BATTERY MODULE FRAME ASSEMBLY

Abstract

A frame assembly for a battery module with at least one battery cell stack. The frame assembly includes end plates forming the ends of the battery cell stack, side plates forming the sides of the battery cell stack, and locking plates that secure each end of the side plates to an end plate. The end plates have studs protruding from them, and the side plates have open-ended slots near the open-ended slots protruding from them to receive the studs and pins. The locking plates have stud and pin openings that receive the studs and pins for attaching the side plates to the end plates. Fasteners engage the studs to hold the locking plates on the studs and pins. The frame assembly maintains the compression of the battery cell stack.

Description

INTRODUCTION

[0001] The present invention relates to a battery module frame assembly with battery cell stacks. More particularly, the present invention relates to the connection of side plates to end plates for forming a compression frame on a battery cell stack.

[0002] As the closest prior art, reference is made at this point to the documents US 2013 / 0 183 571 A1 and US 2011 / 0 104 548 A1.

[0003] Electric and hybrid vehicles have a high-voltage electrical battery system consisting of multiple battery cells. These electric and hybrid vehicles typically require multiple battery cells to meet the vehicle's power and energy needs. The battery cells are often located under the vehicle body, midway between the front and rear wheels.

[0004] To achieve the required power, multiple battery cells are arranged in a stack and compressed together. Multiple battery cell stacks can be comprised within a battery module. In a battery module assembly, the connection between the end plate and the side plate is a very critical joint that must be designed to be easy to assemble, maintain cell compression throughout its life cycle, and meet stringent loading conditions. Typically, end plates and side plates are joined by bonding and welding. Although effective, there is a need for improved assembly techniques that are simpler to assemble and that can be easily disassembled non-destructively to enable module-level maintenance and easy recycling. SUMMARY

[0005] According to the invention, a frame assembly for a battery module with at least one battery cell stack is presented, which is characterized by the features of claim 1.

[0006] The frame assembly includes end plates for forming ends on the battery cell stack, each end plate having a battery side facing the battery cell stack and an outer side opposite the battery side, the outer side having bolts extending away from the outer side, side plates for forming sides on the battery cell stack, the side plates having opposite ends and a sidewall portion extending between the ends, the sidewall portion having a battery side facing the battery cell stack and an outer side opposite the battery side, each side plate end having a locking portion extending away from the sidewall portion in a direction in which the sidewall faces the battery side, the locking portion having an open-ended slot and a pin extending away from the locking portion,Locking plates for attaching the side plates to the end plates, the locking plates having a bolt opening and a pin opening and fasteners that engage the bolts. One of the end plates is arranged at each end of the battery cell stack, the side plates are arranged along opposite sides of the battery cell stack, each locking portion being arranged over the outside of an end plate and the bolt being arranged within the slot, the locking plates are arranged on the locking portions, the bolt being in the bolt opening and the pin being in the pin opening, and the fasteners being attached to the bolts and securing the locking plates to the bolt and the pin, and the frame assembly maintaining compression of the battery cell stack.

[0007] In one aspect, the end plates have side edges and a bolt is disposed adjacent to each side edge.

[0008] Another aspect is that the end plate has bolts adjacent to each side edge, the locking portions of the side plate are provided with pins and have an open-ended slot for each bolt adjacent to the side edge of the end plate.

[0009] In another aspect, the locking plate has opposing end locking portions and an intermediate portion extending between the end locking portions, each locking plate end portion having a bolt opening and a pin opening, and the locking plate secures the side plate on each side of the battery cell stack to the end plate, each locking plate end portion being disposed on the side plate locking portion with the bolt in the bolt opening and the pin in the pin opening.

[0010] Another aspect is that the intermediate portion of the locking plate has a rib portion extending between the end locking portions.

[0011] In another aspect, a center support for forming sides to adjacent battery cell stacks is included, the center support having opposite ends and a center support portion extending between the ends, the center support portion having opposite first and second sides for facing the adjacent battery cell stacks, each center support end having a double locking portion, the double locking portion having a first locking portion extending away from the first center support side and a second locking portion extending away from the second center support side, the first and second locking portions each having an open-ended slot and a pin extending away from the locking portion. One of the end plates is disposed at each end of adjacent battery cell stacks,The center support is arranged between facing sides of adjacent battery cell stacks, each locking portion being disposed over the outer side of an end plate and the bolt being disposed within the slot. The side plates are arranged along non-facing sides of the adjacent battery cell stacks, each locking portion being disposed over the outer side of an end plate and the bolt being disposed within the slot. The locking plates are arranged on the locking portions, the bolt being disposed in the bolt opening and the pin being disposed in the pin opening. The fastening means are attached to the bolts and secure the locking plates to the bolt and the pin. The frame assembly maintains the compression of the battery cell stacks.

[0012] In another aspect, a center beam locking plate is included having a first portion with a bolt opening and a pin opening and a second portion with a bolt opening and a pin opening, wherein the center beam locking plate is disposed on the first and second center beam locking portions with the bolts in the bolt openings and the pins in the pin openings, and the center beam locking plate secures the center beam to two end plates.

[0013] In another aspect, side supports having opposite ends, a rectangular cross-section, and a side wall surface are included, each side panel having a side support attached to the side wall exterior.

[0014] In another embodiment, a battery module is provided. The battery module comprises a plurality of battery cells arranged in a battery cell stack, the battery cell stack having opposite ends and opposite sides extending between the ends, end plates each having a battery side facing the battery cells and an outer side opposite the battery side, the outer side having bolts extending away from the outer side, side plates each having opposite ends and a sidewall portion extending between the ends, the sidewall portion having a battery side facing the battery cells and an outer side opposite the battery side, each side plate end having a locking portion extending away from the sidewall portion in a direction,in which the side wall faces the battery side, wherein the locking portion has an open-ended slot and a pin extending from the locking portion, locking plates for attaching the side plates to the end plates, the locking plates each having a bolt opening and a pin opening, and fasteners engaging the bolts. An end plate is arranged at each end of the battery cell stack, a side plate is arranged along each side of the battery cell stack, each locking portion being arranged over the outside of one of the end plates and the bolt being arranged in the slot, the locking plates are arranged on the locking portions, the bolt being arranged in the bolt opening and the pin being arranged in the pin opening, the fasteners are attached to the bolts and secure the locking plates to the bolt and the pin,and the side plates are attached to the end plates and maintain the compression of the battery cell stack.

[0015] In one aspect, the end plates have side edges and a bolt is disposed adjacent to each side edge.

[0016] Another aspect is that the end plates have bolts arranged adjacent to each side edge, the locking portions of the side plates have pins and have an open slot for each bolt adjacent to the side edge of the end plate.

[0017] In another aspect, the locking plate has opposing end locking portions and an intermediate portion extending between the end portions, each end locking portion of the locking plate having a bolt opening and a pin opening, and the locking plate secures the side plate on each side of the battery cell stack to the end plate, each end locking portion of the locking plate being disposed on the locking portion of the side plate, the bolt being disposed in the bolt opening and the pin being disposed in the pin opening.

[0018] Another aspect is that the intermediate portion of the locking plate has a rib portion extending between the end portions.

[0019] In another aspect, side supports having opposite ends, a rectangular cross-section, and a side wall surface are included, each side panel having a side support attached to the side wall exterior.

[0020] In yet another embodiment, a battery module is provided. The battery module comprises a plurality of battery cells arranged in two battery cell stacks, each of the battery cell stacks having opposite ends and opposite sides extending between the ends, the battery cell stacks being arranged side by side, each battery cell stack having a facing side facing the other battery cell stack and a non-facing side opposite the facing side, end plates each having a battery side facing the battery cells and an outer side opposite the battery side, the outer side having bolts extending away from the outer side, side plates each having opposite ends and a sidewall portion extending between the ends,wherein the side wall portion has a battery side facing the battery cells and an outer side opposite the battery side, wherein each side plate end has a locking portion extending away from the side wall portion in a direction facing the battery side of the side wall, wherein the locking portion has an open-ended slot and a pin extending away from the locking portion, a center beam having opposite ends and a center beam portion extending between the ends, wherein the center beam portion has opposite first and second sides to face the adjacent battery cell stacks, wherein each center beam end has a double locking portion, wherein the double locking portion has a first locking portion extending away from the first center beam side,and a second locking portion extending away from the second center support side, wherein the first and second locking portions each have an open-ended slot and a pin extending away from the locking portion, locking plates for attaching the side plates and the center support to the end plates, each of the locking plates having a bolt opening and a pin opening, and fasteners engaging the bolts. One of the end plates is disposed at each end of the adjacent battery cell stacks, the center support is disposed between the facing sides of the adjacent battery cell stacks, each locking portion being disposed over the outside of an end plate and the bolt being disposed within the slot, the side plates being disposed along the non-facing sides of the adjacent battery cell stacks,wherein each locking portion is disposed over the outside of an end plate and the bolt is disposed within the slot, the locking plates are disposed on the locking portions, the bolt is disposed in the bolt opening and the pin is disposed in the pin opening, and the fastening means are attached to the bolts and secure the locking plates to the bolt and the pin, and the center support and the side plates are attached to the end plates and maintain the compression of the battery cell stacks.

[0021] In one aspect, the end plates have side edges and a bolt is disposed adjacent to each side edge.

[0022] Another aspect is that the end plates have bolts adjacent each side edge, the locking portions of the side plates have pins and have an open-ended slot for each bolt adjacent the side edge of the end plate, and the first and second locking portions of the center beam each have pins and have an open-ended slot for each bolt adjacent the side edge of the end plate.

[0023] In another aspect, the locking plates have opposing end locking portions and a middle locking portion between the end locking portions, each end locking portion having a bolt opening and a pin opening, the middle locking portion having spaced bolt openings and spaced pin openings, the locking plate attaches the side plate on each side of the battery cell stacks to an end plate, each end locking portion on the side plate locking portion being disposed with the bolt in the bolt opening and the pin in the pin opening, and the locking plate attaches the center support to end plates of both battery cell stacks, the middle locking portion being disposed on the locking portions of the double locking portion with the bolts in the bolt openings and the pins in the pin openings.

[0024] In another aspect, the locking plates comprise side locking plates that secure the side plates to the end plates, and center support locking plates that secure the center support to two end plates, each side locking plate having a bolt opening and a pin opening, and each center support locking plate having spaced-apart bolt openings and spaced-apart pin openings, the side locking plates secure the locking portion of a side plate on one side of the battery cell stacks to an end plate, the side locking plate being arranged on the side plate locking portion with the bolt in the bolt opening and the pin in the pin opening, and the center support locking plate securing the center support to end plates of both battery cell stacks,wherein the center beam locking plate is arranged on the locking sections of the double locking section with the bolts in the bolt openings and the pins in the pin openings.,

[0025] In another aspect, side supports having opposite ends, a rectangular cross-section, and a side wall surface are included, each side panel having a side support attached to the side wall exterior.

[0026] Further areas of application will become apparent from the present description. It is understood that the description and specific examples are for illustrative purposes only. BRIEF DESCRIPTION OF THE DRAWINGS

[0027] The drawings described here are for illustrative purposes only. Fig. 1 is a schematic view of an exemplary motor vehicle having a battery pack with battery modules according to the principles of the present invention, Fig. 2 is a fragmented isometric view of a battery module having two battery cell stacks and a one-piece locking plate according to an exemplary embodiment; Fig. 3 is an exploded isometric view of a battery module having two battery cell stacks and a one-piece locking plate according to an exemplary embodiment; Fig. 4 is an isometric view of a side plate according to an exemplary embodiment; Fig. 5 is an isometric view of a center beam according to an exemplary embodiment; Fig. 6 is an isometric view of an end plate according to an exemplary embodiment; Fig. 7 is an isometric view of a side plate with a side support according to an exemplary embodiment; Fig. 8 is a fragmented isometric exploded view of a battery module having two battery cell stacks and a plurality of locking plates according to an exemplary embodiment; Fig. 9 is a fragmented isometric exploded view of a battery module having a battery cell stack and one or more integral locking plates according to an exemplary embodiment. DETAILED DESCRIPTION

[0028] The following description is merely exemplary and is not intended to limit the present invention, application, or uses.

[0029] With reference to Fig. 1, a battery module 10 for a battery pack 12 is illustrated in accordance with the principles of the present invention. The battery module 10 is configured for use with battery cell stacks, as described in more detail below. The battery pack 12 is illustrated with an exemplary vehicle 14. The vehicle 14 is preferably an electric or hybrid vehicle having wheels 16 driven by electric motors / inverters 18. The electric motors / inverters 18 are supplied with motive power by the battery pack 12. Although the vehicle 14 is illustrated as a passenger vehicle, the battery module 10 and battery pack 12 may also be used in various other types of vehicles. The battery module 10 and battery pack 12 may be used, for example, in watercraft, such as boats, or in aircraft, such as drones or passenger airplanes.In addition, the battery module 10 and the battery pack 12 can be used as a stationary power source separately and independently of a vehicle.

[0030] The battery pack 12 generally includes a battery tray 20 connected to the vehicle 14. The battery tray 20 provides structural support for one or a plurality of battery modules 10 disposed within the battery pack 12. The battery modules 10 are preferably lithium-ion battery cells. However, any type of battery cells may be used.

[0031] With reference now to Fig. 2 and Fig. Figure 3 shows the battery module 10 with two battery cell stacks 22, the components of a frame assembly 24, and a cover 25. Each battery cell stack 22 includes battery cells 26 arranged side by side and compressed together. The battery cells 26 are preferably rectangular, plate-shaped lithium-ion battery cells. However, any type of battery cell 26 may be used, as long as the battery cell 26 is compatible with the frame assembly 24.

[0032] The frame assembly 24 serves to assemble the battery module 10 and to secure and maintain the compression of the battery cells 26 in the battery cell stacks 22 throughout the service life of the battery cells 26, as well as to cope with severe load cases. The frame assembly 24 ensures relatively simple assembly of the battery module 10 and enables the battery module 10 to be disassembled non-destructively to enable the serviceability of the battery module 10 and easy recycling. The frame assembly 24 includes end plates 28 that form the ends of the battery cell stack 22, side plates 30 that form the sides of the battery cell stack 22, locking plates 32 that attach the side plates 30 to the end plates 28, and fasteners 34 that attach the locking plates 32 to the end plates 28. The locking plates 32, as described below with reference to Fig. 8 and Fig. 9, can be present in different configurations. The frame assembly 24 can also include side supports 36 that are attached to the side plates 30. For adjacent battery cell stacks 22, the frame assembly 24 can also include a center support 38 that is arranged between the adjacent battery cell stacks 22. The center support 38 forms the sides of the two adjacent battery cell stacks 22. The locking plates 32 secure the center support 38 to the end plates 28.

[0033] With reference to Fig. 6, the end plates 28 have a battery side 40 facing the battery cells 26 and an outer side 42 opposite the battery side 40. The end plates 28 have side edges 44. The end plates 28 have a plurality of bolts 46 extending from the outer side 42. The bolts 46 may be disposed adjacent to each side edge 44. The fasteners 34 may be attached to the bolts 46. The bolts 46 may be threaded to be attached to the fasteners 34.

[0034] With reference to Fig. 4, the side plates 30 have opposite ends 48 and a sidewall portion 50 extending between the ends 48. The sidewall portion 50 has a battery side 52 facing the battery cells 26 and an outer side 54 opposite the battery side 52. The side plates 30 have locking portions 56 at the ends 48, and the locking portions 56 extend from the sidewall portion 50 in a direction facing the battery side 52. The locking portion 56 can be perpendicular to the sidewall portion 50 or at a different angle. The locking portions 56 each have slots 58 with open ends and pins 60 extending away from the locking portions 56. The slots 58 are configured to receive the bolts 46. The pins 60 run parallel to the side wall section 50. The pins 60 engage the locking plates 32 as described below.

[0035] With reference to Fig. 5, the center support 38 has opposite ends 62 and a center support portion 64 extending between the ends 62. The center support portion 64 has a first side 66 and a second side 68 opposite the first side 66. The center support 38 is disposed between adjacent battery cell stacks 22, with the first side 66 of the center support facing a first of the adjacent battery cell stacks 22 and the second side 68 of the center support facing a second of the adjacent battery cell stacks 22. The center support ends 62 each have a double locking portion 70. The double locking portion 70 has a first locking portion 72 extending away from the center support portion 64 in a direction in which the first side 66 faces, and a second locking portion 74 extending away from the center support portion 64 in a direction in which the second side 68 faces.The first and second locking portions 72, 74 of the center beam are perpendicular to the center beam portion 64 or may be arranged at a different angle. Both locking portions 72, 74 have open-ended slots 76 and pins 78 extending from the locking portions 72, 74. The slots 76 are configured to receive the bolts 46. The pins 78 may extend parallel to the center beam portion 64. The pins 78 engage the locking plates 32, as described below.

[0036] With reference to Fig. 7, the side beams 36 have opposite ends 80 and a side surface 82. The side beams 36 have a rectangular cross-section or may have another shape. The side beams 36 are attached to the outer side 54 of the sidewall portion 50 of the side plates 30, with the sidewall surface 82 facing the sidewall portion 50. The side beams 36 may be welded to the side plates 30 or attached using other techniques. The side beams 36 may be sized such that the ends 80 of the side beams 36 extend beyond the ends 48 of the side plates 30. The side beams 36 provide structural support to the side plates 30 and may facilitate movement of the side plates 30 relative to the battery cell stacks 22 to engage the locking portions 56 with the end plates 28.

[0037] With reference to Fig. 2 and Fig. 3, the locking plates 32 can be configured as complete locking plates 83, so that a single locking plate 32 can be used at each end of the battery module 10 with two adjacent battery cell stacks 22. The complete locking plates 83 secure the side plates 30 and the center support 38 to the end plates 28 of the two adjacent battery cell stacks 22, with one complete locking plate 83 provided for each end of the battery module 10. The complete locking plate 83 has opposing end locking portions 84 and a central locking portion 86 disposed between the end locking portions 84. The complete locking plate 83 has intermediate portions 88 between the central locking portion 86 and each end locking portion 84.The end locking sections 84 each have bolt openings 90 and pin openings 92 into which the bolts 46 on the end plate 28 and the pins 60 on the side plate 30 can be inserted. The middle locking section 86 has two sets of spaced-apart bolt openings 90 and pin openings 92 to allow the insertion of the bolts 46 on the two end plates 28 and the pins 78 on the center support 38. The intermediate sections 88 extend along the outer sides 42 of the end plates 28. The intermediate sections 88 can have a rib section 94 extending between the end locking section 84 and the middle locking section 86. The rib sections 94 can increase the stability and rigidity of the complete closure plate 83.

[0038] With reference to Fig. 8, the locking plates 32 can be configured so that a single locking plate 32 can be used at each end of the battery module 10 with two adjacent battery cell stacks 22. The locking plates 32 secure the side plates 30 and the center support 38 to the end plates 28 of the two adjacent battery cell stacks 22 with multiple locking plates 32 for each end of the battery module 10. The locking plates 32 can include a side locking plate 96 for securing a side plate 30 to an end plate 28 and a center support locking plate 98 for securing the center support 38 to two end plates 28. The side locking plate 98 has bolt openings 90 and pin openings 92 that allow insertion of the bolts 46 on the end plate 28 and the pins 60 on the side plate 30 to secure a side plate 30 to an end plate 28.The center beam locking plate 98 has two sets of spaced-apart bolt openings 90 and pin openings 92 that allow insertion of the bolts 46 on two end plates 28 and the pins 78 on the center beam 38 to secure the center beam 38 to two end plates 28. The side locking plate 96 and the center beam locking plate 98 can be configured such that they do not extend along the outer sides 42 of the end plates 28.

[0039] With reference to Fig. 9, the battery module 10 may include a single battery cell stack 22. If the battery module 10 has a single battery cell stack 22, each of the side plates 30 may be individually secured to the end plates 28 using the side locking plates 96. Alternatively, the locking plate 32 may be configured as a two-sided locking plate 100 with opposing end locking portions 102 and an intermediate portion 104 between the locking portions 102. The end locking portions 102 each have bolt openings 90 and pin openings 92 into which the bolts 46 on the end plate 28 and the pins 60 on the side plate 30 can be inserted. The intermediate portion 104 extends along the outer side 42 of the end plate 28. The intermediate portion 104 may include a rib portion 106 extending between the end locking portions 102.The rib portions 106 can increase the stability and rigidity of the double-sided locking plate 100.

[0040] With reference to Fig. 2, Fig. 3, Fig. 8 and Fig. 9, the frame assembly 24 provides bolted, non-slip joints (BASSEJ) for mechanically connecting the side plate 30 and the end plate 28, as well as for mechanically connecting the center beam 38 and the end plates 28 of the battery module 10 with a lockable slip plane to facilitate assembly and structural requirements. The battery module 10 may include one or more battery cell stacks 22. Each battery cell stack 22 may be formed by disposing a plurality of battery cells 26 between two end plates 28 and compressing the battery cells 26 over the end plates 28.

[0041] When forming a single battery cell stack 22, the side plates 30 are positioned on opposite sides of the battery cells 26 with the battery side 52 facing the battery cells 26, and the side plates 30 are moved toward the battery cells 26 and end plates 28. The locking portions 56 move relative to or slide over the outer sides 42 of the end plates 28, and the bolts 46 enter the open-ended slots 58. The locking plates 32 are then positioned with the bolts 46 in the bolt openings 90 and the pins 60 in the pin openings 92. The fasteners 34 are then attached to the bolts 46, securing the side plates 30 to the end plates 28. The engagement of the side plates 30 with the end plates 28 maintains compression of the battery cells 26.

[0042] When two battery cell stacks 22 are formed, the battery cell stacks 22 are arranged side by side, with each battery cell stack 22 having a facing side facing the other battery cell stack 22 (the facing sides) and a non-facing side facing away from the other battery cell stack 22 (the non-facing sides). A center support 38 is arranged between the adjacent battery cell stacks 22, with the first side 66 facing the non-facing side of one of the battery cell stacks 22 and the second side 68 facing the non-facing side of the other battery cell stack 22. The side plates 30 are arranged on the non-facing sides of the battery cell stacks 22, with the battery sides 52 facing the battery cells 26. The side plates 30 are moved toward the battery cells 26 and the end plates 28.The locking portions 56 move relative to or slide over the outer sides 42 of the end plates 28, and the bolts 46 enter the open-ended slots 58. The battery cell stacks 22 are moved toward the center support 38. The first and second locking portions 72, 74 move relative to or slide over the outer sides 42 of the end plates 28, and the bolts 46 enter the open-ended slots 76. The locking plates 32 are then positioned such that the bolts 46 are positioned in the bolt openings 90 and the pins 60 and 78 are positioned in the pin openings 92. The fasteners 34 are then attached to the bolts 46 and secure the side plates 30 and the center support 38 to the end plates 28. The engagement of the side plates 30 and the center support 38 with the end plates 28 maintains the compression of the battery cells 26 in both battery cell stacks 22.

[0043] Using the open-ended slots and pins and bolted anti-slip joints (BASSEJ) to mechanically connect the side plate 30 and the end plate 28, as well as to mechanically connect the center beam 38 and the end plate 28 of the battery module 10 with a lockable sliding plane, offers several advantages. These include an improved and simpler assembly technique that meets structural requirements, and the battery module 10 can be easily disassembled non-destructively to enable module-level maintenance and easy recycling.

Claims

[1] Frame assembly (24) for a battery module (10), wherein the battery module (10) has at least one battery cell stack (22), wherein the frame assembly (24) comprises: End plates (28) for forming ends on the battery cell stack (22), each end plate (28) having a battery side (40) facing the battery cell stack (22) and an outer side (42) opposite the battery side (40), the outer side (42) having bolts (46) extending away from the outer side (42); Side plates (30) for forming sides on the battery cell stack (22), the side plates (30) having opposite ends (48) and a sidewall portion (50) extending between the ends (48), the sidewall portion (50) having a battery side (52) facing the battery cell stack (22) and an outer side (54) opposite the battery side (52), each side plate end (48) having a locking portion (56) extending away from the sidewall portion (50) in a direction facing the battery side (52) of the sidewall (50), the locking portion (56) having an open-ended slot (58) and a pin (60) extending away from the locking portion (56); Locking plates (32) for securing the side plates (30) to the end plates (28), the locking plates (32) having a bolt opening (90) and a pin opening (92); and Fastening elements (34) which engage with the bolts (46), wherein one of the end plates (28) is arranged at each end of the battery cell stack (22), the side plates (30) are arranged along opposite sides of the battery cell stack (22), wherein each locking portion (56) is arranged over the outer side (42) of an end plate (28) and the bolt (46) is arranged within the slot (58), wherein the locking plates (32) are arranged on the locking portions (56) with the bolt in the bolt opening (90) and the pin (60) in the pin opening (92), and wherein the fastening means (34) are attached to the bolt (46) and secure the locking plates (32) on the bolt (46) and the pin (60), and the frame assembly (24) maintains the compression of the battery cell stack (22). [2] Frame assembly (24) according to claim 1, wherein the end plates (28) have side edges (44) and a bolt (46) is arranged on each side edge (44). [3] The frame assembly (24) of claim 2, wherein the end plate (28) has bolts (46) adjacent each side edge (44), the locking portions (56) of the side plate (30) having pins (60) and an open-ended slot (58) for each bolt (46) adjacent the side edge (44) of the end plate (28). [4] The frame assembly (24) of claim 1, wherein the locking plate (32) includes opposite end locking portions (102) and an intermediate portion (104) extending between the end locking portions (102), each locking plate end portion having a bolt opening (90) and a pin opening (92), and the locking plate (32) secures the side plate (30) on each side of the battery cell stack (22) to the end plate (28), each locking plate end portion (102) being disposed on the side plate locking portion (56) with the bolt (46) in the bolt opening (90) and the pin (60) in the pin opening (92). [5] The frame assembly (24) of claim 4, wherein the intermediate portion (104) of the locking plate (32) includes a rib portion (106) extending between the end locking portions (102). [6] The frame assembly (24) of claim 1, further comprising a center beam (38) for forming sides to adjacent battery cell stacks (22), the center beam (38) having opposite ends (62) and a center beam portion (64) extending between the ends (62), the center beam portion (64) having opposite first and second sides (66, 68) for facing the adjacent battery cell stacks (22), each center beam end (62) having a double locking portion (72, 74), the double locking portion (72, 74) having a first locking portion (72) extending away from the first center beam side (66) and a second locking portion (74) extending away from the second center beam side (68), the first and second locking portions (72, 74) each having a slot (76) with open end and a pin (78),which extends away from the locking portion (72, 74), wherein one of the end plates (28) is arranged at each end of adjacent battery cell stacks (22), the center support (38) is arranged between mutually facing sides of adjacent battery cell stacks (22), wherein each locking portion (72, 74) is arranged over the outer side (42) of an end plate (28) and the bolt (46) is arranged in the slot (76), the side plates (30) are arranged along non-facing sides of the adjacent battery cell stacks (22), wherein each locking portion (72, 74) is arranged over the outer side (42) of an end plate (28) and the bolt (46) is arranged in the slot (76), the locking plates (32) are arranged on the locking portions (72, 74), wherein the bolt (46) is in the bolt opening (90) and the pin (78) is in the pin opening (92) and are arranged on the locking sections (72, 74),wherein the bolt (46) is arranged in the bolt opening (90) and the pin (78) is arranged in the pin opening (92), and wherein the fastening means (34) are attached to the bolt (46) and fasten the locking plates (32) to the bolt (46) and the pin (78), and the frame assembly (24) maintains the compression of the battery cell stacks (22). [7] The frame assembly (24) of claim 6, further comprising a center beam locking plate (98) having a first portion with a bolt opening (90) and a pin opening (92) and a second portion with a bolt opening (90) and a pin opening (92), the center beam locking plate (98) being disposed on the first and second center beam locking portions (72, 74) with the bolts (46) in the bolt openings (90) and the pins (78) in the pin openings (92), the center beam locking plate (98) securing the center beam (38) to two end plates (28). [8] The frame assembly (24) of claim 1, further comprising side supports (36) having opposite ends (48), a rectangular cross-section, and a side wall surface, each side panel (30) having a side support (36) attached to the side wall outer surface (54).

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