CHECK FOR A VEHICLE'S AUXILIARY BATTERY TO DETECT WHEN IT NEEDS TO BE REPLACED

Abstract

A control method is implemented for a vehicle comprising a rechargeable auxiliary battery and having an internal resistance that is repeatedly estimated during each driving phase. This method includes a step (10-80) in which it is determined whether successively estimated internal resistances are all greater than a first chosen threshold for at least a first chosen duration, and, if so, a message recommending replacement of the auxiliary battery is generated and provided to the vehicle driver. Figure 3

Description

Title of the invention: MONITORING A VEHICLE SERVICE BATTERY TO DETECT WHEN IT NEEDS TO BE REPLACED Technical field of the invention

[0001] The invention relates to vehicles comprising a rechargeable service battery suitable for supplying electrical energy to electrical equipment, and more specifically to the monitoring of such a service battery to determine when it must be replaced. State of the art

[0002] Certain vehicles, possibly of the automobile type, include a rechargeable service battery capable of supplying electrical energy, via an on-board network, to electrical equipment.

[0003] In the following and the preceding, the term "on-board network" means an electrical power supply network to which electrical (or electronic) equipment (or components) consuming electrical energy are electrically connected 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] When the GMP is hybrid or all-electric, the vehicle usually includes an electrical energy generator primarily responsible for supplying the level of electrical power to the safety components concerned at the time in question, but also, in parallel, the level of electrical power necessary for the operation of the other non-safety components used at this time in question. In the event of the electrical energy generator being unable to supply the electrical power necessary to all the electrical components concerned at the time in question, the service battery is responsible for providing additional electrical power to prevent a collapse. of 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.

[0007] Some vehicles are equipped with a testing device responsible for carrying out tests on their service battery during the driving phases in order to enable a check of their capacity, and therefore to determine when it must be replaced. These tests generally consist of carrying out one or more successive current draws on the service battery to determine parameters such as at least its internal resistance and its minimum voltage.

[0008] When the vehicle does not have such a testing device, it is very difficult, if not impossible, to determine when its service battery needs to be replaced. As a result, it may happen, without the driver knowing, that the service battery is no longer able to perform its functions correctly.

[0009] The invention therefore aims in particular to improve the situation. Presentation of the invention

[0010] For this purpose, it proposes in particular a control method intended to be implemented for a vehicle comprising a rechargeable service battery and having at least one internal resistance estimated repeatedly during each driving phase.

[0011] This control method is characterized by the fact that it comprises a step in which it is determined whether successively estimated internal resistances are all greater than a first chosen threshold for at least a first chosen duration, and, if so, a message is generated recommending replacement of the service battery, and this generated message is provided to a driver of the vehicle.

[0012] Thanks to the invention, it is now possible to recommend to the driver to replace the service battery before the latter is no longer able to perform its functions, which makes it possible to improve the safety of the vehicle and its passengers, but also of living beings and objects located in the environment of the vehicle.

[0013] The control method according to the invention may include other characteristics which may be taken separately or in combination, and in particular:

[0014] - in its step, when the service battery also has an estimated state of charge of repeatedly during each rolling phase, it can be determined, as soon as an estimated internal resistance is greater than the first threshold, whether the successively estimated charge states are all greater than a second chosen threshold for at least a second chosen duration, and, if so, it can be determined whether the resistances internal, successively estimated while the estimated charge states are greater than the second threshold, are all greater than a third threshold chosen strictly greater than the first threshold, and, if so, the message can be generated;

[0015] - in the presence of the first option, in its step, we can determine whether the re internal resistances, estimated successively while the estimated charge states are greater than the second threshold, are all greater than the third threshold for a third duration chosen strictly greater than the first duration, and, if so, the message can be generated;

[0016] - in the presence of the last sub-option, in its step, the third duration can be equal to double the first duration;

[0017] - also in the presence of the first option, in its step, the second duration may be equal to a chosen percentage of the first duration;

[0018] - also in the presence of the first option, in its stage when the vehicle includes a radio communication module, this radio communication module can be used to transmit to a selected server the successively estimated internal resistances and the successively estimated states of charge, and the selected server can make each determination to decide whether the message should be generated, and, if so, can generate the message and then transmit this generated message to the radio communication module and / or to a mobile communication equipment of the driver;

[0019] - in its stage, the first duration can be between 20 days and 40 days;

[0020] - in its step, when the service battery is of the 12 volt type, the first threshold can be between 7 milliohms and 10 milliohms.

[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 control method of the type presented above, for a vehicle comprising a rechargeable service battery and having at least one internal resistance repeatedly estimated during each driving phase, to determine when the service battery must be replaced.

[0022] The invention also proposes a control device intended to at least partially equip a vehicle comprising a rechargeable service battery and having at least one internal resistance repeatedly estimated during each driving phase.

[0023] This control 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 of determining whether successively estimated internal resistances are all greater than a first chosen threshold for at least a first chosen duration, and, in if so, to trigger generation of a message recommending replacement of the service battery, 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, a rechargeable service battery and having at least one internal resistance repeatedly estimated during each driving phase, and, on the other hand, at least part of a control 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 control device according to the invention, an on-board network, a service battery associated with a first supervision computer, and a purely thermal GMP transmission chain and 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 control device according to the invention, and

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

[0029] The invention aims in particular to propose a control method, and an associated DC control device, intended to enable control of the service battery BS of a vehicle V to determine when it must be replaced.

[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 a rechargeable service battery and capable of supplying electrical energy, via an on-board network, to electrical equipment. 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 thermal powertrain (or GMP) (and therefore whose drive is provided exclusively by at least a thermal MMT motor). But the GMP could be of the hybrid type (and in this case it includes at least one thermal MMT motor and at least one electric motor) or all electric.

[0032] [Fig.l] schematically shows a vehicle V comprising a service battery BS associated with a first supervision computer CS1, a thermal GMP transmission chain (and therefore with a thermal motor MMT) and associated with a second supervision computer CS2, an on-board network RB, a radio communication module MC, and a first part PI of a control device DC2 according to the invention (a second part P2 of the latter (DC2) being installed here in a remote chosen server SC).

[0033] The on-board network RB is an electrical power supply network to which electrical (or electronic) equipment (or components) EES and EENS are coupled, which consume electrical energy, and which is coupled to the service battery BS in order to be supplied with electrical energy. Among these electrical (or electronic) equipment (or components), some (EENS) are “non-priority” and some others (EES) are “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 first supervision computer CS1, which is associated with the service battery BS, is in particular responsible for repeatedly determining or estimating (for example periodically) at least the internal resistance rie as well as preferably the state of charge ece of the latter (BS). Generally, it also determines or estimates the internal temperature of the service battery BS.

[0036] For example, the service battery BS may be arranged in the form of a very low voltage type battery (typically 12 V, 24 V or 48 V). 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.

[0037] As illustrated, the transmission chain also comprises, here, a motor shaft AM, a coupling device DC1, a gearbox BV, and a transmission shaft AT.

[0038] The operation of the transmission chain (and therefore of the GMP) is supervised by a second supervision computer CS2.

[0039] The thermal motor MMT comprises a crankshaft (not shown) which is fixedly secured to the engine shaft AM in order to drive the latter (AM) in rotation. This thermal motor MMT is capable of operating according to a speed to provide a first torque, on the order of the second supervision computer CS2. In addition, it (MMT) is capable of being coupled to the primary shaft AP of the gearbox BV speeds via the DC1 coupling device. This DC1 coupling device is capable of delivering a second torque from the first torque produced by the thermal motor MMT, for the BV gearbox. Finally, this BV gearbox is capable of delivering a third torque from the second torque delivered by the DC1 coupling device, for at least one drive wheel set T1. This third torque is defined by a torque setpoint which is transmitted by the second supervision computer CS2.

[0040] For example, the train T1 can be located in the front part PVV of the vehicle V. It is preferably, and as illustrated, coupled to the transmission shaft AT via a differential (here front) DV. But in a variant this train T1 could be that referenced T2 which is located in the rear part PRV of the vehicle V.

[0041] Also for example, the coupling device DC1 can be a clutch (possibly double). But in an alternative embodiment it could be a torque converter, for example.

[0042] The BV gearbox can be automated or manual.

[0043] In the example illustrated without limitation, the crankshaft of the thermal motor MMT is also coupled to a belt CO, itself coupled to an alternator-starter AD which is supplied with electrical energy by the service battery BS, and which can also recharge the latter (BS). Thus, the alternator-starter AD can supply torque to the belt CO, which can supply this torque to the crankshaft.

[0044] It will be noted, although this is not illustrated in [Fig.l], that the first supervision computer CS1 and the radio communication module MC can, for example, communicate via an internal communication network of the vehicle V, possibly multiplexed.

[0045] As mentioned above, the invention proposes in particular a control method intended to enable control of the service battery BS to determine when it must be replaced.

[0046] This (control) method can be implemented at least partially by the control device DC2 (illustrated at least partially in FIGS. 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 control device DC2 can therefore be produced in the form of a combination of electrical or electronic circuits or components (or "hardware") and software modules (or "software"). For example, it can be a microcontroller.

[0047] The memory MD is RAM in order to store instructions for the implementation by the processor PR1 of at least part of the control method. The processor PR1 may comprise integrated (or printed) circuits, or several integrated (or printed) circuits connected by wired or wireless connections. By circuit is meant integrated (or printed) any type of device capable of performing at least one electrical or electronic operation.

[0048] In the example illustrated non-limitingly in Figures 1 and 2, a first part PI of the control device DC2 is part of the first supervision computer CS1 (a second part P2 of this control device DC2 is here installed in a remote chosen server SC). But this is not obligatory. Indeed, at least the first part PI of the control device DC2 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 ensuring at least one other function, for example. Furthermore, as will be seen later, the control device DC2 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).

[0049] As illustrated non-limitingly in [Fig. 3], the (control) method, according to the invention, comprises a step 10-80 which is implemented at least when the vehicle V is in a rolling phase and the first supervision computer CS1 estimates at least the successive internal resistances rie of the service battery BS repeatedly (for example periodically).

[0050] Step 10-80 of the method comprises a sub-step 30 in which it is determined (for example the control device DC2) whether successively estimated internal resistances rie are all greater than a first threshold si chosen for at least a first chosen duration dl. It is important to note that this first duration dl is a cumulative driving duration, and therefore does not take into account the phases during which the vehicle V is not used.

[0051] For example, in step 10-80, when the service battery BS is of the 12 volt type, the first threshold si can be between 7 milliohms and 10 milliohms. As an illustrative example, the first threshold si can be equal to 8 milliohms. But other values ​​of the first threshold si can be used. For example, the value of this first threshold s 1 can be chosen during the development phase of the vehicle V.

[0052] Also for example, in step 10-80 the first duration dl can be between 20 days and 40 days. As an illustrative example, the first duration dl can be equal to 30 days. But other values ​​of first duration dl can be used. For example, the value of this first duration dl can be chosen during the development phase of the vehicle V.

[0053] If at least some of the successively estimated internal resistances rie are lower than the first threshold if during the first duration dl, the method ends in a sub-step 40. It is in fact considered that these estimated internal resistances rie are too low for the capacity of the service battery BS to have become in- sufficient.

[0054] On the other hand, if all the internal resistances rie estimated successively are greater than the first threshold if for at least the first duration dl (and therefore in the affirmative, or in other words if a first criterion is satisfied), step 10-80 of the method comprises a sub-step 70 in which a (for example the control device DC2 triggers the generation of a) (recommendation) message is generated recommending a replacement 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 control device DC2 triggers the provision of the) generated recommendation message is provided to the driver of the vehicle V.

[0056] Thus, it is now possible to recommend to the driver to replace the service battery BS before the latter (BS) is no longer able to perform its functions, and even when the driver is not able to realize it. 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, and as illustrated non-limitingly in [Fig.3], step 10-80 may comprise a sub-step 10 in which one may begin by collecting the (for example the DC control device may begin by triggering the collection of) the successively estimated internal resistances rie.

[0058] In order to increase the accuracy and reliability of the decision-making process for generating a recommendation message, a particular embodiment of the method can be implemented. It consists in determining whether at least one second criterion (as well as preferably a third criterion) is (are) satisfied in addition to the satisfaction of the first criterion and before deciding to generate the recommendation message.

[0059] In this case, as illustrated non-limitingly in [Fig. 3], step 10-80 may comprise a sub-step 50 in which, when the state of charge ece of the service battery BS is also repeatedly estimated during each driving phase, it is possible (for example the control device DC2) to determine, as soon as an estimated internal resistance rie is greater than the first threshold if, if the successively estimated states of charge ece are all greater than a second threshold s2 chosen for at least a second chosen duration d2. It is important to note that this second duration d2 is a cumulative driving duration, and therefore does not take into account the phases during which the vehicle V is not used. Furthermore, it is also important to note that this latter determination is carried out after it has been determined that the first criterion has been satisfied.

[0060] For example, in step 10-80, the second threshold s2 may be between 70% and 90% of a full state of charge of the service battery BS. As an example illustratively, the second threshold s2 can be equal to 80% of the full state of charge of the service battery BS. But other values ​​of second threshold s2 can be used. For example, the value of this second threshold s2 can be chosen during the development phase of the vehicle V.

[0061] Also for example, in step 10-80 the second duration d2 may be equal to a chosen percentage of the first duration d1. In this case, the second duration d2 may be between 50% and 70% of the first duration d1. As an illustrative example, the second duration d2 may be equal to 60% of the first duration d1. But other values ​​of second duration d2 may be used. For example, the value of this second duration d2 may be chosen during the development phase of the vehicle V.

[0062] If at least some of the successively estimated states of charge ece are lower than the second threshold s2 during the second duration d2, the method ends in sub-step 40. It is considered that these estimated states of charge ece are too low to allow a correct and therefore reliable estimation of the estimated internal resistances rie, and therefore it is decided not to take into account the estimated internal resistances rie and the estimated states of charge ece.

[0063] On the other hand, if all the estimated states of charge ece are greater than the second threshold s2 for at least the second duration d2 (and therefore in the affirmative, or in other words if a second criterion is satisfied), step 10-80 of the method may comprise, as illustrated in [Fig. 3], a sub-step 60 in which it is determined whether the internal resistances rie, estimated successively while the estimated states of charge ece are greater than the second threshold s2, are all greater than a third threshold s3 chosen which is strictly greater than the first threshold si. It is important to note that this latter determination is carried out after it has been determined that the first and second criteria have been satisfied, by analyzing the estimated internal resistances rie a second time.

[0064] For example, in step 10-80, when the service battery BS is of the 12 volt type and the first threshold s1 is equal to 8 milliohms, the third threshold s3 can be between 9 milliohms and 11 milliohms. As an illustrative example, the third threshold s3 can be equal to 10 milliohms. But other values ​​of the third threshold s3 can be used. For example, the value of this third threshold s3 can be chosen during the development phase of the vehicle V.

[0065] If at least some of the estimated internal resistances rie are lower than the third threshold s3, the method ends in a sub-step 40. It is in fact considered that there is a doubt about the continuous nature of the degradation of the service battery BS.

[0066] On the other hand, if all the estimated internal resistances rie are greater than the third threshold s3 (and therefore in the affirmative, or in other words if a third criterion is satisfied), the recommendation message is generated (for example the control device DC2 triggers the generation of the) in sub-step 70.

[0067] It is considered in fact that if the estimated internal resistances rie remain at high values ​​for a sufficiently long time (greater than the third threshold s3) even though the estimated states of charge ece are significant (greater than the second threshold s2), this means that there is an effective continuous degradation of the service battery BS and therefore that its capacity has definitely become insufficient, which requires that it be replaced.

[0068] It will be noted that in sub-step 60 of step 10-80, one (for example the control device DC2) can determine whether the internal resistances rie, estimated successively while the estimated states of charge ece are greater than the second threshold s2, are all greater than the third threshold s3 during a third chosen duration d3 which is strictly greater than the first duration d1. It is important to note that this third duration d3 is a cumulative driving duration, and therefore does not take into account the phases during which the vehicle V is not used.

[0069] For example, in step 10-80 the third duration d3 may be equal to twice the first duration d1. As an illustrative example, if the first duration d1 is equal to 30 days, then the third duration d3 may be equal to 60 days. But other values ​​of third duration d3 may be used. For example, the value of this third duration d3 may be chosen during the development phase of the vehicle V.

[0070] If at least some of the estimated internal resistances rie are lower than the third threshold s3 during the third duration d3 or if the estimated internal resistances rie are higher than the third threshold s3 only for a duration strictly lower than the third duration d3, the method ends in sub-step 40. It is in fact considered that this duration is not sufficiently long to make it possible to decide that the degradation of the service battery BS is sufficiently continuous to require its replacement.

[0071] On the other hand, if all the estimated internal resistances rie are greater than the third threshold s3 for at least the third duration d3, it is considered that the estimated internal resistances rie have remained at high values ​​(greater than the third threshold s3) for a sufficiently long time even though the estimated states of charge ece are significant (greater than the second threshold s2), and therefore that the capacity of the service battery BS has definitely become insufficient, which requires its replacement. In this case (and therefore in the affirmative), the recommendation message is generated in sub-step 70.

[0072] At least two embodiments of the method can be envisaged.

[0073] In a first embodiment illustrated non-limitingly in [Fig.3], the step 10-80 may comprise a sub-step 20 between sub-steps 10 and 30 and in which the (for example the control device DC2 can trigger the use of the) radio communication module MC can be used to transmit to a chosen server SC the successively estimated internal resistances rie and the possible successively estimated states of charge ece. 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 the sub-steps 30 to 70. If this generation is decided and carried out in the sub-step 70, the chosen server SC transmits in the sub-step 80 the generated recommendation message to the radio communication module MC and / or to a mobile communication equipment of the driver.

[0074] 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 for the purpose of displaying it on its screen and / or broadcasting it through at least one loudspeaker of the vehicle V. The recommendation message can in fact be textual and / or audible. The driver's mobile communication equipment can, for example, be a smart mobile telephone (or "smartphone") allowing the display of the recommendation message transmitted on its screen and / or its broadcast through its loudspeaker.

[0075] 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.

[0076] This first embodiment requires, as illustrated non-limitingly in [Fig.l], that the control device DC2 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 estimated internal resistances rie and of the possible estimated states of charge ece, for triggering the transmission of the estimated internal resistances rie and possible estimated states of charge ece collected to the chosen 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.

[0077] In a second embodiment (not shown), the control device DC2 is entirely installed in the vehicle V (for example in the first computer of supervision CS1) and is therefore responsible for triggering each collection of estimated internal resistance rie and possible estimated state of charge ece, 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.

[0078] It will also be noted, as illustrated non-limitingly in [Fig. 2], that the first supervision computer CS1 (or the (one) computer of the control device DC2) may also comprise a mass memory MM1, in particular for temporarily storing the estimated internal resistances rie and the possible estimated states of charge ece, as well as any intermediate data involved in all its calculations and processing operations. Furthermore, this first supervision computer CS1 (or the (one) computer of the control device DC2) may also comprise an input interface IE for receiving at least the estimated internal resistances rie and the possible estimated states of charge ece, for using them in calculations or processing operations, possibly after having shaped 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 control device DC2) can also comprise an output interface IS, in particular for delivering a recommendation message or triggering a recommendation message (when it comprises the entire control device DC2) or a message (or order) for transmitting the estimated internal resistances rie and any estimated load states ece (when it only comprises the first part PI of the control device DC2).

[0079] Although this does not appear in Figures 1 and 2, when the control device DC2 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.

[0080] 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 control method described above to control the service battery BS for the vehicle V to determine when it (BS) must be replaced.

Claims

Claims

1. Control method for a vehicle (V) comprising a rechargeable service battery (BS) and having at least one internal resistance repeatedly estimated during each driving phase, characterized in that it comprises a step (10-80) in which it is determined whether successively estimated internal resistances are all greater than a first chosen threshold for at least a first chosen duration, and, if so, a message is generated recommending replacement 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), when said service battery (BS) also has a state of charge estimated repeatedly during each driving phase, it is determined, as soon as an estimated internal resistance is greater than said first threshold, whether said successively estimated states of charge are all greater than a second chosen threshold for at least a second chosen duration, and, if so, it is determined whether said internal resistances, successively estimated while said estimated states of charge are greater than said second threshold, are all greater than a third chosen threshold strictly greater than said first threshold, and, if so, said message is generated.

3. Method according to claim 2, characterized in that in said step (10-80) it is determined whether said internal resistances, estimated successively while said estimated charge states are greater than said second threshold, are all greater than said third threshold for a third duration chosen strictly greater than said first duration, and, if so, said message is generated.

4. Method according to claim 3, characterized in that in said step (10-80) said third duration is equal to twice said first duration.

5. Method according to one of claims 2 to 4, characterized in that in said step (10-80) said second duration is equal to a chosen percentage of said first duration.

6. Method according to one of claims 2 to 5, 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 chosen server (SC) said successively estimated internal resistances and said successively estimated states of charge, 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 over-the-air communication module (MC) and / or to a mobile communication equipment of said driver.

7. Method according to one of claims 1 to 6, characterized in that in said step (10-80), when said service battery (BS) is of the 12 volt type, said first threshold is between 7 milliohms and 10 milliohms.

8. Computer program product comprising a set of instructions which, when executed by processing means, is capable of implementing the control method according to one of claims 1 to 7, for a vehicle (V) comprising a rechargeable service battery (BS) and having at least one internal resistance repeatedly estimated during each driving phase, to determine when said service battery (BS) must be replaced.

9. Control device (DC2) suitable for at least partially equipping a vehicle (V) comprising a rechargeable service battery (BS) and having at least one internal resistance repeatedly estimated 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 of determining whether successively estimated internal resistances are all greater than a first chosen threshold for at least a first chosen duration, and, if so, triggering generation of a message recommending replacement of said service battery (BS), and providing this generated message to a driver of said vehicle (V).

10. Vehicle (V) comprising a rechargeable service battery (BS) and having at least one internal resistance repeatedly estimated during each driving phase, characterized in that it further comprises at least part of a control device (DC2) according to claim 9.

Images