BATTERY COMPRISING A PLURALITY OF RECHARGEABLE CELLS ARRANGED IN A
MATRIX
The present invention relates to a battery comprising a plurality of rechargeable cells arranged in a matrix with a high reliability and to a manufacturing method of such battery, which ensures a high reliability in the connections.
Background of the invention
Known are in the art batteries comprising a plurality of rechargeable cells arranged in a matrix, comprising at least a connection board between terminals arranged in a face of the battery and provided with connection tracks, the terminals being connected by means of cables, wires o strips made of electrical conductive alloys and by means of welding to said connection tracks, the connection board being provided with openings for accessing said terminals through the connection board.
It is an example of such batteries that described in US2008152993. Specifically, this document describes the concept of a connection by one side by means of a plate.
In US201 10097618 a connection plate is described in one of the battery sides, which is arranged on a control PCB (printed circuit board).
In US20100136392A1 a battery control PCB that includes sensors, control devices and the battery connections for control is described.
US 4920019 A (Stoklosa DAVID P et al.), Considered as the closest prior art, describes all the features of the preamble of the first claim.
Furthermore, it is increasingly common to incorporate cell balancing systems into the battery, which operate based on signals from the current and voltage sensors, possibly of the temperature of each of the battery cells.
Power, monitoring and control connections of the cells and rebalancing are very numerous, and especially when it comes to high-voltage batteries which can include hundreds of cells, in which case it may be several thousand. If you also want to provide redundancy, the number of connections is doubled. And it is known that for the batteries to function optimally and to lengthen its life to the fullest, it is necessary for these connections to have a high quality and reliability.
With the state of the art solutions, these requirements pose several technical problems:
- It takes a lot of space to make connections;
- It takes a long time to provide for reliable connections;
- Any change is a complication, making it difficult to scale the connection methods; Description of the invention
The present invention aims to provide a solution to the aforementioned shortcomings of the prior art by means of a battery comprising a plurality of rechargeable cells arranged in a matrix, comprising at least a connection board between terminals arranged in a face of the battery and provided with connection tracks, the terminals being connected by means of cables, wires o strips made of electrical conductive alloys and by means of welding to said connection tracks, the connection board being provided with openings for accessing said terminals through the connection board, which is characterized in that:
- the board is a printed circuit board;
- the tracks are on the surface of the board not oriented towards the cells;
- the cables, wires o strips made of electrical conductive alloys connect the terminals to the connection tracks through said openings; and
- the welding is an ultrasound, laser or electric welding.
Therefore, the present invention is based on the fusion of two technologies, which have so far been isolated. Specifically, the present invention is based on battery technology combined with the technology of welding of PCBs used in electronics. This allows many welds at high speed, in an orderly and fully reliable manner. As will be seen, it allows for connection of a very large number of cells, and especially it allows for including connections to sensors, and also to make redundant connections. This is not possible in U.S. 4920019 A, wherein the features of the characterizing part of the first appended claim are not described.
In a first variant, all the cells have the same orientation, both terminals of each cell being accessible by the same end of the cell, being provided the board of openings for accessing both terminals, such that the connections between both terminals of each cell and the connection tracks are only carried out on the surface of the board not oriented towards the cells.
It can also be provided according to a second variant, apply the invention to a cells having opposed terminals, the cells being arranged with alternate terminals, and comprising in each side of the battery a connection board with the tracks in the surface of the board not oriented towards the cells.
Also advantageously, the board(s) include(s) the control electronics for each cell. This feature is especially advantageous. The inclusion of the control electronics for each cell in the prior art, is performed by dedicated especially plates, as described above. However, the present invention allows for including in a single board both the power connections and the control connections.
Preferably, the control electronics comprises current, voltage and temperature sensors and a data processor with status indicator output to a connection bus.
According to other optional features of the invention:
- the cables, wires o strips made of electrical conductive alloys are aluminium, copper or gold alloys.
- the board(s) are multilayer.
Advantageously, the battery comprises two connection cables between each terminal and the corresponding track.
The invention could be applied to any type of cells, but finds an advantageous application in cylindrical cells.
Advantageously, the cells are LiFePo4 cells.
Preferably, the gaps between cells form cooling channels, the board(s) being provided with openings coincident with said channels. The invention also relates to a battery manufacturing method starting from a plurality of rechargeable cells provided in at least one of their ends of terminals, which comprises the following steps:
- Arranging the cells in a support such that they form a matrix;
Obtaining at least a printed circuit board provided with connection tracks and of openings with a pattern designed for matching with said terminals once arranged onto the battery;
- Arranging the printed circuit board onto the battery with said openings coincident with the terminals and with the tracks in the surface of the board not oriented towards the cells;
Fixing the board to the support;
Connecting by means of cables, wires o strips of electrical conductive material welded by ultrasounds the terminals and the connection tracks.
Advantageously, the connection between each terminal and the corresponding track is carried out by means of two cables.
Preferably, the cables are aluminium, copper or gold alloys.
According to a particularly preferred variant of the invention , all the cells are arranged with the same orientation, leaving both terminals of each cell accessible by the same end of the cell, being provided the board of openings for accessing both terminals, such that the connections between both terminals of each cell and the connection tracks are only carried out on the surface of the board not oriented towards the cells.
According to another embodiment of the method, the cells are arranged with opposed terminals, the cells being arranged with alternate terminals, and arranging in each side of the battery a connection board with the tracks in the surface of the board not oriented towards the cells.
The method can include a previous stage of integrating the control electronics of each cell in the plate or plates .
Finally, the control electronics comprises current, voltage and temperature sensors and a data processor with status indicator output to a connection bus. Brief Description of the Figures
For a better understanding of what has been outlined some drawings are attached in which, schematically and solely by way of non-limiting example, a practical case of embodiment is shown.
Figure 1 is a section view showing the basic components of the battery and especially the connections.
Figure 2 is a plan view.
Description of a Preferred Embodiment
As can be seen in Figure 1 , the invention relates generally to a battery 1 comprising a plurality of rechargeable cells 2 arranged in a matrix, comprising at least a connection board 3 between terminals 4, 5 arranged in a face of the battery 1 and provided with connection tracks 6, the terminals 4, 5 being connected by means of cables, wires o strips made of electrical conductive alloys 7 and by means of welding to said connection tracks 6, the connection board 3 being provided with openings 8 for accessing said terminals 4, 5 through the connection board 3.
These features being already known, the present invention is characterized in that:
- the board 3 is a printed circuit board;
- the tracks 6 are on the surface of the board 3 not oriented towards the cells 2;
- the cables, wires o strips made of electrical conductive alloys 7 connect the terminals 4, 5 to the connection tracks 6 through said openings 5; and
- the welding is an ultrasound, laser or electric welding.
In the figures there is shown an embodiment wherein all the cells 2 have the same orientation, both terminals 4, 5 of each cell 2 being accessible by the same end of the cell 2, being provided the board 3 of openings 8 for accessing both terminals 4, 5, such that the connections between both terminals 4, 5 of each cell 2 and the connection tracks 6 are only carried out on the surface of the board 3 not oriented towards the cells 2. The inventive battery can be obtained with the following method: arranging the cells 2 in a support such that they form a matrix;
obtaining at least a printed circuit board 3 provided with connection tracks 6 and of openings 8 with a pattern designed for matching with said terminals 4, 5 once arranged onto the battery 1 ;
arranging the printed circuit board 3 onto the battery 1 with said openings 8 coincident with the terminals 4, 5 and with the tracks 4 in the surface of the board 3 not oriented towards the cells 2;
- fixing the board to the support;
connecting by means of cables, wires o strips of electrical conductive material 7 welded by ultrasounds the terminals 4, 5 and the connection tracks 6.
As can be seen in Figure 2, the connection between each terminal and the corresponding track is carried out by means of two o more cables.
Although reference has been made to a specific embodiment of the invention, it is apparent to one skilled in the art that the battery and method described are susceptible of numerous variations and modifications, and that all the details mentioned can be replaced by other technically equivalent, without departing from the scope of protection defined by the appended claims.