DESCRIPTION

TITLE: ELECTRIC VEHICLE BATTERY

The invention relates to the field of electric vehicle batteries. More specifically, the invention relates to the field of electrical interconnection of electrical load cells of an electrical battery.

[0002] Electric batteries, particularly in the case of electric vehicles, generally consist of an assembly of electric load cells, also called accumulators. When they are interconnected, in series or in parallel, these accumulators make it possible to deliver electrical power, for example intended to electrically supply the equipment of the vehicle or even its engine.

[0003] In order to interconnect the cells, it is known to use connecting strips, soldered to each terminal of each cell. However, this solution is not satisfactory, insofar as it requires a large number of welding operations and prevents the battery from being disassembled, for example to replace worn cells in the context of a maintenance or reconditioning operation. battery.

Another known solution, from document FR3071671, consists in interconnecting the cells by means of two printed circuit boards arranged on either side of the cells, each being provided with electrical connection elements each intended to come into contact with a contact terminal of one of the cells. Since the batteries are subjected to shocks or vibrations, in particular when the vehicles in which they are installed travel on an irregular road, the connection elements are generally designed to be elastically deformable, so as to maintain contact with the cells. These connection elements are thus welded or brazed to the electronic card. This solution is not satisfactory either, insofar as the electronic card equipped with such connection elements is complex to manufacture. Further, spring-type elastically deformable contact members are not capable of providing contact for all types of vibration or shock. The choice of contact elements can thus prove to be tedious and expensive.

[0005] There is thus a need for a battery in which the contact between the electrical load cells and a printed circuit board is resistant to vibrations, the battery being simple to assemble and to recondition. The invention falls within this context and aims to meet this need.

For these purposes, the subject of the invention is an electric battery, comprising:

has. a plurality of electrical load cells, each cell having end faces located on opposite sides of the cell, each end face being provided with a contact terminal;

b. at least a first printed circuit board arranged in line with the end faces located on one of the sides of the cells, the printed circuit board being provided with a plurality of first electrical connection elements, each of the first connection elements electric being located opposite one of the contact terminals of the cells;

The invention is characterized in that the first printed circuit board comprises a main portion in which a plurality of notches are formed, each notch defining an elastically deformable tongue with respect to the main portion, each first connection element electrical being disposed on one of the tabs of the first printed circuit board.

It is thus understood that the formation, by means of the notches, of elastically deformable tongues makes it possible to maintain contact between the first electrical connection elements of the first printed circuit board and the contact terminals of the cells without requiring elements contact points specifically designed to withstand the vibrations and shocks that the battery could suffer. In other words, it is possible to use particularly simple and standard contact elements, which makes it possible to simplify the design of the battery and to reduce its cost. In addition, it is possible to provide notches specifically designed for a particular vibratory regime, the elasticity of the tongues thus being able to be defined according to a precise need, for example by adapting their dimensions. Finally, the use of a printed circuit board instead of connection strips soldered to the cells allows the replacement of one or more cells when they are worn.

[0009] The term "electric load cell" means an elementary device, for example electrochemical, for storing electricity, which can be discharged and charged. Each cell can be of the lithium type, for example of the lithium-ion type or of the lithium-polymer type. Each cell can for example be of generally cylindrical shape, the contact terminals being provided on each outer face. remite delimiting the cylinder.

[0010] The term "printed circuit board" means a printed circuit board, or PCB (Printed Circuit Board), provided with electrical tracks interconnecting the connection elements, and in particular connected to an output connector so collecting the electrical power stored in each of the electrical load cells to this output connector. If desired, the first printed circuit board may include a battery management circuit (also called BMS, English Battery Management System).

[0011] Advantageously, the first printed circuit board is arranged with respect to the cells so that each cell creates a mechanical force on each tab directed towards the outside of the battery, and in which each tab of the first circuit board circuit board forms a spring with a restoring force directed towards the inside of the battery. If necessary, each notch of the first printed circuit board may have a U-shape. The tongue defined by each notch is thus connected to the main portion of the first printed circuit board by only one of its edges. If desired, the notches can be made by cutting out the main portion of the first printed circuit board, prior to assembling the battery.

In one embodiment of the invention, each first connection element is provided with a bump made of an electrically conductive material coming into contact with the contact terminal of one of the cells. This bump can for example be made by depositing the molten electrically conductive material, for example tin, at the level of an end of an electrical track located on the tongue. This embodiment makes it possible to facilitate contact between the electrical track and the contact terminal in the case where the contact terminal is flat.

In another embodiment of the invention, the contact terminal of each cell intended to come into contact with one of the first connection elements protrudes from the end face of the cell. In this case, the first connection element can be flat.

[0014] Advantageously, the battery comprises a spacing member arranged to hold the cells at a distance from each other, the spacing member and the first printed circuit board being arranged to hold the cells and the first circuit board printed so that each of the first electrical connection elements is located opposite one of the contact terminals of the cells. For example, the battery may comprise a single spacer member. Preferably, the spacing member is arranged to maintain the cells in a matrix arrangement, one beside the other. If necessary, the first connection elements are distributed on the first printed circuit board according to an arrangement corresponding to that of the cells.

[0015] Preferably, the spacer consists of a single plate having a plurality of primary through passages, each cell being engaged through one of the primary through passages. Where appropriate, each through passage may have a profile substantially corresponding, in shape and in dimensions, to that of the cell it receives.

[0016] Advantageously, the battery comprises a second printed circuit board arranged in line with the end faces located on the other side of the cells, the second printed circuit board being provided with a plurality of second electrical connection elements , each of the second electrical connection elements being located opposite one of the contact terminals of the cells. Where appropriate, the second printed circuit board comprises a main portion in which a plurality of notches are formed, each notch defining an elastically deformable tongue with respect to the main portion, each second electrical connection element being arranged on one tabs on the second circuit board.

[0017] Also advantageously, the battery comprises a fixing member arranged to hold the first printed circuit board to the second printed circuit board. If necessary, the fixing member can be arranged to exert a force on each of the first and second printed circuit boards directed towards the interior of the battery. This puts the printed circuit boards under stress, so that the cells create a mechanical force on the tabs.

[0018] For example, the fixing member may comprise one or more connecting rods fixed to the first printed circuit board, and optionally to the second printed circuit board. If necessary, each printed circuit board has one or more holes, each connecting rod being intended to be e engaged through one of these holes. Advantageously, the fixing member may comprise one or more secondary through-passages, each arranged opposite one of the orifices of the first and/or second printed circuit boards, each connecting rod being intended to be engaged through one of the secondary through passages. Alternatively or cumulatively, the fixing member may comprise a housing to which the first and second printed circuit boards are fixed. If necessary, the casing may comprise protrusions, each arranged opposite a zone of the main portion of the first and/or of the second printed circuit board located in line with the tongues, so as to exert a force on this first and/or second printed circuit board directed towards the interior of the battery.

[0019] Advantageously, the battery comprises a casing arranged to receive the plurality of cells and the first printed circuit board, the casing comprising means for assembly to an element of a vehicle, in particular to a chassis of an electric vehicle or a frame of a bicycle.

The present invention is now described using only illustrative examples and in no way limiting the scope of the invention, and from the accompanying illustrations, in which:

[0021] [Fig. 1] represents, partially and schematically, an exploded view of a battery according to a first embodiment of the invention;

[0022] [Fig. 2] represents a sectional view of the battery of [Fig. 1]; and

[0023] [Fig. 3] shows a sectional view of a battery according to a second embodiment of the invention.

In the following description, the identical elements, by structure or by function, appearing in different figures retain, unless otherwise specified, the same references.

[0025] Illustrated in [Fig. 1] an exploded view of an electric battery 1 of an electric vehicle according to a first embodiment of the invention. Also shown in [Fig. 2] a section of battery 1 of [Fig. 1] when assembled.

The battery 1 comprises a plurality of electrical load cells 2, each cell 2 being a lithium-ion type accumulator of cylindrical shape and having an upper end face 21 and a lower end face 22 each provided with a planar contact terminal 23.

The cells 2 are arranged next to each other, in a matrix arrangement. The battery 1 comprises a single spacer plate 3 provided with a plurality of primary cylindrical through-passages 31 distributed on the plate in a matrix fashion and whose dimensions correspond to those of the cells 2. Each cell 2 is engaged in one of the passages 31, so that the spacer plate 3 maintains the cells 2 at a distance from each other.

The battery 1 comprises a first printed circuit board 41, arranged above the cells 2, on the side of the upper end faces 21, and a second printed circuit board 42, arranged below the cells 2, of the side of the lower end faces 22.

Each printed circuit board 41 and 42 comprises a plurality of electrical connection elements 43, interconnected by electrical tracks to an output terminal of the printed circuit board (not shown), the output terminals of the boards 41 and 42 being connected to a power connector of battery 1 (not shown). Thanks to the spacer plate 3, the cells 2 are held so that each of their contact terminals 23 is opposite one of the electrical connection elements 43 of the printed circuit boards 41 and 42.

Each printed circuit board 41 and 42 has a main portion 44, in which have been cut U-shaped notches 45. Each of the notches 45

defines a tab 46, connected to the main portion by only one of its edges. Each tongue 46 is thus elastically deformable with respect to the main portion 44 and forms a spring having a return force bringing the tongue 46 towards the main portion 44 when a force is exerted on this tongue 46.

In the example of [Fig. 1] and [Fig. 2], each electrical connection element 43 is formed on one of the tongues 46 of the printed circuit boards 41 and 42, and for this purpose comprises a pewter bump 47 arranged at the level of an end of an electrical track s extending over this tab 46.

Furthermore, the battery 1 comprises several connecting rods 5, intended to be inserted between the printed circuit boards 41 and 42, being engaged in secondary through passages 32 of the spacer plate 3, provided between the primary through passages 31 . Holes 48 are formed in the main portions 44 of the printed circuit boards.rhymed 41 and 42, between the notches 45 and vis-à-vis the primary through passages 31. Each connecting rod 5 comprises a threaded protrusion 51 at each of its ends, intended to be engaged through the orifices 48 of the control cards. printed circuit 41 and 42. A washer 61 is inserted into each protrusion 51 and a bolt 62 is assembled to each protrusion 51 to fix each connecting rod 5 to the cards 41 and 42. It will be noted that the orientations of the notches 45 provided on both sides other orifices 48 are opposite, so as to allow the maintenance of the washers 61 on the cards 41 and 42, these washers allowing a uniform maintenance.

To assemble the battery 1, the cells 2 are inserted into the primary through passages 31 of the spacer plate 3 and the connecting rods 5 are inserted into the secondary through passages 32. The first and second printed circuit boards 41 and 42 are arranged on either side of the assembled cells 2, so that the contact terminals 23 come face to face with the connection elements 43. The washers 61 are then mounted on the protrusions 51 of the connecting rods and the bolts 62 screwed onto these protrusions 51 so as to constrain the cards 41 and 42 and thus generate a force on the tabs 46 towards the inside of the battery. The assembly is arranged in a box (not shown) which can be mounted, via an assembly means, on the vehicle, for example on the frame of an electrically assisted bicycle.

[0034] As illustrated in [Fig. 2], during the assembly of the battery 1, the screwing of the bolts 62 on the protrusions 51 of the connecting rods 5 exerts a uniform force, via the washers 62, on the printed circuit boards 41 and 42 towards the inside the battery 1, namely towards the cells 2. This effort thus maintains the cells 2 in position between the printed circuit boards 41 and 42. In return, each of the cells 2 exerts, at its end face upper 21, respectively lower 22, a force on the tongue 46 of the first printed circuit board 41, respectively of the second printed circuit board 42, opposite which it is arranged. Each tongue 46 is thus elastically deformed by one of the cells 2 by being pushed towards the outside of the battery 1.

The force created by the cell 2 on each tongue 46 being oriented towards the outside of the battery 1, the restoring force of the spring formed by this tongue 46 is therefore exerted towards the inside of the battery 1, which maintains contact between the bump 47 of the connection element 43 located on this tab 46 and the planar contact terminal 23 of the cell 2. Consequently, it is guaranteed that the contact between the connection element 43 and the contact terminal 23 can be maintained even when the electrically assisted bicycle is traveling on an uneven road causing vibrations. In addition, the assembly of the battery 1 as well as the replacement of the cells 2 when they are worn out, can be carried out simply and quickly, without a soldering or welding operation.

[0036] There is shown in [Fig. 3] a section of a battery 10 according to a second embodiment of the invention.

[0037] Unlike the first embodiment of the invention of [Fig. 1] and [Fig. 2], the cells 2 have connection terminals 24, which are not flat, but protrude from the upper 21 and lower 22 end faces.

In addition, the fixing between them of the printed circuit boards 41 and 42 is not carried out by means of connecting rods 5 but directly by means of a housing 7 having an upper wall 71 and a lower wall 72 provided each of internal protuberances 73, arranged opposite the printed circuit boards 41 and 42, at the level of zones located between the tabs 46. When assembling the case, by known means, a effort, by the internal protrusions 73, on the

printed circuit boards 41 and 42 directed towards the interior of the battery, which creates in return a force of the cells 2 on the tabs directed towards the exterior of the battery.

[00B9] The foregoing description clearly explains how the invention makes it possible to achieve the objectives it has set itself, and in particular by proposing a battery whose printed circuit board has notches defining elastically deformable tabs receiving the elements electrical connection intended to be in contact with the contact terminals of the cells. It is thus understood that the formation of these elastically deformable tabs makes it possible to make contacts between the connection elements and the contact terminals thanks to connection elements not specifically designed for this purpose, making it possible to assemble the battery and to change the cells. quickly and easily,The contacts are therefore resistant to vibrations.

In any case, the invention cannot be limited to the embodiments specifically described in this document, and extends in particular to all equivalent means and to any technically effective combination of these means. In particular, other profiles of notches and tongues, or even other methods of fixing the printed circuit boards than those described, may be provided.

CLAIMS

[Claim 1] [Electric battery (1, 10), comprising:

has. a plurality of electrical load cells (2), each cell having end faces (21, 22) located on opposite sides of the cell, each end face being provided with a contact terminal (23); b. at least one first printed circuit board (41) arranged in line with the end faces located on one of the sides of the cells, the printed circuit board being provided with a plurality of first electrical connection elements (43), each of the first electrical connection elements being located opposite one of the contact terminals of the cells;

characterized in that the first printed circuit board comprises a main portion (44) in which a plurality of notches (45) are formed, each notch defining a tongue (46) elastically deformable with respect to the main portion, each first element electrical connection being disposed on one of the tabs of the first printed circuit board.

[Claim 2] Battery (1, 10) according to the preceding claim, in which the first printed circuit board (41) is arranged with respect to the cells (2) so that each cell creates a mechanical force on each tongue ( 46) directed towards the outside of the battery, and in which each tongue of the first printed circuit board forms a spring having a restoring force directed towards the interior of the battery.

[Claim 3] Battery (1, 10) according to one of the preceding claims, in which each notch (45) of the first printed circuit board (41) has a U-shape.

[Claim 4] Battery (1) according to one of the preceding claims, in which each first connection element (43) is provided with a bump (47) made of an electrically conductive material coming into contact with the terminal of contact (23) of one of the cells (2).

[Claim 5] Battery (1, 10) according to one of the preceding claims, characterized in that it comprises a spacing member (3) arranged to keep the cells (2) at a distance from each other, the spacing member and the first printed circuit board (41) being arranged to hold the cells and the first printed circuit board so that each of the first electrical connection elements (43) is located opposite each other one of the contact terminals (23) of the cells.

[Claim 6] Battery (1, 10) according to the preceding claim, in which the spacing member (3) consists of a single plate having a plurality of primary through passages (31), each cell (2) being engaged at the through one of the primary through passages.

[Claim 7] Battery (1, 10) according to one of the preceding claims, characterized in that it comprises a second printed circuit board (42) arranged in line with the end faces (22) located on the other the sides of the cells (2), the second printed circuit board being provided with a plurality of second electrical connection elements (43), each of the second electrical connection elements being located opposite one of the terminals contact (23) of the cells and in which the second printed circuit board comprises a main portion (44) in which are formed a plurality of notches (45), each notch defining a tongue (46) elastically deformable with respect to the main portion, each second electrical connection element being arranged on one of the tabs of the second printed circuit board.

[Claim 8] Battery (1, 10) according to the preceding claim, characterized in that it comprises a fixing member (5, 7) arranged to hold the first printed circuit board (41) to the second printed circuit board (42).

[Claim 9] Battery (1, 10) according to one of the preceding claims, characterized in that it comprises a casing (7) arranged to receive the plurality of cells (2) and the first printed circuit board (41) , the housing comprising a means of assembly to an element of a vehicle.