Description:4. DESCRIPTION
FIELD OF THE INVENTION
This invention is relates to a cell holder for joining of multiple cells together in series-parallel combination to build Lithium-ion battery packs to achieve the specific voltage and capacity demanded by the application. This invention more particularly relates to a modular cylindrical cell holder; for holding standard Lithium-ion cells available in the market. The cell holder is having integrated mounting features to mount the sensing harness using lugs. The cell holders can be assembled together to build Lithium-ion battery packs of required voltage and capacity by holding multiple cells. The cell holder is having a provision to firmly hold cylindrical cells by accommodating variations in the diameter of the cells for preventing failure of Lithium-ion battery packs by absorbing mechanical vibrations and high impact loads.
BACKGROUND OF THE INVENTION
A lithium-ion battery is one of the most widely used rechargeable battery types for portable electronics due to their high energy density. In the lithium-ion battery, lithium ions travel from the negative to positive electrode during discharge and back from the positive to negative electrode during charging. Chemistry, performance, cost and safety characteristics vary across lithium-ion battery types.
A lithium-ion battery possess the best energy-to-weight ratios, high open circuit voltage, low self-discharge rate, no memory effect and a slow loss of charge when not in use. Other areas of application of the lithium-ion battery include consumer electronics, military and aerospace applications.
Electromobility becomes increasingly important due to projected shift from internal combustion engines technology (working of fossil fuel) to alternative propulsion technologies at world level. This will result in high demand for electric vehicles as electromobility is the most mature alternative propulsion technology. For high energy requirements applications (like electric vehicles) energy is stored in battery packs consisting of interconnected individual battery cells. Three different battery cell types employed in the automotive field includes small solid cylindrical cells, larger solid prismatic cells, and larger soft pouch or polymer cells. These three types of battery cells differ in size, geometry, and individual cell parameters as capacity and supplied power. The dimensions of the three cell types, particularly for the prismatic and pouch cells, vary depending upon cell manufacturers. The standards DIN 91,252:2016–11 defines the dimensions of all three types of battery cells.
Due operation and safety requirements, battery modules are exposed to mechanical, thermo-mechanical, electro-thermal, electro-mechanical and metallurgical challenges.
In electromobility field, battery modules are exposed to dynamic loading and random vibrations during operation. This may cause short circuits and fire. In modules with a large number of single cells, due to their periodic structure, random vibrations have high influence. As a high modal density in many frequency ranges is promoted, the module's structural dynamics can be impaired. The battery interconnection joints are also pre-stressed due to method of joining, affecting the dynamic response of the entire battery back noticeably. Lithium-ion batteries behave dynamically in terms of structure and dimension during charging and discharging, which has a considerable impact if the casing is soft. This effect can remain permanent due to an irreversible expansion of the electrode, other material and pressure changes in the cell.
Inhomogeneous thermal expansion at the contact interface of the different materials join together introduces shear loading and may results into plastic deformation or fracture in the contact region.

Due to vibration, the mechanical joints between batteries and conductors are subjected to fatigue loading promoting increase in electrical resistance due to electromechanical effect.
Fretting or fretting corrosion is defined as surface degradation at a metal to metal contact interface caused by oscillatory movements of the two surfaces with slip amplitudes of less than 125 µm as a result of vibrations. Fretting has a noticeable influence on the connection resistance.
Electrical vehicle safety is of at most concern in present era. Robust vehicle exterior provides protection to the battery pack, there is a possibility of damage to the battery pack and its components because of in service vibrations, collisions, or improper assembly. As a result, electric vehicle battery modules and packs must be designed considering various challenges discussed above.
Battery cell holder is an important component of the battery pack. It is a thin walled light weight structure used to affix and prevent movement of cell groups and modules. Many different cell holder designs are reported in order to overcome one or more of the changes as discussed above.
DESCRIPTION OF THE RELATED ART
Patent no. CN111525056A discloses a cell holder and cell block for holding battery cells in which manufacturing-related tolerances or changes in the operating state of the battery cells in the range of a plurality of percentages can be compensated by the cell holder in order to permanently ensure a stable and defined support of the battery cells.
Patent no. EP3316342A1 discloses a battery cell holder and battery module housing for resiliently receiving at least one battery cell and a battery module and a method for producing the battery module in which the inclusion of battery cells is non-positively and releasably, whereby dimensional tolerances of a recorded battery cell can be compensated.
Patent no. EP3809515A1 discloses a battery module with at least one individual cell and a cell holder designed in one piece for receiving the at least one individual cell, wherein the at least one individual cell is received by the cell holder and wherein the cell holder is designed in such a way that the cell holder mechanically fixes the at least one individual cell and, a device for producing a battery module.
Patent no. KR1020190053106 discloses a battery pack for energy storage having an improved cell holder, which secures expandability of a battery pack, packaging the battery pack module by various bonding or bolting, inserting, etc. to fundamentally prevent electrical contact resistance generated from a plurality of connection points generated by the battery pack module, lowers charging/discharging efficiency due to uneven contact resistance, and reduces durability and ensures durability and operational stability.
Patent No. KR1020190091631 discloses a vibration absorption type battery cell fixing holder and a battery pack including the same, capable of ventilation between battery cells by maintaining a gap between battery cells in a strip shape along a stacking direction of a battery cell in a laminate of a battery cell and stably fixing a battery cell by installing a plurality of battery cells along the circumferential surface of the laminate.
Patent application publication no. US201303162O2A1 relates to a battery cell holder with improved connection reliability and a battery module including the same, and, more particularly, to a battery cell holder configured so that a cylindrical battery cell is mounted therein, the battery cell holder including an upper cover including a first main body to cover an upper part of the battery cell in a state in which a first electrode terminal of the battery cell is exposed and at least one first extension fastening part extending downward from the first main body and a lower cover including a second main body to cover a lower part of the battery cell in a state in which a second electrode terminal of the battery cell having a polarity opposite to that of the first electrode terminal is exposed and at least one second extension fastening part extending upward from the second main body, wherein an end of the at least one first extension fastening part and an end of the at least one second extension fastening part are fastened to each other in a state in which the battery cell is mounted in the battery cell holder, and the upper cover and/or the lower cover is provided at an outer side thereof with at least one side fastening part, by which a side of the battery cell holder is fastened to that of another battery cell holder.
Patent application publication no. US20170237051A1 discloses a folding battery cell holder that may be used to form an interconnection of cells in series and/or parallel and thereby form a battery pack comprising a plurality of such interconnected cells.
There are multiple types of cell holders exist in the market, but they do not carry a provision made up of terminals which can accommodate screw type fasteners and they cannot accommodate any variation in the diameter of the cell. Also, for assembling different number of cell to create battery pack of different capacity, cell holder with different designs are required.
There is a need to provide a cell holder that firmly holds the cell in its position restricting its movement in radial as well as lateral directions absorbing dynamic vibrations and accommodating variation in the dimensions either due to manufacturing tolerances or due to thermo-mechanical or electro-mechanical effects. There is a need to provide a cell holder that has a provision to mount the sensing harness. There is need to provide cell holders that does not lead to non-parallel modules and prevents variations in the spot welding leading to a non-reliable welded structure. There is a need to provide cell holder that is modular in design can be assembled together mechanically to create battery pack of different capacity by assembling different number of unit cells.
OBJECT OF THE INVENTION

The principal object of this invention is to provide a battery cell holder that is modular in design and can be used to prepare battery pack with any number of cells as per the required capacity.
Another object of the present invention is to provide a battery cell holder that prevents vibrations of individual battery cells and in turn a battery pack as a whole by firmly holding the battery cell at constant pressure preventing its radial and longitudinal movement.
Another object of the present invention is to provide a battery cell holder that accommodates variation in the battery cell diameter due to manufacturing tolerances, due to thermo-mechanical effect and due to variation in diameter due to its operation (i.e. charging and discharging).
Another object of the present invention is to provide a battery cell holder that requires a less assembly time and need not required any fasteners for assembling and locking battery cell in the battery cell holder.
Another object of the present invention is to provide a battery cell holder that acts as a fixture for shouldering of buss bar to positive terminals and to negative terminals of battery cells used in battery pack and prevents non parallelism in battery pack modules.
Further object of the present invention is to provide a battery cell holder in which terminal for voltage and temperature measurement is mounted on cell holder itself utilizing the space on the battery cell holder making it more compact.
Further object of the present invention is to provide a battery cell holder that maintains uniform and accurate gap (flow passage) in between battery cells of a battery pack for cooling air for thermal management.

SUMMARY OF THE INVENTION
The present invention aims at providing a modular cylindrical battery cell holder with integrated sensing mounts for building a battery pack of different capacity as per the requirement. The cell holder is having integrated mounting features to mount the sensing harness using lugs. The cell holders can be assembled together to build Lithium-ion battery packs of required voltage and capacity by holding multiple cells. The cell holder is having a provision to firmly hold cylindrical cells by accommodating variations in the diameter of the cells for preventing failure of Lithium-ion battery packs by absorbing mechanical vibrations and high impact loads.
The modular cylindrical battery cell holder is having a terminal side face, a cell side face parallel to the terminal side face, a pair of cylindrical cavity extending from the terminal side face to the cell side face, an inner cylindrical face forming the cylindrical cavity, a plurality of screw mounting mold-in inserts opening on the terminal side face and integrated with the modular cylindrical battery cell holder to mechanically mount sensing harnesses on battery cell busbars, a plurality of lateral stops projected out in the radial direction towards the center of the cylindrical cavity from the terminal side face for maintaining lateral positioning of the modular cylindrical battery cell holder on the battery cells in assembled condition, a plurality of locking pin slots extending from the terminal side face to the cell side face forming a recess for assembling the multiple modular cylindrical battery cell holders using a locking pin, a pair of flexible radial gripper provided on the inner cylindrical face starting from the intermediate portion of the inner cylindrical face and extending towards the terminal side face wherein, the flexible radial gripper is consisting of a flexible redial grip having a battery cell side face and a locking pin side face and, is positioned in the recess formed by the locking pin slot.
Nominal diameter of a concentric circle (i.e. concentric to the cylindrical cavity) passing through the battery cell side face of the flexible radial gripper is kept smaller than the minimum diameter of the battery cells considering lower tolerance limit. A diameter of the cylindrical cavity is kept greater than the maximum diameter of the battery cells considering higher tolerance limit so that, all the battery cells assembled with the modular cylindrical battery cell holder is gripped eccentrically in the cylindrical cavity by the pair of the flexible redial grip and supported on the inner cylindrical face of the cylindrical cavity establishing a line contact. In the assembled condition, locking pin pushes the flexible radial grip towards the battery cell cylindrical face generating adequate gripping pressure for preventing vibration of the individual cell due to in-service dynamic loading of the battery pack. To build a battery pack, individual battery pack modules consisting of the battery cells held with the help of two modular cylindrical battery cell holders, one at the top and another at the bottom are assembled together using the locking pins. To prevent thermomechanical damage to the battery cells by avoiding soldering, the sensing harnesses are mounted mechanically on the battery cell busbars.
To build the battery pack, individual battery pack modules consisting of the battery cells held with the help of two modular cylindrical battery cell holders, one at the top and another at the bottom are assembled together using the locking pins. The battery pack of different capacity with either even number of total battery cells or odd number of total battery cells is buildup.
BRIEF DESCRIPTION OF THE DRAWINGS
The features of the invention as per the present patent application are described with reference to the following drawings in which like elements are labeled similarly. The present invention will be more clearly understood from the detailed description and the accompanying drawings, wherein:
FIG. 1 is a schematic diagram showing a three dimensional view of a modular cylindrical battery cell holder.
FIG. 2 shows an orthographic view of a modular cylindrical battery cell holder.
FIG. 3 shows a cross sectional view of a modular cylindrical battery cell holder for a cut section plane – AA shown in FIG. 2.
FIG. 4 shows a cross sectional view of a modular cylindrical battery cell holder for a cut section plane – BB shown in FIG. 2.
FIG. 5 shows a cross sectional view of a modular cylindrical battery cell holder for a cut section plane – DD shown in FIG. 2.
FIG. 6 is a schematic diagram showing three dimensional view of an assembly of two modular cylindrical battery cell holders.
FIG. 7 shows an orthographic view of an assembly of two modular cylindrical battery cell holders.
FIG. 8 shows a cross sectional view of an assembly of two modular cylindrical battery cell holders for a cut section plane – AA shown in FIG. 7.
FIG. 9 shows a cross sectional view of an assembly of two modular cylindrical battery cell holders for a cut section plane – BB shown in FIG. 7.
FIG. 10 shows a cross sectional view of an assembly of two modular cylindrical battery cell holders for a cut section plane – CC shown in FIG. 7.
FIG. 11 shows a cross sectional view of an assembly of two modular cylindrical battery cell holders for a cut section plane – DD shown in FIG. 7.
FIG. 12 is a schematic diagram showing three dimensional view of a battery pack module.
FIG. 13 is a schematic diagram showing three dimensional view of an assembly of two battery pack modules.
FIG. 14 shows an orthographic view of an assembly of two battery pack modules.
FIG. 15 shows a cross sectional view of an assembly of two battery pack modules for a cut section plane – BB shown in FIG. 14.
FIG. 16 shows a cross sectional view of an assembly of modular cylindrical battery cell holders along with battery cells for a cut section plane – CC shown in FIG. 14.
FIG. 17 shows a cross sectional view an assembly of modular cylindrical battery cell holders along with battery cells for a cut section plane – DD shown in FIG. 14.
FIG. 18 is a schematic diagram showing three dimensional view of a locking pin for assembling battery pack modules.
FIG. 19 shows an orthographic view of a locking pin.
FIG. 20 shows a cross sectional view of a locking pin for a cut section plane – AA shown in FIG. 19.
FIG. 21 shows a cross sectional view of a locking pin for a cut section plane – BB shown in FIG. 19.
FIG. 22 is a schematic diagram showing a three dimensional view of a single battery cell holder.
FIG. 23 shows an orthographic view of a single battery cell holder.
FIG. 24 shows a cross sectional view for a cut section plane – AA shown in FIG. 23.
FIG. 25 shows a cross sectional view for a cut section plane – BB shown in FIG. 23.
FIG. 26 shows a cross sectional view for a cut section plane – CC shown in FIG. 23.
FIG. 27 is a schematic diagram showing a three dimensional view of a battery pack with even number of battery cells.
FIG. 28 is a schematic diagram showing a three dimensional view of a battery pack with odd number of battery cells.
FIG. 29 is a schematic diagram showing gripping of a battery cell in a cylindrical cavity (4).
List of designations/ reference numbers in figure
1. a modular cylindrical battery cell holder
2. a terminal side face
3. a cell side face
4. a pair of cylindrical cavity
5. an inner cylindrical face forming the cylindrical cavity (4)
6. a pair of screw mounting mould-in insert
7. a pair of flexible radial gripper provided on the inner cylindrical face (5)
8. a plurality of lateral stops
9. a plurality of locking pin slots
10. a flexible redial grip
11. a battery cell side face of the flexible radial gripper (7)
12. a locking pin side face of the flexible radial gripper (7)
13. a recess formed by the locking pin slot (9)
14. an annular clearance space
15. a locking pin
16. a single battery cell holder
17. a battery pack module
18. a battery cell
19. an annular clearance space
DETAILED DESCRIPTION OF THE INVENTION
The following description of the preferred embodiment(s) is merely exemplary in nature and is in no way intended to limit the invention, its application, or uses.
The description of illustrative embodiments according to principles of the present invention is intended to be read in connection with the accompanying drawings, which are to be considered as a part of the entire written description. In the description of embodiments of the invention disclosed herein, any reference to direction or orientation is merely intended for convenience of description and is not intended in any way to limit the scope of the present invention. Relative terms and directives thereof are for convenience of description only and do not require that the apparatus be constructed or operated in a particular manner unless explicitly indicated as such. Terms such as “attached,” “affixed,” “connected,” “coupled,” “interconnected,” and similar refer to a relationship wherein structures are secured or attached to one another either directly or indirectly through intervening structures, as well as both movable or rigid attachments or relationships, unless expressly described otherwise. Moreover, the features and benefits of the invention are illustrated by reference to the exemplified embodiments. Accordingly, the invention expressly should not be limited to such exemplary embodiments illustrating some possible non-limiting combination of features that may exist alone or in other combinations of features; the scope of the invention being defined by the claims appended hereto.
FIG. 1 shows a three dimensional view of a modular cylindrical battery cell holder (1) for assembling battery cells for building up a battery pack. FIG. 2 shows an orthographic view of the modular cylindrical battery cell holder (1). The modular cylindrical battery cell holder (1) is consisting of a terminal side face (2), a cell side face (3), a pair of cylindrical cavity (4), an inner cylindrical face (5) forming the cylindrical cavity (4), a pair of screw mounting mould-in insert (6), a pair of flexible radial gripper (7) provided on the inner cylindrical face (5), a plurality of lateral stops (8) and a plurality of locking pin slots (9). The pair of cylindrical cavity (4) is extending from the terminal side face (2) to the cell side face (3). The modular cylindrical battery cell holder (1) is made up of a non-conducting material.
In case of a conventional battery cell holder with the cylindrical cavity disclosed in the prior art, because of the variation in the dimensions (i.e. diameter) of the cylindrical battery cell due to manufacturing tolerances, cylindrical battery cell assembled with the battery cell holder may form a clearance or transition or interference fit with the cylindrical cavity. When battery cell diameter forms clearance fit with the cylindrical cavity of the battery cell holder, battery cells of the battery pack and hence battery pack are prone to failure due to fatigue loading and/or fretting because of the vibration of the battery cells due to dynamic loading during the in service conditions. Further, in case of a battery cell diameter forming interference fit with the cylindrical cavity of the battery cell holder, there will be a problem in assembly of the battery cell with the battery cell holder. Further, interference fit between the battery cell and the battery cell holder also results into high contact stresses at the battery cell and a battery cell holder interface.
Lithium-ion batteries behave dynamically in terms of structure and dimension during charging and discharging. Electrode of the battery cell expands during charging. In case of the conventional battery cell holder, this will also transform clearance fit to transition or interference and increase of contact stresses.
To overcome this problem, as shown in FIG. 1, 2, 3 and 5, the modular cylindrical battery cell holder (1) is provided with the pair of flexible radial gripper (7) on the inner cylindrical face (5) forming the cylindrical cavity (4). The pair of flexible radial gripper (7) provided on the inner cylindrical face (5) starting from the intermediate portion of the inner cylindrical face (5) and extending towards the terminal side face (2).
As shown in FIG. 5, the flexible radial gripper (7) is consisting of a flexible redial grip (10) having a battery cell side face (11) and a locking pin side face (12). The flexible radial gripper (7) on the inner cylindrical face (5) is positioned in a recess (13) formed by the locking pin slot (9).
As shown in FIG. 25, nominal diameter of a concentric circle (i.e. concentric to the cylindrical cavity (4)) passing through the battery cell side face (11) of the flexible radial gripper (7) is kept smaller than the minimum diameter of the battery cells considering lower tolerance limit so that, all the battery cells assembled with the modular cylindrical battery cell holder (1) is fitted with an interference fit between the pair of the flexible redial grip (10). As the flexible radial gripper (7) is positioned in the recess (13) formed by the locking pin slot (9), during the assembly of the battery cell with the modular cylindrical battery cell holder (1), the flexible radial grip (10) displaces radially into the recess (13) formed by the locking pin slot (9) and holds the battery cell eccentrically in the cylindrical cavity (4) accommodating its diameter. Further, the a diameter of the cylindrical cavity (4) is kept greater than the maximum diameter of the battery cells considering higher tolerance limit so that, all the battery cells assembled with the modular cylindrical battery cell holder (1) is gripped by the pair of the flexible redial grip (10) and supported on the inner cylindrical face (5) of the cylindrical cavity (4) establishing a line contact. FIG. 29 shows gripping of the battery cell (18) in a cylindrical cavity (4) between the pair of the flexible redial grip (10) and inner cylindrical face (5). The battery cells (18) assembled with the modular cylindrical battery cell holder (1) is gripped eccentrically in the cylindrical cavity (4) by the pair of the flexible redial grip (10) and supported on the inner cylindrical face (5) of the cylindrical cavity (4) establishing a line contact. Because of such arrangement an annular clearance space (19) is created between outer surface of the battery cell and the inner cylindrical face (5) of the cylindrical cavity (4). Because of such arrangement always clearance is maintained between the outer peripheral face of the battery cell and the inner cylindrical face (5). The annular clearance space (19) also act as a flow passage for cooling media resulting into effective heat management in a battery pack. Such type of arrangement lead to parallel modules and prevents variations in the spot welding and results into a reliable welded structure.
For assembling, the battery cell is inserted (or pushed) into the modular cylindrical battery cell holder (1) from the cell side face (3). Because of such an arrangement, assembly of the battery cell with the modular cylindrical battery cell holder (1) becomes easy.
From the terminal side face (2) of the modular cylindrical battery cell holder (1), the plurality of lateral stops (8) is projected out in the radial direction towards the center of the cylindrical cavity (4). The end flat face of the battery cell stop against these lateral stops (8) and maintains the lateral positioning of the modular cylindrical battery cell holder (1) on the battery cells in assembled condition.
FIG. 6 shows a three dimensional view of an assembly of two modular cylindrical battery cell holders (1). As shown in FIG. 6, the modular cylindrical battery cell holders (1) are assembled together by inserting a locking pin (15) into the locking pin slots (9). The plurality of locking pin slots (9) is extended from the terminal side face (2) to the cell side face (3) to form a recess (13). The locking pin (15) is press fitted into the locking slot (9). FIG. 7 shows an orthographic view of an assembly of two modular cylindrical battery cell holders. FIG. 8-10 shows a cross sectional view of an assembly of two modular cylindrical battery cell holders for a cut section plane – AA BB and CC respectively as shown in FIG. 7. As shown in FIG. 10, the locking pin (15) pushes the flexible redial grip (10) in the radial direction towards the center of the cylindrical cavity (4).
FIG. 12 shows a three dimensional view of a battery pack module (17) in which the battery cells are hold with the help of two modular cylindrical battery cell holders (1), one at the top and another at the bottom. FIG. 13 shows a three dimensional view of an assembly of two battery pack modules (17). This individual battery pack modules (17) are assembled together using the locking pins (15) to build the battery pack. Number of the battery pack modules (17) assembled using the locking pins (15) depend upon the required capacity of the battery pack. FIG. 14 shows an orthographic view of an assembly of two battery pack modules (17). The battery pack of different capacity requirement is built by assembling different number of the battery pack modules (17).
FIG. 15-17 shows a cross sectional view of an assembly of two battery pack modules (17) for a cut section plane – BB, CC and DD respectively shown in FIG. 13.
FIG. 18 shows a three dimensional view of the locking pin (15) for assembling battery pack modules (17). FIG. 19 shows an orthographic view of the locking pin (15). FIG. 20-21 shows a cross sectional view of the locking pin (15) for a cut section plane – AA and BB respectively shown in FIG. 19.
As shown in FIG. 15-17, the locking pin (15) pushes the flexible redial grip (10) in the radial direction towards the center of the cylindrical cavity (4), firmly holding the battery cell in the cylindrical cavity (4). This prevents vibration of the individual battery cells assembled with the help of the modular cylindrical battery cell holders (1) of the battery pack due to the dynamic loading to which the battery pack is subjected to in operating condition. Further, in case of expansion of the electrode of the battery cells during charging also clearance is maintained between the outer surface of the battery cell and an inner cylindrical face (5) forming the cylindrical cavity (4). This prevents stressing of the battery cells as contact stresses are limited to small contact area.
Inhomogeneous thermal expansion at the contact interface of the different materials join together for generating soldering joint introduces shear loading and may results into plastic deformation or fracture in the contact region. The screw mounting mold-in inserts (6) are opening on the terminal side face (2) and integrated with the modular cylindrical battery cell holder (1) to mechanically mount sensing harnesses on the battery cell busbars, so that the soldering of those these sensing harnesses on the cell busbars is avoided. This prevents damage of the battery cells due to heating during soldering of the sensing harness. These sensing harnesses are used for measurement and monitoring of temperature as well as voltage at the different locations on the busbars of the battery pack for conditioning monitoring as well as testing. FIG. 6-9 shows the screw mounting mold-in inserts (6).
FIG. 27 is a schematic diagram showing a three dimensional view of a battery pack built with even number of battery cells. FIG. 28 is a schematic diagram showing a three dimensional view of a battery pack built with odd number of battery cells. For building the battery pack with odd number of battery cells a single battery cell holder (16) is used in combination with the modular cylindrical battery cell holder (1). FIG. 22 is a schematic diagram showing a three dimensional view of a single battery cell holder. As shown in FIG. 23-26, the single battery cell holder (16) is also having the pair of flexible radial gripper (7) on the inner cylindrical face (5) forming the cylindrical cavity (4). The flexible radial gripper (7) on the inner cylindrical face (5) is positioned in a recess (13) formed by the locking pin slot (9). The single battery cell holder (16) is assembled with the modular cylindrical battery cell holder (1) using the locking pin (15). The single battery cell holder (16) is also provided with the plurality of lateral stops (8).
In another embodiment of the present invention, number of cylindrical cavity (4) in the modular cylindrical battery cell holder (1) may vary.
In another embodiment of the present invention, for building the battery pack with odd number of battery cells a single battery cell holder (16) is used in combination with the modular cylindrical battery cell holders (1).
BEST METHOD OF PERFORMING THE INVENTI ON
FIG. 27 is a schematic diagram showing a three dimensional view of a battery pack with even number of battery cells. FIG. 28 is a schematic diagram showing a three dimensional view of a battery pack with odd number of battery cells. , Claims:We claim:
1. A modular cylindrical battery cell holder (1) with integrated sensing mounts comprising:
• a terminal side face (2);
• a cell side face (3) parallel to the terminal side face (2);
• a pair of cylindrical cavity (4) extending from the terminal side face (2) to the cell side face (3);
• an inner cylindrical face (5) forming the cylindrical cavity (4);
• a plurality of screw mounting mold-in inserts (6) opening on the terminal side face (2) and integrated with the modular cylindrical battery cell holder (1) to mechanically mount sensing harnesses on battery cell busbars;
• a plurality of lateral stops (8) projected out in the radial direction towards the center of the cylindrical cavity (4) from the terminal side face (2) for maintaining lateral positioning of the modular cylindrical battery cell holder (1) on the battery cells in assembled condition;
• a plurality of locking pin slots (9) extending from the terminal side face (2) to the cell side face (3) forming a recess (13) for assembling the multiple modular cylindrical battery cell holders using a locking pin (15);
• a pair of flexible radial gripper (7) provided on the inner cylindrical face (5) starting from the intermediate portion of the inner cylindrical face (5) and extending towards the terminal side face (2) wherein, the flexible radial gripper (7) is consisting of a flexible redial grip (10) having a battery cell side face (11) and a locking pin side face (12) and, is positioned in the recess (13) formed by the locking pin slot (9);
Wherein
• nominal diameter of a concentric circle (i.e. concentric to the cylindrical cavity (4)) passing through the battery cell side face (11) of the flexible radial gripper (7) is kept smaller than the minimum diameter of the battery cells considering lower tolerance limit, a diameter of the cylindrical cavity (4) is kept greater than the maximum diameter of the battery cells considering higher tolerance limit so that, all the battery cells (18) assembled with the modular cylindrical battery cell holder (1) is gripped eccentrically in the cylindrical cavity (4) by the pair of the flexible redial grip (10) and supported on the inner cylindrical face (5) of the cylindrical cavity (4) establishing a line contact creating annular clearance space (19) between outer surface of the battery cell and the inner cylindrical face (5) of the cylindrical cavity (4) acting as a flow passage for cooling media for effective cooling of a battery pack leading to parallel modules preventing variations in the spot welding and results into a reliable welded structure;
• in the assembled condition, locking pin (15) pushes the flexible radial grip (10) towards the battery cell cylindrical face generating adequate gripping pressure for preventing vibration of the individual cell due to in-service dynamic loading of the battery pack;
• to build a battery pack, individual battery pack modules (17) consisting of the battery cells held with the help of two modular cylindrical battery cell holders (1), one at the top and another at the bottom are assembled together using the locking pins (15) and;
• to prevent thermomechanical damage to the battery cells by avoiding soldering, the sensing harnesses are mounted mechanically on the battery cell busbars.
2. The modular cylindrical battery cell holder (1) with integrated sensing mounts as claimed in claim 1, wherein the battery pack of different capacity requirement is built by assembling different number of the battery pack modules (17).
3. The modular cylindrical battery cell holder (1) with integrated sensing mounts as claimed in claim 1, wherein the battery pack of different capacity with either even number of total battery cells or odd number of total battery cells is buildup.
4. The modular cylindrical battery cell holder (1) with integrated sensing mounts as claimed in claim 1, wherein the modular cylindrical battery cell holder (1) is made up of a nonconducting material.
5. The modular cylindrical battery cell holder (1) with integrated sensing mounts as claimed in claim 1, wherein number of cylindrical cavity (4) in the modular cylindrical battery cell holder (1) may vary.
6. The modular cylindrical battery cell holder (1) with integrated sensing mounts as claimed in claim 1, wherein for building the battery pack with odd number of battery cells a single battery cell holder (16) is used in combination with the modular cylindrical battery cell holders (1).