Battery pack with removable electronic module

Abstract

The invention relates to a battery pack (10) for supplying energy to a drive unit of a bicycle, wherein the battery pack (10) comprises: a battery module (14) with several battery cells (16) which are electrically connected to each other and an electronic module (12), wherein the electronic module (12) and the battery module (14) are detachably connected to each other. The invention further relates to a bicycle with a drive unit and a battery pack (10) and a method for mounting a battery pack (10).

Description

[0001] The invention relates to a battery pack according to claim 1. The battery pack serves to supply energy to a drive unit of a bicycle. The invention further relates to a bicycle with such a battery pack according to claim 10 and a method for mounting such a battery pack according to claim 11.

[0002] Battery packs for powering a bicycle's drive unit are well-known from the prior art. Such bicycles with a drive unit and a battery pack are also called e-bikes or pedelecs. The drive unit is, in particular, an electric motor, which is connected to the battery pack for energy transfer. A battery pack typically comprises a housing in which one or more battery cells are arranged. Several battery cells are usually combined into a battery module and interconnected within the module.

[0003] Furthermore, battery packs typically include an electronic module with electronics and a battery management system (BMS). The BMS serves, among other things, to monitor the voltage and temperature of the battery cells, as well as to control the load and charging of the battery cells and to balance the battery cells. The electronic module also usually has a (main) connector for charging and discharging the battery pack.

[0004] The electronic module is typically welded to the battery module and / or connected via cables. If a defect occurs that requires opening the battery pack for repair, this will destroy the connection between the electronic module and the battery module, and consequently, both the electronic module and the battery module themselves.

[0005] The fundamental object of the invention is therefore to provide a battery pack, as well as a bicycle with such a battery pack, which enables a simple and sustainable method of assembly and repair of the battery pack. A method is also to be provided that enables simple assembly of the battery pack with as few components as possible.

[0006] The problem is solved according to the invention by the features of the independent claims. Further practical embodiments and advantages are described in connection with the dependent claims.

[0007] A battery pack according to the invention serves to supply energy to a drive unit of a bicycle. The battery pack comprises a battery module with several battery cells. The battery cells are electrically connected to one another. The battery module has several battery cells, and in particular between 20 and 35 battery cells, preferably 24 or 33 battery cells at 3.6 V each. The battery cells are connected in a configuration of 11s3p, 12s2p, or 13s1p. In an 11s3p configuration, 11 battery cells are connected in series in 3 parallel strings. In a 12s2p configuration, 12 battery cells are arranged in series in each of two parallel strings (12s2p). The arrangement of the battery cells in the 12s2p configuration is particularly in two layers, each with two rows of battery cells, each row containing 4 batteries. The battery cells are particularly cylindrical in shape.The battery module is, in particular, a battery module with a supply voltage in the low-voltage range. The nominal voltage of the battery module is, in particular, below 60 V and is preferably between 35 and 45 V, and more preferably 39.6 V or 43 V.

[0008] The battery pack comprises a battery module and an electronics module. The electronics module includes, in particular, a battery management system (BMS). The BMS serves, in a known manner, to monitor the battery cells, especially with regard to their state of charge (cell voltage) and temperature, to control the battery cells, and to protect them. The electronics module also includes a connector through which the battery pack can be charged and discharged. The cell voltage of the interconnected battery cells is provided via this connector.

[0009] The electronic module comprises, in particular, at least one circuit board on which the BMS is implemented and / or the connector is located. The electronic module may, in particular, comprise at least one further circuit board, especially for the implementation of a human-machine interface (HMI), specifically for displaying and reading the state of charge of the battery pack.

[0010] The battery module and the electronic module are both compact units. They are detachably connected. "Detachably" in this context means that the electrical and / or mechanical connection between the battery module and the electronic module can be broken without damage and can also be re-established. Specifically, the battery module and the electronic module are connected by frictional and / or form-fitting means, and not by material bonding.

[0011] The detachable connection, which will be described in more detail below, allows the battery module and the electronics module to be separated again after connection without damaging the components. The individual components remain undamaged and reusable. Furthermore, the avoidance of permanent (material-bonded) connections and especially cables significantly simplifies the manufacturing of the battery pack. Overall, this results in a sustainable battery pack that is easy to assemble and disassemble.

[0012] In particular, the battery module and the electronics module are connected by means of at least one plug connection. This plug connection can be established by moving the battery module and the electronics module relative to each other along a plugging direction, either to establish or to disconnect the connection. Specifically, the electronics module has at least one first plug element, and the battery module has at least one corresponding second plug element. The at least one first plug element and the at least one second plug element are interlockable and create a positive and / or frictional connection. In particular, the plug elements also serve to establish an electrical connection.

[0013] In one embodiment of the battery pack, different first connector elements and second connector elements are provided, in particular for transmitting the cell voltage and for transmitting the status data (such as state of charge or temperature) of the individual battery cells.

[0014] In a practical embodiment, the electronic module has at least one first connector element that is a clamping element, which is clamped to a corresponding second connector element of the battery module. In particular, the electronic module has two clamping elements. Specifically, the clamping elements project longitudinally from the rest of the electronic module and, in particular, from a circuit board of the electronic module, and are oriented in a plug-in direction. The at least one clamping element is designed such that it is connected to the corresponding second connector element by a clamping force, in particular by a spring-like design.

[0015] The at least one clamping element has, in particular, a U-shaped base. The U-shaped base has two legs which are connected to each other via a base section. A continuous slot is formed between the two legs. Electrical contacts are provided on the opposing sides of the legs for contacting the corresponding second connector element. In particular, the legs are spring-loaded to generate a clamping force and / or the electrical contacts arranged on the inside are spring-loaded. The second connector element is positively locked laterally by the two legs.

[0016] The at least one clamping element serves in particular to transmit the cell voltage. Specifically, a first clamping element serves to connect the electronic module to the negative terminals of the battery cells, and a second clamping element serves to connect it to the positive terminals of the battery cells.

[0017] In particular, the width of the slot is designed such that the corresponding second connector element is securely fixed within it by friction or clamping. Specifically, the slot width is in the range of 0.3–0.5 mm.

[0018] As described above, the slot is continuous, meaning it has three open sides. This offers several advantages: the corresponding second connector element can be moved within the slot over a relatively large length and can even be positioned protruding from the slot at the end face of the U-shaped base body, thus compensating for tolerances. Another advantage is that the connection between the electronic module and the battery module can be established not only along one direction, but also along another direction, transverse and especially perpendicular to the first, by inserting the second connector element into the clamping element along the slot.In particular, the first insertion direction extends parallel to the longitudinal direction of the battery pack and the second insertion direction parallel to the vertical direction of the battery pack.

[0019] In another practical embodiment, the battery module has, as a second connector element, at least one plate-shaped intermediate element connected to a printed circuit board (busbar), which is clamped into the clamping element. In particular, the battery module has two intermediate elements, one of which is connected to the negative terminals of the battery cells and the other to the positive terminals of the battery cells. The cell voltage of the battery cells is therefore transmitted via the intermediate element. The plate-shaped intermediate element has a greater material thickness than the printed circuit board. The intermediate element is more rigid than the printed circuit board and thus less sensitive to force applied during the manufacture or disconnection of the connector than the printed circuit board (busbar) itself.

[0020] The plate-shaped intermediate element can extend in only one plane (especially in an xz-plane), but it is also conceivable that the intermediate element is curved or has two parallel sections connected to each other, so that the intermediate element also extends in the y-direction. Overall, it is a flat element with a small material thickness compared to its longitudinal and transverse dimensions. The intermediate element is made of metal.

[0021] Alternatively, it is also possible to connect the clamping element directly to the respective circuit board in a detachable manner and, in particular, to plug it onto it.

[0022] The at least one intermediate element is, in particular, metallurgically bonded, especially welded, to a printed circuit board that directly contacts the battery cells. The at least one intermediate element has, in particular, a contact section. The contact section has, in particular, a triangular geometry.

[0023] The at least one intermediate element has a plug-in section which, in an assembled position, is at least partially inserted within the slot of the clamping element. The plug-in section can protrude from one or both sides of the continuous slot.

[0024] In another practical embodiment, the at least one intermediate element is positively locked to the battery module to prevent it from being pulled out against a specific insertion direction (in particular, parallel to the x-direction). Specifically, the at least one intermediate element has a hook section which, in an installed position, engages an undercut in the battery module. In particular, the undercut is formed by a cover of the battery cells and acts as a stop for the hook section. This is intended to prevent, as far as possible, the connecting element from detaching from the battery module or the circuit board when the connection between the electronic module and the battery module is disconnected against the insertion direction.

[0025] In another practical embodiment, the battery cells are interconnected by a flexible circuit board, and the flexible circuit board (flex-PCB) is connected to the electronic module via a plug connector, in particular an FPC connector. The electronic module has a corresponding plug contact (or socket) as its first connector element. The FPC connector represents a second connector element. The flexible circuit board serves, in particular, to transmit the battery cell status data to the BMS and to control and balance the battery cells. This connection between the electronic module and the battery module can also be disconnected and reconnected without damage and requires no cables.

[0026] In particular, the electronic module has a connector (or socket) through which the battery cells are charged and / or discharged, the connector being permanently attached to the electronic module. Specifically, the connector is welded or soldered to a circuit board of the electronic module. A cable connection is therefore unnecessary.

[0027] The invention further relates to a bicycle (also called an electric bicycle, e-bike or pedelec) with a drive unit, in particular an electric drive unit, and a battery pack as described above. The drive unit is connected to the battery pack for energy supply. The battery pack, comprising the battery module and the electronic module, is in particular arranged in a frame of the bicycle.

[0028] The invention also relates to a method for assembling a battery pack with an electronic module and a battery module, in particular a battery pack as described above. In this method, an electronic module with at least one first connector element is provided as a pre-assembly, and a battery module with several battery cells and at least one second connector element is provided as a further pre-assembly.

[0029] Subsequently, the electronic module and the battery module are connected by creating a plug connection through relative movement of the battery module and the electronic module along a plugging direction, wherein at least one first plug element is clamped to a corresponding second plug element to create a connection that can be removed without damage.

[0030] The ability to connect the electronic module and the battery module using simple plug connections makes the assembly of the battery module particularly easy.

[0031] As described above, a first plug element can be a clamping element with a continuous slot, which then allows assembly in a first plugging direction and a second plugging direction, parallel to the extent of the slot.

[0032] The assembly can be carried out by first establishing a first plug contact between an FPC connector of a flexible printed circuit board and a corresponding plug contact, and then by performing the relative movement to create a clamping connection between two clamping elements and corresponding second plug elements.

[0033] For further details and benefits, please refer to the description above.

[0034] Further practical embodiments and advantages are described in conjunction with the figures. They show: Fig. 1 A battery pack with a battery module and an electronics module in a separated position in a perspective view from a rear oblique angle, Fig. 2 the battery pack out Fig. 1 in a connected position of the battery module and the electronics module, Fig. 3 the battery pack out Fig. 2 in a detailed view, Fig. 4 the battery pack out Fig. 1 with a battery module and an electronics module in a separated position in a perspective view from an oblique front view, Fig. 5 the battery pack out Fig. 1 with a battery module and an electronics module in a separated position in a top view, Fig. 6 the battery pack out Fig. 5 with a battery module and an electronics module in a connected position in a top view, Fig. 7 the battery module Fig. 1, Fig. 2, Fig. 3, Fig. 4, Fig. 5 to Fig. 6 without intermediate elements in a perspective view from a slightly oblique front view, Fig. 8a a second intermediate element in a perspective view from a rear oblique angle, Fig. 8b the second intermediate element in a perspective view from a slanted front view, Fig. 9a a first intermediate element in a perspective view from a slant behind, Fig. 9b the first intermediate element in a perspective view from a slanted front view, and Fig. 10 The electronic module without cover in a perspective view from a slanted front view.

[0035] In the Fig. 1, Fig. 2, Fig. 3, Fig. 4, Fig. 5 to Fig. Figure 6 shows a battery pack 10 with an electronic module 12 and a battery module 14. As can be clearly seen, the battery module 14 and the electronic module 12 are largely self-contained modules, each of which is supplied as an assembly and is only connected to the corresponding other module for assembly to form the battery pack 10.

[0036] The battery pack 10 has a longitudinal extension (x-direction), a transverse extension (y-direction) and a vertical extension (z-direction).

[0037] The battery module 14 comprises several cylindrical battery cells 16 (see figure). Fig. 1 and Fig. 4 and Fig. 7), which are arranged in two rows one above the other and each extend in the transverse direction (y-direction). The poles 18 of the battery cells 16 are connected via a first circuit board (busbar) 20a to a first end face of the battery cells 16 (see figure). Fig. 1 and Fig. 4) and a second circuit board 20b (busbar) on the second end face of the battery cells 16 (see Fig. 7) electrically contacted. The battery module 14 has a cover 22 which at least partially surrounds and holds together the battery cells 16.

[0038] The electronics module 12 comprises a printed circuit board 24 (see figure). Fig. 1) and here also a cover 26, as well as a seal 27. The electronic module 12 includes a connector 28 (see. Fig. 10) and a battery management system (BMS) (not shown).

[0039] The connector 28 is located on the circuit board 24. (cf. Fig. 10) The connector 28 is metallurgically bonded to the circuit board 24, namely by welding. The connector 28 serves to transmit the cell voltage, to charge and discharge the battery cells 16.

[0040] To connect the electronic module 12 to the battery module 14, the electronic module 12 has three first connector elements 30a, 30b, 30c, namely two clamping elements 32a, 32b and a connector contact 34. The battery module 14 has three corresponding second connector elements 36a, 36b, 36c, namely two intermediate elements 38a, 38b and a flexible printed circuit board 40 with an end-mounted FPC connector 41.

[0041] The cell voltage for charging and discharging the battery cells 16 is transmitted via the terminal elements 32a, 32b and the intermediate elements 38a, 38b and connected to the connector 28. The status data of the battery cells 16 are transmitted to the BMS via the flexible circuit board 40, the FPC connector 41 and the connector contact 34.

[0042] The clamping elements 32a, 32b are well suited to Fig. 1 and Fig. 4, Fig. 5 to Fig. 6 can be seen. The clamping elements 32a, 32b are each arranged at the edge of the circuit board 24 and each protrude in the longitudinal direction (x-direction) of the battery pack 10 opposite the circuit board 24.

[0043] The clamping elements 32a, 32b each have a U-shaped base body 42 with a first leg 44a and a second leg 44b. The two legs 44a, 44b are connected to each other by a base section 46. A slot 48 extending vertically (in the z-direction) is formed between the legs 44a, 44b. As shown in Fig. As can be seen in Figure 5, electrical contacts 50 are formed on the opposing surfaces of the legs 44a, 44b. The legs 44a, 44b are designed to be resilient outwards for clamping the corresponding intermediate elements 38a, 38b in the slot 48, or the contacts 50 are designed to be spring-elastic.

[0044] As described above, plate-shaped intermediate elements 38a, 38b are arranged on the battery module 14, corresponding to the terminal elements 32a, 32b. The terminal elements 32a, 32b are not directly connected to the circuit board 20a, 20b for voltage transmission.

[0045] The intermediate elements 38a, 38b are individually in the Fig. 8a, Fig. 8b, Fig. 9a and Fig. Figure 9b shows the intermediate elements 38a and 38b. These intermediate elements are configured differently due to the structure of the battery module 14. However, the functionality of the intermediate elements 38a and 38b is identical.

[0046] The intermediate elements 38a, 38b are essentially plate-shaped and extend in the xz-plane when installed.

[0047] The intermediate elements 38a, 38b each have a plug-in section 52, which extends vertically (in the z-direction) and is received within the slot 48 of the respective clamping element 32a, 32b in an installed position. The plug-in section 52 extends over a greater height than the slot 48 or the base body 42 of the clamping element 32a, 32b, so that the plug-in section 52 protrudes partially from the slot 48 at the top and / or bottom in an installed position (see Figure 1). Fig. 2).

[0048] The intermediate elements 38a, 38b also have a contact section 54 at which the intermediate elements 38a, 38b can be materially bonded to the respective printed circuit board 20a, 20b, or connected in their installed position. The contact section 54 extends at the lower end of the respective intermediate element 38a, 38b. The contact section 54 is triangular in shape. In the first intermediate element 38a, the contact section 54 is offset from the plug-in section 52 by a curved shoulder in the y-direction. However, the contact section 54 of the first intermediate element 38a extends parallel to the plug-in section 52.

[0049] Furthermore, the intermediate elements 38a, 38b have a hook section 56, which serves for a positive-locking connection with the battery module 14. This is particularly relevant in conjunction with Fig. Figure 7 clearly shows that the hook section 56 engages the cover 22 of the battery module 14 by means of undercuts 58a and 58b. This serves to provide a positive locking mechanism to prevent the intermediate element 38a and 38b from being pulled out when the connection between the electronic module 12 and the battery module 14 is disconnected in the opposite direction S. In the second intermediate element 38b, the hook section 56 is spaced from the plug-in section 52 by a curved shoulder in the y-direction and extends parallel to the plug-in section 52 in an xz-plane.

[0050] In order to additionally fix the intermediate element 38b in the transverse direction of the battery pack 10, a further plate 60 is also arranged adjacent to the hook section 56 in the undercut 58a, 58b.

[0051] In the Fig. 1, Fig. 2, Fig. 3, Fig. 4, Fig. 5 to Fig. Figure 6 shows the intermediate elements 38a and 38b in an installation position within the battery module 14. The intermediate elements 38a and 38b are each inserted with their hook section 56 into the undercuts 58 and are connected to the respective circuit board 20a and 20b via the contact section 54 (not visible). The plug section 52 protrudes longitudinally from the surrounding part of the battery module 14 to establish the connection.

[0052] In addition, the battery module 14 also has a second connector element 36c, the flexible circuit board 40 (see below). Fig. 4 and Fig. 5) with an end-mounted FPC connector 41. Correspondingly, the electronics module 12 has the connector contact 34. The flexible circuit board 40 is bent at one end and guided in two parallel sections to compensate for relative movement between the battery module 14 and the electronics module 12.

[0053] The following describes how to connect the electronic module 12 and the battery module 14. To create a non-destructive connection, the battery module 14 and the electronic module 12 are moved towards each other in a plug-in direction S. Here, the plug-in direction S is parallel to the longitudinal direction (x-direction) of the battery pack 10.

[0054] The end-mounted connector 41 of the flexible circuit board 40 is connected to, or plugged into, the connector contact 34 of the electronic module 12. This connects the battery cells 16 to the BMS for transmitting status data.

[0055] The respective plug-in section 52 of the intermediate elements 38a, 38b is clamped into the slot 48 of the corresponding clamping elements 32a, 32b, and the clamping force creates a force-fit and conductive connection. The clamping elements 32a, 32b also provide a positive fit in the transverse direction (y-direction) of the battery pack 10. Relative movement of the battery module 14 to the electronic module 12 is possible in the vertical direction (z-direction) because the intermediate elements 38a, 38b have a certain amount of play in the slot 48 both in the vertical and opposite directions.

[0056] In addition to the connection in the plug-in direction S parallel to the longitudinal direction, it is also possible to mount the battery module 14 and the electronic module 12 in a second plug-in direction S2 parallel to the vertical direction (z-direction) and to the extension direction of the slot 48. In this case, the electronic module 12 can be plugged onto the battery module 14 against the vertical direction, so that the plug-in sections 52 slide into the respective slot 48 from below.

[0057] To disconnect the connection, the electronic module 12 and the battery module 14 are moved apart opposite to the insertion direction S or the second insertion direction S2. The connecting section 52 of the intermediate elements 38a, 38b, which is held only by clamping force, can be easily pulled out of the slot 48 after overcoming the clamping force and released from the clamping element 32a, 32b. The flexible circuit board 40 can then be unplugged from the connector contact 34.

[0058] This creates a plug connection between the electronic module 12 and the battery module 14, which is easy to assemble and can be disconnected without damage. No cables are provided to connect the individual components in the battery pack 10. Reference symbol list 10 battery packs 12 Electronic module 14 battery module 16 battery cells 18 poles 20a, 20b Circuit board / busbar 22 Cover 24 circuit boards 26 Cover 27 Seal 28 connector plugs 30a, 30b, 30c first connector elements 32a, 32b clamping element 34 Plug contact 36a, 36b, 36c second connector elements 38a, 38b Intermediate element 40 flexible printed circuit boards 41 FPC connectors 42 Base body (clamping element) 44a, 44b thigh 46 Basic section 48 slots 50 electrical contacts 52 Plug section 54 Contact section 56 Hook section 58a, 58b Undercut 60 plates S Plug direction S2 Plug direction

Claims

Battery pack for supplying energy to a drive unit of a bicycle, wherein the battery pack (10) comprises: - a battery module (14) with several battery cells (16) which are electrically connected to each other and - an electronic module (12), wherein the electronic module (12) and the battery module (14) are detachably connected to each other. Battery pack according to the preceding claim, characterized in that the battery module (14) and the electronic module (12) are connected to each other by means of a plug connection. Battery pack according to one of the preceding claims, characterized in that the electronic module (12) has as at least one first connector element (30a, 30b) a clamping element (32a, 32b) which is clamped to a corresponding second connector element (36a, 36b) of the battery module (14). Battery pack according to one of the preceding claims, characterized in that the at least one clamping element (32a, 32b) has a u-shaped base body (42). Battery pack according to one of the two preceding claims, characterized in that the clamping element (32a, 32b) has a continuous slot (48). Battery pack according to one of the preceding claims, characterized in that the battery module (14) has as a second connector element (36a, 36b) at least one plate-shaped intermediate element (38a, 38b) connected to a circuit board (20a, 20b), which is clamped in the corresponding clamping element (32a, 32b). Battery pack according to the preceding claim, characterized in that the intermediate element (38a, 38b) is positively locked against being pulled out against a plugging direction (S) on the battery module (14). Battery pack according to one of the preceding claims, characterized in that the battery module (14) has as a second connector element (36c) an FPC connector (41) which connects a flexible circuit board (40) connected to the battery cells (16) to a first connector element (30c) in the form of a connector contact (34) on the electronic module (12). Battery pack according to one of the preceding claims, characterized in that the electronic module (12) has a connector (28) via which the battery cells (16) are charged and / or discharged, wherein the connector (28) is materially bonded to the electronic module (12). Bicycle with a drive unit and a battery pack (10) according to any one of the preceding claims 1 to 9 . Method for assembling a battery pack (10) characterized by the following steps: - Providing an electronic module (12) with at least one first connector element (30a, 30b, 30c); - Providing a battery module (14) with several battery cells (16), and at least one second connector element (36a, 36b, 36c); - Establishing a plug connection between the electronic module (12) and the battery module (14) by relative movement along a plugging direction (S, S2), wherein the at least one first connector element (30a, 30b, 30c) is clamped to the corresponding second connector element (36a, 36b, 36c).

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