WO2025198479A1

WO2025198479A1 - A detection device

Info

Publication number: WO2025198479A1
Application number: PCT/NO2025/050049
Authority: WO
Inventors: Morten Revill
Original assignee: Icbrg AS
Current assignee: Icbrg AS
Priority date: 2024-03-20
Filing date: 2025-03-20
Publication date: 2025-09-25
Anticipated expiration: 2026-09-20
Also published as: NO20240266A1

Abstract

A detection device (1; 100) for detecting and communicating a potential fire in a lithium-ion battery of a hybrid or battery electric vehicle (20). The detection device (1; 100) comprises a housing (2), a battery (14) for powering the detection device (1; 100), an audio sensor (15) for sensing a sound profile caused by degradation of the lithium-ion battery, a vibration sensor (19) for sensing a vibration from the lithium-ion battery, a processor (16) connected to the audio sensor (15) and vibration sensor (19), and a signal transmitter (10) for communicating an alarm signal to an external alarm central (21) and/or other detection devices (1; 100).

Description

A DETECTION DEVICE

TECHNICAL FIELD

The invention relates to a detection device. More specifically, the invention relates to a detection device for detecting and communicating a potential fire in a lithium-ion battery of a battery electric vehicle.

BACKGROUND

Battery electric vehicles and hybrid electric vehicles are electric vehicles where energy for powering the vehicle is stored in a lithium-ion battery. Battery- and hybrid electric vehicles are becoming ever more popular, and continuously increase in numbers worldwide. However, as with all appliances comprising a battery, there is a risk of battery failure, which could lead to overheating and risk of fire. Numerous factors could lead to a battery failure, which may induce thermal runaway. Many of these involve a breakdown or failure of the insulation between the cells which in turn leads to short circuits. The factors may be overheating through external sources or excessive current draw, water ingress or damage. The effects are often seen as release of gas and jets of flame, and also crackling sounds and sparks are often reported.

Battery failure can be due to malfunction, production flaws, wear and tear, knocks sustained during vehicle incidences, or other circumstances. If the battery electric vehicle has been involved in an accident, or been exposed to a sudden shock or similar mishap, the risk of damaging the battery increases. A fire in an electric battery is notoriously difficult to control and put out, and therefore poses a great risk not only to the vehicle itself but also to the surroundings. This is especially true during shipping and transport of battery electric vehicles. Cargo ships are known to have caught fire because of a fire originating from a battery of a battery electric vehicle on board. In fact, the number of such incidences is increasing and is now the highest in a decade according to insurance companies.

Battery electric vehicles commonly comprises a battery management system (BMS) which monitors the state of the battery. However, in case of battery malfunction and overheating, such systems are prone to fail. Because the BMS is an integrated part of the vehicle, and is powered by the battery of the vehicle, the readings and monitoring of the BMS are mostly reliable when the battery is functioning as intended, and no fire is imminent.

There is therefore a need for a detection device which can effectively and reliably monitor a battery, and especially a detection device which can detect a potential fire, before the battery catches fire. There is further a need for a detection device that can easily be attached to or in the vicinity of a battery electric vehicle, and which can easily be moved from one vehicle to another, e.g. during transport on a cargo ship or train. There is further a need in the art for a detection device which can signal an alarm prior to the battery catching fire, to prevent the fire from starting and enable personnel or means to prevent a potential fire from escalating. It is an objective of the invention to achieve this and to provide further advantages over the state of the art.

SUMMARY OF THE INVENTION

According to a first aspect, there is provided a detection device for detecting and communicating a potential fire in a lithium-ion battery of a hybrid or battery electric vehicle. The detection device comprises a housing, a battery for powering the detection device, an audio sensor for sensing a sound profile caused by degradation of the lithium-ion battery, a vibration sensor for sensing a vibration from the lithium-ion battery, a processor connected to the audio sensor and vibration sensor and a signal transmitter for communicating an alarm signal to an external alarm central and/or other detection devices.

According to an embodiment the audio sensor comprises a MEMS microphone.

According to an embodiment the audio sensor comprises an analogue MEMS microphone and a digital MEMS microphone.

According to an embodiment the audio sensor is a single digital MEMS microphone configured for sensing sound profiles in a range of 100Hz-10kHz.

According to an embodiment the detection device comprises a light source for signalling a visual alarm.

According to an embodiment the detection device comprises a speaker for signalling an audio alarm.

According to an embodiment the detection device comprises at least one of an off-gassing sensor, a CO sensor, a temperature sensor and a humidity sensor. According to an embodiment the detection device comprises fixing means for removably fixing the detection device to the battery electric vehicle.

According to an embodiment the housing comprises a first housing element configured for positioning on an outside of a battery electric vehicle and a second housing element configured for positioning on an inside of a battery electric vehicle, wherein the first and second housing elements are connected by a cable element.

According to an embodiment the signal transmitter is provided in the first housing element and the audio sensor is provided in the second housing element.

According to an embodiment the fixing means comprises magnets provided on the first and/or second housing elements for biasing the first and second housing elements towards each other.

According to an embodiment the audio sensor has a sensitivity at 94 dB SPL, 1kHz of -26 dB FS.

According to an embodiment the audio sensor has a signal to noise ratio at 94 dB SPL, 1kHz of 65 dBA.

According to an embodiment the signal transmitter comprises a radio sender with 2,5 GHz communication.

According to an embodiment the detection device comprises a port for connection to an outlet port of a battery electric vehicle.

According to an embodiment the fixing means are magnets.

According to an embodiment the magnets are provided on a contact side of the detection device.

According to second aspect, there is provided a mesh network formed by a plurality of detection devices, where the detection devices are in communication with each other.

According to third aspect, there is provided a method of detecting and communicating a potential fire in a battery of a battery electric vehicle using a detection device, comprising sensing sound profiles and vibrations indicating a potential fire and signalling an alarm to an external alarm central and/or other detection devices.

BRIEF DESCRIPTION OF THE FIGURES

The aspects of the invention, including its particular features and advantages, will be readily understood from the following detailed description and the accompanying figures. The figures are provided to illustrate the general structures of the invention. Like reference numerals refer to like elements throughout.

Fig. 1 shows a perspective view of an embodiment of the detection device.

Fig. 2 shows a second perspective view of the detection device.

Fig. 3 shows a perspective view of the internal components of the detection device.

Fig. 4 shows a side view of the internal components of the detection device.

Fig. 5 shows a schematic view of a plurality of battery electric vehicles provided with detection devices in communication with each other and an alarm central.

Fig. 6 shows a perspective view of a second embodiment of the detection device.

Fig. 7 shows a battery electric vehicle with a detection device provided on the underside.

Fig. 8a shows an exploded view of the second embodiment of the detection device of a front and upper side.

Fig. 8b shows an exploded view of the second embodiment of the detection device of a rear and under side.

DETAILED DESCRIPTION

The invention will now be described with reference to the accompanying figures, in which preferred example embodiments of the invention are shown. The invention may, however, be embodied in other forms and should not be construed as limited to the herein disclosed embodiments. The disclosed embodiments are provided to fully convey the scope of the invention to the skilled person.

It is also to be understood that the terminology used herein is for purpose of describing particular embodiments only, and is not intended to be limiting. It should be noted that, as used in the specification and the appended claim, the articles "a", "an" and "the" are intended to mean that there are one or more of the elements or steps unless the context explicitly dictates otherwise. Thus, for example, reference to "a unit" or "the unit" may include several devices, and the like. Furthermore, the words "comprising", "including", "containing" and similar wordings does not exclude other elements or steps.

Referring initially to figures 1 and 2, an embodiment of a detection device 1 is shown. The detection device 1 is a portable device configured for detecting and communicating a potential fire in a battery of a battery electric vehicle, a hybrid electric vehicle or any lithium-ion battery in principal. Though the primary focus is on vehicles, modern society is permeated with lithium-ion batteries in everything from smart watches to phones, laptops, electric bikes and scooters, even ferries and airplanes, to mention a few. Lithium-ion batteries are commonly utilized in battery electric vehicles, but such batteries are known to degrade and potentially self-ignite. Upon degradation, the batteries may swell, and make distinct sound profiles commonly described as popping, crackle and hiss. The detection device 1 can also detect electromagnetic noise which may also occur during the failing of a battery. Electromagnetic noise is transients and noise observable in the visible and radio frequency bands. The detection device 1 is configured to detect characteristic sound profiles and notify an external alarm central or sound an alarm, or both. The detection device 1 comprises a housing 2 enclosing internal components of the detection device 1. In the shown embodiment, the housing 2 comprises a first housing element 3 and a second housing element 4. In other embodiments, the detection device 1 may comprise a single housing enclosing all the internal components.

The first and second housing elements 3,4 are separate housing elements, connected by a cable element 5. Because the housing 2 comprises first and second housing elements 3,4, the detection device 1 is configured for fixation to e.g. a surface element 6. The surface element 6 may be a window pane, a car door or similar element comprising two opposite sides. The two opposite sides may be spaced apart a few millimeters or centimeters. A longer cable element 5 allows the two opposite sides of a surface element 6 to be spaced further apart. The first housing element 3 may be positioned on one side of the surface element 6, and the second housing element 4 may be positioned on the corresponding other side of the surface element 6. In the illustrated embodiment, the first housing element 3 is configured for positioning on an outside of a car (such as the outside of a car window or car door), and the second housing element 4 is configured for positioning on an inside of a car (such as the inside of a car window or car door).

The cable element 5 connects the first and second housing elements 3,4, such that signals and power can be distributed between the first and second housing elements 3,4, even if e.g. a car door is closed shut, or a car window is fully closed. The cable element 5 is preferably an element with small thickness, and may have a width greater than the thickness. The cable element 5 is further a flexible element, such that it may allow a car door or window being closed tight even in the presence of the cable element 5 and with the first and second housing elements 3,4 being provided on the outside and inside of the door or window, respectively.

The housing 2 is configured for releasable fixing to a surface, such that the detection device 1 may easily be attached to and removed from e.g. one car to another. This is very useful e.g. during transport of a vehicle, as the detection device 1 may be fixed to a vehicle as it enters e.g. a cargo ship, and as the vehicle leaves the cargo ship the detection device 1 may be easily removed from the vehicle. To ensure the detection device 1 is securely fixed to the surface element 6, the detection device 1 may be provided with fixing means 7. The fixing means 7 may in a first embodiment be magnets provided on the first and/or second housing elements 3,4. As the first and second housing elements 3,4 are positioned on opposite sides of a surface element 6, the magnetic force between the first and second housing elements 3,4 force the first and second housing elements 3,4 towards each other, providing releasable fixation of the detection device 1.

Alternatively, the fixing means 7’ may in further embodiment comprise a biasing element for biasing the first and second housing elements 3,4 towards each other. The biasing element may connect the first and second housing elements 3,4. Preferably, the biasing element may be part of the cable element 5. The biasing element may force the first and second housing elements 3,4 towards each other. When pulled apart, and positioned on each side of a surface element 6, the first and second housing elements 3,4 are forced together by means of the biasing element, fixing the detection device 1 to the surface element 6. As such, the detection device 1 is easy to both position and remove from a vehicle. In the further embodiment, the fixing means 7’ thus comprises a biasing element connecting the first and second housing elements 3,4. In a third embodiment, the fixing means 7 may comprise a suction cup for fixing the detection device 1 ta a smooth surface such as a window pane, a body component of a vehicle, etc.

The housing 2 may comprise openings 8 provided at various locations such that gases, sounds and other indicators of a potential fire are allowed unobscured into the housing 2. The gases, sounds and electromagnetic signals are analyzed by various sensors described with reference to figures 3 and 4. If the sensors are provided on the inside of the housing 2, the housing 2 protects the sensors, and the openings 8 allow the sensors to operate efficiently. The openings 8 may be provided on both the first and second housing elements 3,4, depending on where the sensors are located.

The detection device 1 may comprise a display 9. The display 9 is provided on the housing 2, and preferably provided on the first housing element 3, facing outwards from the detection device 1. As such, data from the detection device 1 can be read without interfering with, or even touching, the detection device 1. The display 9 may visualize sensed data, and e.g. a status of the battery the detection device 1 is monitoring. If an alarm is triggered, the display 9 may also indicate which type of sensor has triggered the alarm.

The detection device 1 further comprises a signal transmitter 10. The signal transmitter 10 may comprise a radio, Bluetooth, Wi-Fi or a combination thereof. Preferably, the signal transmitter 10 comprises a signal sender and receiver such that different detection devices 1 can communicate with each other. A sender unit of the signal transmitter 10 may be separate from a receiver unit. If the detection device 1 detects that the battery is degrading, or other signals of a potential fire are detected, the detection device 1 may communicate this to an alarm central (described further with reference to figure 5) by means of the signal transmitter 10. The detection device 1 may also communicate the potential fire to other, nearby detection devices. In an embodiment, the signal transmitter 10 comprises a radio with 2,5 GHz communication. Such communication may not interfere with other communication, and is beneficial e.g. on board cargo ships carrying battery electric vehicles. If the detection device 1 comprises a housing 2 with a first and second housing elements 3,4, where the second housing element 4 is configured for positioning on the outside of a battery electric vehicle, the signal transmitter 10 is preferably provided in the second housing element 4 to optimize the transmitter’s 10 signal strength and reach. In an embodiment, the signal transmitter 10 comprises at least one antenna. In another embodiment, the signal transmitter comprises a plurality of antennas for monitoring the radio bands of interest for characteristic transients and/or increases in the broadband noise emitted when the battery begins to breakdown, leading to partial discharge and short circuit events.

The detection device 1 may comprise a light source 11. The light source 11 may be a LED light or other known source of light. If the detection device 1 detects signs of a degrading battery, or other sources that may indicate a potential fire, the light source 11 may signal a visual alarm. A visual alarm may be a flashing light, a constant, bright light, a red light, or other visual alarms indicating danger. E.g. cargo ships may be very loud, plus that during an incident power is often shut off leaving cargo decks in darkness. In such instances, even if decks are covered in smoke, a visual alarm is a very effective way of locating a detection device 1 with a triggered alarm. If the communication signals from the transmitter 10 are limited or jammed, the visual alarm caused by the light source 11 is a reliable way of detecting and locating the detection device 1 and the vehicle in danger.

The detection device 1 may further comprise a speaker 12. The speaker 12 may signal an audio alarm and as such alert the surroundings of the detection device 1. The audio alarm may simply be a sound indicating danger, or may be a voice attracting immediate attention and alerting the status of the detection device 1.

The detection device 1 may further comprise a signal port 13. The signal port

13 is configured for connection to an outlet port of a vehicle, such as a USB port of a battery electric vehicle. The signal port 13 is preferably provided on the first housing element 3, and may as such easily be connected to an outlet port inside a vehicle. The signal port 13 may be connected to the vehicle by a USB connection. The signal port 13 may also be utilized to charge or maintain a rechargeable battery (described with reference to figures 3 and 4) of the detection device 1. The detection device 1 is not dependent on a cabled connection to an external power source to function, but being connected to an outlet port of a vehicle may maintain the battery of the detection device 1 fully charged. If the battery of the vehicle the detection device 1 is connected to, fails, the detection device 1 may operate with it’s own fully charged battery. The signal port 13 may also connect the detection device 1 to the BMS system of the vehicle, communicating further data of the vehicle’s battery status to the detection device 1.

Referring now to figures 3 and 4, an embodiment of the internal components of a detection device 1 is shown. As mentioned previously, the detection device 1 comprises a battery 14. The battery 14 powers the detection device, and the battery

14 is preferably a rechargeable battery. The battery 14 allows the detection device 1 to function even if the detection device 1 is not connected to an external power source. In the illustrated embodiment, the battery 14 is provided in the second housing element 4, but may be provided anywhere on the detection device 1.

The detection device 1 comprises an audio sensor 15. The audio sensor 15 may be a microphone, and the audio sensor 15 may comprise a MEMS microphone. MEMS microphones have low distortion and high acoustic overload, while being physically small. The audio sensor 15 may in an embodiment comprise an analogue MEMS microphone and the audio sensor 15 may in another embodiment comprise a digital MEMS microphone. In an embodiment, the audio sensor 15 comprises an analogue MEMS microphone and a digital MEMS microphone. The audio sensor 15 may be connected to a serial audio interface, implemented in a micro controller unit.

The audio sensor 15 senses sound profiles caused by degradation failure of a battery. The audio sensor 15 is preferably configured for sensing sound profiles in a range of 100Hz-10kHz. The audio sensor 15 is connected to a processor 16 which interprets the amount of energy of the sensed sound, along with duration and volume. The processor 16 may be a microcontroller on a printed circuit board. The processor 16 is further connected to the signal transmitter 10. Lithium-ion batteries make a distinct sound as they degrade, and the audio sensor 15 is configured to detect such sounds. The particular sound profiles emitted from a degrading battery are due to movement in the battery cells, known as swelling. The audio sensor 15 may be configured such that it listens e.g. every 1/100 msec. The sound profiles may be characterized by the aforementioned “hiss”, “crackle” and “pop”. An example of a hissing sound profile, though this can vary greatly, is a sound in the in the spectrum 100hz-10kz with a duration of at least a few seconds at a sound level of 70 dB SPL. An example of a crackling sound profile may be a sound in the spectrum 100hz-10kz with a duration of less than one second at a sound level of 80 dB SPL. An example of a popping sound profile is a sound in the spectrum 100hz-10kz with a duration of at least 50 milliseconds at a sound level of 90 dB SPL. The audio sensor 15 is configured to specifically recognize and detect these sound profiles. An example of electromagnetic noise may be increases in the radio “white noise” across various frequency bands, transients in the RF or visible flashes and visible sparks. The detection devices 1 are be able to monitor EM bands and potentially also detect optical flashes, distinguishable by the high frequency blue/white flashes. In addition, audio sensors may be configured to specifically recognize and detect the sound profiles of sparks created when short circuits occur.

Further, the audio sensor 15 has preferably a sensitivity at 94 dB SPL, 1kHz of -26 dB FS. This makes the audio sensor very adapted for sensing “hiss”, “crackle” and “pop” sound signatures as well as “white” or electromagnetic noise. The audio sensor 15 is preferably provided on the second housing element 4, such that it can easily pick up the sound signatures from within a vehicle compartment and with minimized distortion and noise from the environment. Further, the audio sensor 15 has preferably a signal to noise ratio at 94 dB SPL, 1kHz of 65 dBA. This further makes the audio sensor adapted for sensing “hiss”, “crackle” and “pop” sound characteristics. The processor 16 may compare a set of sensed sound profiles with a stored or predetermined set of sounds made by a degrading battery. If the characteristics of the sensed sound profiles match or resemble the stored sound profiles, the processor 16 may transmit a warning signal by means of the signal transmitter 10.

The detection device 1 may preferably comprise further sensors, in addition to the audio sensor 15. The further sensors may be provided to increase the reliability of the detection device 1 , and to further confirm the data from the audio sensor 15. If the detection device 1 comprises first and second housing elements 3,4, the further sensors may preferably be provided on the second housing element 4, configured for positioning on an inside of a vehicle.

A further sensor may include an off-gassing sensor 17, and the detection device 1 may preferably comprise an off-gassing sensor 17. The off-gassing sensor 17 may also comprise a temperature sensor 23 and a humidity sensor 24. The temperature sensor 23 is configured to detect a sudden increase in temperature. Gas generation (volume swelling of the battery, also called off-gassing) is a common phenomenon in the degradation of a battery. This is generally a result of the electrolyte decomposition of lithium-ion batteries, and the off-gassing increases as the battery degrades faster, such as before a potential fire. Such increased offgassing may be detected by an off-gassing sensor 17.

The detection device 1 may further comprise a CO sensor 18. Increased levels of carbon monoxide are known to be an indicator of a degrading lithium-ion battery, and CO-levels inside e.g. a battery electric vehicle may be measured to confirm the data from the audio sensor 15. In itself a CO sensor inside the vehicle is useful in any vehicle, as the presence of CO is hard to detect and has caused deaths even in recent times in modern vehicles.

The detection device 1 may further comprise a vibration sensor 19. If a battery, or a vehicle comprising a battery, is exposed to an impact or a sudden shock, the battery may be affected. As such, a vibration sensor 19 may register such an event, and thereby set the detection device 1 in a state of increased alert. Such a state might include an increased mode of sensing. The detection device may also transmit an alert that the monitored vehicle or battery has experienced an unwanted incident in the form of an impact. If the audio sensor 15, and alternatively some of the optional further sensors, senses signs of potential fire, the detection device 1 may communicate an alarm signal by means of the signal transmitter 10. The alarm signal may be communicated to an external alarm central. The external alarm central may be an app on a mobile phone, configured to receive the alarm signal. The alarm signal may also be communicated to a dedicated device, or to any means capable of receiving a radio, Bluetooth or Wi-Fi-signal.

Referring now to figure 5, a schematic view of a plurality of battery electric vehicles 20 is shown. The battery electric vehicles 20 may e.g. be on board a cargo ship, during transport of the battery electric vehicles 20. A cargo ship may commonly carry thousands of battery electric vehicles 20. Each battery electric vehicle 20 is provided with a detection device 1 while on board the cargo ship. The plurality of detection devices 1 are in communication with each other and an alarm central 21. The alarm central 21 may be a separate monitoring unit, or simply an application on a computer or a mobile. On e.g. a cargo ship the detection device 1 may communicate an alarm signal to a recipient such as the bridge, a response unit, or other preferred alarm centrals. The alarm central 21 may provide an operator of the alarm central 21 with information regarding which sensor has been triggered, where it is located, etc.

The plurality of detection devices 1 may be linked together to form a mesh network 22. The mesh network 22 may effectively route data between the detection devices 1, and also to the external alarm central 21. In this example a 2,5 GHz radio signal is a preferred communication method from the detection devices 1. The mesh network 22 enables a detection device 1 where an alarm has been triggered to be easily located, and may also send a warning signal to nearby detection devices 1 warning of imminent danger. Nearby detection devices 1 may also signal e.g. a visual alarm for easy detection of the exposed area surrounding the triggered detection device 1. In an embodiment, a plurality of detection devices 1 are configured to triangulate the direction of a source from which any transient EM pulses or acoustic events have originated.

A method of detecting a potential fire in a lithium-ion battery of a battery electric vehicle may comprise a detection device 1 according to any one of the embodiments described above. The audio sensor 15 of the detection device 1 is connected to a processor 16, and sounds detected by the audio sensor 15 are analyzed and compared to known sound profiles associated with a degrading lithium-ion battery. If the detected sounds are assessed to originate from a degrading lithium-ion battery, the processor 16 and signal transmitter 10 transmit an alarm signal to an external alarm central 21 , warning of a potential fire. According to an embodiment, if the detection device 1 comprises a light source 11 or a speaker 12, these may also be activated to attract attention and help identify and localize the detection device 1 and the degrading battery. Alternatively, or simultaneously, the alarm signal may be transmitted to other detection devices in proximity to the detection device 1 , such that the other detection devices may also signal e.g. visual or audio alarms.

Referring to figure 6, a second embodiment of a detection device 100 is shown. Unless otherwise described, the second embodiment of the detection device 100 comprises the same features as the first embodiment. The description of the features related to the first embodiment are thus valid for the features related to the second embodiment as well, unless otherwise described. The second embodiment of the detection device 100 comprises one housing 2. All the elements of the detection device 100 according to the second embodiment are housed in the housing 2 or attached to the housing 2. The housing 2 of the second embodiment may comprise a main body housing 23 and front end piece 24 and rear end piece 25. The end pieces 24,25 may close the main body housing 23 to protect and seal the internal components of the detection device 100 within the housing 2. The main body housing 23 may comprise an extruded part, such as an extruded aluminum profile. The housing 2 makes the detection device 100 compact and portable.

The housing 2 comprises openings 8, such that gases, sounds and other indicators of a potential fire are allowed unobscured into the housing 2. In the illustrated embodiment, the openings 8 are provided at least on the front end piece 24. The signal transmitter 10 is in the illustrated embodiment provided on the front end piece 24. The signal transmitter may comprise, in addition to the examples described with reference to the first embodiment, a cellular modem. The second embodiment of the detection device 100 comprises fixing means in the form of magnets. The fixing means are not visible in figure 6, but are shown and described in further detail with reference to figures 8a and 8b.

Referring to figure 7, the detection device 100 of the second embodiment is shown attached to the underside of a battery electric vehicle 20. The detection device 100 may be placed directly on the underside of the lithium-ion battery of the battery electric vehicle 20 because of the fixing means in the form of one or more magnets. The magnets allow the detection device 100 to be easily and safely attached to the battery electric vehicle 20, or directly onto a battery casing. The magnets also allow easy removal of the detection device 100 from the battery electric vehicle 20, or re-positioning of the detection device 100. The detection device 100 may as such be placed on and attached to any magnetic surface in the vicinity of any battery it is intended to monitor.

Referring to figures 8a and 8b, the exploded views of the second embodiment of the detection device 100 show the components of the detection device 100. The detection device 100 comprises one or more fixing means 7 in the form of magnets. The magnets may be provided inside the housing 2, such that they are not visible nor accessible from outside the housing 2. The magnets are preferably fastened to the housing 2. The one or more magnets are preferably provided at a contact side 26 of the housing 2 of the detection device 100, such that one side of the detection device 100 is configured for releasable fixing to a corresponding magnetic surface. The contact side 26 thus comprises the magnets. The contact side 26 is in the illustrated embodiment the bottom side of the detection device 100. The contact side 26 may preferably be indicated or marked on the outside of the housing 2, such that the contact side 26 is easy to identify for a user of the detection device 100. The contact side 26 is preferably flat, and configured for contact with a surface which the detection device 100 is to be removably fixed to.

The detection device 100 may preferably be supplied with an external magnet 27. The external magnet 27 is a magnet separate from the housing 2, allowing the detection device 100 to be mounted to a non-magnetic surface, such as a window pane of a car. The external magnet 27 is configured for positioning on one side of a non-magnetic surface or wall, and the detection device 100 is configured for positioning on the opposite side of the non-magnetic surface or wall. The magnetic forces between the contact side 26 of the detection device 100 and the external magnet 27 retains the detection device 100 on the non-magnetic surface or wall. By means of the external magnet 27 it is easy to both install and remove the detection device 100 on a non-magnetic surface or wall.

The detection device 100 further comprises an audio sensor 15. The detection device 100 may comprise several audio sensors 15, and in the illustrated second embodiment, the detection device 100 comprises two audio sensors 15. The two audio sensors 15 may be two different audio sensors, as mentioned with reference to the first embodiment. Two audio sensors may comprise an analogue and a digital sensor. The processor 16 is illustrated in the center of a printed circuit board of the detection device 100. The processor 100 may comprise a micro controller. The detection device 100 may further comprise an off-gassing sensor 17, a CO sensor 18 and at least one light source 11. A battery 14 is provided in the housing 2, for powering the detection device 100. Similar to the first embodiment, the battery 14 may preferably be rechargeable, but may also include a replaceable battery. The signal port 13 is in the second embodiment provided on the rear end piece 25 of the detection device 100.

The detection device 100 comprises a vibration sensor 19. As explained with reference to the first embodiment, a degrading lithium-ion battery is known to make distinct sound profiles. Along with such sounds, small vibrations also occur due to the degradation of the battery, and the vibration sensor 19 is configured to detect such small, constant vibrations. Preferably, the vibration sensor 19 is configured for detecting vibrations along one or more axes in space, such as the X, Y and Z-axis. As sound waves are also vibrations, the vibration sensor 19 is configured to detect such abnormal vibrations. If a pattern of vibrations, associated with degradation of a battery, is sensed by the vibration sensor 19, the detection device 100 may trigger an alarm. The vibration sensor 19 is connected to the processor 16. The processor 16 and/or the vibration sensor 19 may interpret e.g. the amount of energy of the sensed vibration, along with duration and other distinct factors of a degrading battery. The processor 16 is further connected to the signal transmitter 10, enabling the detection device 100 to communicate an alarm signal to an external alarm central and/or other detection devices 100.

The vibration sensor 19 may comprise an accelerometer, to enhance the sensitivity of the vibration sensor 19. The data from the vibration sensor 19 may be checked and verified together with input from the audio sensor 15, making the detection device 100 highly sensible and reliable in detecting a degrading battery. The detection device 100 may as such be used in monitoring batteries at a wide range of locations, such as at battery and storage facilities, container ships and ports, recycling facilities, etc. At least one detection device 100 may be placed in the vicinity of one or more batteries, and being in communication with an alarm central the at least one detection device 100 may efficiently and reliably monitor the batteries to detect and communicate a potential fire.

While the invention has been described with reference to the embodiments mentioned above, it is to be understood that modifications and variations can be made without departing from the scope of the present invention, and such modifications and variations shall remain within the field and scope of the invention, as defined by the appended claims.

Claims

1. A detection device (1 ; 100) for detecting and communicating a potential fire in a lithium-ion battery of a hybrid or battery electric vehicle (20), comprising; a housing (2); a battery (14) for powering the detection device (1 ; 100); an audio sensor (15) for sensing a sound profile caused by degradation of the lithium-ion battery; a vibration sensor (19) for sensing a vibration from the lithium-ion battery; a processor (16) connected to the audio sensor (15) and vibration sensor (19); a signal transmitter (10) for communicating an alarm signal to an external alarm central (21) and/or other detection devices (1 ; 100).

2. The detection device (1 ; 100) according to claim 1 , wherein the audio sensor (15) comprises a MEMS microphone.

3. The detection device (1 ; 100) according to claim 1 or 2, wherein the audio sensor (15) comprises an analogue MEMS microphone and a digital MEMS microphone.

4. The detection device (1 ; 100) according to claim 1 or 2, wherein the audio sensor (15) is a single digital MEMS microphone configured for sensing sound profiles in a range of 100Hz-10kHz.

5. The detection device (1 ; 100) according to any one of the preceding claims, wherein the detection device (1 ; 100) comprises a light source (11) for signalling a visual alarm.

6. The detection device (1 ; 100) according to any one of the preceding claims, wherein the detection device (1) comprises a speaker (12) for signalling an audio alarm.

7. The detection device (1 ; 100) according to any one of the preceding claims, wherein the detection device (1) comprises at least one of an off-gassing sensor (17), a CO sensor (18), a temperature sensor (23) and a humidity sensor (24).

8. The detection device (1 ; 100) according to any one of the preceding claims, wherein the detection device (1) comprises fixing means (7) for removably fixing the detection device (1 ; 100) to the battery electric vehicle (20).

9. The detection device (1 ; 100) according to any one of the preceding claims, wherein the signal transmitter (10) comprises a radio sender with 2,5 GHz communication.

10. The detection device (1 ; 100) according to any one of the preceding claims, wherein the detection device (1) comprises a port (13) for connection to an outlet port of a battery electric vehicle (20).

11. The detection device (1 ; 100) according to claim 8, wherein the fixing means (7) are magnets.

12. The detection device (100) according to claim 11 , wherein the magnets are provided on a contact side (26) of the detection device (100).

13. A mesh network (22) formed by a plurality of detection devices (1 ; 100) according to any one of the previous claims, where the detection devices (1 ; 100) are in communication with each other.

14. A method of detecting and communicating a potential fire in a battery of a battery electric vehicle (20) using a detection device (1 ; 100) according to any one of claims 1-12, comprising sensing sound profiles indicating a potential fire and signalling an alarm to an external alarm central (21) and/or other detection devices (1 ; 100).