WO2018098628A1

WO2018098628A1 - Battery pack with multiple output modes

Info

Publication number: WO2018098628A1
Application number: PCT/CN2016/107698
Authority: WO
Inventors: Denis Gaston Fauteux; Hei Man Raymond LEE; Jiang Zhao; Jian Guo Zhao; Ya Bin LIU
Original assignee: Tti (Macao Commercial Offshore) Limited
Priority date: 2016-11-29
Filing date: 2016-11-29
Publication date: 2018-06-07
Also published as: CN210693472U; EP3549229A1; TW201820741A; EP3549229A4

Abstract

A battery pack configured to be detachably installed in an electrical device. The battery pack contains a housing; N sets of electrically connected battery cells housed within the housing; N pairs of switching terminals; and a voltage control module. N is an integer. Two switching terminals in each one of the N pairs electrically connect to a positive output and a negative output respectively of one of the N sets of electrically connected battery cells. The voltage control module is electrically connected between the switching terminals and a plurality of output terminals configured on the housing. The voltage control module is arranged to connect the N switching terminal pairs in series or in parallel in order to output an electrical power from the battery pack to the electrical device. The battery pack is able to perform an internal switch-over of series and parallel connections between the sets of battery cells, therefore providing a great flexibility to the battery output.

Description

Battery Pack with Multiple Output Modes

FIELD OF INVENTION

This invention relates to an electrical device, and in particular an energy storing device with respect to the interface between the energy storing device and other electrical devices.

BACKGROUND OF INVENTION

Battery-powered power tools are widely used in domestic and industrial applications, due to its mobility rendered by battery backs detachably installed to such power tools. The power tool usually contains a motor as an electrical load which consumes electrical power provided by the battery pack to output a driving force for completing desired works.

However, conventional power tools are usually made to be compatible with only dedicated battery packs produced by the same manufacturer. In other words, for different types of power tools, different battery packs have to be designed as the battery packs are not interchangeable during use. One of the reasons is that different types of power tools usually have different voltage and current requirements, and a single battery pack is not able to provide different voltages and currents for different power tools. This is the case even for power tools made by the same manufacturer.

On the other hand, in some cases for the same power tool, the required electrical power for operating the power tool may be different depending on the output modes of the power tool. For example, for an impact tool the output mode may be either a high power mode, delivering a higher torque on the workpiece, or a lower power mode delivering a lower torque on the workpiece. To produce a high torque output the current drawn from the battery needs to be higher, and vice versa. Conventional power tool battery packs are not able to provide such variable output currents.

SUMMARY OF INVENTION

In the light of the foregoing background, it is an object of the present invention to provide an alternate power tool and battery pack which eliminate or at least alleviate the above technical problems.

The above object is met by the combination of features of the main claim； the sub-claims disclose further advantageous embodiments of the invention.

One skilled in the art will derive from the following description other objects of the invention. Therefore, the foregoing statements of object are not exhaustive and serve merely to illustrate some of the many objects of the present invention.

Accordingly, the present invention, in one aspect, is a battery pack configured to be detachably installed in an electrical device. The battery pack contains a housing； N sets of electrically connected battery cells housed within the housing； N pairs of switching terminals； and a voltage control module. N is an integer. Two switching terminals in each one of the N pairs electrically connect to a positive output and a negative output respectively of one of the N sets of electrically connected battery cells. The voltage control module is electrically connected between the switching terminals and a plurality of output terminals configured on the housing. The voltage control module is arranged to connect the N switching terminal pairs in series or in parallel in order to output an electrical power from the battery pack to the electrical device.

Preferably, the voltage control module further includes a controller and a plurality of switching elements. The plurality of switching elements each is connected between two of the electrical terminals. The controller connects to and controls the switching actions of the plurality of switching elements.

More preferably, the switching elements include semiconductor switches which are configured on a PCB board.

In one specific implementation, the semiconductor switches are MOSFETs.

In another specific implementation, the number of switching elements in the voltage control module is N+1.

In a further specific implementation, the output terminals include a positive terminal and a negative terminal.

According to a variation of the invention, the N sets of electrically connected battery cells are electrically isolated from each other when the battery pack is detached from the electrical device.

According to another variation of the invention, each set of electrically connected battery cells outputs a voltage of 18V.

According to a further variation of the invention, the electrical device is a power tool.

There are many advantages to the present invention. By configuring an internal switch-over circuit in the battery pack, the electrical power outputted by the battery pack can be flexibly adjusted. For example, when a high current and low voltage output is required for a particular power tool (e.g. in case of a high output torque) , the sets of battery cells in the battery pack can be connected in parallel. When a low current and high voltage output is required for the same power tool (e.g. in case of a low output torque) , the sets of battery cells in the battery pack can be connected in series. With the internal switch-over circuit in the battery pack, there is no need for other voltage /current converting circuit in the power tool, as such operations have been completed in the battery pack. Therefore, the structural complexity of the power tool can be simplified.

Another advantage of the present invention is that the same battery pack can be used for different types of power tools which have different voltage /current requirements. Preferably, there is no need for the user to manually select the output mode of the battery pack, but the battery pack is able to automatically detect the power tool type that the battery is installed to and switch to the appropriate output mode. For example, the battery pack may have communication terminals which exchange data with the power tool /battery charger, and thus the battery automatically adjusts its internal circuit configuration depending on the type of the power tool /battery charger. This is an intelligent process and makes a battery pack being compatible with a full range of power tools possible.

BRIEF DESCRIPTION OF FIGURES

The foregoing and further features of the present invention will be apparent from the following description of preferred embodiments which are provided by way of example only in connection with the accompanying figures, of which:

Fig. 1a is a perspective view of the battery pack according to a first embodiment of the present invention.

Fig. 1b is the top view of the battery pack in Fig. 1b.

Fig. 2a shows the perspective view of the battery pack in Fig. 1a with the housing removed to expose its internal parts.

Fig. 2b is a side view of the battery pack internal parts in Fig. 2a.

Fig. 3 shows the voltage control module in the battery pack connected with two power terminals among the four output terminals on a terminal holder of the batter pack.

Fig. 4 shows the corresponding terminal holder on a power tool or battery charger for engaging the battery terminals in Fig. 3.

Fig. 5 shows the equivalent circuit diagram of the battery pack of Fig. 1a-2b.

Fig. 6 is the internal schematic diagram of the battery pack of Fig. 1a-2b.

Fig. 7 shows the two sets of battery cells in the circuit of Fig. 5 connected in series.

Fig. 8 is an equivalent circuit of that in Fig. 7.

Fig. 9 shows the four electrical terminals in the circuit of Fig. 5 connected in series and parallel.

Figs 10a and 10b show two different connection states of a plurality of battery cells in a battery pack according to another embodiment of the present invention.

Fig. 11 shows a generalized connection diagram of N sets of battery cells in a battery pack with each set containing n battery cells, according to an embodiment of the present invention.

Fig. 12a shows a terminal holder of a batter pack with two pairs of output terminals according to an embodiment of the present invention.

Fig. 12b shows a terminal holder of a corresponding power tool for receiving the terminal holder of the battery pack in Fig. 12a.

Fig. 13a shows a terminal holder of a batter pack with two pairs of output terminals as well as two signal pins according to an embodiment of the present invention.

Fig. 13b shows a terminal holder of a corresponding power tool for receiving the terminal holder of the battery pack in Fig. 13a.

Fig. 14a shows a side view of a battery pack with three sets of battery cells and three pairs of output terminals according to an embodiment of the present invention.

Fig. 14b shows a perspective view of the battery pack in Fig. 14a.

Fig. 14c shows a front view of the battery pack in Fig. 14a.

Fig. 14d shows a top view of the battery pack in Fig. 14a.

Fig. 15 shows separately the terminal holder of the battery pack in Fig. 14a.

In the drawings, like numerals indicate like parts throughout the several embodiments described herein.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

In the claims which follow and in the preceding description of the invention, except where the context requires otherwise due to express language or necessary implication, the word “comprise” or variations such as “comprises” or “comprising” is used in an inclusive sense, i.e. to specify the presence of the stated features but not to preclude the presence or addition of further features in various embodiments of the invention.

As used herein and in the claims, “couple” or “connect” refers to electrical coupling or connection either directly or indirectly via one or more electrical means unless otherwise stated.

Terms such as “horizontal” , “vertical” , “upwards” , “downwards” , “above” , “below” and similar terms as used herein are for the purpose of describing the invention in its normal in-use orientation and are not intended to limit the invention to any particular orientation.

Referring now to Fig. 1a and 1b, the first embodiment of the present invention is a battery pack adapted to be used for power tools. The power tools are examples of electrical devices which require electrical power to perform normal functions. The battery pack contains a housing 20 in which all the internal components of the battery pack including the battery cells and the control circuit are housed. On the exterior surface of the battery pack there are mechanical features 24 such as latches or particular geometrical shape for installing the battery pack to a power tool or a battery charger. The mechanical features 24 are well known to people skilled in the art and will not be elaborated further. On the top side of the battery pack, there is a region of the housing 20 used as a receptacle 26 for receiving terminal holders (not shown) on the power tool or battery charger. At the end of the receptacle 26, there are configured four output terminals 22 of the battery pack which are connected electrically with the inner circuit of the battery pack.

Turning now to Figs. 2a and 2b, inside the housing of the battery pack there are a plurality of battery cells 32 installed to a frame 33. The frame 33 allows the individual battery cells 32 to be secured and kept in position. As shown in Figs. 2a and 2b there are in total ten battery cells 32. The connections between the battery cells 32 battery cells 32 will be described in details later. However, at its cathode and anode, each battery cell 32 is mechanically to another battery cell 32 or the output terminals 22 by a connecting strip 36.The connecting strip 36 has an elongate shape, and at the two ends of the connecting step 36 there are contact pads 36 in firm contact with the cathode /anode of the respective battery cell 32. On top of the frame 33, there is mounted a PCB board 28 which carries a voltage control module (not shown) and other circuit components necessary for the operation of the battery pack. There is a battery terminal holder 30 fixed to the PCB board 28, on which the four output terminals 22 are secured.

Referring now to Fig. 3, the battery terminal holder 30 contains four output terminals 22 as mentioned above, and in particular the four terminals include a positive (+) terminal 22d, a negative (-) terminal 22a, a first signal terminal (T1) 22b, and a second signal terminal (T2) 22c. The T1 terminal 22b and T2 terminal 22c are used to carry out data communication between the batter pack and the external power tool and/or battery charger. It is the positive terminal 22d and negative terminal 22a which are connected to the voltage control module 38. Each one of the four output terminals 22 has a bent shape with an end protruding forward. In turn, the tool terminal holder 40, which is shown in Fig. 4, contains metal clips 42 arranged in a similar side-by-side fashion as the output terminals 22. There are at least two metal clips 42 on the tool terminal holder 40 for connecting at least the positive and

negative terminals

22d, 22a.

Fig. 5 shows the internal circuit diagram of the battery pack. As mentioned above there are ten battery cells 32 in the battery pack. The ten battery cells 32 in the battery pack are split into two sets each containing five battery cells 32, and these five battery cells 32 are connected in series. Each battery cell 32 outputs a voltage of 3.6V so together the five battery cells 32 connected in series outputs a total voltage of 18V. The first set 44 of battery cells is connected to a positive switching terminal 52b and a negative switching terminal 52d respectively. The second set 46 of battery cells is connected to a positive switching terminal 52a and a negative switching terminal 52c respectively. The four switching terminals 52a-d are also denoted by “b2+” , “b1+” , “a2-” and “a1-” respectively.

The four switching terminals 52a-d are connected to the voltage control module 38, which on the other side is connected to the four output terminals 22a-22d. Note that

only output terminals

22d and 22a (i.e. positive and negative terminals respectively) serve as the power outputs, but the

output terminals

22b and 22c (i.e. T1 and T2 respectively) are used for bi-directional signal communication between the battery pack and the charger /power tool. The voltage control module 38 includes a microcontroller (MCU) 48, and three switching elements 50. The MCU 48 is connected to the three switching elements 50 and is configured to control the switching operations of the latter. Note that the number of sets of battery cells, and thus the number of pairs of switching terminals, can be represented by a variable N, where N is an integer. Then, the number of switching elements required for performing series /parallel switch-over is N-1. In the case of Fig. 5, N is 2, and the number of switching element required is N-1, which is 3.

Fig. 6 shows the detailed schematic diagram of the battery pack described above. The MCU 48 is coupled to the T2 terminal 22c and T1 terminal 22b via a communication module 54. The T2 terminal 22c and T1 terminal 22b can be used for the MCU 48 communicating with external power tool /battery charger, such as supplying the operating status of the battery pack, or receiving information of the power tool /charger for adjusting the switching elements 50. Each switching element 50 includes two MOSFETs 56. The first set 44 of five battery cells is connected with its positive output to b1+ terminal 52b and its negative output to a1- terminal 52d. The second set 46 of five battery cells is connected with its positive output to b2+ terminal 52a and its negative output to a2- terminal 52c. Each one of the first set 44 and second set 46 of five battery cells is also coupled with an Analog Front End (AFE) module 58, which functions to sample and provide status of the battery cells to the MCU 48. On the other side, for the two MOSFETs 56 in a switching element 50, a high side driver 60 is configured for driving the MOSFETs 56 based on signals received from the MCU 48. The b2+ terminal 52a is directly connected to the negative output terminal 22d, and the a1- terminal 52d is directly connected to the negative output terminal 22a.

Now turning to the operation of the device described above, Fig. 7 and Fig. 8 show the circuit connections of the first set 44 and second set 46 of battery cells when they are connected in series. Such a circuit configuration is realized by controlling the two MOSFETs 56 between the b1+ terminal 52b and the a2-terminal 52c in Fig. 6 to be in conducting status. In the meantime, the two MOSFETs 56 between the b2+ terminal 52a and the b1+ terminal 52b, as well as the two MOSFETs 56 between the a2- terminal 52c and the a1- terminal 52d are in the cut-off status. Since all ten battery cells are now connected in series, the output voltage at the positive and

negative output terminals

22d and 22a is 36V.

Fig. 9 shows, in a simplified circuit form, how the circuit shown in Figs. 5-6 can be figured in either series or parallel connection modes. The box 60 shows that when the switching terminals b1+ and a2- are connected, but switching terminals b2+ and b1+ are not connected as well as switching terminals a2- and a1- are not connected, then the 2 pairs of switching terminals are connected in series, thus outputting a 36V voltage. The box 62 shows that when the switching terminals b1+ and a2- are not connected, but switching terminals b2+ and b1+ are connected as well as switching terminals a2- and a1- are connected, then the 2 pairs of switching terminals are connected in parallel, thus outputting a 18V voltage. The battery pack when outputting the 18V voltage is able to output the current twice as much as the current when outputting the 36V voltage.

Fig. 10a shows the equivalent circuit diagram of ten battery cells 122 in a battery pack, according to another embodiment of the present invention. In Fig. 10a, each two battery cells 122 are connected in parallel to form a set 145, and thus there are five such sets 145 in the battery pack. Assuming a single battery cell 122 outputs a 3.6V voltage, then the total output voltage at positive and negative terminals 122d and 122a is 18V. In the configuration of Fig. 10b, the output voltage positive and negative terminals 122d and 122a is also 18V, but instead of having five sets of battery cells, there are only two sets 147 connected in parallel in Fig. 10b. The circuit configuration can be switched from that in Fig. 10a to that in Fig. 10b, or vice versa, by implementing switching elements similar to those shown in Figs. 5-6.

Turning now to Fig. 11, which shows a generalized internal circuit connection of battery packs according to the present invention with a scalable battery capacity and output ratings. In particular, the number of sets of battery cells 232, and thus the number of pairs of switching terminals, can be represented by a variable N, where N is an integer. On the other hand, within each set the number of battery cells 232 is n. Therefore, the total number of battery cells 232 in the battery pack is N × n, and this total number is proportional to the capacity of the battery pack. Note that there is no limit as to the value or N or n. Within each set of battery cells 232, all the n battery cells 232 are connected in series and each battery cell 232 has an output voltage of V. This means that for a set of battery cells 232 the total output voltage will be V × n at the two output terminals generally denoted by BN+ 252e and BN-252f respectively. For example. If n ＝ 5 then the output voltage of the set of battery cells 232 will be V × 5 as shown in Fig. 11. Therefore, there is a scalability provided for battery packs made according to the present invention in which by providing N sets of battery cells 232 a variety of different output voltage /output current may be provided by selective serial and/or parallel connections of the N pairs output terminals.

In Fig. 11 there is shown a first set 244 of battery cells is connected to a positive switching terminal 252b and a negative switching terminal 252d respectively. A second set 246 of battery cells is connected to a positive switching terminal 252a and a negative switching terminal 252c respectively. The four switching terminals 252a-d are also denoted by “B2+” , “B1+” , “A2-” and “A1-” respectively.

Referring now to Figs. 12a and 12b, in another embodiment of the invention a battery terminal holder 330 contains four output terminals 322 similar to those shown in Fig. 3, and in particular the four terminals 322 include a first positive (+) terminal 322d, a first negative (-) terminal 322a, a second positive (+) terminal 322b, and a second negative (-) terminal 322c. Each one of the four output terminals 322 has a bent shape with an end protruding forward, while being in sheet shapes with little thickness. One can see that all

negative terminals

322c, 322a are arranged on one side of the battery terminal holder 330, while all the

positive terminals

322d, 322b are arranged on another side of the battery terminal holder 330.

The tool terminal holder 340, which is shown in Fig. 12b, contains four metal clips 342 arranged in a similar side-by-side fashion as the output terminals 322 on the corresponding battery terminal holder 330. The metal clips 342 are received in a frame 343 and are separated from each other by three dividers 341 integrally formed with the frame 343. Each divider 341 is in a substantially “L” shape and includes a vertical part 341a and a bottom part 341b. The frame 343 similarly includes vertical walls 343a and a bottom part 343b. Among the four metal clips 342, two of them include a further vertical metal pin 349, while the other two do not have such vertical metal pins.

Figs. 13a and 13b further show another embodiment of the invention including a battery terminal holder 430 and a tool terminal holder 440. The tool terminal holder 440 is identical to the tool terminal holder shown in Fig. 12b. The battery terminal holder 430 is also largely similar to the battery terminal holder shown in Fig. 12a. Therefore, any similar structures or shapes which have been described above will not be discussed again herewith for the sake of brevity. However, a major different in the battery terminal holder 430 as compared to the battery terminal holder shown in Fig. 12a is that there are two additional signal terminals 451 in the battery terminal holder 430 between two terminals 422. These two signal terminals 451 each is in a L shape but with a substantial width as compared to the terminals 322 in Fig. 12a which only have minimum width. The width herein is defined as the span of distance along the direction where the multiple terminals are arranged. The two signal terminals 451 have the top surface on their open ends acting as the conductive surface for signal coupling with the power tool. In addition, there are two additional pins 453 extending from the vertical part of the two signal terminals 451 respectively along the same direction as the terminals 422. The pins 453 are designed to perform the similar functions as terminals 422 for providing electric power from the battery pack to the power tool.

Figs. 14a-14d and Fig. 15 show another embodiment of the present invention which includes a battery pack. The differences of this battery pack as compared to that illustrated in Figs. 1a-2b include that there are now three sets of battery cells 532, with the number of battery cells 532 within each set remaining five. All these battery cells 532 are accommodated in a housing (not shown) and thus the overall height of the battery pack in Figs. 14a-14e is larger than that in Figs. 1a-2b. The plurality of battery cells 532 is installed to a frame 533. The frame 533 allows the individual battery cells 532 to be secured and kept in position. On top of the frame 533, there is mounted a PCB board 528 which carries a voltage control module (not shown) and other circuit components necessary for the operation of the battery pack. There is a battery terminal holder 530 fixed to the PCB board 528, on which six

output terminals

522, 551 are secured.

As shown most clearly in Figs. 14c-d and 15, among the six output terminals four of them are L-shaped power output terminals 522. The four terminals 522 include a second positive (+) terminal 522d, a second negative (-) terminal 522a, a third positive (+) terminal 522b, and a third negative (-) terminal 522c. Between the second negative (-) terminal 522a and the second positive (+) terminal 522d, There are two

signal terminals

551a, 551b each is in a L shape but with a substantial width as compared to the terminals 322 in Fig. 12a which only have minimum width. The width herein is defined as the span of distance along the direction where the multiple terminals are arranged. The two

signal terminals

551a, 551b have the top surface on their open ends acting as the conductive surface for signal coupling with the power tool. In addition, there are two

additional pins

553a, 553b extending from the vertical part of the two signal terminals 551 respectively along the same direction as the terminals 522. The

pins

553a, 553b are designed to perform the similar functions as terminals 522 for providing electric power from the battery pack to the power tool.

The exemplary embodiments of the present invention are thus fully described. Although the description referred to particular embodiments, it will be clear to one skilled in the art that the present invention may be practiced with variation of these specific details. Hence this invention should not be construed as limited to the embodiments set forth herein.

While the invention has been illustrated and described in detail in the drawings and foregoing description, the same is to be considered as illustrative and not restrictive in character, it being understood that only exemplary embodiments have been shown and described and do not limit the scope of the invention in any manner. It can be appreciated that any of the features described herein may be used with any embodiment. The illustrative embodiments are not exclusive of each other or of other embodiments not recited herein. Accordingly, the invention also provides embodiments that comprise combinations of one or more of the illustrative embodiments described above. Modifications and variations of the invention as herein set forth can be made without departing from the spirit and scope thereof, and, therefore, only such limitations should be imposed as are indicated by the appended claims.

It is to be understood that, if any prior art publication is referred to herein, such reference does not constitute an admission that the publication forms a part of the common general knowledge in the art, in Australia or any other country.

For example, the electrical device described in the embodiments above is a power tool. However, those skilled in the art would realize that other types of energy-consuming appliances can also be used with the battery pack in spirit of the present invention. Such energy-consuming appliances for example include light emitting devices, audio devices, or measurement instruments.

Claims

A battery pack configured to be detachably installed in an electrical device, the battery pack comprising:

a) a housing；

b) N sets of electrically connected battery cells housed within the housing； N being an integer； and

c) N pairs of switching terminals； two switching terminals in each one of the N pairs electrically connect to a positive output and a negative output respectively of one of the N sets of electrically connected battery cells； and

d) a voltage control module electrically connected between the switching terminals and a plurality of output terminals configured on the housing；

wherein the voltage control module is arranged to connect the N switching terminal pairs in series or in parallel in order to output an electrical power from the battery pack to the electrical device.
The battery pack of claim 1, wherein the voltage control module further comprises a controller and a plurality of switching elements； the plurality of switching elements each connected between two of the switching terminals； the controller connecting to and controlling the switching actions of the plurality of switching elements.
The battery pack of claim 2, wherein the switching elements comprise semiconductor switches which are configured on a PCB board.
The battery pack of claim 3, wherein the semiconductor switches are MOSFETs.
The battery pack of claim 2, wherein the number of switching elements in the voltage control module is N+1.
The battery pack of any one of the preceding claims, wherein the output terminals comprises a positive terminal and a negative terminal.
The battery pack of any one of the preceding claims, wherein the N sets of electrically connected battery cells are electrically isolated from each other when the battery pack is detached from the electrical device；
The battery pack of any one of the preceding claims, wherein each set of electrically connected battery cells outputs a voltage of 18V.
The battery pack of any one of the preceding claims, wherein the electrical device is a power tool.