of the battery module and the electrical device. A closing parameter is calculated by the electronic control system that is based on the first comparison, the second comparison, the third comparison and/or the fourth comparison. The closing parameter is compared to a predefined closing parameter value to result in a connect determination as to whether it is desirable to connect the first battery module to the electrical device. The electronic isolation system connects the battery pack to the first set of power contacts based on a positive result of the connect determination. The electronic isolation system disconnects the battery pack and the first set of power contacts based on a negative result of the connect determination. 
     A battery module system in accordance with one or more aspects of the present disclosure includes a battery module system power bus and a plurality of battery modules. A first battery module of the plurality of battery modules includes a first set of power contacts electrically connected to the power bus, a first set of signal contacts and a first battery pack operable to deliver electrical power to the first set of power contacts. A first electronic isolation system is operable to electrically disconnect and connect the first battery pack and the first set of power contacts. A first electronic control system is electrically connected to the electronic isolation system and to the first set of signal contacts and/or the first set of power contacts. The electronic control system is operable to obtain a first comparison between a state of charge of the first battery module and a second battery module of the plurality of battery modules, obtain a second comparison between a state of health of the first battery module and the second battery module, obtain a third comparison between a temperature of the first battery module and the second battery module and obtain a fourth comparison between a power of the first battery module and the second battery module. A closing parameter is calculated based on the first comparison, the second comparison, the third comparison and/or the fourth comparison. The closing parameter is compared to a predefined closing parameter value to result in a connect determination as to whether it is desirable to connect the first battery module to the second battery module. The electronic isolation system connects the battery pack to the first set of power contacts based on a positive result of the connect determination. The electronic isolation system disconnects the battery pack and the first set of power contacts based on a negative result of the connect determination. 
     A computer implemented method of connecting a battery module to an electrical device, in accordance with one or more aspects of the present disclosure, includes measuring a temperature of a battery module and an electrical device with the at least one temperature sensor, measuring a current of the battery module and the electrical device with the at least one current sensor and measuring a voltage of the battery module and the electrical device with the at least voltage sensor. A state of charge, a state of health and a power of the battery module is calculated from at least one of the current, temperature or voltage of the battery module. A state of charge, a state of health and a power of the electrical device is calculated from at least one of the current, temperature or voltage of the electrical device. A first comparison is obtained between a state of charge of the battery module and the electrical device. A second comparison is obtained between a state of health of the battery module and the electrical device. A third comparison is obtained between a temperature of the battery module and the electrical device. A fourth comparison is obtained between a power of the battery module and the electrical device. A closing parameter is calculated based on the first, second, third and fourth comparisons. The closing parameter is compared to a predefined closing parameter value to result in a connect determination. 
    
    
     
       DRAWINGS 
       The disclosure will be more fully understood from the following detailed description taken in conjunction with the accompanying drawings, in which: 
         FIG.  1    depicts an example of a schematic of a battery module and its outside interfaces, according to aspects described herein; 
         FIG.  2    depicts an example of a schematic of an embodiment of power and communication systems of the battery module of  FIG.  1   , according to aspects described herein; 
         FIG.  3    depicts an example of a schematic of a control interface between a battery module (such as in  FIG.  1   ) and an electrical device, according to aspects described herein; 
         FIG.  4    depicts an example of a schematic of an embodiment of circuitry of an electrical control system, an electrical isolation system and a power flow control system of  FIG.  2   , according to aspects described herein; 
         FIG.  5    depicts an example of a schematic of an embodiment of a battery module system having a plurality of battery modules of  FIG.  1   , according to aspects described herein; 
         FIG.  6    depicts an example of a schematic of another embodiment of power and communication systems of the battery module of  FIG.  1   , according to aspects described herein; 
         FIG.  7    depicts an example of a schematic of another embodiment of circuitry of an electrical control system and an electrical isolation system of  FIG.  6   , according to aspects described herein; 
         FIG.  8    depicts an example of a schematic of another embodiment of a battery module system having a plurality of battery modules of  FIG.  1   , according to aspects described herein; and 
         FIG.  9    depicts an example of a flow diagram a method for connecting a battery module, such as the battery module of  FIG.  1   , to an electrical device, according to aspects described herein. 
     
    
    
     DETAILED DESCRIPTION 
     Certain examples will now be described to provide an overall understanding of the principles of the structure, function, manufacture, and use of the methods, systems, and devices disclosed herein. One or more examples are illustrated in the accompanying drawings. Those skilled in the art will understand that the methods, systems, and devices specifically described herein and illustrated in the accompanying drawings are non-limiting examples and that the scope of the present disclosure is defined solely by the claims. The features illustrated or described in connection with one example maybe combined with the features of other examples. Such modifications and variations are intended to be included within the scope of the present disclosure. 
     The terms “significantly”, “substantially”, “approximately”, “about”, “relatively,” or other such similar terms that may be used throughout this disclosure, including the claims, are used to describe and account for small fluctuations, such as due to variations in processing from a reference or parameter. Such small fluctuations include a zero fluctuation from the reference or parameter as well. For example, they can refer to less than or equal to ±10%, such as less than or equal to ±5%, such as less than or equal to ±2%, such as less than or equal to ±1%, such as less than or equal to ±0.5%, such as less than or equal to ±0.2%, such as less than or equal to ±0.1%, such as less than or equal to ±0.05%. 
     Referring to  FIG.  1   , an example is depicted of a schematic of a first battery module  100  and its outside interfaces, according to aspects described herein. The outside interfaces include one or more sets of power contacts  102  and one or more sets of signal contacts  104 . Each set of power contacts  102  may have one or more contacts that are operable to conduct power generated from a battery pack  106  (see  FIG.  2   ) to the battery module  100 . Each set of signal contacts  104  may have one or more contacts that are operable to communicate with, send and/or receive signals. 
     As an overview, battery modules, such as battery module  100 , may be electrically isolated from the outside world during transportation and storage to prevent the risk of electric shock and other safety hazards, such as arcing. As will be described in greater detail herein, the battery module  100  uses hardware and software redundancies before allowing for the energization of the power contacts  102 . 
     This ensures that the power contacts  102  only become energized after being connected to a second electrical device  120  (see  FIG.  3   ) when certain measured parameters of either the battery module  100  or the second electrical device  120  have an acceptable value. The second electrical device may be, for example, an energy transfer module, a specific battery module charger, a specific predetermined load, and/or additional battery modules. The battery module  100  may be used in energy dense battery module systems  200  (see  FIG.  5   ) used, by way of example, for charging a battery  206  of an electric vehicle  207  (see  FIG.  5   ). In addition, the battery module  100  contains electrical hardware that ensures multiple battery modules connected do not discharge into each other. The power flow control system  108  of battery module  100  ensures substantially insignificant reverse currents no matter what voltage the battery module  100  and a second electrical device  120  are at. This improves the efficiency and reliability of the battery module  100 . 
     Referring to  FIG.  2   , an example is depicted of a schematic of an embodiment of power and communication systems of the battery module  100 , according to aspects described herein. As mentioned earlier, the battery module  100  includes, one or more sets of power contacts  102  and signal contacts  104  as outside interfaces. Additionally, inside the battery module  100  is battery pack  106 , power flow control system  108 , an electronic isolation system  110 , and an electronic control system  112  for both the battery module  100  and the other electrical devices, such as the second electrical device  120  depicted in  FIG.  3   . 
     The power contacts  102  provide the ability to charge or discharge the battery module  100 . The signal contacts  104  transfer auxiliary voltages, control signals, and serial communication lines between battery modules  100  and other electrical devices  120 . As depicted in  FIG.  2   , the power flow control system  108  prevents or inhibits a battery module  100  with a lower state of charge (SOC) from being charged by a battery module  100  with a higher SOC. The electronic isolation system  110  is a system that may include active switching elements (see  FIG.  4   ) that ensure that the power connectors  102  are not energized in the absence of a control voltage (not shown) on the electronic isolation system  110 . The electronic control system  112  in the battery module  100  handles a multitude of functions. By way of example, the electronic control system  112  may provide auxiliary voltages to devices external to the battery module  100 , determine the number of connected battery modules  100  in a battery module system  200  (see  FIG.  5   ), provide serial communication between the battery module  100  and external devices (such as electrical device  120  of  FIG.  3   ), and determine when to safely turn on and off the electronic isolation system  110 . 
     The electronic control system  112  contains several electrical signals and sensors (see  FIG.  4   ) that may be used to control the electronic isolation system  110  and the power flow control system  108 . Those signals and sensors include, but are not limited to battery count, top detect, bottom detect, CAN bus, battery enable, and control voltages. The combination of these signals and sensors allow for the battery module  100  and battery module system  200  to ensure that they only energize the power terminals  102  when an appropriate device (such as second electrical device  120  of  FIG.  3   ) is connected and ready to use the energy stored in the battery modules  100  and/or batter module systems  200 . 
     Referring again to  FIGS.  1  and  2   , the first battery module includes a first set of power contacts  102  and a first set of signal contacts  104  as outside interfaces. A battery pack  106  is operable to deliver electrical power to the set of power contacts  102 . The battery pack  106  may be comprised of a system of battery cells (not shown). Each battery cell may include one or more anodes and cathodes separated by an electrolyte. 
     An electronic isolation system  110  is operable to electrically disconnect and electrically connect the battery pack  106  and the first set of power contacts  102 . An electronic control system  112  is electrically connected to the electronic isolation system  110  and to at least one of the first set of signal contacts  104  or the first set of power contacts  102 . The electronic control system  112  is operable to measure a parameter associated with the first battery module  100  and/or a second electrical device  120  (see  FIG.  3   ) and to compare the parameter to a predefined value to determine if it is desirable to connect the first battery module  100  to the second electrical device  120 . The electronic isolation system  110  may connect the battery pack  106  to the first set of power contacts  102  based on a positive result of the comparison of the parameter to the predetermined value. The electronic isolation system may disconnect the battery pack  106  and the first set of power contacts  102  based on a negative result of the comparison. 
     The second electrical device  120  can be several different types of devices. For example, it could be another battery module  100 . Also, it could be a charging device, or an energy transfer module or a specific predetermined load. 
     The measured parameter described above may be one of several parameters and/or characteristics of either the first battery module  100  or the second electrical device  120  that are important for functioning. For example, the measured parameter could indicate the presence or absence of a certain characteristic in the first battery module  100  and/or second electrical device  120 . Also, by way of example, the parameter could be a resistance, a current, a voltage, State of Charge (SOC) or a state of health (SOH) of either the first battery module  100  or the second electrical device  120 . 
     The parameter associated with the first battery module  100  and/or the second electrical device  120  may also include a first parameter associated with the first battery module  100 , and a second parameter associated with the second electrical device  120 . Additionally, the comparison of the parameter to a predefined value may further include a comparison of a difference between the first parameter and the second parameter to a predefined acceptable range of the difference. If the difference is within the acceptable range, the electronic isolation system  110  may connect the battery pack  106  to the first set of power contacts  102 . If the difference is not within the acceptable range, the electronic isolation system  110  may disconnect the battery pack  106  and the first set of power contacts  102 . 
     In other words, the parameter may also be a differential of two parameters measured in both the first battery module  100  and the second electrical device  120 . For example, the parameter may be a difference between a state of health (SOH) or a state of charge (SOC) between the first battery module  100  and the second electrical device  120 . 
     The predetermined value that the parameter is compared to may be a value that is significant for functioning of the first battery module  100  and/or the second electrical device  120 . For example, the predetermined value may be an acceptable range for a difference in the SOC between the first battery module  100  and the second electrical device  120  (e.g., the second electrical device  120  may be a second battery module  100 ). For example, an acceptable range may be that the SOC of the first battery module  100  be within plus or minus 50 percent, plus or minus 30 percent, plus or minus 25 percent, plus or minus 15 percent, plus or minus 10 percent, or plus or minus 5 percent of the SOC of the second electrical device. 
     The first battery module  100  also includes a power flow control system  108  that is connected between the battery pack  106  and the first set of power contacts  102 . In the example illustrated in  FIG.  2   , the power flow control system  108  is connected between the electronic isolation system  110  and the first set of power contacts  102 . The power flow control system  108  is operable to prevent or inhibit reverse flow of current from the first set of power contacts  102  to the battery pack  106 . The power flow control system  108  may include at least one diode  140  (see  FIG.  4   ) connected between the battery pack  106  and the first set of power contacts  102 . 
     Referring to  FIG.  3   , an example is depicted of a schematic of a control interface  128  between the first battery module  100  and a second electrical device  120 , according to aspects described herein. The first battery module  100  includes a first set of power contacts  102  that are operable to electrically connect at control interface  128  to a second set of power contacts  122  of the second electrical device  120 . Additionally, the first set of signal contacts  104  of the battery module  100  are operable to electrically connect to a second set of signal contacts  124  of the second electrical device  120 . 
     As illustrated in  FIG.  3   , the electronic control system  112  of the battery module  100  and the electronic control system  126  of the second electrical device  120  are both operable to measure a difference between a first parameter associated with the battery module  100  and a second parameter associated with the second electrical device  120  when the first and second sets of signal contacts  104 ,  124  are connected together and/or when the first and second sets of power contacts  102 ,  122  are connected together. The electronic control system  112  of the battery module  100  may measure the parameter through the first set of power contacts  102  and/or through the first set of signal contacts  104 . The electronic control system  126  of the second electrical device  120  may measure the parameter through the second set of power contacts  122  and/or through the second set of signal contacts  124 . 
     Referring to  FIG.  4   , an example is depicted of a schematic of circuitry of the electronic control system  112 , the electronic isolation system  110  and the power flow control system  208  of the battery module  100 , according to aspects described herein. The electronic control system  112  may include a microprocessor  130  having a memory and an executable program in the memory. The microprocessor  130  may be in communication with, receive and/or process signals from the signal contacts  104  and/or the power contacts  102 . 
     The electronic control system  112  may include various voltage sensors  132 ,  134 , in electrical communication with the microprocessor  130 , to measure various voltages between the first set of power contacts  102  and the battery pack  106 . Further, the electronic control system  112  may include a current sensor  136 , in electrical communication with the microprocessor  130 , to measure the current being conducted between the battery pack  106  and the first set of power contacts  102 . 
     The electronic isolation system  110  may include at least one switching device  138  electrically connected between the battery pack  106  and the first set of power contacts  102 . When the at least one switching device  138  is in an open position, the first set of power contacts  102  are isolated from the battery pack  106 . When the at least one switching device  138  is in a closed position, the first set of power contacts  102  are electrically connected to the battery pack  106 . The at least one switching device  138  may include one or more relays, MOSFET and/or other types of transistor switches or the like. 
     The power control system  108  may include one or more diodes  140 . Additionally, other unidirectional current elements and/or circuits may be utilized. 
     Referring to  FIG.  5   , an example is depicted of a schematic of a battery module system  200  having a plurality of battery modules  100 , according to aspects described herein. The battery module system  200  includes a battery module system power bus  202  that directs the power output from the electrically parallel connected battery modules  100  to an external electric load, such as the battery  206  of electric vehicle  207 . By way of example, the power output of the battery module system  200  may be connected to the external electric load through a load connector  208 . 
     In the example illustrated in  FIG.  5   , an external electric load is a battery  206  for an electric vehicle  207  that the battery module system  200  is charging. However, the external electric load may include any number of electric devices, systems and applications. For example, the external electric load may include power tools, aircraft systems or the like. 
     The battery module system  200  includes the plurality of battery modules  100   a - 100   e , which are connected together in parallel at the power bus  202 . However, any number of battery modules  100  may be used in the battery module system  200 . 
     The like reference numbers for like components are used in  FIG.  5    when referring to any, or all, of the battery modules, and/or the components and systems of the battery modules, in the battery module system  200 . However, for purposes of clarity, when referring to a specific battery module, component or system in  FIG.  5   ., the letters “a-e” are appended to the end of the reference number. 
     A first battery module  100   a  of the plurality of battery modules  100   a - 100   e  includes a first set of power contacts  102   a , which are electrically connected to the power bus  202 . First battery module  100   a  also includes a first set of signal contacts  104   a , which are electrically connected together through a signal bus  204 . Alternatively, the signal contacts may be independently connected to sources of signals such as various sensors. Such independent signals could be passed through a larger cable harness with independent conductors carrying such signals but without a common signal bus. 
     A first battery pack  106   a  of the first battery module  100   a  is operable to deliver electrical power to the first set of power contacts  102   a . A first electronic isolation system  110   a  of the first battery module  100   a  is operable to electrically disconnect and connect the first battery pack  102   a  and the first set of power contacts  102   a . A first electronic control system  112   a  is electrically connected to the first electronic isolation system  110   a  and to one, or both, of the first set of signal contacts  104   a  and the first set of power contacts  102   a.    
     The electronic control system  112   a  of first battery module  100   a  may be operable to measure a parameter associated with the first battery module  100   a  and/or a second battery module  100   b  of the plurality of battery modules  100   a - 100   e . The electronic control system  112   a  may also be operable to compare the parameter to a predefined value to determine if it is desirable to connect the first battery module  100   a  to the second battery module  100   b . The electronic isolation system  110   a  of battery module  100   a  may then connect the battery pack  106   a  of battery module  100   a  to the first set of power contacts  102   a  of battery module  100   a  based on a positive (e.g., compatible state of charge or compatible voltages before charging) result of the comparison. The electronic isolation system  110   a  may disconnect the battery pack  106   a  and the first set of power contacts  102   a  based on a negative (e.g., non-compatible state of charge) result of the comparison. 
     Though the first and second battery modules of the battery module system  200  were specifically referenced as battery module  100   a  and battery module  100   b  respectively, the first and second battery modules may each be any battery module  100  of the battery module system  200 . In other words, the first battery module  100  may include any battery module  100   a - 100   e  of the plurality of battery modules of battery module system  200 . Additionally, the second battery module  100  may include any other battery module  100   a - 100   e  of the plurality of batter modules of battery module system  200 . 
     The parameter measured by electronic control system  112   a  and associated with one, or both, of the first battery module  100   a  and the second battery module  100   b , may further include: a first state of charge associated with the first battery module  100   a , and a second state of charge associated with the battery module  100   b . Additionally, the comparison of the parameter to a predefined value may further include: a comparison of a difference between the first state of charge and the second state of charge to a predefined acceptable range of the difference. 
     If the difference between the first state of charge (first SOC) and the second state of charge (second SOC) is within the acceptable range, the electronic isolation system  110   a  may connect the battery pack  106  to the first set of power contacts  102   a . If the difference is not within the acceptable range, the electronic isolation system  110   a  may disconnect the battery pack  106   a  and the first set of power contacts  102   a . An acceptable range may be that the SOC of the first battery module  100   a  be within plus or minus 50 percent, plus or minus 30 percent, plus or minus 25 percent, plus or minus 15 percent, plus or minus 10 percent, or plus or minus 5 percent of the SOC of the second battery module  100   b.    
     The first battery module  100   a  of the battery module system  200  also may include a first power flow control system  108   a  connected between the first battery pack  106   a  and the first set of power contacts  102   a . The first power flow control system  108   a  is operable to prevent, or inhibit to a substantially insignificant level, reverse flow of current from the first set of power contacts  102   a  to the first battery pack  106   a . This may be done with one or more diodes  140  (see  FIG.  4   ) of with the use of other unidirectional current elements or circuits. 
     The second battery module  100   b  may also include a second power flow control system  108   b  connected between the second battery pack  106   b  and the second set of power contacts  102   b . The second power flow control system  108   b  is operable to prevent or inhibit reverse flow of current from the second set of power contacts  102   b  to the second battery pack  106   b.    
     The various battery modules  100   a - 100   e  of the battery module system  200  may also include a top detection device and a bottom detection device. For example, the first battery module  100   a  may include a top detection device that is operable to detect another battery module  100  of the plurality of battery modules  100   a - 100   e  positioned on a top of the first battery module  100   a . Additionally, the first battery module  100   a  may include a bottom detection device that is operable to detect another battery module  100  of the plurality of battery modules  100   a - 100   e  positioned on a bottom of the first battery module  100   a.    
     The top and bottom detection devices may include any number of circuit elements and systems designed to determine if a battery module  100  is in the middle portion of the stack of battery modules  100 . The top and bottom detection devices may also aid in determining how many battery modules  100  are above or below any given battery module  100 . In an example, a CAN bus contact may be enabled on a bottom side of a bottommost battery module (e.g., battery module  100   a ) in a stack of battery modules to allow the contact to connect to such a CAN bus. In the remainder, i.e., non-bottommost battery modules, such a CAN bus contact would not be enabled since the CAN bus would only be connected to the bottommost module and a CAN bus contact on a middle or top module in a stack would not be useful. Thus, a location detection device (e.g., a top or bottom detection device) may be useful when only one or more of a stack of battery modules connect to another device, or otherwise function differently that a rest of the stack of battery modules. Another example of a use for the top and bottom detectors is that they may be able to determine if the power bus may be safely isolated from a user/operator. On the bottommost batter a base or cover may be included to ensure the power bus remains fully isolated. 
     Referring to  FIG.  6   , an example is depicted of a schematic of another embodiment of power and communication systems of the battery module  100 , according to aspects described herein. The main difference between the embodiment of module  100  in  FIG.  6    and the embodiment of module  100  in  FIG.  1    is that the power flow control system  108  is removed. By removing the power flow control system  108  including its diodes  140  (see  FIG.  4   ) and/or other unidirectional circuitry, the efficiency of the battery module may be increased. However, as will be explained in greater detail herein, the circuitry of the electronic control  112 , may be modified to compensate for the removal of the power flow control system  108 . 
     In the remaining  FIGS.  6 - 9   , many of the components described have the same or similar form fit and function as components described earlier herein. When that is the case, the components will be referred to with the same reference numbers. 
     The battery module  100  includes a first set of power contacts  102  and a first set of signal contacts  104 . A battery pack  106  is operable to deliver electrical power to the set of power contacts  102 . An electronic isolation system  110  is operable to electrically disconnect and electrically connect the battery pack  106  and the first set of power contacts  102 . 
     An electronic control system  212  is electrically connected to the electronic isolation system  110  and to the first set of signal contacts  104  and/or the first set of power contacts  102 . However, the electronic control system  212  is designed to compensate for the removal of the power flow control system  108 . 
     Referring to  FIG.  7   , an example is depicted of a schematic of circuitry of the electrical control system  212  and the electronic isolation system  110 , according to aspects described herein. The electronic isolation system  110  is similar to that described earlier in  FIG.  4    and may include at least one switching device  138  electrically connected between the battery pack  106  and the first set of power contacts  102 . 
     However, a microprocessor  214  of electronic control system  212  includes an algorithm in its memory specifically designed to compensate for the removal of the power flow control system  108 . The algorithm is stored in a memory of the microprocessor  214  as a set of instructions for execution by the microprocessor to perform one or more methods to determine the optimal time and conditions for connecting the battery module to another electrical device (such as a second battery module) with minimum current backflow. Additionally, the microprocessor  214  may be in communication with more instruments in order to execute the methods of connecting the battery module  100  to another electrical device. In the example illustrated in  FIG.  7   , the microprocessor is in electrical communication with one or more voltage sensors  132 ,  134 , one or more current sensors  136  and one or more temperature sensors  216 . 
     Accordingly, the electronic control system  212  is operable to obtain a first comparison between a state of charge of the battery module  100  and an electrical device, such as electrical device  120  in  FIG.  3   . The electronic control system  212  is also operable to obtain a second comparison between a state of health of the battery module  100  and the electrical device  120 . The electronic control system  100  is also operable to obtain a third comparison between a temperature (such as an average temperature) of the battery module  100  and the electrical device  120 . The electronic control system  100  is also operable to obtain a fourth comparison between a power (such as output power) of the battery module  100  and the electrical device  120 . 
     The electronic control system  212 , may then calculate a closing parameter based on the first comparison, the second comparison, the third comparison and/or the fourth comparison. Thereafter the closing parameter may be compared to a predefined closing parameter value to result in a connect determination as to whether it is desirable to connect the first battery module to the electrical device. The electronic isolation system may connect the battery pack  106  to the first set of power contacts  102  based on a positive result of the connect determination. The electronic isolation system  212  may disconnect the battery pack  106  and the first set of power contacts  102  based on a negative result of the connect determination. 
     The battery module  100  may be a first battery module, such a first battery module  100   a  (see  FIGS.  5  and  8   ) and the electrical device  120  may be a second battery module, such second battery module  100   b  (see  FIGS.  5  and  8   ). That being the case, then the first comparison may include a difference between a state of charge of the first battery module  100   a  and the second battery module  100   b . The second comparison may include a difference between a state of health of the first battery module  100   a  and the second battery module  100   b . The third comparison may include a difference between a temperature of the first battery module  100   a  and the second battery module  100   b . Finally, the fourth comparison may include a difference between a power of the first battery module  100   a  and the second battery module  100   b.    
     Referring to  FIG.  8   , an example is depicted of a schematic of another embodiment of a battery module system  300  having a plurality of battery modules  100   a - 100   e , according to aspects described herein. The battery module system  300  includes a power bus  302  connected to the power contacts  102   a - 102   e  of the battery modules  100   a - 100   e  in similar fashion that that shown in  FIG.  5   . The battery module system  300  also incudes a signal bus  304  connected to the signal contacts  104   a - 104   b  in similar fashion to that shown in  FIG.  5   . 
     In the example illustrated in  FIG.  8   , the first battery module  100   a  and the second battery module  100   b  are at least a portion of the plurality of battery modules  100   a - 100   e  of the battery module system  300 . The battery module system  300  includes the power bus  302  that is operable to be connected to the first set of power contacts  102   a  of the first battery module  100   a  and the first set of contacts  102   b  of the second battery module  100   b.    
     The closing parameter, as described earlier, may be an absolute value of a difference between a closing voltage and a sag voltage. The sag voltage, as used herein, is a measured voltage on the power bus  302  prior to the power contacts  102   a  of the battery module  100   a  being connected to the power bus  302 . The closing voltage, as used herein, is be a predicted value of what the sag voltage will become if the power contacts  102   a  of the battery module  100   a  are connected to the power bus  302 . 
     The predefined closing parameter value, that the closing parameter will be compared to, may vary. For example, the closing parameter may be less than 5 volts, less than 4 volts, less than 3 volts, less than 2 volts or less than 1 volts. 
     The algorithm stored as instructions in the memory of microprocessor  212 , may calculate the closing parameter and determine a connect determination by measuring the temperature of the battery module  100   a  and the electrical device, such as second battery module  100   b  with the one temperature sensor  216  (see  FIG.  7   ). A current of the battery module  100   a  and the second battery module  100   b  may be measured with the current sensor  136 . A voltage of the first battery module  100   a  and the second battery module  100   b  may be measured with the voltage sensors  132 ,  134 . A state of charge, a state of health and power of the first and second battery modules  100   a ,  100   b  may be calculated with the measured temperature, current and voltage. The temperature, the power, the state of charge and the state of health may then be used to obtain the first, second, third and fourth comparisons discussed earlier. The closing parameter may then be calculated based on the first, second, third and fourth comparisons. The closing parameter may then be compared to the predefined closing parameter value to result in a connect determination. 
     Additionally, a running state of the first battery module  100   a  will affect the closing parameter and, therefore, the results of the connect determination. Three running states that are of most significance are a “before power draw” running state, a “during power draw” running state and a “after power draw” running state. They are defined herein as follows: 
     “Before power draw”: is when a system, such as the battery module system  300 , is idle and hasn&#39;t been run yet since being connected to an external electrical load, such as a battery  206  of an electric vehicle  207 . This occurs before any energy is drawn from a battery module, such as battery module  100   a . In this state the battery module could be closed into the power bus or it could still be open. A main factor, which distinguishes this state over the other two states, is that once a battery module is closed into the power bus, no power will flow into the external electric load. With a load such as an electric vehicle  207 , this would be the time before the vehicle starts charging. 
     “During power draw”: is when the battery module, such as battery module  100   a , is supplying energy to the external electric load, such as a battery  206  of an electric vehicle  207 . With a load such as an electric vehicle  207 , this is the time while the vehicle is charging. In this state, power is flowing from the battery module into the external electric load. 
     “After power draw”: is the time that a battery module, such as battery module  100   a , is still connected into a system, such as battery module system  300 , but no more power is being drawn. This could be when an external electric load, such as electric vehicle  207 , stops charging or when the external electronic load is removed from the system. This is different than the “before power draw” state in that the battery module will have any voltage sag removed due to the power draw stopping. Therefore, the battery module voltage will rise back up to its open circuit voltage. 
     Accordingly, the method used by the microprocessor  214  to calculate a connect determination may include the steps of determining the running state of the battery module, the running state being the “before power draw” state, the “during power draw” state and/or the “after power draw” state. Thereafter, the running state may be used to calculate the closing parameter. 
     Referring to  FIG.  9   , an example is depicted of a flow diagram  400  of a computer implemented method for connecting a battery module to an electrical device, according to aspects described herein. By way of example and as used herein, the battery module may be first battery module  100   a  and the electrical device may be second battery module  100   b . Both battery modules  100   a ,  100   b  may be connected to a battery module system, such as battery module system  300 . 
     The method starts at  402  when the first battery module  100   a  is initially turned on and its control circuits, including its microprocessor  214 , are active. Additionally, the electrical device, e.g., battery module  100   b , is also turned on and providing signals to the battery module  100   a . At this point of initial start-up, the electronic isolation system  110  defaults to disconnect the battery pack  106  from the power contacts  102  of the battery module  100   a.    
     At  404 , a temperature of the first battery module  100   a  and the second battery module  100   a  is measured by one or more temperature sensors, such as temperature sensors  216 . The temperature may be an average temperature of both first and second battery modules  100   a ,  100   b . The temperature sensors may be positioned as several locations throughout the battery modules  100   a ,  100   b . The temperature data from battery module  100   b  may be transmitted as signal data into the signal contacts  104   a  and to the microprocessor  214  of battery module  100   a.    
     Additionally, at  404 , a current of the first and second battery modules  100   a ,  100   b  may be measured with a current sensor, such as current sensor  136 . The current may be the output current of the battery modules  100   a ,  100   b.    
     Additionally, at  404 , a voltage of the first and second battery modules  100   a ,  100   b  may be measured with a voltage sensor, such as voltage sensors  132  and  134 . The voltage may be the output voltage of the first and second battery modules  100   a ,  100   b.    
     At  406 , a state of charge, a state of health and a power of the first and second battery modules  100   a ,  100   b  is calculated from at least one of the current, temperature and/or voltage of the battery modules. The power may be the output power of the first and second battery modules  100   a ,  100   b.    
     At  408 , the measured and calculated values are sent to the algorithm of the microprocessor  214 . The algorithm is in the form of executable instructions stored in the memory of the microprocessor  214 . 
     At  410 , the running state of the battery module  100   a  is determined. The running state may be a before power draw state, a during power draw state and an after-power draw state. 
     At  412 , the algorithm obtains a first comparison between a state of charge of the first battery module  100   a  (i.e., the battery module) and the second battery module  100   b  (i.e., the electrical device). The algorithm also obtains a second comparison between a state of health of the first battery module  100   a  and the second battery module  100   b . The algorithm also obtains a third comparison between a temperature of the first battery module  100   a  and the second battery module  100   b . The algorithm also obtains a fourth comparison between a power of the first battery module  100   a  and the second battery module  100   b . One form of comparison may be a difference. That is, the comparisons of the state of charge, state of health, temperature and power between first and second battery modules  100   a ,  100   b  may be a difference between the values of the state of charge, state of health, temperature and power of the first and second battery modules  100   a ,  100   b.    
     At  414 , a closing parameter is calculated based on the first, second, third and/or fourth comparisons. The closing parameter may also be based on the determined running state. For example, the closing parameter may be an absolute value of a difference between a closing voltage and a sag voltage. The sag voltage may be a measured voltage on the power bus  302  prior to the power contacts  102   a  of the first battery module  100   a  being connected to the power bus  320 . The closing voltage may be a predicted value of what the sag voltage will become if the power contacts  102   a  of the first battery module  100   a  are connected to the power bus  302 . 
     At  416 , the closing parameter is compared to a predefined closing parameter value to result in a connect determination. For the case where the closing parameter is an absolute value of a difference between a closing voltage and a sag voltage, the predefined closing parameter value may be that the absolute value must be less than 5 volts, less than 4 volts, less than 3 volts less than 2 volts or less than 1 volt. The predefined closing parameter value may vary with the running state. 
     If the connect determination is a negative result, for example, if the closing parameter does not fall within the range of the predetermined closing parameter value, then the first battery module  100   a  will be disconnected (or remain disconnected) from the second battery module  100   b . This will be implemented by the microprocessor  214  of the electronic control system  212  providing a signal command to the electronic isolation system  110  to not connect the battery pack  106  to the power contacts  104   a  of battery module  100   a . The method will then loop back to  404  and begin a new sequence of steps. 
     At  418 , if the connect determination is a positive result, for example, if the closing parameter falls within the range of the predetermined closing parameter value, then the first battery module  100   a  will be connected to the second battery module  100   b . This will be implemented by the microprocessor  214  of the electronic control system  212  providing a signal command (such as a control voltage) to the electronic isolation system  110  to connect the battery pack  106  to the power contacts  104   a  of battery module  100   a . The batter pack  106  of the first battery module  100   a  may then be connected to the power bus  302  of the battery module system  300  and to the second battery module  100   b . The method will then stop at  420 . 
     Although systems (e.g., battery module  100 , electric device  120 , battery module system  200 , and battery module system  300 ) and methods are described herein for charging a battery (e.g., battery  206 ) of an electric vehicle (e.g., electric vehicle  207 ) such systems and methods may be used to supply electrical energy to an electrical load and/or charge to other energy storage devices. Such other energy storage devices could be grid tied energy storage devices, or mobile energy storage devices for uses ranging from personal electronics to industrial electrical vehicles (e.g., forklift trucks or other work vehicles). 
     It should be appreciated that all combinations of the foregoing concepts and additional concepts discussed in greater detail herein (provided such concepts are not mutually inconsistent) are contemplated as being part of the inventive subject matter disclosed herein. In particular, all combinations of claimed subject matter appearing at the end of this disclosure are contemplated as being part of the inventive subject matter disclosed herein. 
     Although the invention has been described by reference to specific examples, it should be understood that numerous changes may be made within the spirit and scope of the inventive concepts described. Accordingly, it is intended that the disclosure not be limited to the described examples, but that it have the full scope defined by the language of the following claims.