Seismic node

Abstract

A method, a system and a marine autonomous seismic node for recording seismic waves on land or under water. The autonomous seismic node includes a autonomous seismic node body, a power source (typical rechargeable batteries), seismic recorders including seismic sensors, a battery discharge switch and a discharge unit with sufficient heat dissipation to discharge the power.

Description

Technical field

[0001] The present invention relates to autonomous seismic nodes with rechargeable batteries and in particular to discharging batteries in autonomous seismic nodes.Background

[0002] Seismic surveying may be performed using several different solutions.Example solutions are e.g. autonomous seismic recorders / nodes arranged on the ocean bottom. The autonomous seismic recorders may be individually placed on the ocean bottom by e.g. remotely or autonomous operated vehicles (ROV or AUV), by dropping the autonomous seismic recorders into the sea from a vessel, or alternatively the autonomous seismic nodes may be arranged on the ocean bottom attached to a cable deployed from the vessel. The cable may be a rope or a wire. The autonomous seismic nodes may be recovered attached to the cable, picked up by an ROV / AUV or picked up from the sea after floating to the surface.

[0003] Autonomous seismic nodes are independent seismic recorders that can operate on their own while on the sea floor. Autonomous seismic nodes typically comprise one or more compartments containing sensors (such as geophones or accelerometers and hydrophones), a data recording device and a power source. The power source may typically be one or more lithium-ion cells. Autonomous seismic nodes are thus self-contained and do not need to be connected to anything nor communicate with anything when positioned on the sea floor.

[0004] Autonomous seismic nodes are commonly used around the world for different projects. A typical project typically requires between 1000 and 10.000 autonomous seismic nodes and each autonomous seismic node typically have rechargeable batteries as power source. The power source can consist of lithium-ion battery cells with high capacity. Transporting large numbers of autonomous seismic nodes with such power sources byair, cargo vessels or road transport is strictly regulated due to the risk of fire.

[0005] It is known from the patent US 9,768,626 B2 a system for simultaneously charging multiple autonomous seismic nodes on a marine vessel, used for marine seismic data acquisition. Each seismic node is equipped with rechargeable batteries, power connectors, and a battery management system, designed to interface with a vessel-based charging system. The charging system operates within a CSC-approved ISO container using charging rails that connect to the nodes' power connectors, enabling efficient simultaneous charging. The system aims to enhance marine seismic survey efficiency by automating the charging process, reducing manual labour, and improving the reliability of node operations.

[0006] It is the goal of the present invention to address and solve the problems related to the risk of fire for battery cells in autonomous seismic nodes.Summary of the invention

[0007] The present invention provides a self-discharging autonomous seismic node at least comprising: a) one or more rechargeable batteries, b) a discharging load element; where the load element is configured to be connected to the one or more rechargeable batteries to discharge the batteries.

[0008] Moreover, the self-discharging autonomous seismic node may further comprise: c) a water-tight casing; d) electronics for seismic recordings; e) seismic sensors; f) heat transfer element, and g) communication interface; and where the communication interface is configured to communicate with a remote control.

[0009] The water-tight casing can be: fully or partly made of aluminium, steel or titanium, fully or partly made of rubber, fully or partly made of a metal alloy, and fully or partly made of a composite material.

[0009] In one aspect of the invention the communication interface may comprise: an RF-receiver configured to communicate with a remote control and with self-discharging autonomous seismic nodes and an RF- transmitter configured to communicate with self-discharging autonomous seismic nodes in a mesh network. In one aspect of the invention the RF- transmitter and the RF-transmitter are Bluetooth enabled.

[0010] In one aspect of the invention can the electronics for seismic recordings be connected to the seismic sensors, to the one or more batteries and to the communication interface.

[0011] The heat transfer element can be one of: a) a heat sink for electronic components, b) a thermal conductive connection with the casing of the autonomous seismic node, and / or c) a convectional connection with the casing of the autonomous seismic node.

[0012] The communication interface may include an RF-receiver and RF- transmitter and an ADC, i.e. an analogue to digital converter.

[0013] The autonomous seismic node may include one or more antennas.

[0014] In one aspect of the invention can the autonomous seismic node include a logical comparator which is configured to compare the energy level of the rechargeable batteries with a threshold value, where the logical comparator can be one of: a hardware logical comparator circuit, and a software program routine with a programmable comparator function.

[0015] The discharging load element may comprise a semiconductor used as a load component and where the load component can be one of: a MOSFET, a transistor and a thyristor. In another aspect of the invention can the discharging load element comprise a switch and a passive load component, where the switch is configured to decouple and couple thepassive load component to a discharging circuitry. The switch can be a hardware switch or a software switch.

[0016] The present invention also provides a method for discharging an autonomous seismic node at least comprising the steps of: a) providing one or more rechargeable batteries, b) providing a discharging load element; where the load element is configured to be connected to the one or more rechargeable batteries to discharge the batteries.

[0017] The method for discharging an autonomous seismic node may further comprise the steps of: c) providing a water-tight casing; d) providing electronics for seismic recordings; e) providing seismic sensors; f) providing a heat transfer element, and g) providing a communication interface; and where the communication interface is configured to communicate with a remote control.

[0018] The method may further comprise the steps of: a) configuring an RF-receiver of the communication interface to communicate with a remote control and with self-discharging autonomous seismic nodes; b) configuring an RF-transmitter of the communication interface to communicate with self-discharging autonomous seismic nodes in a Bluetooth mesh network. In one aspect of the invention the RF- transmitter and the RF-receiver are Bluetooth enabled.

[0019] The method for discharging an autonomous seismic node may further comprise the steps of: a) connecting the electronics for seismic recordings to the seismic sensors, b) connecting the electronics for seismic recordings to the one or more batteries, andc) connecting the electronics for seismic recordings to the communication interface.

[0020] Still further the method for discharging an autonomous seismic node may further comprise the steps of: a) providing a logical comparator circuit to the autonomous seismic node, and b) configuring the logical comparator circuit to compare the energy level of the rechargeable batteries with a defined threshold value. where the logical comparator can be a hardware logical comparator circuit or where the logical comparator is a software routine with a programmable comparator function.

[0021] In one embodiment of the invention it is provided a method to initiate discharging of an autonomous seismic nodes, comprising one of the steps: a. sending a "discharge command" hard wired from a remote control to one or more autonomous seismic nodes; b. sending a "discharge command" wireless from remote to one or more autonomous seismic nodes; c. pre-programming a discharge regime where, discharging and charging will take place at defined points of time; and

[0022] Sending a "discharge command" wireless from remote to one or more autonomous seismic nodes, where the autonomous seismic nodes are interconnected in a mesh-network.

[0023] In one embodiment the present invention provides an autonomous seismic node comprising one or more rechargeable batteries, where the autonomous seismic node is configured for discharging of the one or more rechargeable batteries.

[0024] The invention enables reducing the energy level in the batteries in a faster way than by normal use. Autonomous seismic nodes that are charged to a high level and which shall be transported to another location, need to be discharged to a predetermined level due to transport regulations as explained earlier. This reduces the risk of a damaging fireduring transport or storage. There may also be other reasons for faster reduction of the energy levels in the batteries than what is possible during normal use.

[0025] Other advantageous features will be apparent from the accompanying claims.Brief description of the drawings

[0026] To make the invention more readily understandable, the discussion that follows will refer to the accompanying drawings, in which:

[0027] Figure 1 shows an autonomous seismic node according to one embodiment of the present invention, and

[0028] Figure 2 shows an autonomous seismic node according to another embodiment of the present invention.Detailed description of the Invention

[0029] In the following, general embodiments as well as exemplary embodiments of the invention will be described. The general and exemplary embodiments are examples only and not limiting for the invention. References and possible numerals will be made to the accompanying drawings. It shall be noted, however, that the drawings are exemplary embodiments only, and that other features and embodiments may well be within the scope of the invention as described.

[0030] Regarding the figures, these are intended to illustrate the invention and some of the elements in the autonomous seismic node can be moved. The communication interface is shown as part of the electronics for seismic recording, but the communication interface can also be separated from the electronics for seismic recording.

[0031] Autonomous seismic nodes that are charged to a high level and which shall be transported to another location, can be discharged to a predetermined level to reduce the risk of fire. Seismic autonomous seismic nodes are designed to use as little power as possible to maintain a good endurance on the seabed. Therefore, waiting until the batteries are discharged without a dedicated discharge solution will normally takeweeks or months, while according to the present invention this can be done within hours or a few days.

[0032] One purpose of the present invention is to provide a self-discharging autonomous seismic node, which can discharge itself to a desired energy level. Typically, the self-discharging autonomous seismic node can drain internal charged batteries down to 20% - 45% of its full capacity. In one embodiment the self-discharging autonomous seismic node can drain its internal batteries to a range of 25% - 35%.

[0033] An autonomous seismic node according to an exemplary embodiment typically contains, among other things, a water-tight casing 1, a power supply 2 provided by rechargeable batteries, electronics and sensors for recording and storing seismic data 3, seismic sensors 6, and a communication interface 8. The batteries are normally charged before the autonomous seismic nodes are deployed on land or seabed to register seismic data.

[0034] The autonomous seismic node may be adapted to a docking station for charging internal batteries, therefore the housing of the autonomous seismic node may be provided with an interface for engagement with a docking station. In another embodiment, the autonomous seismic node is provided with a connector for connecting charging current. The docking solution can include an interface for data transfer between docking and the autonomous seismic node, the same applies to the connector solution.

[0035] The autonomous seismic node connector and the docking connector may be provided with plugs or connecting devices for at least one of electrical connection, inductive charging, connectors for optical fibres and wireless communication.The Casing

[0036] The casing 1 of the autonomous node can be made of a thermically conductive material, for example aluminium. In one embodiment the casing 1 is made of Aluminium 6082, which is a medium-strength alloy with a thermal conductivity in the range of 150 - 170 W / mK. The highthermal conductivity ensures that heat can be quickly transferred away from components, preventing overheating during operation.

[0037] Other materials may be used in the casing. The casing can also be made of different materials. The casing must naturally be made to withstand the pressure for the purposes it is intended for. The thermal conductivity does not need to be critical. The importance of good thermal conductivity depends, among other things, on the discharge rate, how much air there is around critical components that can become hot. There are several ways to divert heat from components, depending on how critical the heat of the components in question can be. The casing can be directly thermally connected to critical components to cool these. If this is the case, the thermal conductivity of the casing will be significant. Heat will be transferred by convection from heat-critical components to the surroundings / casing. The choice of material for the casing, therefore, depends on several factors. Good candidates for the design of the casing can be: fully or partly made of aluminium, fully or partly made of steel, fully of partly made of titanium, fully or partly made of rubber, fully or partly made of a metal alloy, and fully or partly made of a composite material.

[0038] The casing 1 is a watertight enclosure which is adapted to contain all necessary components for operational operation of an autonomous seismic node. The examples of materials given above includes materials with poor thermal conductivity, still they might serve well as a casing, depending on the heat produced inside the casing. The heat produced inside the casing is dependent on the discharging rate i.e. the power consumption and the how power consumption is distributed internally on printed circuit boards. Heat sinks can be provided directly on critical components.

[0039] The volume of the casing can be in the range of 5 - 10 litres and the weight of an autonomous seismic node can be 8 - 30 kg. Some casings may be designed to withstand pressure down to 500 meter depth, whilst other casings can be designed for pressures down to 5000m depth.

[0040] The volume of the casing and the casing and casing material can be adapted to the use of the seismic node.Power supply

[0041] The autonomous seismic node includes an internal power supply 2 for operational operation and for communication with external sources. The power supply 2 can be one or more rechargeable battery cells. The type of cells can be lithium-ion or polymer type. The nominal voltage level can be 3.3 V DC. The charging voltage can be 48V. In one embodiment two 3.6 V battery packs (33 cells / pack) of lithium-ion type with 100 - 160 AH is used.

[0042] Considering that more than 1000 autonomous seismic nodes can be stored together the aggregated energy from the battery cells are considerable.Electronics for seismic recordings

[0043] For seismic recording in a seismic node, the electronics for seismic recordings 3 may comprise one or more of:

[0044] A Data Acquisition System : This is the core of a seismic node, which may consist of a multi-channel system capable of handling input from various sensors;

[0045] An analogue-to-Digital Converter (ADC): To convert the analogue signals from the seismic sensors into digital data that can be processed and recorded;

[0046] Memory Storage: Solid-state memory is used for storing the recorded seismic data.

[0047] Control Electronics, and

[0048] A clock among others for synchronising purposes and for time stamping acquired data.Load Element and discharging circuitry.

[0049] Autonomous seismic nodes that are charged to a high level and which shall be transported to another location, need to be discharged to a predetermined level due to transport regulations as explained earlier. An object of the invention is to reduce the energy level in the batteries in a faster way than by normal use to reduce the risk of a damaging fire during transport or storage. This is done by connecting a load 4 so that the power consumption in the autonomous seismic node increases considerably. Such a load 4 must be able to emit sufficient heat to a heat transfer element 5, either by it emitting heat to the surrounding air or by being thermally connected to other material that can emit the heat. An alternative is to thermally couple it to the autonomous seismic node casing 1. As mentioned above, the casing 1 can be of aluminium and thus represent a very efficient heat sink. The load can be anything that increases the power consumption.

[0050] Initiation of such discharge is done while the autonomous seismic nodes are available for connection and can be controlled by an external device. The connection can be by a physical cable, an optical or a cable-free connection so that a single autonomous seismic node or multiple autonomous seismic nodes can be connected at the same time. One will typically then initiate a fast discharge and define a limit for how much the energy level of the battery must be reduced before the autonomous seismic node switches to another mode that uses less or no power.

[0051] The load 4 must be able to be switched on for discharge and it must be able to be switched off when the desired charge level is reached. The load can consist of a semiconductor such as a transistor, MOSFET or a thyristor. A control current to the semiconductor will be able to regulate the impedance of the semiconductor and thus a discharge rate. When the desired charge level is reached, the control current to the semiconductor can be changed so that the semiconductor switches off, i.e. the impedance becomes very high.

[0052] In an alternative embodiment, one can think of a fixed resistor as a load 4, where the fixed resistor is coupled into a discharge circuit for discharge and where the resistor is decoupled from the discharge circuit when the desired charge level is reached. The coupling / decoupling function can be provided using a solid-state switch.

[0053] Discharging can be initiated in one of the following ways: a) Sending a "discharge command" hard wired from remote to one or more autonomous seismic nodes. Where the autonomous node can be docketed or connected by wires to connectors, b) Sending a "discharge command" wireless from remote to one or more autonomous seismic nodes, c) Pre-programming a discharge regime where, discharging and charging will take place at defined points of time, d) Sending a "discharge command" wireless from remote to one or more autonomous seismic nodes, where the autonomous seismic nodes are interconnected in e mesh-network.

[0054] The "discharge command" may include operating parameters. The operating parameters can include parameters indicating the discharge level to reach, the speed of the discharging, a discharging ramp etc.

[0055] An advantage with the three latter examples is that the need for cabling is reduced and for the solution in item b and d the discharge command can be broadcasted to several autonomous seismic nodes. The mesh solution in item d does not necessitate that the discharge command is received by more than one autonomous seismic node as the received "discharge command" will be communicated within the whole mesh network thereby reaching out to several thousand autonomous seismic nodes. There are many types of wireless mesh networks.Wi-Fi Mesh Network uses radio nodes or devices that are interconnected wirelessly.

[0056] Bluetooth Mesh Networks is a standard that allows for many-to-many communication over Bluetooth radio. It's optimized for creating large- scale device networks and is ideally suited for applications likecommunicating between seismic nodes. Bluetooth mesh networks operate on a flood network principle, where messages are relayed by nodes until they reach their destination.

[0057] Zigbee can operate in mesh networks. It's designed to create a mesh network of interconnected devices, enabling low-power and short-range wireless communication among them. In a Zigbee mesh network, each device, also known as a node, can act as a sender, receiver, or repeater, which helps to increase the overall coverage and reliability of the network.

[0058] In one embodiment of the mesh communication regime in item d above a Bluetooth mesh is provided for communication between autonomous seismic nodes.

[0059] In one embodiment of the invention the discharge rate is 5w and 3.6V which approximately equals Z-2.6 . Such a low discharge rate does not necessitate advanced cooling solutions. Thermally connecting the load 4 to the casing 1 will be more than sufficient. The charging rate is faster than the discharging rate and in fact the heat generation can be higher when charging the batteries than when discharging the batteries at a 5w rate. With a discharge rate of approximately 5w it will typically take 72 to 120 hours to drain the batteries to a desired energy level of 20 to 45% - in contrast to a month or more for an autonomous seismic node without the discharging system described herein.

[0060] The discharging circuitry is switched off at specific energy levels of the batteries, thus there is a need to monitor the level of charging and when the desired level is reached to switch off the discharging mode. The basic components for monitoring can be one or more of:

[0061] Voltage meter: A circuit that measures the battery voltage directly. This can for instance be done through an analogue-to-digital converter (ADC) to convert the voltage into a digital signal that can be processed.

[0062] Battery Monitoring IC: A dedicated microchip designed to monitor and report the condition of the battery, such as remaining capacity and voltage level.

[0063] Microcontroller: A device that processes data from the ADC and / or the battery monitoring IC to calculate the state of the battery and provide "reached discharge level" and thereby turn off the discharging.

[0064] As a collective term, the battery monitoring circuit is called a logical comparator circuit as the purpose is to compare an energy level in the battery packs with a desired energy level - a threshold value.

[0065] The logical comparator can be a hardware comparator, or it can be a software comparator routine. A software comparator routine can be veery flexible and scalable. Such a software comparator routine may read parameters received from a discharge command.Heat transfer element.

[0066] The heat transfer element 5 shall ensure that the temperature of the internal electronic circuitry of the autonomous seismic node is within limits determined by the individual components recommended operational temperature range. During normal operation the energy consumption is neglectable with concern to heat generation. It is only during charging and discharging that heating can be a minor issue. As mentioned above, the casing 1 can be made of a thermally conductive material and thus is a candidate as a heat transfer element for the circuitry inside the casing. Hence, in one embodiment of the invention heat generating components are thermally and conductively connected to the casing. In another embodiment the thermal connection between heat generating electronic circuitry and the casing is by convection only.Seismic sensors

[0067] The seismic sensors 6 provides measure data to the electronics for seismic recordings 3. The seismic sensors 6 can be one or more of the following sensors:

[0068] Geophones: These are velocity sensors that measure the ground's motion.

[0069] Accelerometers.

[0070] MEMS Accelerometers: Microelectromechanical system accelerometers are used for their and ability to integrate into loT solutions for seismic sensor networks. The MEMS accelerometers often have the advantage of having good sensitivity in low frequency spectres.Communication interface

[0071] The autonomous seismic node can communicate with remote devices through a communication interface 8. There are several different types of information to be acquired from the autonomous seismic nodes, it concerns measurement data, it concerns the operational state of the node such as charge level, deviation from clock operation, temperature level and more.

[0072] When the autonomous seismic nodes are in standby mode, which is the typical state during storage, and are activated by a remote control, they can detect the signal from the remote control because they are not completely powered off, independent off whether the remote is wired or wireless. They operate in a low-power state where the essential components needed to detect a signal remain active.

[0073] In one embodiment the autonomous seismic node is configured to communicate using a communication interface 8 that is connected to external units with wired connections. The wired communication can be provided with traditional cables and connectors, or the autonomous seismic node can be connected to external units in a docking station with direct connection between the docking station and contact surfaces of the autonomous seismic node. The wired communication regime may also apply to charging of the rechargeable batteries.

[0074] Charging of the rechargeable batteries may in one embodiment be provided by inductive charging.

[0075] GPIO Pins General Purpose Input / Output (GPIO) pins can be a candidate as a wake-up circuit. GPIO Pins can be configured to detect external events like button presses or other signals.

[0076] In one embodiment the autonomous seismic node is configured to communicate using radio frequency (RF) signals instead of cabled communication. To receive RF-signals one or more antennas El must be present to capture the RF-signals. The one or more antennas El is connected with an RF-receiver 9. RF-communication means that the interface between the autonomous seismic node and remote units can be analogues. Hence, the communication interface according to this embodiment can include an ADC 10 to enable communication with the logical circuitry of the autonomous seismic node. In one alternative RF analogue signals are modulated with digital data. The modulation can be done in various ways, such as by altering the amplitude, frequency, or phase of the carrier wave to represent the digital data. RF signals can travel through walls and do not require a direct line of sight, hence is ideal to reach out to numerous autonomous seismic nodes, in some instances more than thousand. The autonomous seismic nodes have a part that remains alert to detect these RF-signals and activate selfdischarging. The "wake up" circuitry can be provided by one of:

[0077] Microcontrollers: A low-power microcontroller may remain active to monitor for wake-up signals.

[0078] RF Modules: For devices that use radio frequency (RF) remote controls, the corresponding receivers or modules are powered to detect signals.

[0079] Internal RTC / Timers: Master clock or internal timers can be set to wake the device after a certain period or at specific times.

[0080] Power Management ICs: These integrated circuits manage power requirements and can control the power state of the device, enabling it to wake up when necessary.

[0081] These components consume very little power, allowing the device to remain in a standby state while still being able to respond quickly to wake-up events.A first embodiment of the present invention

[0082] With reference to figure 1 a first embodiment of the invention will be described. The casing 1 is made of aluminium or an aluminium alloy. The size of the casing is 35x20x 11 cm and the weight of the autonomous seismic node is between 8 - 13 kg. The casing shall withstand pressures on depths down to at least 4000m. The casing has a thermal conductivity in the range of 150 - 170 W / mK, and the casing is used as a heat sink for electronic components that generates heat by thermally connecting these components to the casing 1 either conductively or by convection. The power supply 2, seismic sensors 6 and electronic for seismic recordings 3 are designed as indicated in the respective sections above.

[0083] The communication interface 8 is of a wired type with either a docking connection via connectors or via cables and connectors. A combination of docking connection and wired power supply connection is an alternative of this embodiment. Inductive charging of the batteries can also be an option.

[0084] GPIO pins are configured to detect wake up commands from a wired remote control, such as "initiate discharging".

[0085] In one aspect of the first embodiment the load includes a semiconductor component as the integral component. Control circuitry connected with the semiconductor regulates the discharging, i.e. the impedance of the semiconductor.

[0086] In another aspect of the first embodiment the load includes a passive resistor component as the integral component. A switch is connected to the resistor component and the switch can include or exclude the resistor element from the discharging circuitry and thereby turn discharging on or off. The switch can be of a solid-state type, a transistor, MOSFET or it can be a thyristor.A second embodiment of the present invention

[0087] With reference to figure 2 a second embodiment of the invention will be described. The casing 1 is made of aluminium or an aluminium alloy. The size of the casing is 35x20x 11 cm and the weight of the autonomousseismic node is between 8 - 13 kg. The casing shall withstand pressures on depths down to at least 4000m. The casing has a thermal conductivity in the range of 150 - 170 W / mK, and the casing is used as a heat sink for electronic components that generates heat by thermally connecting these components to the casing 1 either conductively or by convection. The power supply 2, seismic sensors 6 and electronic for seismic recordings 3 are designed as indicated in the respective sections above.

[0088] The communication interface 8 is of a wireless RF type. A wired power supply connection is an alternative of the second embodiment. Inductive charging can also be an option. The communication interface includes an RF-receiver 9 and optionally an analogue to digital converter 10. The RF- receiver communicates with a remote control. The communication between the remote and the RF-receiver of the autonomous seismic node in this embodiment follows a Bluetooth protocol. Each autonomous seismic nodes of the second embodiment also includes an RF-transmitter. Each of the autonomous seismic nodes of the second embodiment can be configured to be a transceiver element in a Bluetooth mesh network. The autonomous seismic node includes one or more antennas El. The one or more antenna El can be compact loop antennas.

[0089] In one aspect of the second embodiment the load includes a semiconductor component as the integral component. Control circuitry connected with the semiconductor regulates the discharging, i.e. the impedance of the semiconductor.

[0090] In another aspect of the second embodiment the load includes a passive resistor component as the integral component. A switch is connected to the resistor component and the switch can include or exclude the resistor element from the discharging circuitry and thereby turn discharging on or off. The switch can be of a solid-state type, a transistor, MOSFET or it can be a thyristor.

[0091] Ref table

Claims

Claims1. A self-discharging autonomous seismic node at least comprising: a. one or more rechargeable batteries (2), and b. a discharging load element (4); where the load element (4) is connected to the one or more rechargeable batteries (2) for discharging the batteries.

2. A self-discharging autonomous seismic node according to claim 1, where the seismic node further comprises: c. One or more heat transfer element (5).

3. A self-discharging autonomous seismic node according to claim 1, where the seismic node further comprises: d. a water-tight casing (1); e. electronics for seismic recordings; f. seismic sensors (6); and g. communication interface (8); and where the communication interface (8) is configured to communicate with a remote control.

4. A self-discharging autonomous seismic node according to claim 3, where the communication interface (8) at least comprises: an RF-receiver (9) configured to communicate with a remote control and with self-discharging autonomous seismic nodes; and an RF-transmitter configured to communicate with self-discharging autonomous seismic nodes, where the self-discharging autonomous seismic node is enabled to communicate in a mesh network.

5. A self-discharging autonomous seismic node according to anyone of claims 2 - 4 where the heat transfer element (5) is one of: a. a heat sink for electronic components, b. a thermal conductive connection with the casing of the autonomous seismic node, and / or c. . a convectional connection with the casing of the autonomous seismic node.

6. A self-discharging autonomous seismic node according to anyone of the previous claims where the autonomous seismic node includes a logical comparator configured to compare the energy level of the rechargeable batteries (2) with a threshold value, where the logical comparator is one of: a hardware logical comparator circuit, and a software program routine with a programmable comparator function.

7. A self-discharging autonomous seismic node according to anyone of the previous claims where the discharging load element (4) comprises a semiconductor used as a load component.

8. A self-discharging autonomous seismic node according to anyone of the previous claims where the discharging load element (4) comprises a switch and a passive load component, where the switch is configured to decouple and couple the passive load component to a discharging circuitry, where the switch can be a hardware switch or a software switch.

9. A method for discharging a self-discharging autonomous seismic node at least comprising the steps of: a. providing one or more rechargeable batteries (2), b. providing a discharging load element (4); where the load element (4) is configured to be connected to the one or more rechargeable batteries (2) to discharge the batteries.

10. A method for discharging an autonomous seismic node according to claim 9 further comprising: a. providing a heat transfer element (5), and b. providing a communication interface (8); and where the communication interface (8) is configured to communicate with a remote control.

11. A method for discharging a self-discharging autonomous seismic node according to claim 10, where the method further comprises the steps of:configuring a RF-receiver (9) of the communication interface (8) to communicate with a remote control and with self-discharging autonomous seismic nodes; configuring a RF-transmitter of the communication interface (8) to communicate with self-discharging autonomous seismic nodes in a mesh network.

12. A method for discharging a self-discharging autonomous seismic node according to claim 11 where the RF-receiver (9) and the RF-transmitter is Bluetooth enabled.

13. A method for discharging an autonomous seismic node according to anyone of claims 9 - 12 further comprising: a. providing a logical comparator circuit to the autonomous seismic node, and b. configuring the logical comparator circuit to compare the energy level of the rechargeable batteries with a threshold value, where the logical comparator can be a hardware logical comparator circuit or where the logical comparator is a software routine with a programmable comparator function.

14. A Method to initiate discharging of an autonomous seismic nodes, comprising the one of: a. sending a "discharge command" hard wired from a remote control to one or more autonomous seismic nodes; b. sending a "discharge command" wireless from remote to one or more autonomous seismic nodes; c. pre-programming a discharge regime where, discharging and charging will take place at defined points of time; and d. sending a "discharge command" wireless from remote to one or more autonomous seismic nodes, where the autonomous seismic nodes are interconnected in a mesh-network.

15. An autonomous seismic node comprising one or more rechargeable batteries, where the autonomous seismic node is configured for discharging of the one or more rechargeable batteries.

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