Patent Publication Number: US-2023151815-A1

Title: Portable power supply device for an electric tool

Description:
TECHNICAL FIELD 
     The present invention relates to a portable power supply device, in particular a portable power supply device for an electric tool, for example, a submersible pump. 
     BACKGROUND ART 
     With the development of battery technology, more and more electric tools are using batteries to supply power. Although AC electric tools can usually provide higher power and will not suffer from restricted time of use, the market for battery-driven DC electric tools has rapidly been developed by virtue of their manoeuvrability and portability. With most DC electric tools, a battery mounting interface is provided on the housings to allow a user to quickly replace the battery when the battery energy is used up. 
     Some electric tools may be placed in an environment where the battery may be damaged. For example, garden pumps usually work in a rain or water environment, and they may be placed in a pool or water tank. To obtain portability, a battery compartment sealed off from the external environment is provided in the housing of such electric tools to protect the battery. However, when the battery energy is used up, it is necessary to take the electric tool out of the working environment to replace the battery. In addition, the battery replacement process is unfriendly to ordinary users, which significantly affects the working efficiency of electric tools. 
     SUMMARY OF THE INVENTION 
     To overcome the above-mentioned defects, the present invention provides a portable power supply device for an electric tool. The portable power supply device for an electric tool comprises: a housing, a power supply receiving portion, provided in or on the housing and used to receive a power supply supplying power to the electric tool, and a control unit, comprising a controller provided in the housing and used to control the electric energy supplied to the electric tool. 
     In one embodiment, the power supply receiving portion comprises a power supply compartment. The power compartment is transparent or semi-transparent and is at least partially defined by a cover which can move relative to the housing between an opened position and a closed position. The cover may be provided with a locking member used to releasably retain the cover in the closed position. A biasing component may be further provided for the cover to bias the cover towards the opened position or closed position. 
     In one embodiment, the cover has a first sealing edge, and the power supply receiving portion or the housing has a second sealing edge aligned with the first sealing edge. A groove may be formed in one of the first sealing edge and the second sealing edge to accommodate at least a part of a sealing component. The other of the first sealing edge and the second sealing edge may have a ridge portion extending outward. When the cover is in the closed position, the ridge portion abuts against the sealing component. 
     In one embodiment, the control unit further comprises a sensor used to detect the position of the cover, and the controller performs protection operations when the sensor detects that the cover has left the closed position. The protection operations may include at least one of the following operations: immediately cutting off the power supply, starting timing and cutting off the power supply after a predetermined length of time has elapsed since the cover left the closed position, changing the working mode, sending out a visually or audibly perceptible alarm. 
     In one embodiment, the power supply device comprises a control interface provided on the housing, and the control interface comprises at least one of the following control elements: power switch, working mode selector, output power selector, timer, programmer, menu selector and parameter configurator. The control interface may further comprise a display, used to display at least one of the following items of information: power supply level, working mode, output power, timing information, system menu, parameter setting and alarm information. 
     In one embodiment, the power supply device comprises a positioning accessory detachably and replaceably attached to the housing and/or the power supply receiving portion. The power supply device may be fixed in different ways by use of different positioning accessories. The positioning accessory may fix the power supply device onto a supporting component with the aid of at least one of the following means: hanging means, fastener, binder, holding means, vacuum pull and magnetic force. 
     In one embodiment, the power supply device comprises a first joint portion and a second joint portion, and the positioning accessory comprises a third joint portion fitting the first joint portion and a fourth joint portion fitting the second joint portion. The first joint portion and the second joint portion may be provided on the housing and the power supply receiving portion, respectively. At least one of the fit between the first joint portion and the third joint portion and the fit between the second joint portion and the fourth joint portion may be a snap fit. 
     In one embodiment, the positioning accessory is a holding accessory, which comprises a pair of holding arms pivoting relative to each other and is used to hold the power supply device onto a plate-like supporting component. A first holding arm of the pair of holding arms is fixed onto the power supply device, and a second holding arm is pivotably connected with the first holding arm. 
     In one embodiment, the positioning accessory is a wall-mounted accessory, which comprises at least one fastener hole, and the fastener hole is configured to receive a fastener fixing the wall-mounted accessory onto a supporting wall. The fastener hole may be formed into a stepped hole. 
     In one embodiment, the power supply device is independent of the electric tool and supplies power to the electric tool through a power cable. The power cable is detachably connected to a power cable interface provided on the housing. The power cable interface alternatively comprises an adapter to connect power cables in different sizes. The power cable interface may be a power socket. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         FIG.  1    shows the portable power supply device according to one embodiment of the present invention. 
         FIGS.  2 A and  2 B  show the power supply receiving portion of the portable power supply device according to one embodiment of the present invention. 
         FIG.  3    shows the cover of the portable power supply device according to one embodiment of the present invention. 
         FIG.  4    shows the control interface of the portable power supply device according to one embodiment of the present invention. 
         FIGS.  5 A and  5 B  show the portable power supply device bonded with a positioning accessory according to one embodiment of the present invention. 
         FIG.  6    shows the rear side of the portable power supply device according to one embodiment of the present invention. 
         FIG.  7    shows the positioning accessory in  FIG.  5 A . 
         FIGS.  8 A and  8 B  show the positioning accessory in  FIG.  5 B . 
         FIG.  9    shows a submersible pump used together with the portable power supply device according to one embodiment of the present invention. 
         FIG.  10    shows the top of the submersible pump. 
         FIG.  11    shows the working state of the portable power supply device and the submersible pump. 
     
    
    
     SPECIFIC EMBODIMENTS 
       FIG.  1    shows the portable power supply device  10 , which is used to supply power to an electric tool according to one embodiment of the present invention. The electric tool may be a handheld tool or garden tool, for example, a cutting tool, a pump, a sprayer, a cleaner, a hair dryer, a lawn mower, or a hedge trimmer. The power supply device  10  comprises a housing  100 , a power supply receiving portion  200  used to receive a power supply and a control unit used to control the electric energy supplied to the electric tool. The power supply comprises at least a battery pack detachably mounted in the power supply receiving portion  200 , for example, a rechargeable lithium battery pack, and the rated voltage, including but not limited to 9V, 12V, 18V, 24V, 40V, 48V, 60V and 80V, may be selected according to the type of the electric tool. When the power supply comprises a plurality of battery packs, the plurality of battery packs may be connected in series or in parallel, or only some of the battery packs of the plurality of battery packs are electrically connected with the power supply device  10  and the other battery packs are only used as spare battery packs. 
     The power supply device  10  is independent of the electric tool and supplies power to the electric tool through a power cable. The power cable is detachably connected to a power cable interface  160  provided on the housing  100 . The power cable interface  160  alternatively comprises an adapter to connect power cables in different sizes. Preferably, the power cable interface  160  is a power socket. In an embodiment not shown, a charging interface is further provided on the housing  100  of the power supply device  10  and is used to charge battery packs mounted in the power supply receiving portion  200 . The power socket and the charging interface may be the same interface. 
       FIGS.  2 A and  2 B  show the power supply receiving portion  200  according to one embodiment of the present invention. The power supply receiving portion  200  may be a component independent of the housing  100  and the power supply receiving portion is mounted at the bottom of the housing  100  through fasteners, for example.  FIG.  2 A  shows the upper side of the power supply receiving portion  200 . The power supply receiving portion  200  comprises a plate-like body, the body comprises a middle portion  201  and a surrounding portion  202 , and the border of the surrounding portion  202  is defined by the surrounding wall  210 . In the present embodiment, the shape of the middle portion  201  corresponds to the outline of the battery packs. The middle portion  201  forms a platform  203  and the platform  203  is raised relative to the surrounding portion  202 . At least one fastener hole  206  is provided in the surrounding portion  202  and is used to position the fastener (for example, screw) fixing the power supply receiving portion  200  and the housing  100 . Preferably, reinforcing members are formed on the middle portion  201  and/or the surrounding portion  202  to increase the strength of the power supply receiving portion  200  without a significant increase of the weight.  FIG.  2 A  shows that honeycomb reinforcing ribs  204  are formed on the middle portion  201  and that radially and circumferentially extending ribs  205  are formed on the surrounding portion  202 . It should be understood that reinforcing ribs  204 , reinforcing ribs  205  and fastener holes  206  are not a must. The strength of the power supply receiving portion  200  may be improved by use of other means and the power supply receiving portion is fixedly connected with the housing  100 . 
     The surrounding wall  210  of the power supply receiving portion  200  has an upper edge  211 , which has a shape that matches the lower edge of the housing  100 . Favourably, a sealing member, for example, an O-ring is provided between the upper edge  211  and the lower edge of the housing  100  to prevent a fluid, particles, dust or scraps from entering the housing  100  from outside. After the installation, the power supply receiving portion  200  and the housing  100  form an integrated body, and the power supply receiving portion  200  forms the extension portion at the bottom of the housing  100 . That is, besides being used to receive a power supply, the power supply receiving portion  200  is further used as a cover plate covering the bottom opening of the housing  100  in the present embodiment, which helps to reduce the size of the housing  100 . In other embodiments, the power supply receiving portion  200  may be provided inside the housing  100  or may be integrated with the housing  100 . 
     A power adapter may be attached to the power supply receiving portion  200 . In view of a variety of types of electric tools, the mounting interface of battery packs is designed differently, and the same battery pack usually cannot be used for electric tools of different brands. The power supply receiving portion  200  in the present embodiment forms the cover plate of the housing  100 . Therefore, it is convenient for the user to remove and replace the power adapter to match different battery packs, without any space restriction. 
       FIG.  2 B  shows the lower side of the power supply receiving portion  200 . The power supply receiving portion  200  comprises a guide means  220  used to guide a battery pack, and the guide means guides the battery pack to a correct mounting position. In the present embodiment, the guide means  220  is a hollow column, wherein a guide slot  221  is defined, and the guide slot  221  extends towards the inside of the housing  100  roughly perpendicular to the plane where the body of the power supply receiving portion  200  is located. The shape and size of the guide slot  221  match the guide column on the battery pack (not shown). At least one recessed portion  222 ,  223  is formed on the bottom surface of the power supply receiving portion  200 , and the guide slot  221  extends from the recessed portion  222 . The recessed portion  222 ,  223  corresponds to the platform  203  shown in  FIG.  2 A  and is configured to serve as a positioning portion of the battery pack. When the battery pack is located in the correct mounting position, the guide column of the battery pack is inserted into the guide means  220  of the power supply receiving portion  200 , and in addition at least a part of the external surface of the battery pack is accommodated in the recessed portion  222 ,  223 . A battery pack locking portion, for example, a fastener  224  located on the side wall of the recessed portion  222 , may be further provided on the power supply receiving portion  200 . The fastener  224  is jointed with a locking portion in a corresponding position on the battery pack so that the fastener can releasably lock the battery pack. It should be understood that the guide slot  221 , the recessed portions  222 ,  223  and the fastener  224  shown in  FIG.  2 B  are all designed based on the positioning features on the battery pack to keep the battery pack in the correct mounting position. Guide means, positioning portions and locking portions in other forms also fall within the scope of the present invention. For example, the guide means may be guide rails extending in parallel to the plane in which the body of the power supply receiving portion  200  is located. 
     To protect the power supply, a power supply compartment may be provided for the power supply device. The power supply device  10  shown in  FIG.  1    comprises a power supply compartment  120  used to accommodate battery packs. The power supply compartment  120  may be transparent or semi-transparent to allow the user to observe the condition in the power supply compartment. If water or foreign matters are found in the power supply compartment  120 , the user can immediately clean the power supply compartment. This is especially favourable to preventing water from entering the battery pack and/or an electric interface. 
     The power supply compartment  120  in  FIG.  1    is defined by the power supply receiving portion  200  and the cover  300 . In other embodiments, the power supply compartment may be separately defined by the cover  300 , or jointly defined by the housing  100  and the cover  300 , or jointly defined by the housing  100 , the power supply receiving portion  200  and the cover  300 . The cover  300  may move relative to the housing  100  and/or the power supply receiving portion  200  between an opened position and a closed position.  FIG.  3    shows one embodiment of the cover  300 . The pivot  230  (shown in  FIG.  2 B ) passes through the pivot connecting portion  207  located on one side of the power supply receiving portion  200  and the pivot connecting portion  303  located on one side of the cover  300  to pivotably connect the power supply receiving portion  200  and the cover  300 . Alternatively, a biasing component, for example, a biasing spring surrounding the pivot  230 , is provided for the cover  300 . In one embodiment, the biasing spring is configured to bias the cover  300  toward the opened position. If the cover  300  is not locked in the closed position, the biasing spring will force the cover  300  to be at least partially opened, playing the function of giving the user a prompt. In another embodiment, the biasing spring is configured to bias the cover  300  toward the closed position. Even if the cover  300  is not locked in the closed position, the cover  300  can still cover at least a part of the battery pack under the action of the biasing spring, playing the function of protecting the battery pack. It may also be imagined that a proper biasing component is selected to keep the angle the cover  300  is opened within a predetermined range, for example, from 1° to 85°, from 5° to 70°, from 10° to 50°, from 15° to 45°, without any force on the cover  300 . On the one hand, the angle the cover  300  is opened can give the user a prompt that the cover  300  is not locked in the closed position. On the other hand, even if the battery pack is not fixed in the correct mounting position for some reason at this time, for example, the battery pack is not completely inserted into the guide slot  221  or the fastener  224  is loosened, the cover  300  can still support the battery pack apart from the power supply receiving portion  200  under the action of the biasing component to prevent the battery pack from dropping off. 
     The size of the power supply compartment  120  may be designed so that a clearance exists between the power supply and the bottom of the power supply compartment  120  when the power supply (for example, battery pack) is correctly mounted. In the embodiment shown in  FIG.  1   , the existence of a clearance can be realised by designing the depth of the cover  300  to be greater than the thickness of the battery pack. The size of the power supply compartment  120  may be designed so that a clearance exists between the power supply and the sides of the power supply compartment  120  when the power supply is correctly mounted. In the embodiment shown in  FIG.  2 A and  2 B , the surrounding portion  202  of the body of the power supply receiving portion  200  defines the clearance between the battery pack and the side walls of the power supply compartment  120 . If a liquid enters the power supply compartment  120 , the liquid will flow through the clearance and accumulate at the bottom of the power supply compartment  120  but will not immediately contact the contacts of the battery pack. As mentioned above, the user can observe the liquid in the power supply compartment  120  through the transparent or semi-transparent cover  300  and clean it immediately. When the power supply device suffers an impact, the cover  300  can absorb the majority of the impact. Even if the cover  300  is deformed because of the impact, the clearance between the cover  300  and the battery pack can also reduce the impact on the battery pack. In addition, air in the clearance can also dissipate heat to some extent. 
     As an independent component, the power supply receiving portion  200  shown in  FIG.  2 A and  2 B  is provided on one side of the housing  100 , and the power supply receiving portion  200  comprises a single power supply mounting base to accommodate a single battery pack. In other embodiments, the power supply receiving portion  200  may comprise at least two power supply mounting bases to accommodate two or more battery packs. The at least two power supply mounting bases may be arranged side by side on the same side of the housing  100 , for example, at the bottom of the housing, or may be arranged on different sides of the housing, respectively, for example, on the front side, left side and right side. The plurality of battery packs may be connected in series or in parallel to improve the output power or working time of the electric tool. 
     The cover  300  shown in  FIG.  3    has a first sealing edge  310 . The surrounding wall  210  of the power supply receiving portion  200  shown in  FIG.  2 B  has a lower edge  212 , which is aligned with the first sealing edge  310  and serves as a second sealing edge. When the cover  300  is in the closed position, the first sealing edge  310  is seal jointed with the second sealing edge  212 . Preferably, a groove  213  is formed in one of the first sealing edge  310  and the second sealing edge  212  to accommodate at least a part of a sealing component, and the groove  213  is configured to accommodate at least a part of the sealing component  250 . The other of the first sealing edge  310  and the second sealing edge  212  has a ridge portion  311  extending outward. When the cover  300  is in the closed position, the ridge portion  311  abuts against the sealing component  250 . 
     The cover  300  may be locked together with the power supply receiving portion  200  through a locking member  330 . One embodiment of the locking member  330  shown in  FIG.  3    comprises a latch  331 , a pin  332  and a jump ring  333 . The latch  331  is pivotably connected with a locking member connecting portion  304  formed on one side of the cover  300  through the pin  332 , and the jump ring  333  is pivotably connected to the latch  331 . When the locking member  330  is in the locking position, the jump ring  333  is tightly buckled on a protruding portion  208  (shown in  FIG.  2 B ) formed on one side of the cover  300 . The user can release the locking by rotating the latch  331 . It should be understood that although locking is realised by use of a latch in the present embodiment, a locking member in any form, mechanical, magnetic, electrical or otherwise, is feasible. 
     In one embodiment, the control unit of the power supply device comprises a sensor used to detect the position of the cover  300 . The sensor may be a contact sensor, a pressure sensor, a photoelectric sensor, or a magnetic sensor. The sensor may be provided on the cover  300  or the power supply receiving portion  200 , and is electrically connected with a controller (for example, a control PCB) in the housing  100 . When the sensor detects that the cover  300  has left the closed position, the controller may perform protection operations in response to a signal the sensor sends out. The protection operations may include at least one of the following operations: immediately cutting off the power supply, starting timing and cutting off the power supply after a predetermined length of time has elapsed since the cover left the closed position, changing the working mode, sending out a visually or audibly perceptible alarm. 
     Go back to  FIG.  1   , which shows the gripping portion  110  of the portable power supply device  10 . The gripping portion  110  is located at the top of the housing  100  and is arranged opposite to the power supply receiving portion  200 . The gripping portion  110  may be a gripping handle integrated with the housing  100  or an independent handle connected to the housing  100 . In embodiments not shown, the gripping portion  110  may be pivotably connected to the housing  100 . At least a part of the gripping portion  110  may be covered with an elastic material, for example, rubber, to improve the comfort when the user grips the portable power supply device. Preferably, the gripping portion  110  intersects with a vertical line passing through the centre of weight of the whole power supply device. 
     To help the user to control the power supply device, a control interface  150  allowing the user to interact with the control unit may be provided on the housing  100 .  FIG.  4    shows one embodiment of the control interface  150 . The control interface  150  comprises at least one control element  151 , for example, power switch, working mode selector, output power selector, timer, programmer, menu selector and parameter configurator. The control interface  150  may further comprise a display  160 , which is used to display at least one of the following items of information: power supply level, working mode, output power, timing information, system menu, parameter setting and alarm information. It should be understood that the control interface  150  may have different designs to adapt to specific applications of different electric tools. 
     The portable power supply device may be supported on the ground or other horizontal supporting surfaces through a base. In the embodiment shown in  FIG.  1   , the cover  300  located at the bottom of the power supply device serves as a base. To reduce the wear, a wear-resistant member may be provided in a position where the cover  300  contacts the horizontal supporting surface. In some scenarios, the user may expect to fix the power supply device  10  onto a non-horizontal supporting component, for example, a vertical wall or a bent surface.  FIGS.  5 A and  5 B  show the portable power supply device bonded with a positioning accessory. The positioning accessories  400 ,  500  are detachably and replaceably attached to the housing  100  and/or the power supply receiving portion  200 . Favourably, the power supply device may be fixed in different ways by use of different positioning accessories. In a non-restrictive embodiment, the positioning accessory may fix the power supply device onto a supporting component with the aid of at least one of the following means: hanging means, fastener, binder, holding means, vacuum pull and magnetic force. For example, when fixing is realised by use of hanging means, the positioning accessory may comprise a hook. When fixing is realised by use of a vacuum pull, the positioning accessory may comprise a sucker. The user may select positioning accessories according to different environments so that the same power supply device can adapt to different application scenarios. 
     To help the user to remove and replace positioning accessories and meanwhile guarantee a solid connection, it is favourable to use at least two groups of joint portions fitting each other to realise the connection between the positioning accessories and the power supply device.  FIG.  6    shows the rear side of the power supply device, and a first joint portion  130  and a second joint portion  140  are formed on the rear side. The first joint portion  130  comprises a connecting strip  131 , a first concave portion  132  and a second concave portion  133 . The first concave portion  132  and the second concave portion  133  are separated by the connecting strip  131 , with the openings in different directions. The second joint portion  140  is formed into a card slot and is located below the first joint portion  130 . In the present embodiment, the first joint portion  130  is formed on the housing  100 . Specifically, the opening of the first concave portion  132  faces the upper side of the housing  100 , the opening of the second concave portion  133  faces the rear side of the housing  100 , and the connecting strip  131  is integrated with the housing  100 . The second joint portion  140  is formed on the surrounding wall of the power supply receiving portion  200 . It should be understood that the structures and positions of the first joint portion  130  and the second joint portion  140  can be changed. For example, the two joint portions  130 ,  140  may both be formed on the housing  100 , or the second joint portion  140  is formed on the cover  300 . 
       FIG.  7    shows a positioning accessory  400 , which serves as a wall-mounted accessory. The positioning accessory  400  is designed to fix the power supply device onto a supporting wall, for example, a wall, with the aid of fasteners. The positioning accessory  400  comprises a mounting plate  410 , a supporting portion  420  extending in a first direction from the mounting plate  410 , and a connecting portion  430  extending in a second direction from the supporting portion  420 . In the present embodiment, the supporting portion  420  is roughly perpendicular to the plane where the mounting plate  410  is located, and the connecting portion  430  is roughly parallel to the plane where the mounting plate  410  is located. At least one fastener hole  440 ,  450  is formed in the mounting plate  410  and is used to accommodate a fastener  460  (shown in  FIG.  5 A ) (for example, a screw) fixing the positioning accessory  400  onto a supporting wall. The fastener holes  440 ,  450  may have different shapes or sizes to adapt to different fasteners. The fastener holes  440 ,  450  shown in  FIG.  7    are stepped holes, which respectively comprise an outer hole  441 ,  451  and an inner hole  442 ,  452 ; the outer hole and the inner hole of the fastener hole are configured to accommodate the head and the body of the fastener, respectively. 
     An elastic portion  411  is provided in the middle of the mounting plate  410  and the elastic portion is separated from the other parts of the mounting plate  410  through the clearances  413 ,  414  and  415 . The elastic portion  411  may be integrated with the mounting plate  410 , with the thickness less than the thickness of any other part of the mounting plate  410 . The elastic portion  411  may be obtained by removing a part of the mounting plate  410  from the rear side and the removed part forms a recess  416 . A snap-in portion  412  is provided at one end of the elastic portion  411 . When a force is exerted on the snap-in portion  412 , the elastic portion  411  can bend and at least partially enter the recess  416 . 
     In the embodiment shown in  FIG.  7   , the supporting portion  420  and connecting portion  430  of the positioning accessory  400  forms a third joint portion, and the third joint portion fits the first joint portion  130  on the power supply device. The snap-in portion  420  of the positioning accessory  400  forms a fourth joint portion, and the fourth joint portion fits the second joint portion  140  on the power supply device. When mounting the power supply device, the user first uses the fastener  460  to fix the positioning accessory  400  onto a wall, with the rear side of the mounting plate  410  in close contact with the wall surface. Then, the user moves the power supply device to let the connecting portion  430  of the positioning accessory  400  enter the first concave portion  132  on the housing  100  and let the connecting strip  131  on the housing  100  abut against the supporting portion  420  of the positioning accessory  400 , thus completing the fitting between the first joint portion and the third joint portion. Finally, the user pushes the power supply device toward the positioning accessory  400  until the snap-in portion  420  of the positioning accessory  400  is jointed with the card slot in the power supply receiving portion  200 , thus completing the fitting between the second joint portion and the fourth joint portion. In this way, the positioning accessory  400  is fixedly connected with the housing  100  and the power supply receiving portion  200  through the third and fourth joint portions. Even if the snap-in portion  420  is separated from the card slot in the power supply receiving portion  200 , the supporting portion  420  of the positioning accessory  400  can also separately provide support for the power supply device. 
       FIG.  8 A  shows another positioning accessory  500 , which serves as a holding accessory. The positioning accessory  500  comprises a pair of holding arms  510 ,  520  pivoting relative to each other and allows the power supply device to be held onto a plate-like supporting component. A first holding arm  510  of the pair of holding arms is fixed onto the power supply device, and a second holding arm  520  is pivotably connected with the first holding arm  510  through a pivot  530 . The biasing component  540  surrounding the pivot  530  exerts a clamping force on the first holding arm  510  and the second holding arm  520 . 
       FIG.  8 B  is an exploded view of the positioning accessory  500 . Similar to the positioning accessory  400  shown in  FIG.  7   , the first holding arm  510  comprises a mounting plate  511 , a supporting portion  512  extending from the mounting plate  511 , a connecting portion  513  extending from the supporting portion  512 , an elastic portion  514  and a snap-in portion  515 . The differences between the two positioning accessories are that the mounting plate  511  of the first holding arm  510  has a gripping portion  516  extending beyond the supporting portion  512  and helping the user to exert a force on the first holding arm  510  and that the first holding arm  510  further comprises a pivot receiving portion  517 . 
     The second holding arm  520  of the positioning accessory  500  comprises a gripping portion  521 , a holding portion  522  and a pivot receiving portion  523 . The holding portion  522  consists of two holding pieces  524 ,  525  forming a certain angle, and the lower holding piece  525  is roughly parallel to the gripping portion  521 . It should be understood that the holding portion  522  may have different configurations. For example, the holding portion consists of a single or more than three holding pieces or has a bent outline. The holding portion may be designed according to the expected maximum holding force. Alternatively, a plurality of positioning accessories  500  are provided for the power supply device  10 , and the plurality of positioning accessories have different maximum holding sizes so that the user can select a positioning accessory according to the actual application scenario. When mounting the power supply device, the user can first use the gripping portions  516 ,  521  to open the holding arms  510 ,  520  and keep them clamped on the plate-like supporting component, and then follow the way described above to fix the power supply device  10  onto the positioning accessory  500  through the fittings between two groups of joint portions. The user can also first fix the power supply device  10  onto the positioning accessory  500  to let the positioning accessory  500  form a part of the power supply device, and then keep the holding arms  510 ,  520  clamped on the plate-like supporting component. 
     One application of the portable power supply device according to the present invention is described below in combination with  FIGS.  9 - 11   .  FIG.  9    shows a submersible pump, which is used for pumping a fluid, for example, water. The inlet  601  of the submersible pump  600  is defined by the base  630 , and the outlet  602  extends outward from the side wall and is used for connecting a drain pipe, for example, a garden hose. The housing of the submersible pump  600  comprises a driving unit housing  610  and a pumping unit housing  620 . A driving unit is provided in the driving unit housing  610 , and the driving unit may be a motor, for example, a brushless DC motor or a brushed DC motor. A pumping unit is provided in the pumping unit casing  620 , and comprises a pumping chamber, and an impeller located in the pumping chamber and driven by the electric motor. The impeller may be a centrifugal impeller or an axial-flow impeller. The pumping unit housing  620  is detachably mounted on the driving unit housing  610  to help the user to replace the motor or impeller when necessary. The base  630  is connected to the pumping unit casing  620  and is used to stably support the entire submersible pump. When the submersible pump is used to pump water from a pool or a water tank, the base  300  can contact the bottom wall of the pool or water tank. 
     The submersible pump  600  further comprises a float control unit  640 , which is used to detect the liquid surface position of a fluid source and control the working of the submersible pump based on the liquid surface position. The float control unit  640  may be kept on the outer wall of the submersible pump or formed into a part of the outer wall of the submersible pump. Therefore, no relative motion or collision will happen between the float control unit  640  and the submersible pump  600  when the submersible pump works. 
       FIG.  10    shows the top of the submersible pump  600 . The submersible pump  600  comprises a handle  611  for a user to grip; the handle  611  may be formed integrally with the drive unit casing  610 . A power cable  650  protrudes from the edge  614  of the driving unit housing  610 . A power cable retaining trough  613  may be formed in the handle  611 , and the power cable retaining trough is roughly located in the middle of the handle  611  and extends in the vertical direction. When the user lifts the submersible pump  600  by virtue of the power cable  650 , the submersible pump will not tilt significantly, the base  630  of the submersible pump is kept roughly horizontal, and the user can smoothly put down the submersible pump  600  and place it at the bottom wall of a pool or water tank. To help to accommodate the power cable  650 , at least one groove  612  may be formed in the outer wall of the driving unit housing  610 . When the submersible pump is not used, the user can wind the power cable  650  around the housing and fix the power cable by virtue of the groove  612  to prevent the power cable from dropping off. 
     When the submersible pump is used, the user first connects the two ends of the power cable  650  to the submersible pump  600  and the power cable interface  160  of the power supply device, respectively, and then steadily places the submersible pump  600  in a working position, for example, a pool or a water source container. If a supporting wall is available near the working position, the power supply device may be fixed onto the supporting wall with the aid of the positioning accessory  400 . The user can start the submersible pump and set the parameters such as pumping mode, output power and pumping time through the control interface  160  on the housing  100  of the power supply device. The display  160  can display various items of information, for example, remaining power energy, pumping mode, output power and timing information, in real time. When the energy of the battery pack is used up, the user can open the cover  300  to replace the battery pack, without having to take the submersible pump  600  out of the pool or water tank. 
       FIG.  11    shows a working state of the power supply device  10  and the submersible pump  600 . The submersible pump  600  is placed at the bottom of a water tank  700 . The user can use the positioning accessory  500  to clamp the power supply device  10  onto the wall of the water tank  700 . The power supply device  10  supplies power to the submersible pump  600  through the power cable  650 . The outlet of the submersible pump is connected to a water pipe  660  to drain water to a predetermined position. 
     The portable power supply device according to the present invention can supply power to other equipment, besides traditional electric tools (including various handheld tools and garden tools). In one embodiment, a lighting device comprises the portable power supply device and a lamp string electrically connected with the power supply device. The lighting device can be used as an accessory of an electric tool to provide a light source for the user at work or can be separately used for lighting. 
     Although the present invention has been explained in detail with reference to limited embodiments, it should be understood that the present invention is not restricted to these disclosed embodiments. Those skilled in the art may envisage other embodiments conforming to the spirit and scope of the present invention, including changes to the numbers of components, alterations, substitutions or equivalent arrangements, all such embodiments falling within the scope of the present invention.