Patent Publication Number: US-2020295324-A1

Title: Modular smart battery and battery module for fast secure field assembly

Description:
RELATED APPLICATION 
     This application claims priority to U.S. Provisional Application Ser. No. 62/818,593 (entitled MODULAR SMART BATTERY AND BATTERY MODULE FOR FAST SECURE FIELD ASSEMBLY, filed Mar. 14, 2019) which is incorporated herein by reference. 
    
    
     BACKGROUND 
     The importance of distributed energy storage is increasing rapidly, due to the growth of solar and other distributed energy technologies, which have become a significant source of energy on electric grids worldwide. However, electricity storage products are often heavy, cumbersome, and expensive to install, increasing the cost and slowing the growth of this important energy technology. Further, the complexity of assembly and setup impacts the scalability of energy storage solutions. 
     SUMMARY 
     A modular energy storage product comprises an enclosure and one or more battery modules, each of which is equipped with features that facilitate a fast, tool-free, secure installation. 
     In one embodiment, the battery module features ramps and slots, and the enclosure features flexural catches that engage the slots to secure the module without additional tools or parts. In other embodiments, while no tool is required to assemble the module, a tool may be required to remove the module. In further embodiments, the same motion that assembles the module to the enclosure also completes the electrical connection. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         FIG. 1A  is a cross-section view of a battery enclosure according to an example embodiment. 
         FIG. 1B  is a perspective view of the battery enclosure of  FIG. 2A  showing internal battery modules and a battery management unit in broken line form according to an example embodiment. 
         FIGS. 2A, 2B, and 2C  are block diagrams illustrating battery modules in various stages of insertion into a battery enclosure according to an example embodiment. 
         FIG. 2D  is a perspective representation of a guide for latching battery modules in place according to an example embodiment. 
         FIG. 3A  is a side elevation view of an alternative battery module according to example embodiments. 
         FIG. 3B  is an illustration of insertion of the battery module of  FIG. 2A  into the battery enclosure according to an example embodiment. 
         FIG. 4  is a block schematic diagram illustrating electrical connections inside a battery enclosure according to an example embodiment. 
     
    
    
     DETAILED DESCRIPTION 
     In the following description, reference is made to the accompanying drawings that form a part hereof, and in which is shown by way of illustration specific embodiments which may be practiced. These embodiments are described in sufficient detail to enable those skilled in the art to practice the invention, and it is to be understood that other embodiments may be utilized, and that structural, logical and electrical changes may be made without departing from the scope of the present invention. The following description of example embodiments is, therefore, not to be taken in a limited sense, and the scope of the present invention is defined by the appended claims. 
     The importance of distributed energy storage is increasing rapidly, due to the growth of solar and other distributed energy technologies, which have become a significant source of energy on electric grids worldwide. However, electricity storage products are often heavy, cumbersome, and expensive to install, increasing the cost and slowing the growth of this important energy technology. Further, the complexity of assembly and setup impacts the scalability of energy storage solutions. 
     The industry would benefit from modular energy storage solutions that could be installed very quickly from simple, lightweight, components by assemblers with minimal training. 
     One prior energy storage system has a 13 kWh of capacity and weighs approximately 125 kg. Another prior energy storage system has a 9 kWh of capacity and weighs approximately 100 kg. A further commercial/industrial-type energy storage product has a housing and several rack-type horizontally oriented battery modules which must be secured with multiple small fasteners and connected using several external cables. 
     In various embodiments of the present inventive subject matter, a modular energy storage product comprises an enclosure and one or more battery modules, each of which is equipped with enclosure features that facilitate a fast, tool-free, secure installation. Electrical connections between battery modules may be internal to the energy storage product, obviating the need for separate cables between batteries. 
     In one embodiment, the battery module features ramps and slots, and the battery module features include flexural catches that engage the slots to secure the module without additional tools or parts. In other embodiments, while no tool is required to assemble the module, a tool may be required to remove the module. In further embodiments, the same motion that assembles the module to the enclosure also completes the electrical connection. 
       FIG. 1A  illustrates a cross-section of an energy storage system  100  that includes a smart battery enclosure  110 . Enclosure  110  may include a battery management unit  120 , one or more guides  130 ,  131 ,  132 ,  133  with catch features, and one or more smart battery modules  140 ,  141  etc. The guides  130  may have sufficient structural support to fully support one or more battery modules within the enclosure  110  and be securely mounted within the enclosure such as by welding, or other means of securing the guides  130  within the enclosure  110 . 
     The smart battery modules  140 ,  141  may include one or more battery cells enclosed within a case. The case may incorporate case features  143 ,  144  as illustrated on smart battery module  140 . The mating features  143 ,  144  are configured to bypass and then securely engage the guide/catch features  130 ,  131  on the enclosure  110 . The enclosure  110  may be self-supported or may attach to or be positioned adjacent a wall  150 . The enclosure  110  may also be supported by a floor, and a foot, frame, or riser  160  may be used to elevate the enclosure  110  a desired distance from the floor. 
       FIG. 1B  is a perspective transparent isometric view of the enclosure  110 . While the stack configuration illustrated comprises two battery modules deep by two modules high, other configurations are readily devised, including single module depth, multiple modules side-by-side, etc. In some applications a plenum  170  provides a space to allow easy access to touch-safe electrical connectors on the side of the module to enable electrical coupling of the battery modules in various desired serial and parallel combination to obtain desired electrical properties of the system  110 . 
     A removable panel  175  on a front side of enclosure  110  provides access to the inside of the enclosure  110 , allowing insertion of the battery modules to engage with the matting features  143 ,  144  and hold the battery modules in place within the enclosure  110 . 
       FIGS. 2A, 2B, and 2C  are a series of a block diagram illustrating a process or method of secure battery module assembly and capture. In one embodiment, the installation may be performed without the use of tools. The system  100  provides a fast, secure module capture means is used to secure battery modules. Reference numbers for like parts in the various figures are used consistently. 
     At assembly, an installer may approach the enclosure  110  with panel  175  removed with one module  240  at a time. One or more guides  230  equipped with catches  239  are exposed with the panel  175  removed and enable the installer to laterally move the battery module  240  into the enclosure (not shown). The guides  230  may be supported within the enclosure as previously illustrated. The battery module  240  may include multiple cells  249 , indicated in broken line form. 
     Ramp features  241  enable the module  240  to displace the catches  239  outward away from the battery module  240 . In one orientation, the battery modules are vertically oriented, and the catches  239  are vertically displaced through an opening  270  of guide  230  as illustrated at  260  in  FIG. 2B , allowing the module to slide further back into the enclosure, whereupon the catches  239  on guides  230  located to engage both ends of the battery module  240  securely engage female receiving features  242  on the battery modules  240 , securing the module in place as illustrated in  FIG. 2C . 
     A  FIG. 2D  is a perspective representation of the guide  230  for latching battery modules in place. In one embodiment, catch  239  is a flexural catch formed from a rectangular piece of sheet metal. The catch  239  is formed roughly into an elongated P shape, comprising a male catch feature  231 , a flexure  232 , and an attachment  233 , such as a weld, adhesive, or other means of securing the flexure  232  to the guide  230  to allow flexing of the male catch feature  231 . In  FIG. 2D , the catch feature  231  is shown as extending downward, with a near end extending above the surface of guide  230 , and having a hole or slot  234  that can receive a tool such as a screwdriver to lift the male catch feature out of engagement with the receiving feature for removing the battery module. The flexure  232  and male catch feature  231  may be formed of a single piece of flexible material, such as plastic or metal in various embodiments. Other materials that have a spring constant sufficient to provide suitable flexibility and retentive strength may be used in further embodiments. 
     The male catch feature  231  has an arcuate portion extending convexly towards the intended position of an installed battery through an opening  270  in the guide  230 . The male catch feature may have a shape that mates with the corresponding concave female receiving feature  242  of the battery module, or otherwise suitably engages with the male catch feature to provide spring force to retain the battery module in a desired position. There are two opposed guides  230  spanning a distance commensurate with a battery module. There are also two opposed catches  239  for each battery module to be installed. In one embodiment, there are two battery modules for each pair of guides  203 , resulting four catches  239 . Each level in the enclosure  110  may be similarly configured and may accommodate different size batteries and different numbers of batteries with corresponding number of pairs of catches. 
     In operation, as the module is pushed toward the back of the enclosure, the battery module diagonal ramps  241  contact the catch features  231 , displacing the catch features away from the module against the elastic restoring force of the flexures  232 , until the module slides to the point where the catches  231  can relax into the receiving features  242 , urged by the flexures  232 . This construction is relatively simple and compatible with sheet metal fabrication techniques. In other embodiments, spring-loaded catches, stamped or formed catches, magnetic catches, or other securing means may be employed. In still other embodiments, the catch may be integrated with the module, and the receiver integrated with the housing. Different shape catches and catch features may be used with different shaped receiving features  242  to provide similar ease of installation. While the diagonal ramps  241  are shown as similar to large chamfers, other shaped ramps, such as arcuate or otherwise may be used to provide a similar catch displacement function. The ramps should have angles that result in a reasonable amount of force being able to displace the catches so the catches can engage with the receiving features  242 . 
       FIG. 2B  shows bottom catch  260  being displaced by ramp feature  241 , just before the catch  231  snaps into receiving feature  242  of the battery module  240 . 
       FIG. 2C  shows bottom catch  231  retentatively engaged in receiving feature  242  of the bottom of battery module  241 , securing it in place upon insertion. Note that top catches  231  may be similarly displaced and then engaged at the same time or sequentially to complete installation of each battery module, followed making appropriate electrical connections and closing of the panel  175 . 
     In some embodiments, the catch feature  231  may be designed such that no tool is required to secure the module to the smart battery enclosure. The catch feature  231  may also be designed so that a tools may be required to remove a battery module.  FIG. 2D  illustrates the catch feature  231  with the slot  234  that is substantially parallel to the guide  230  that effectively allows a screwdriver or other thin tool to engage and lever the catch  231  out of position. The slot  234  may be positioned proximate or above the guide  230  such that it is accessible for such levering of the catch  231 . The slot  234  may comprise a round hole or even a protrusion or other structure sufficient to allow a tool to lever the catch out of position in further embodiments. 
     While the catch/receiver features are shown on the top and bottom of the module, other configurations may be advantageous depending on the overall product architecture. For instance, the battery modules are shown as having an elongated box or book-like shape. In further embodiments, a cube or other structure may prove more efficient or otherwise desirable. Guides with catches may be positioned vertically to contact mating receiving features on opposing sides of the battery modules. 
       FIG. 3A  is a side elevation view of an alternative battery module  340 . In some embodiments such as that of  FIG. 1A  with multiple modules stacked in the direction normal to the wall surface, it may be advantageous for the modules to be formed to facilitate streamlined tool-free assembly. Module  340  has top and bottom arcuate surfaces substantially taking the form of a cylinder illustrated by broken line  310 , having arcuate top and bottom ends, with receivers  442  as previously described. The cylinder has a diameter the same as or slightly less than the distance between opposing guides of the enclosure in one embodiment. The arcuate surfaces may provide a ramp feature to displace catches  331  in some embodiments. 
       FIG. 3B  is an illustration of insertion of the battery module  340  in a partially diagonal orientation, readily bypassing several catches  331  before engaging the rearmost opposing set of catches as described above, with movement illustrated by arrow  350 . 
     In some embodiments, the battery module  340  may have the convex shaped receivers with the enclosure including the concave catches. In still further embodiments, the battery module  340  may have a different feature on each end, such as a concave feature for a positive or negative terminal and a convex feature for the opposite polarity terminal, or vice versa. The enclosure and/or guides  230  may have suitable mating features to provide a keyed engagement mechanism. The features may be referred to as male and female features. 
     In some embodiments, electrical connectors may be integrated into the catches, such that engaging the module also forms the necessary electrical connections to the module, with the receiving features  342  of each battery module  340  including electrical connections to positive and negative terminals of the battery cells within each battery module  340 . 
     In some embodiments, modules may be staggered, offset, or otherwise configured without departing from the design intent, for instance to permit backplane connectors on the modules to engage with mating connectors on the enclosure. 
       FIG. 4  is a block schematic diagram illustrating electrical connections inside a battery enclosure generally at  400 . A battery module  410  is shown captured by opposing guides  415  and  416 . While one module  410  is shown for simplicity of illustration, there may be multiple installed battery modules in further embodiments. The battery module  410  is shown comprising multiple battery cells  420  that are connected in parallel via positive and negative conductors  422  and  423  respectively. The conductors are coupled to the respective guides  415  and  416  at electrical contact points  425  and  426  respectively. The electrical contact points  425  and  426  provide an electrical contact through respective receiving features  427  and  428 . The contact points  425  and  426  may comprising a conductive plate in one embodiment, or any other type of contact suitable for connecting to opposing contacts. 
     The contact points  425  and  426  provide a means to contact respective contacts  430  and  431  on catch features  432  and  433 . The contacts  430  and  431  are electrically coupled to connectors  440  and  441  which may be coupled to a load  445  or coupled to other battery modules in series or in parallel, or a combination of serial and parallel connection to provide an energy storage system with desired voltage and current characteristics. 
     The contacts  430  and  431  on the catch features  432  and  433  may be biased against the contacts  425  and  426  due to spring force exerted by the catch features. The contacts  430  and  431  may comprise a bulged construction suitable for conductively contacting the corresponding contacts  425  and  426 . 
     In further embodiments, the battery cells  420  or battery module  410  may have external connections to allow wiring via such connections to provide desired electrical characteristics. 
     Although a few embodiments have been described in detail above, other modifications are possible. For example, the logic flows depicted in the figures do not require the particular order shown, or sequential order, to achieve desirable results. Other steps may be provided, or steps may be eliminated, from the described flows, and other components may be added to, or removed from, the described systems. Other embodiments may be within the scope of the following claims.