MONITORING A VEHICLE'S AUXILIARY BATTERY TO DETECT A POSSIBLE DECOUPAGE

Abstract

A monitoring method is implemented for a vehicle comprising an on-board electrical system powered by an electric power generator with a voltage across its terminals, and to which a service battery is coupled, carrying a current. These currents and voltages are measured repeatedly during each driving phase. This method includes a step (10-80) in which, given successive voltage measurements over a chosen time interval characteristic of normal generator behavior, it is determined whether successive current measurements over this time interval exhibit a pattern characteristic of a disconnection of the service battery. If so, a message is generated recommending verification of the connection of the service battery to the on-board electrical system, and this generated message is provided to the driver. Figure 3

Description

Title of the invention: MONITORING OF A VEHICLE SERVICE BATTERY TO DETECT POSSIBLE DECOUPLING Technical field of the invention

[0001] The invention relates to vehicles comprising an on-board network electrically powered by an electrical energy generator and to which a service battery is coupled, and more precisely the monitoring of such a service battery to determine whether it is subject to possible decoupling from the on-board network. State of the art

[0002] Certain vehicles, possibly of the automobile type, comprise an on-board network which is electrically powered by an electrical energy generator, suitable for supplying electrical energy to electrical equipment, and to which is coupled a service battery rechargeable by this electrical energy generator.

[0003] In the following and the preceding, the term "on-board network" means an electrical power supply network to which a service battery and electrical (or electronic) equipment (or components) consuming electrical energy are electrically coupled and being "non-priority" for some of them and "safety" (and therefore priority) for certain others of them.

[0004] Furthermore, in what follows and what precedes, the term "safety equipment (or component)" means equipment (or component) providing at least one so-called "safety" function because it concerns the safety of the passengers of a vehicle, and therefore must be supplied with electrical energy as a priority. This is the case, for example, of electric power steering or an electric braking device (service brake, emergency brake, braking assistance system or anti-skid, for example).

[0005] The service battery is usually responsible for supplying electrical energy to the on-board network at least each time the vehicle is woken up (after a standby phase), and each time the vehicle's powertrain (or GMP) is started.

[0006] The electrical energy generator is primarily responsible, in a hybrid or all-electric GMP vehicle, for supplying the level of electrical power to the safety components concerned at the time in question, but also, in parallel, for the level of electrical power necessary for the operation of the other non-safety components used at this time in question, and for recharging the service battery (at least during the driving phases).

[0007] In the event of the electrical energy generator being unable to supply the power electrical power required by all the electrical components concerned at the time in question, the service battery is responsible for ensuring a supplementary electrical supply to prevent a collapse in the voltage at the terminals of the on-board network and therefore to prevent a safe electrical component from being able to function correctly (i.e. with a sufficient level of performance), which could endanger the passengers of the vehicle and / or the latter and / or people located in the vicinity of this vehicle.

[0008] It may happen that the coupling of the service battery to the on-board network has been carried out incorrectly in the factory or in an after-sales service or by a user of the vehicle and / or that strong vibrations or strong shocks induce over time a poor coupling of the service battery to the on-board network, or even a total decoupling. Such situations can prove potentially dangerous given the importance of the service battery within a hybrid or all-electric GMP vehicle.

[0009] However, there are currently no known means for detecting a possible partial or total decoupling of the service battery of a hybrid or all-electric GMP vehicle, and therefore in certain situations in the life of this vehicle, the passengers of the latter may be in danger without knowing it or the driver of this vehicle may have difficulty, or even be unable to, start this vehicle after a driving phase.

[0010] The invention therefore aims in particular to improve the situation. Presentation of the invention

[0011] It proposes in particular for this purpose a monitoring method intended to be implemented for a vehicle comprising an on-board network, on the one hand, electrically powered by an electrical energy generator having a voltage at its terminals, and, on the other hand, to which is coupled a service battery in which a current circulates, these currents and voltages being measured repeatedly during each driving phase.

[0012] This monitoring method is characterized by the fact that it comprises a step in which, in the presence of voltages measured successively in a chosen time interval and characteristic of normal behavior of the electrical energy generator, it is determined whether currents measured successively in this time interval have a development characteristic of decoupling of the service battery, and, if so, a message is generated recommending a check of the coupling of the service battery to the on-board network, and this generated message is provided to a driver of the vehicle.

[0013] Thanks to the invention, it is now possible to detect a possible decoupling of the service battery and to recommend to the driver to check the coupling of the service battery, before the latter is no longer able to correctly perform (or no longer at all) its functions, which improves the safety of the vehicle and its passengers, but also of living beings and objects located in the vehicle's environment.

[0014] The monitoring method according to the invention may include other characteristics which may be taken separately or in combination, and in particular:

[0015] - in its step, we can determine a characteristic evolution of a decoupling when the evolution indicates that the current remains constant over the time interval;

[0016] - in the presence of the first option, in its step, we can determine an evolution characteristic of decoupling when the evolution indicates that the current remains constant in the time interval with a zero value or a predefined value;

[0017] - in its step, the time interval can have a duration of between 1 minute and ten minutes;

[0018] - in its step, it can be determined whether the voltages measured successively in the chosen time interval are characteristic of normal behavior of the electrical energy generator, and, if so, it can be determined whether the currents measured successively in the time interval have an evolution characteristic of decoupling of the service battery;

[0019] - in the presence of the last option, in its step, when the service battery is of the 12 volt type, we can consider that the voltages are characteristic of normal behavior of the electric energy generator when they are between 13 volts and 15 volts;

[0020] - in its step, when the vehicle comprises a communication module by wave channel, this wave communication module can be used to transmit to a selected server the successively estimated currents and voltages, and this selected server can make each determination in order to decide whether the message should be generated, and, if so, can generate this message and then transmit this generated message to the wave communication module and / or to a mobile communication equipment of the driver.

[0021] The invention also provides a computer program product comprising a set of instructions which, when executed by processing means, is capable of implementing a monitoring method of the type presented above, for a vehicle comprising an on-board network, on the one hand, electrically powered by an electrical energy generator having a voltage at its terminals, and, on the other hand, to which is coupled a service battery in which a current circulates, these currents and voltages being measured repeatedly during each driving phase, to detect a possible decoupling of the on-board network from the service battery.

[0022] The invention also proposes a monitoring device intended to equip at least partially a vehicle comprising an on-board network, on the one hand, electrically powered by an electrical energy generator having a voltage at its terminals, and, on the other hand, to which is coupled a service battery in which a current circulates, these currents and voltages being measured repeatedly during each driving phase.

[0023] This monitoring device is characterized by the fact that it comprises at least one processor and at least one memory arranged to carry out the operations consisting, in the presence of voltages measured successively in a chosen time interval and characteristic of normal behavior of the electrical energy generator, in determining whether currents measured successively in this time interval have a development characteristic of decoupling of the service battery, and, if so, in triggering generation of a message recommending verification of the coupling of the service battery to the on-board network, and provision of this generated message to a driver of the vehicle.

[0024] The invention also proposes a vehicle, possibly of the automobile type, and comprising, on the one hand, an on-board network electrically powered by an electrical energy generator having a voltage at its terminals, and to which is coupled a service battery in which a current circulates, these currents and voltages being measured repeatedly during each driving phase, and, on the other hand, at least part of a monitoring device of the type presented above. Brief description of the figures

[0025] Other characteristics and advantages of the invention will appear on examining the detailed description below, and the appended drawings, in which:

[0026] [Fig-1] schematically and functionally illustrates an example of the embodiment of a vehicle comprising a first part of a monitoring device according to the invention, an on-board network, a service battery associated with a first supervision computer, and a purely electric GMP transmission chain associated with a second supervision computer,

[0027] [Fig.2] schematically and functionally illustrates an exemplary embodiment of a first supervision computer comprising an exemplary embodiment of a first part of a monitoring device according to the invention, and

[0028] [Fig.3] schematically illustrates an example of an algorithm implementing a monitoring method according to the invention. Detailed description of the invention

[0029] The invention aims in particular to propose a monitoring method, and a associated DS monitoring device, intended to enable monitoring of the service battery BS of a vehicle V to determine whether it is subject to possible decoupling from the on-board network RB of the latter (V).

[0030] In the following, it is considered, by way of non-limiting example, that the vehicle V is of the automobile type. It is for example a car, as illustrated in [Fig.l]. But the invention is not limited to this type of vehicle. It relates in fact to any type of vehicle comprising an on-board network electrically powered by an electric energy generator and to which a service battery is coupled. Thus, it relates to land vehicles (utility vehicles, camper vans, minibuses, coaches, trucks, motorcycles, road machinery, construction machinery, agricultural machinery, leisure machinery (snowmobile, kart), tracked vehicles, trains and trams, for example), aircraft and boats.

[0031] Furthermore, it is considered in the following, by way of non-limiting example, that the vehicle V comprises a transmission chain with a purely electric powertrain (or GMP) (and therefore whose drive is provided exclusively by at least one electric motor MME). But the GMP could be of the hybrid type (and in this case it comprises at least one thermal motor and at least one electric motor MME).

[0032] [Fig.l] schematically shows a vehicle V comprising a service battery BS associated with a first supervision computer CS1, an all-electric GMP transmission chain (and therefore with an electric motor MME) and associated with a second supervision computer CS2, an on-board network RB, an electrical energy generator GE, a radio communication module MC, and a first part PI of a monitoring device DS according to the invention (a second part P2 of the latter (DS) being installed here in a remote chosen server SC).

[0033] The on-board network RB is an electrical power supply network to which the service battery BS and electrical (or electronic) equipment (or components) EES and EENS that consume electrical energy are coupled (or even connected). Among these electrical (or electronic) equipment (or components), at least one (EENS) is “non-priority” and at least one other (EES) is “safety” (and therefore priority).

[0034] The radio communication module MC is responsible for communications between the vehicle V and remote communication equipment (or possibly temporarily present in the vehicle V).

[0035] The service battery BS is responsible for supplying electrical energy to the on-board network RB, in addition to that supplied by the electrical energy generator GE (when it is powered by a rechargeable battery BP), and sometimes instead of this generator electric energy generator GE (in particular each time the vehicle V wakes up (after a standby phase) and each time the GMP is started). For example, this service battery BS can be arranged in the form of a very low voltage type battery (typically 12 V, 24 V or 48 V). It is rechargeable at least by the electric energy generator GE (when it is powered by a rechargeable battery BP associated with the electric motor MME). It is considered in the following, by way of non-limiting example, that the service battery BS is of the 12 V Lithium-ion type.

[0036] It will be noted that at least the current ib flowing in this service battery BS can be measured (or estimated) repeatedly during each driving phase of the vehicle V by the first supervision computer CS1 which is associated with this service battery BS. For example, this current ib is measured periodically. The period can, for example, be between 100 ms and 500 ms. As an illustrative example, the period can be equal to 100 ms.

[0037] The electrical energy generator GE is here coupled to the rechargeable battery BP, to the on-board network RB and to the service battery BS. It is for example a direct current / direct current (or DC / DC) converter. The electrical energy generator GE is responsible for converting part of the electrical current stored in the rechargeable battery BP to supply the on-board network RB and the service battery BS with converted electrical current (to recharge it). It will be noted that this electrical energy generator GE can also, possibly, allow the rechargeable battery BP to be recharged (at least in direct current) by an external power source (or charger) temporarily coupled to a charging connector of the vehicle V.

[0038] It will also be noted that at least the voltage vg at the terminals of the electrical energy generator GE can be measured (or estimated) repeatedly during each rolling phase of the vehicle V. For example, this voltage vg is measured periodically. Preferably, the period is equal to that used for the current ib.

[0039] It will also be noted, although this does not appear in [Fig.l], that the electrical energy generator GE can be part of an internal charger also comprising a computer responsible, at least, for controlling the recharges of the rechargeable battery BP.

[0040] The transmission chain has a GMP which is, here, all electric and therefore which comprises, in particular, an electric motor MME, a motor shaft AM, and a transmission shaft AT. Here, the term "electric motor" means an electric machine arranged so as to provide torque to move the vehicle V when it is supplied with electrical energy, as well as possibly to recover torque in the transmission chain.

[0041] The operation of the transmission chain (and therefore of the GMP) is supervised by the second CS2 supervision calculator.

[0042] The electric motor MME (here an electric motor) is here coupled to the rechargeable battery BP in order to be supplied with electrical energy, as well as possibly to supply this rechargeable battery BP with electrical energy, for example during a regenerative braking phase.

[0043] Furthermore, this electric motor MME is coupled to the motor shaft AM, to provide it with torque by rotational drive. This motor shaft AM is here coupled to a reducer RD which is also coupled to the transmission shaft AT, itself coupled to a first train T1 (here of wheels), preferably via a differential DV.

[0044] This first train T1 is here located in the front part PVV of the vehicle V. But in a variant this first train T1 could be the one which is here referenced T2 and which is located in the rear part PRV of the vehicle V.

[0045] The rechargeable battery BP here powers the electric motor MME, it constitutes a main (or traction) battery. It can, for example, comprise electrical energy storage cells, possibly electrochemical (for example of the lithium-ion (or Li-ion) or Ni-Mh or Ni-Cd type). Also for example, the rechargeable battery BP can be of the low voltage type (typically 450 V for illustration purposes). But it could be of the medium voltage or high voltage type.

[0046] It will be noted that in the example illustrated non-limitingly in [Fig.l] the vehicle V also comprises a distribution box BD to which the service battery BS, the electrical energy generator GE, and the on-board network RB are coupled. This distribution box BD is responsible for distributing in the on-board network RB the electrical energy stored in the service battery BS or produced by the electrical energy generator GE, for the supply of the electrical components (or equipment) EES and EENS coupled to the on-board network RB according to power supply requests received (in particular from the second supervision computer CS2 associated with the GMP). Furthermore, the distribution box BD also comprises a management computer CG responsible for ensuring the management of the couplings between equipment (or components or devices) which are coupled to it.

[0047] As mentioned above, the invention proposes in particular a monitoring method intended to enable monitoring of the service battery BS of the vehicle V to determine whether it is subject to possible decoupling from the on-board network RB of the latter (V).

[0048] This (monitoring) method can be implemented at least partially by the monitoring device DS (illustrated at least partially in Figures 1 and 2) which comprises for this purpose at least one processor PR1, for example a digital signal processor (or DCP ("Digital Signal Processor")), and at least one memory MD. This monitoring device DS can therefore be implemented in the form of a combination of circuits or electrical or electronic components (or "hardware") and software modules (or "software"). For example, this could be a microcontroller.

[0049] The memory MD is RAM in order to store instructions for the implementation by the processor PR1 of at least part of the monitoring method. The processor PR1 may comprise integrated (or printed) circuits, or several integrated (or printed) circuits connected by wired or wireless connections. An integrated (or printed) circuit is understood to mean any type of device capable of carrying out at least one electrical or electronic operation.

[0050] In the example illustrated non-limitingly in Figures 1 and 2, a first part PI of the monitoring device DS is part of the first supervision computer CS1 (a second part P2 of this monitoring device DS is here installed in a remote chosen server SC). But this is not obligatory. Indeed, at least the first part PI of the monitoring device DS could comprise its own dedicated computer, which is then coupled to the first supervision computer CS1, or could be part of another computer on board the vehicle V and providing at least one other function, for example. Furthermore, as will be seen later, the monitoring device DS could be an integral part of the first supervision computer CS1 (and in this case it does not need to comprise first PI and second P2 parts).

[0051] As illustrated non-limitingly in [Fig. 3], the (monitoring) method, according to the invention, comprises a step 10-80 which is implemented when the vehicle V is in a rolling phase and the voltage vg at the terminals of the electrical energy generator GE and the current ib circulating in the service battery BS are measured repeatedly (for example periodically).

[0052] Step 10-80 of the method comprises a sub-step 50 in which, in the presence of voltages vg measured successively in a chosen time interval it and characteristic of normal behavior of the electrical energy generator GE, it is determined (for example the monitoring device DS) whether currents ib measured successively in this time interval it have a development which is characteristic of decoupling of the service battery BS.

[0053] If the evolution of the currents ib during the time interval it is normal (and therefore not representative of decoupling), the method ends in a sub-step 60.

[0054] On the other hand, if the evolution of the currents ib during the time interval it is abnormal (and more precisely characteristic of decoupling), and therefore in the affirmative, step 10-80 of the method comprises a sub-step 70 in which a message is generated (for example the monitoring device DS triggers the generation of a) recommending a verification of the coupling to the on-board network RB of the service battery BS.

[0055] When the recommendation message has been generated, step 10-80 of the method comprises a substep 80 in which this (for example the monitoring device DS triggers the provision of the) generated recommendation message is provided to the driver of the vehicle V.

[0056] Thus, it is now possible to detect a possible partial or total decoupling of the service battery BS and to recommend to the driver to check the coupling of the service battery BS, himself or in an after-sales service, before this service battery BS is no longer able to correctly perform (or no longer at all) its functions. This makes it possible to improve the safety of the vehicle V and its passengers, but also of living beings and objects located in the environment of the vehicle V.

[0057] For example, in step 10-80 the time interval it may have a duration of between 1 minute and ten minutes. As an illustrative example, this duration may be equal to 3 minutes. But other values ​​of duration of the time interval it may be used. For example, this duration may be chosen during the development phase of the vehicle V.

[0058] Also for example, in sub-step 50 of step 10-80 one (for example the monitoring device DS) can determine that the evolution of the currents ib is characteristic of a decoupling when this evolution indicates that the current ib remains constant in the time interval it. By way of non-limiting example, in sub-step 50 of step 10-80 one (for example the monitoring device DS) can determine that the evolution of the currents ib is characteristic of a decoupling when this evolution indicates that the current ib remains constant in the time interval it with a zero value or a predefined value.

[0059] Any other method known to those skilled in the art and making it possible to determine whether the evolution of the currents ib is characteristic of decoupling can be used.

[0060] Also for example, and as illustrated non-limitingly in [Fig.3], step 10-80 can comprise a sub-step 30 in which one (for example the monitoring device DS) can determine whether the voltages vg measured successively in the chosen time interval it are characteristic of normal behavior of the electrical energy generator GE.

[0061] If not, and therefore if the voltages vg measured in the time interval it are characteristic of abnormal behavior, as illustrated non-limitingly in [Fig. 3], step 10-80 may comprise a sub-step 40 in which an alert may be generated (for example the monitoring device DS may trigger the generation of an alert), for example to the second supervision computer CS2.

[0062] On the other hand, if so, one (for example the monitoring device DS) carries out sub-step 50 to determine whether the currents ib measured successively in the time interval it has a characteristic evolution of a decoupling of the BS service battery.

[0063] Also for example, and as illustrated non-limitingly in [Fig.3], when it is desired to carry out the analyses of the currents ib and voltages vg, step 10-80 can comprise a sub-step 10 in which it is possible to start by collecting the (for example the monitoring device DS can start by triggering the collection of) the voltages vg and currents ib estimated successively, with a view to analyzing their respective evolutions.

[0064] Also for example, in sub-step 30 of step 10-80, when the service battery BS is of the 12 volt type, it can be considered (for example the monitoring device DS) that the voltages vg are characteristic of normal behavior of the electrical energy generator GE when they are between 13 volts and 15 volts. It can be even more restrictive by checking whether the voltages vg are all substantially equal to 14 volts in the time interval it considered. Those skilled in the art will know how to adapt the range of values ​​to which the voltages vg must belong when the voltage of the service battery BS is of a type other than 12 volts (for example 24 volts or 48 volts).

[0065] Any other method known to those skilled in the art and making it possible to determine whether the evolution of the voltages vg is characteristic of normal behavior of the electrical energy generator GE can be used.

[0066] At least two embodiments of the method can be envisaged.

[0067] In a first embodiment illustrated non-limitingly in [Fig. 3], step 10-80 may comprise a sub-step 20 between sub-steps 10 and 30 and in which the (for example the monitoring device DS may trigger the use of the) MC wave communication module may be used to transmit to a chosen server SC the successively estimated currents ib and voltages vg and any information indicating that the vehicle V is in a rolling phase. In this case, it is the chosen server SC which is responsible for carrying out each determination in order to decide whether the recommendation message must be generated, and, if so, to generate this recommendation message and therefore to carry out sub-steps 70 and 80.If this generation is decided and carried out in sub-step 70, the chosen server SC transmits in sub-step 80 the generated recommendation message to the radio communication module MC and / or to a mobile communication device of the driver.

[0068] When the transmission of the recommendation message is made to the communication module by radio waves MC, the latter (MC) can, for example, communicate it to the central handset of the vehicle V with a view to its display on its screen and / or its broadcast by at least one loudspeaker of the vehicle V. The recommendation message can in fact be textual and / or audio. The driver's mobile communication equipment can, for example, be a smart mobile phone (or "smartphone") allowing the recommendation message transmitted to be displayed on its screen and / or broadcast through its loudspeaker.

[0069] It will be understood that the transmissions are made by waves via at least one wireless communication network of an operator to which the MC wave communication module can be connected.

[0070] This first embodiment requires, as illustrated non-limitingly in [Fig.l], that the monitoring device DS comprises first PI and second P2 parts. The first part PI is installed in the vehicle V, for example in the first supervision computer CS1, and is responsible for triggering each collection of the successively estimated currents ib and voltages vg and of any information signaling that the vehicle V is in a rolling phase, for triggering the transmission of the collected currents ib and voltages vg and of any information collected to the selected server SC by the radio communication module MC, and for triggering each communication of the recommendation message received by the radio communication module MC to the central handset of the vehicle V and / or to the driver's mobile communication equipment.The second part P2 is installed in the chosen server SC and is at least responsible for carrying out each of the determinations described above (sub-steps 30 to 60), and for triggering the generation of a possible recommendation message and the transmission of the latter to the driver.

[0071] In a second embodiment (not illustrated), the monitoring device DS is entirely installed in the vehicle V (for example in the first supervision computer CS1) and is therefore responsible for triggering each collection of currents ib, possible voltages vg and information signaling that the vehicle V is in a rolling phase, for carrying out each of the determinations described above (sub-steps 30 to 60), and for triggering the generation of a possible recommendation message and the provision of the latter to the driver.

[0072] It will also be noted, as illustrated non-limitingly in [Fig. 2], that the first supervision computer CS1 (or the (one) computer of the monitoring device DS) may also comprise a mass memory MM1, in particular for temporarily storing the collected currents ib, and any voltages vg and information (signalling that the vehicle V is in a rolling phase) collected, as well as any intermediate data involved in all its calculations and processing. Furthermore, this first supervision computer CS1 (or the (one) computer of the monitoring device DS) may also comprise an input interface IE for receiving at least the collected currents ib and any voltages vg and information collected, to use them in calculations or processing, possibly after having formatted and / or demodulated and / or amplified them, in a manner known per se, by means of a digital signal processor PR2. In addition, this first supervision computer CS1 (or the (one) computer of the monitoring device DS) may also include an output interface IS, in particular to deliver a recommendation message or triggering of a recommendation message (when it includes the entire monitoring device DS) or a message (or order) for transmitting the collected currents ib and any voltages vg and information collected (when it only includes the first part PI of the monitoring device DS).

[0073] Although this does not appear in Figures 1 and 2, when the monitoring device DS comprises a second part P2, the latter P2 may be part of another computer of the chosen server SC or may comprise its own other computer installed in the chosen server SC. In this case, this other computer may also comprise a mass memory similar to MM1, an input interface similar to IE, a digital signal processor similar to PR2, and an output interface similar to IS.

[0074] It will also be noted that the invention also proposes a computer program product (or computer program) comprising a set of instructions which, when executed by processing means of the electronic circuit (or hardware) type, such as for example the processor PR1, is capable of implementing the monitoring method described above to monitor the service battery BS of the vehicle V to detect a possible decoupling of the on-board network RB from this service battery BS.

Claims

Claims

1. Monitoring method for a vehicle (V) comprising an on-board network (RB) i) electrically powered by an electrical energy generator (GE) having a voltage at its terminals, and ii) to which is coupled a service battery (BS) in which a current flows, said current and voltage being measured repeatedly during each driving phase, characterized in that it comprises a step (10-80) in which, in the presence of voltages measured successively in a chosen time interval and characteristic of normal behavior of said electrical energy generator (GE), it is determined whether currents measured successively in this time interval have a development characteristic of a decoupling of said service battery (BS), and, if so, a message is generated recommending a verification of the coupling to said on-board network (RB) of said service battery (BS),and this generated message is provided to a driver of said vehicle (V).,

2. Method according to claim 1, characterized in that in said step (10-80) a characteristic evolution of a decoupling is determined when said evolution indicates that said current remains constant in said time interval.

3. Method according to claim 2, characterized in that in said step (10-80) a characteristic evolution of a decoupling is determined when said evolution indicates that said current remains constant in said time interval with a zero value or a predefined value.

4. Method according to one of claims 1 to 3, characterized in that in said step (10-80) said time interval has a duration of between 1 minute and ten minutes.

5. Method according to one of claims 1 to 4, characterized in that in said step (10-80) it is determined whether said voltages measured successively in said chosen time interval are characteristic of normal behavior of said electrical energy generator (GE), and, if so, it is determined whether said currents measured successively in said time interval have a development characteristic of decoupling of said service battery (BS).

6. Method according to claim 5, characterized in that in said step (10-80), when said service battery (BS) is of the 12 volt type, it is considered that said voltages are characteristic of a behavior normal of said electric power generator (EG) when they are between 13 volts and 15 volts.

7. Method according to one of claims 1 to 6, characterized in that in said step (10-80), when said vehicle (V) comprises a radio communication module (MC), said radio communication module (MC) is used to transmit to a selected server (SC) said successively estimated currents and voltages, and said selected server (SC) makes each determination in order to decide whether said message must be generated, and, if so, generates said message and then transmits this generated message to said radio communication module (MC) and / or to a mobile communication equipment of said driver.

8. Computer program product comprising a set of instructions which, when executed by processing means, is capable of implementing the monitoring method according to one of claims 1 to 7, for a vehicle (V) comprising an on-board network (RB) i) electrically powered by an electrical energy generator (GE) having a voltage at its terminals, and ii) to which is coupled a service battery (BS) in which a current flows, said current and voltage being measured repeatedly during each driving phase, to detect a possible decoupling of said on-board network (RB) from said service battery (BS).

9. Monitoring device (DS) suitable for equipping at least partially a vehicle (V) comprising an on-board network (RB) i) electrically powered by an electrical energy generator (GE) having a voltage at its terminals, and ii) to which is coupled a service battery (BS) in which a current flows, said current and voltage being measured repeatedly during each driving phase, characterized in that it comprises at least one processor (PR1) and at least one memory (MD) arranged to carry out the operations consisting, in the presence of voltages measured successively in a chosen time interval and characteristic of normal behavior of said electrical energy generator (GE), in determining whether currents measured successively in this time interval have a development characteristic of decoupling of said service battery (BS), and, if so,to trigger a generation of a message recommending a verification of the coupling to said on-board network (RB) of said service battery (BS), and a supply of this generated message to a, driver of said vehicle (V).

10. Vehicle (V) comprising an on-board network (RB) i) electrically powered by an electrical energy generator (GE) having a voltage at its terminals, and ii) to which is coupled a service battery (BS) in which a current circulates, said current and voltage being measured repeatedly during each driving phase, characterized in that it further comprises a monitoring device (DS) according to claim 9.

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