Swimming and diving aid with a battery module

Abstract

Swimming and diving aid (10) with a rechargeable battery module (26) comprising a moisture-tight housing (28) in which a plurality of rechargeable battery cells (31) are arranged, the contacts of which are electrically interconnected and which are led to external contacts (30) of the rechargeable battery module (26) which are arranged on the outside of the housing (28), characterized in that a protective device (35) is arranged in the interior of the housing (28), which protective device comprises a detection device (36) which is designed to detect a short circuit between the external contacts (30), in that the housing (28) is in turn arranged in a moisture-tight, sealable receptacle in the hull (11) of the swimming and diving aid and is in contact with the electrical system of the swimming and diving aid.

Description

[0001] The present invention relates to a swimming and diving aid with a battery module comprising a moisture-proof housing in which several battery cells are arranged, the contacts of which are electrically interconnected and which are led to external contacts of the battery module, which are arranged on the outside of the housing.

[0002] The invention further relates to a swimming and diving aid with a hull having a flow channel and, on its upper side, a support surface for the upper body of a user of the swimming and diving aid. An electric motor-driven drive unit, in particular a propeller, is assigned to the flow channel. Furthermore, handles designed to hold the user are attached to the swimming and diving aid. Operating elements for the user to control the drive unit are arranged on the handles. Such a swimming and diving aid is known, for example, from DE 10 2017 101 146 A1.

[0003] DE 10 2018 101 213 A1 discloses an electric motor-driven kickboard. The kickboard has a recess on its top side into which two removable batteries can be inserted.

[0004] Electrically powered mobile devices typically draw their energy from rechargeable batteries, known as accumulators. Due to the often high energy requirements, lithium-ion cells are predominantly used for these applications, as they have a relatively high energy density and offer a very good energy density-to-price ratio.

[0005] In many applications, high performance is required alongside high capacity. The battery cells must therefore be able to deliver high current and be interconnected accordingly. The electrical connections of a battery cell are arranged on the outside of the battery cell housing in a freely accessible manner, as this is necessary for connecting the cells to the battery module. In the event of a short circuit, very high currents flow between the contacts of the battery cells, which can often lead to overheating (defects) and the cells catching fire, or ultimately the entire electrical device supplied with electrical energy by the battery cells. A short circuit can be triggered, for example, by the ingress of moisture, particularly salt or seawater.This can happen in particular when the accumulator module is used in a watercraft for use in sea water and during sporty, dynamic operation of the watercraft above and below water, as is the case, for example, with a swimming and diving aid of the type mentioned above.

[0006] Various battery cell designs are known from the state of the art. Examples include Li-ion battery cells with a substantially cylindrical shape (e.g., type 18650 or VL41M) and battery cells with a substantially rectangular shape (e.g., pouch cells). All designs have in common that the contact terminals are freely accessible from the outside. Contact or bridging of these terminals with a conductive material (e.g., salt water) inevitably leads to a short circuit and significant heating of the battery cell, even leading to a fire. The battery cells can be installed in cylindrical, rectangular, or any other shaped battery module housings.

[0007] To prevent a short circuit between the terminals of the battery cells, it is known to arrange the battery cells in a moisture-proof housing of the battery module. However, in this case, the electrical connections of the battery module are also routed to the outside of the module housing as external contacts. To prevent a short circuit between the external contacts, the battery module itself is arranged in a watertight, sealable container in the hull or at another location on the vessel.

[0008] Even with careful design and implementation of a moisture-proof housing for the battery module, seawater can penetrate the housing over an extended period of time and / or under the high dynamic loads of the watercraft. This can result in a short circuit between the external contacts of the module housing, overheating of the battery module, and even a fire.

[0009] Certain battery technologies (e.g., lithium iron phosphate batteries, LiFePO4) are safer, but have a significantly lower energy density and are therefore only a practical alternative in a few cases. Particularly in the case of a dynamically demanding swimming and diving aid for above- and underwater operation, particularly high-performance batteries are desired, and LiFePO4 batteries therefore offer no alternative.

[0010] Based on the described prior art, the present invention is based on the object of designing and developing a swimming and diving aid with a battery module of the type mentioned at the outset in such a way that overheating and catching fire of the battery module or the electrical device supplied with it can be effectively prevented in a simple manner in the event of a short circuit.

[0011] To achieve this object, a swimming and diving aid with the features of claim 1 is proposed. In particular, it is proposed that a protective device be arranged inside the housing of the rechargeable battery module of the type mentioned above, said protective device comprising a detection device designed to detect a short circuit between the external contacts. This has the advantage that the rechargeable battery module according to the invention, with the rechargeable battery cells arranged in the housing and the protective device, can be handled as a single unit and inserted into a corresponding receptacle provided for this purpose in the electrical device. The moisture-proof housing ensures that, as far as possible, no water can penetrate into the interior of the housing and the rechargeable battery cells.If the external contacts of the housing are short-circuited, this is detected safely and reliably by the integrated protective device, allowing appropriate countermeasures or warning measures to be initiated at an early stage. In the event of a detected short circuit, possible measures could include issuing an acoustic and / or visual warning signal to the user of the electrical device, switching to emergency operation, and / or shutting down the battery module whose external contacts have detected a short circuit. If the electrical device has multiple battery modules, the remaining modules where no short circuit was detected can continue to operate. The arrangement of the protective device in the module housing also has the advantage that it is generally protected from moisture.According to the invention, it is further provided that the accumulator module, with its moisture-proof housing, is arranged in a receptacle in the hull or at another location of the swimming and diving aid. The receptacle can be sealed in a moisture-proof manner, for example, by means of a lid and a seal.

[0012] According to an advantageous development of the invention, it is proposed that the protective device comprise an interruption device configured to interrupt a current flow via the external contacts of the accumulator module upon detection of a short circuit between the external contacts. In this way, overheating of the accumulator module can be quickly and effectively prevented. Furthermore, the arrangement of the interruption device in the module housing has the advantage that the interruption device is generally protected from moisture and cannot be bypassed or impaired in its function by moisture.

[0013] According to a preferred embodiment, it is proposed that the protective device comprise one or more fuses. The fuse can be adapted to the current flow typically occurring during intended operation of the electrical device. At least a portion of the current flowing through the external contacts flows through the fuse(s). If the maximum current flow occurring during intended operation (or a variable dependent thereon or representing the current flow) is exceeded by a certain value and / or for a certain period of time, the fuse is triggered, thereby interrupting the current flow through the external contacts of the battery module. The fuse thus combines the detection device and the interruption device of the safety device.The use of one or more fuses represents a particularly simple and cost-effective, yet highly reliable, way to implement the invention. By using several different fuses connected in parallel, a gradual reduction in the power output of the battery module could also be achieved. Instead of a fuse, other protective devices, such as a circuit breaker, a self-resetting fuse, or an electronic fuse, can also be used.

[0014] According to an alternative embodiment, it is proposed that the protective device comprises an electronic circuit. This is preferably designed as an integrated circuit. In this sense, it is proposed that the electronic circuit have means for monitoring a current flow via the external contacts of the battery module and for detecting a short circuit between the external contacts if the monitored current flow exceeds a predeterminable limit value. The electronic circuit can comprise, as a detection device, an operational amplifier for comparing the current value of the current flowing via the external contacts (or a variable dependent thereon or representing the current flow) with a predeterminable limit value and, if appropriate, an electrical switching element, e.g. in the form of a transistor, as an interruption device. As soon as the current value of the current flowing via the external contacts (orof the corresponding size) exceeds or falls below the limit value, the operational amplifier outputs a control signal to activate the electrical switching element, causing it to open and interrupt the flow of current. It is conceivable that the electrical current flowing through the external contacts does not flow directly through the electrical switching element, but rather, for example, through a circuit breaker that is controlled by the electrical switching element. Furthermore, it is conceivable that the electronic circuit is implemented in software using a processor and a computer program running on it. In this embodiment, too, it is particularly advantageous that the electrical circuit is protected from moisture by the module housing.

[0015] The accumulator cells can have any shape and be assembled to form accumulator modules of any shape. However, according to a preferred embodiment, it is proposed that the accumulator cells each have a substantially cylindrical shape and the contacts of the accumulator cells are arranged on the end faces of the cylindrical accumulator cells. Advantageously, the accumulator cells are held in a two-part holder, preferably made of plastic, with the parts of the holder enclosing the accumulator cells at opposite ends. This has the advantage that cavities are formed between the individual accumulator cells, which can serve to cool the accumulator cells during operation of the electrical device provided with the accumulator module for power supply. Preferably, the cavities are filled with air.However, it is also conceivable that the cavities are filled with a material with higher thermal conductivity than air, e.g. a plastic (polyethylene (PE), polyetheretherketone (PEEK), polyamides (nylon, perlon) or polyimides (Pl)).

[0016] Preferably, the battery cells are held in the two-part holder by clamping and / or the two parts of the holder are clamped against each other after the battery cells have been arranged in the two-part holder. In the first case, the battery cells can be inserted into corresponding receiving recesses in the holding parts by press fitting and are then held therein by frictional engagement. In the second case, the opposite ends of the battery cells can be inserted into the holding parts and the holding parts can then be clamped against each other, for example by at least one threaded rod being guided lengthwise (parallel to the longitudinal extent of the cylindrical battery cells) through the battery module and secured to the outer sides of the holding parts, for example by means of a nut. Other clamping mechanisms for clamping the holding parts against each other could also be used.

[0017] Preferably, the contacts of the accumulator cells are electrically interconnected by means of a plurality of contact plates and led to the external contacts of the accumulator module. The accumulator cells can be interconnected in series or parallel, or partially in series and partially in parallel. The aim of interconnecting the cells is to obtain an accumulator module with a desired voltage applied to the external contacts and a desired current flowing through the external contacts. The voltage and current of the accumulator module are adapted to the electrical requirements of the electrical device that is supplied with electrical energy by the accumulator module. It is conceivable for the electrical device to have more than one accumulator module according to the invention. The various accumulator modules can be interconnected in series or parallel, or partially in series and partially in parallel.In a battery module for use in a swimming and diving aid according to the invention as the sole battery module, this can, for example, have a voltage of 48 V, an electrical charge of 42 Ah, and a capacity of 2.0 kWh. Depending on the type and electrical properties of the battery cells used, these are connected in series and / or parallel. The external contacts arranged on the outside of the module housing can be contacted with the battery cells or the contact plates by means of a waterproof feedthrough. However, it would also be conceivable for some of the contact plates to be led outwards to the outside of the module housing through a waterproof feedthrough and form the external contacts.

[0018] Advantageously, the contacting plates are attached to the parts of the holder. For example, it would be conceivable for the contacting plates to be attached to the holder parts by caulking, gluing, welding, soldering, bracing, or clamping. In this way, the battery cells can be fastened to one another by means of the holder parts and, at the same time, electrically interconnected in the desired manner using the contacting plates attached to the holder parts. The fastened and interconnected battery cells can be inserted into the module housing as a unit, and the housing can then be sealed watertight. When the unit is inserted into the housing, it is either automatically contacted by the external contacts, or parts of the unit's contact plates slide automatically into the positions provided for the external contacts during insertion, forming the external contacts.

[0019] The accumulator module according to the invention is particularly well suited for use in the buoyancy and diving aid according to the invention, for operating an electric motor and for driving a propulsion unit of the watercraft. The propulsion of the propulsion unit provides propulsion and / or steering of the watercraft. The highly dynamic operation of the buoyancy and diving aid above and below water in fresh and salt water requires a particularly safe and reliable accumulator module to supply power to the electric motor. The accumulator module, with its moisture-proof housing, is arranged in a receptacle in the hull or at another location of the buoyancy and diving aid and is connected to the watercraft's electrical system. The receptacle can preferably be sealed in a moisture-proof manner, e.g., by means of a lid and a seal.For improved heat dissipation, the receptacle with the accumulator module arranged therein can be positioned in the flow channel, adjacent to it, or at another location in the swimming and diving aid in contact with the surrounding water. Furthermore, the swimming and diving aids according to the invention are generally operated in a highly dynamic manner above and below water in fresh and salt water. The resulting hydrostatic pressure can cause water to penetrate the receptacle and cause leakage currents or a short circuit between the external contacts of the accumulator module. These are detected by the protective device in the module housing, and appropriate countermeasures or protective measures are initiated if necessary.

[0020] Further features and advantages of the present invention are explained in more detail below with reference to the figures. The features described and / or shown in connection with the various embodiments can also be combined in any way other than that shown in the figures. The figures show: Fig. 1 a swimming and diving aid according to the invention in a perspective view from behind; Fig. 2 the swimming and diving aid Fig. 1 in a perspective view from the front; Fig. 3 a swimming and diving aid according to the invention in a side view; Fig. 4 shows an accumulator module according to the invention in a perspective view obliquely from above; Fig. 5 shows several accumulator cells of an accumulator module according to the invention in a perspective view obliquely from above; and Fig. 6 an accumulator module according to the invention in a sectional view.

[0021] Fig. 1 shows a perspective view from behind of a swimming and diving aid 10 according to the present invention. Fig. 2 is the Fig. 1 shown swimming and diving aid 10 in a perspective side view from the front.

[0022] The swimming and diving aid 10 has a hull 11. The hull 11 is made up of an upper part 11.6 and a Fig. 2. Of course, the hull 11 can also be formed in one piece, in which case a watertight, sealable maintenance hatch is preferably provided on the upper side of the hull 11. The upper part 11.6 is provided in the front area of ​​the swimming and diving aid 10 with two handles 16, which are arranged on both sides of the hull 11 and which a user of the swimming and diving aid 10 can hold on to during normal operation. Control elements 16.1 for controlling the swimming and diving aid 10 by the user are attached to the handles 16. In particular, the power of an electric motor of the swimming and diving aid 10 can be varied here. Preferably, an operating element for increasing the motor speed is arranged on one of the handles 16, and an operating element for decreasing the motor speed is arranged on the other handle 16.

[0023] A switching element 16.2 is also arranged on one of the handles 16 and a switching element 16.3 is arranged on the other handle 16. During normal operation, the user, who holds on to the handles 16, rests with his upper body on a support surface 11.3 on the upper side of the torso 11, wherein the support surface 11.3 extends approximately from the middle of the torso 11 to the rear. The support surface 11.3 is arranged in particular in an area behind a display 20 on the upper part 11.6. In this position, during normal operation of the swimming and diving aid 10, the user can read the display 20 located in his field of vision in a particularly ergonomic manner and operate the control elements 16.1, the switching element 16.2 and the switching element 16.3 located within easy reach.Up and down movement is preferably carried out by the user shifting his weight while holding on to the handles 16.

[0024] A bracket 11.7 is attached to the support surface 11.3 for attaching a belt system, with which the user can strap themselves to the swimming and diving aid 10. This enables dynamic and, at the same time, particularly fatigue-free operation of the swimming and diving aid 10.

[0025] A closure 12.1 for a charging socket located behind it is arranged in front of the support surface 11.3. Batteries arranged in the fuselage 11 can be charged via the charging socket. The batteries preferably comprise a plurality of interconnected battery cells 31 (see FIG. Fig. 5 and Fig. 6), which form a battery module 26. The battery cells 31 are preferably designed as lithium-ion batteries. The battery cells 31 are arranged in a moisture-proof housing 28 of the battery module 26 (see Fig. 4 and Fig. 6).

[0026] Carrying handles 11.2 can be arranged on the side of the hull 11, by which the swimming and diving aid 10 can be carried outside of the water. A removable cover 14 can be attached to the hull 11 in front of the display 20 and between the two handles 16. As shown in Fig. 2, ventilation openings 15.1 are provided in the cover 14, which can be connected to a flooding space provided in the hull 11.

[0027] How Fig. As can be seen from Figure 2, water inlet openings 15.2 can be provided in the area of ​​the bow 11.1 or at another suitable location on the hull, through which water can flow into the flooding compartment. For this purpose, the flooding compartment can be vented via the vent openings 15.1, which are preferably provided in the cover 14. The water-filled flooding compartment adjusts the buoyancy of the swimming and diving aid 10 so that a predetermined buoyancy force is maintained, allowing both swimming and diving operations without great effort.

[0028] At the Fig. Water outlet openings 15.3, preferably covered by slats, which also communicate with the flooding chamber, can be provided on the stern 11.5 shown in Figure 1 or at another suitable location on the hull of the swimming and diving aid 10. As soon as the swimming and diving aid 10 is placed in the water, the flooding chamber is flooded with water entering through the water inlet openings 15.2 and water outlet openings 15.3. As soon as the swimming and diving aid 10 enters operation, a current is generated in the flooding chamber. The water enters the flooding chamber through the water inlet openings 15.2, flows through the flooding chamber, and thereby washes around any electrical components arranged in the flooding chamber, such as an electric motor for driving a drive unit, in particular a propeller, of the swimming and diving aid 10 or the associated accumulators.The water absorbs the power loss (heat) from the electrical components, transports it away, and thus cools the components. After flowing through the flooding chamber, the water exits through the water outlet openings 15.3, which can be arranged symmetrically on either side of a jet outlet 17 of a flow channel 18.

[0029] In the flow channel 18, as in Fig. 3, the drive unit of the swimming and diving aid 10 is arranged, which sucks in water and expels it from the jet outlet 17 at the rear, whereby the swimming and diving aid 10 receives a thrust forward.

[0030] A flow stator 18.2 can be arranged on the outlet side of the flow channel 18 in the area of ​​the jet outlet 17. This stator counteracts the rotation of the water flowing through the flow channel 18, so that the water flows out of the flow channel 18 from the jet outlet 17 with as little rotation as possible. The rotational movement of the water is converted into a linear movement and thus serves to drive the swimming and diving aid 10.

[0031] The hull 11 of the swimming and diving aid 10 is preferably made of a plastic or composite material. This makes the swimming and diving aid 10 lightweight, allowing it to be carried by a single person outside of the water.

[0032] A bow tip 11.8 forming the front area of ​​the bow 11.1 is made of an elastic material, such as rubber or silicone. This increases the impact resistance of the buoyancy and diving aid 10 in the area of ​​the bow 11.1.

[0033] Fig. Figure 3 shows the swimming and diving aid 10 according to the invention in a side view. The flow channel 18 extends from an inlet opening 21 in the area of ​​the bow 11.1 to the jet outlet 17 in the rear area of ​​the hull 11. The inlet opening 21 extends from a central area of ​​the hull 11 toward the bow 11.1. Arranged in the flow channel 18, which is slightly curved downward in the area of ​​the inlet opening 21 and the jet outlet 17, are a drive unit 22, which may be in the form of a propeller, as well as the flow stator 18.2, an electric motor 23, and a motor control unit 24. The flow stator 18.2 is fixedly connected to the hull 11. Of course, the electric motor 23 and the engine control unit 24 can also be arranged outside the flow channel 18 at any other location in the hull 11, for example in the flooding compartment.

[0034] The flow channel 18 can be formed integrally in the fuselage 11. In the present embodiment, the flow channel 18 is defined by the upper part 11.6 and the lower part 11.4. The components are connected to one another by suitable fastening means. For maintenance of the drive unit 22, the electric motor 23, and the engine control unit 24, the flow channel 18 can be made accessible by removing the lower part 11.4. However, a maintenance hatch or the like can also be provided below the drive unit 22, the electric motor 23, and the engine control unit 24, through which access to the components in the flow channel 18 is possible.

[0035] In the area of ​​the bow 11.1 of the hull 11, a receptacle 25 can be formed in the underside, in which the at least one accumulator module 26 is arranged. In a preferred variant of the invention, the at least one accumulator module 26 is accommodated in the flooding space for cooling purposes. In the example shown, two accumulator modules 26 are provided. The receptacle 25 can be closed in a watertight manner by means of a maintenance flap 27 or the like. Despite the watertight closure, due to the highly dynamic operation of the swimming and diving aid above and below water, small amounts of water can penetrate into the receptacle 25. Particularly in the case of sea or salt water, penetrating moisture can cause a short circuit in external contacts on the outside of the housings of the accumulator modules 26.As will be described in detail below, the accumulator modules 26 according to the invention are designed in a special way to detect a short circuit at an early stage and to prevent damage to the accumulator modules 26 due to the short circuit.

[0036] By arranging the accumulator modules 26 so that they are at least indirectly exposed to water flowing past them in the flooding space or along both of their sides (port and starboard) and / or on the keel side, they can be optimally cooled to prevent excessive heating of the accumulator modules 26 during operation.

[0037] In Fig. 4 shows an accumulator module 26 according to the invention, which can be used in the swimming and diving aid 10 according to the invention. The module 26 comprises a moisture-proof housing 28 in which several accumulator cells (cf. Fig. 5). The housing 28 can have any shape; in the example shown, it has a substantially cylindrical shape. The housing 28 has an opening through which the battery cells can be inserted. The opening can be closed in a moisture-tight manner by a cover 29. It is conceivable that the cover 29 is glued, welded, or otherwise permanently connected to the rest of the housing 28. It is also conceivable that the cover 29 is detachably connected to the rest of the housing 28, in which case a sealing element is preferably arranged between the cover 29 and the upper edge of the housing 28, which edge delimits the opening. External contacts 30 of the battery module 26 (a positive pole and a negative pole) are arranged on the outside of the housing 28.

[0038] Several accumulator cells 31 of the accumulator module 26 are in Fig. 5. The cells 31 preferably each have a substantially cylindrical shape. The contacts (not visible) of the accumulator cells 31 are arranged on the end faces of the cylindrical accumulator cells 31. In the example shown, the accumulator cells 31 are held in a two-part holder 32, 33, which is preferably made of plastic. The parts 32, 33 of the holder enclose the accumulator cells 31 at opposite ends. The accumulator cells 31 can be clamped in the two-part holder 32, 33, for example by means of a press fit. Alternatively or additionally, the two parts 32, 33 of the holder can be clamped against one another after the accumulator cells 31 have been arranged in the two-part holder 32, 33.

[0039] The contacts of the accumulator cells 31 can be electrically connected in series or parallel to one another and led to the external contacts 30 of the accumulator module 26. By electrically connecting the cells 31, the desired values ​​for voltage and current at the external contacts 30 can be achieved. Preferably, the contacts of the accumulator cells 31 are electrically connected to one another by means of several contact plates 34 and led to the external contacts 30 of the accumulator module 26. The contact plates 34 are preferably attached to the parts 32, 33 of the holder. The attachment can be detachable or non-detachable. The plates 34 can be attached to the holder parts 32, 33 by caulking, gluing, welding, soldering, bracing, or clamping.

[0040] The accumulator cells 31 with the holder 32, 33 and the contacting plates 34 form a separately handleable unit in which the cells 31 are held and electrically contacted and which can be inserted as a whole through the opening into the housing 28.

[0041] In Fig.Figure 6 shows a section through a rechargeable battery module 26 according to the invention, wherein the two-part holder 32, 33 is not shown. The rechargeable battery cells 31 can also be held in the housing 28 in another way instead of the holder 32, 33. The rechargeable battery cells 31, which are connected in series and are in electrical contact with the external contacts 30, can be seen inside. Furthermore, a protective device 35 is arranged inside the housing 28, which includes a detection device 36 designed to detect a short circuit between the external contacts 30. In the event of a short circuit between the external contacts 30, the voltage between the two external contacts 30 or the conductor tracks (contact plates 34) leading thereto drops sharply, whereas the strength of the current I flowing through the external contacts 30 increases sharply.In the example shown, the detection device 36 measures the current via a current measuring resistor (so-called shunt) R arranged in the current path, across which a voltage U depends on the current I. The measured voltage U is representative of the current I. If the voltage U exceeds a predeterminable limit value, a short circuit between the external contacts 30 is assumed.

[0042] The protective device 35 preferably comprises an interruption device 37, which is designed to interrupt the current flow I via the external contacts 30 of the accumulator module 26 upon detection of a short circuit between the external contacts 30. The interruption device 37 comprises, for example, an electrical switching element 38, for example a transistor, which is controlled by a control signal 39 generated by the detection device 36 in the event of a detected short circuit. By controlling the electrical switching element 38, the current flow I is interrupted (open position of the switching element 38 shown in dashed lines).

[0043] The protective device 35 is preferably designed as an electronic circuit, in particular as an integrated circuit (e.g., IC or ASIC). This makes the protective device 35 particularly compact and can be easily arranged in the housing 28 of the accumulator module 26. The protective device 35 can also be designed in any other way. It is important that it has means for monitoring the current flow I via the external contacts 30 of the accumulator module 26 and for detecting a short circuit between the external contacts 30 if the monitored current flow I exceeds a predeterminable limit value. The exact details of how the short circuit is detected are not important for the invention.

[0044] In a particularly simple, cost-effective, and compact example, the protective device 35 can comprise one or more fuses (not shown). The fuse can be adapted to the current flow I typically occurring during intended operation of the electrical device. At least a portion of the current I flowing through the external contacts 30 flows through the fuse(s). If the maximum current flow occurring during intended operation (or a variable dependent thereon or representing the current flow) exceeds a certain value and / or for a certain period of time, the fuse is triggered, thereby interrupting the current flow I through the external contacts 30 of the accumulator module 26. The fuse thus combines the detection device 36 and the interruption device 37 of the safety device 35 in a single component.Instead of a fuse, other protective devices can be used, e.g. in the form of a circuit breaker, a self-resetting fuse or an electronic fuse.

Claims

[1] Swimming and diving aid (10) with a battery module (26) comprising a moisture-proof housing (28) in which several battery cells (31) are arranged, the contacts of which are electrically interconnected and which are led to external contacts (30) of the battery module (26) which are arranged on the outside of the housing (28), characterized by that a protective device (35) is arranged inside the housing (28), which protective device comprises a detection device (36) which is designed to detect a short circuit between the external contacts (30), that the housing (28) is in turn arranged in a moisture-tight, sealable receptacle in the hull (11) of the swimming and diving aid and is in contact with the electrical system of the swimming and diving aid. [2] Swimming and diving aid (10) according to claim 1, characterized bythat the protective device (35) comprises an interruption device (37) which is designed to interrupt a current flow (I) via the external contacts (30) of the accumulator module (26) upon detection of a short circuit between the external contacts (30). [3] Swimming and diving aid (10) according to claim 1 or 2, characterized by that the protective device (35) comprises one or more fuses. [4] Swimming and diving aid (10) according to claim 1 or 2, characterized by that the protective device (35) comprises an electronic circuit. [5] Swimming and diving aid (10) according to claim 4, characterized by that the electronic circuit has means (35) for monitoring a current flow (I) via the external contacts (30) of the accumulator module (26) and for detecting a short circuit between the external contacts (30) when the monitored current flow (I) exceeds a predeterminable limit value. [6] Swimming and diving aid (10) according to one of the preceding claims, characterized by that the accumulator cells (31) each have a substantially cylindrical shape and the contacts of the accumulator cells (31) are arranged on end faces of the cylindrical accumulator cells (31). [7] Swimming and diving aid (10) according to claim 6, characterized by that the accumulator cells (31) are held in a two-part holder (32, 33), which is preferably made of plastic, wherein the parts (32, 33) of the holder enclose the accumulator cells (31) at opposite end sides. [8] Swimming and diving aid (10) according to claim 7, characterized by that the accumulator cells (31) are held in a clamped manner in the two-part holder (32, 33) and / or the two parts (32, 33) of the holder are clamped against one another after the accumulator cells (31) have been arranged in the two-part holder (32, 33). [9] Swimming and diving aid (10) according to one of the preceding claims, characterized by that the contacts of the accumulator cells (31) are electrically interconnected by means of several contact plates (34) and are led to the external contacts (30) of the accumulator module (26). [10] Swimming and diving aid (10) according to claim 9, characterized by that the contact plates (34) are attached to the parts (32, 33) of the holder. [11] Swimming and diving aid (10) according to one of the preceding claims, characterized by that the accumulator module (26) is designed for use in a swimming and diving aid (10) for driving an electric motor (23) to realize propulsion of the swimming and diving aid (10). [12] Swimming and diving aid (10) according to one of claims 1 to 11, characterized bythat the hull (11) has on its underside a flow channel (18) to which an electric motor-operated drive unit (22), in particular a propeller, is assigned, and on its upper side a support surface (11.3) for an upper body of a user of the swimming and diving aid (10), with handles (16) attached to the swimming and diving aid (10) which are designed to hold the user, that the accumulator module (26) serves to supply energy to the drive unit (22), and that operating elements (16.1) arranged on the handles (16) are provided for controlling the drive unit (22) by the user.

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