Monitoring the performance of tests on a low-voltage battery of a vehicle

Description

Technical field of the invention

[0001] The invention relates to vehicles comprising an on-board network supplied with electrical energy by a service battery and a converter, and more specifically to the supervision of tests of the service battery. State of the art

[0002] As is known to those skilled in the art, certain vehicles, possibly of the automobile type, comprise an on-board network which is supplied with electrical energy by a service battery and a converter. The latter may be of the direct current / direct current (or DC / DC) type and may be associated with a main battery of the low, medium or high voltage type and responsible for supplying electrical energy to at least one electric motor of the powertrain (or powertrain) of the vehicle.

[0003] In the following and the above, the term “service battery” means a rechargeable battery, for example by the converter, and of the very low voltage type (typically 12 V, 24 V or 48 V).

[0004] Furthermore, in the following and the preceding, the term "on-board network" means an electrical supply network to which electrical (or electronic) equipment (or components) consuming electrical energy are coupled (or connected) and which are "non-priority" for at least one of them and "safe" (and therefore priority) for at least one other of them.

[0005] Furthermore, in the following and the preceding, 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), or a trajectory control device.

[0006] In certain situations in the life of a vehicle, such as during so-called emergency maneuvers (such as emergency braking or avoidance), it is essential that the safety equipment (or components) involved in these maneuvers are supplied with a level of electrical power that guarantees their operation, as well as their expected level of performance.

[0007] The service battery and the converter are responsible for supplying this level of electrical power to the relevant safety equipment at the time in question, but also, in parallel, the level of electrical power required for the operation of the other non-safety components used at that time in question. In the event of an inability to supply the necessary electrical power to all the relevant electrical components at the time in question, a voltage collapse could occur at the terminals of the on-board network and therefore of the safety electrical equipment, which would not allow the latter to operate correctly (i.e. with a sufficient level of performance), and therefore could endanger the vehicle's passengers and / or the vehicle and / or persons located in the vicinity of the vehicle.

[0008] When the vehicle includes both a service battery and a main battery, it is the main battery that is primarily used to power the on-board network after conversion by the converter. The service battery provides electrical energy to start any thermal engine in the powertrain, and provides additional electrical power to prevent the on-board network from collapsing in the event of high transient energy consumption. However, when the converter fails, it is the service battery that must supply all the electrical energy to the on-board network, ensuring minimum voltage levels for the safety components.

[0009] It is therefore essential that the service battery is frequently tested independently of the converter to determine its current condition, and more specifically its ability to supply the aforementioned minimum voltage levels. It has therefore been proposed to equip the vehicle with an isolation device capable of isolating the service battery from the converter (but also of coupling them), if necessary and in particular when a test device must test the service battery.

[0010] A test consists of stressing the service battery, for example by means of one or more successive current draws, in order to evaluate parameters of the service battery such as its internal resistance and its minimum voltage reached.

[0011] Currently, when a test is requested by a vehicle computer, the isolation device is ordered to isolate the service battery from the converter, and then the test device is ordered to perform this test. However, it may happen that the isolation device is unable to ensure complete isolation of the service battery during a test, for example due to a current leak at a switch, and in this case the test is distorted. It may then be decided internally to use the service battery to compensate for a converter failure even though in reality this service battery is not able to provide the aforementioned minimum voltage levels, which can be (very) dangerous. It may also happen that the isolation device is unable to isolate, even partially, the service battery from the converter, which can distort the test results.

[0012] US 2018 / 364311 A1 concerns the measurement of a characteristic of batteries.

[0013] US 7,193,392 B2 discloses determining and balancing the state of charge between series-connected electrical energy storage units.

[0014] The invention therefore aims in particular to improve the situation by supervising the tests of the service battery. Presentation of the invention

[0015] For this purpose, it proposes in particular a supervision method intended to be implemented in a vehicle comprising an on-board network supplied with electrical energy by a service battery and a converter, an isolation device suitable for isolating the latter from each other or for coupling the latter, and a test device suitable for carrying out a test of the service battery to determine a minimum voltage at the terminals of the latter and an internal resistance of this service battery.

[0016] This supervision method is characterized by the fact that it includes a step in which, in the event of a test request, it is determined whether the isolation device is suitable for ensuring isolation, and if so, this isolation is ordered and then the test is ordered to be carried out.

[0017] Thus, we are certain, when the capacity of the isolation device to ensure total isolation is effective, that the result of the test to be carried out will not be distorted and therefore can be used by the calculator which requested this test.

[0018] The supervision method according to the invention may include other characteristics which may be taken separately or in combination, and in particular: in its step it is also possible to determine whether the test device is suitable for carrying out the requested test, and if so and when the isolation device is suitable for ensuring isolation it is possible to order the latter and then the test can be ordered to be carried out; in the presence of the first option, in its step, when the isolation device is suitable for ensuring isolation and the test device is suitable for carrying out the test, it is possible to determine whether the test device is already carrying out a test, and if not it is possible to order isolation and then the test can be ordered to be carried out; in its step, if coupling between the converter and the service battery is required during the test, this coupling can be ordered and an interruption of the test can be ordered;in its step, at the end of the test, a state of the service battery BS can be determined based on the minimum voltage and internal resistance determined, then information on the reliability of the test can be determined based on at least the minimum voltage and internal resistance; in its step, the test can be carried out by causing at least two predefined current calls by the service battery, during each of which an intermediate minimum voltage at the terminals of the service battery and an intermediate internal resistance of the latter are determined, and the minimum voltage can be determined from these determined intermediate minimum voltages and the internal resistance from these determined intermediate internal resistances. ;

[0019] The invention also proposes a computer program product comprising a set of instructions which, when executed by processing means, is capable of implementing a supervision method of the type presented above for supervising the carrying out of tests of a service battery equipping a vehicle comprising an on-board network supplied with electrical energy by this service battery and a converter, an isolation device capable of isolating the latter from each other or of coupling the latter, and a test device capable of carrying out the tests of the service battery to determine a minimum voltage at the terminals of the latter and an internal resistance of the service battery.

[0020] The invention also proposes a supervision device intended to equip a vehicle comprising an on-board network supplied with electrical energy by a service battery and a converter, an isolation device suitable for isolating the latter from each other or for coupling the latter, and a test device suitable for carrying out a test of the service battery to determine a minimum voltage at the terminals of the latter and an internal resistance of the service battery.

[0021] This supervision 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 event of a test request, of determining whether the isolation device is suitable for ensuring isolation, and if so, of ordering this isolation and then ordering the test to be carried out.

[0022] The invention also proposes a vehicle, possibly of the automobile type, and comprising an on-board network supplied with electrical energy by a service battery and a converter, an isolation device suitable for isolating the latter from each other or for coupling the latter, a test device suitable for carrying out a test of the service battery to determine a minimum voltage at the terminals of the latter and an internal resistance of the service battery, as well as a supervision device of the type presented above. Brief description of the figures

[0023] Other characteristics and advantages of the invention will appear on examining the detailed description below, and the appended drawings, in which: [ Fig. 1] schematically and functionally illustrates an exemplary embodiment of a vehicle comprising an on-board network, powered by a service battery and a converter, an isolation device, a test device, and a supervision device according to the invention, [ Fig. 2 ] schematically and functionally illustrates an exemplary embodiment of a supervision device according to the invention, and [ Fig. 3 ] schematically illustrates an example of an algorithm implementing a supervision method according to the invention. Detailed description of the invention

[0024] The invention aims in particular to propose a supervision method, and an associated supervision device DS, intended to enable the supervision of the carrying out of tests of a service battery BS equipping a vehicle V comprising an on-board network RB supplied with electrical energy by this service battery BS and a CV converter.

[0025] In the following, it is considered, by way of non-limiting example, that the vehicle V is of the automobile type. This is for example a car, as illustrated in the figure 1 . 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 supplied with electrical energy by a service battery and a converter. Thus, it relates, for example, to land vehicles (utility vehicles, camper vans, minibuses, coaches, trucks, motorcycles, road machinery, construction machinery, agricultural machinery, leisure machinery (snowmobile, kart), and tracked vehicles, for example), boats and aircraft.

[0026] Furthermore, it is considered in the following, by way of non-limiting example, that the vehicle V comprises a powertrain (or GMP) of the all-electric type (and therefore whose drive is provided exclusively by at least one electric motor). But the GMP could be of the hybrid type (thermal and electric).

[0027] We have schematically represented on the figure 1 a vehicle V comprising an electric GMP transmission chain, an on-board network RB, a service battery BS, a converter CV, an isolation device DI, a test device DT, and a supervision device DS according to the invention.

[0028] The on-board network RB is an electrical power supply network to which electrical (or electronic) equipment (or components) are coupled (or connected) which consume electrical energy and some of which are "non-priority" and some of which are "safe" (and therefore priority). For example, a safety equipment (or component) may be an electric power steering, or an electric braking device (service brake, emergency brake, brake assist system or anti-skid, for example), or a trajectory control device. Also, for example, a non-safe equipment (or component) may be a heating / air conditioning system or a seat heating device or a seat massage device.

[0029] The service battery BS is responsible for supplying electrical energy to the on-board network RB, in addition to that supplied by the CV converter (powered by a main battery BP described later). For example, this service battery BS may be arranged in the form of a very low voltage type battery (typically 12 V, 24 V or 48 V). Here it is rechargeable at least by the CV converter of the vehicle 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.

[0030] The transmission chain has a GMP which is, here, purely electric and therefore which includes, in particular, an electric prime mover MM1, a motor shaft AM, a main battery BP and a transmission shaft AT. Here, the term "electric prime mover" means an electric machine arranged to provide or recover torque to move the vehicle V.

[0031] The prime mover MM1 (here an electric motor) is coupled to the main battery BP, in order to be supplied with electrical energy, as well as possibly to supply this main battery BP with electrical energy. It is coupled to the motor shaft AM, to provide it with torque by rotating it. 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 D1.

[0032] This first train T1 is here located in the front part PVV of 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 vehicle V.

[0033] For example, the main BP battery can be of low voltage type (typically 400 V for illustration). But it could be of medium voltage or high voltage type.

[0034] The MM1 prime mover is, here, also coupled to the CV converter which is also indirectly coupled to the BS service battery, in particular to recharge it with electrical energy from the BP main battery and converted.

[0035] This CV converter is of the direct current / direct current (or DC / DC) type, for example. It is also responsible for supplying the on-board network RB with electrical energy from the main battery BP and converted, in addition to recharging the service battery BS.

[0036] It should be noted that in the example illustrated without limitation on the figure 1the vehicle V comprises a distribution box BD to which the service battery BS, the converter CV 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 converter CV, for the supply of the electrical components (or equipment) according to power supply requests received. The supervision of the distribution of this electrical energy can be ensured by a supervision computer CS. In the example illustrated non-limitingly on the figure 1 , the CS supervision computer is part of the BD distribution box. But in an alternative embodiment (not shown) the CS supervision computer could not be part of the BD distribution box.

[0037] The test device DT is suitable for carrying out a test of the service battery BS to determine a minimum voltage across the terminals of the latter (BS) and an internal resistance of the service battery BS. For example, it may comprise a dedicated electrical load CE connected in series with at least one switch, based on MOSFET(s) and intended to isolate (in its open state) the service battery BS from the electrical load CE or to couple (in its closed state) the service battery BS to the electrical load CE to call for a predefined discharge current (for example 60 A).

[0038] The isolation device DI is arranged to isolate the service battery BS and the CV converter from each other or to couple them (BS, CV), as required. In particular, it can be placed in an open state in which it is intended to isolate the service battery BS from the CV converter, for example during a test of the service battery BS intended to determine at least its internal resistance and its minimum voltage reached, and in a closed state in which it couples the service battery BS to the CV converter.

[0039] For example, the isolation device DI may include at least one MOSFET(s) based switch for isolating the service battery BS from the CV converter (in its open state) or for coupling the service battery BS to the CV converter (in its closed state).

[0040] As mentioned above, the invention proposes in particular a supervision method intended to enable the supervision of the performance of the tests of the BS service battery.

[0041] This (supervision) method can be implemented at least in part by a DS supervision device of the type illustrated in the figure 2 and comprising at least one processor PR1 and at least one memory MD which are arranged to carry out operations when it has been woken up, for example by the supervision computer CS when the latter (CS) wants to obtain a diagnosis of the state of the service battery BS, or possibly as soon as the on-board electronics are woken up by a master computer of the vehicle.

[0042] It should be noted that in the example illustrated without limitation on the figure 1, the DS supervision device is part of the CS supervision computer. But it could be a device coupled to the CS supervision computer. Generally speaking, the DS supervision device is produced in the form of a combination of electrical or electronic circuits or components (or "hardware") and software modules (or "software").

[0043] The PR1 processor may, for example, be a digital signal processor (or DSP). This PR1 processor may include integrated (or printed) circuits, or several integrated (or printed) circuits connected by wired or wireless connections. An integrated (or printed) circuit is any type of device capable of performing at least one electrical or electronic operation. Thus, it may, for example, be a microcontroller.

[0044] The MD memory is live in order to store instructions for the implementation by the PR1 processor of at least part of the supervision method described below (and therefore of its functionalities).

[0045] As illustrated without limitation on the figure 3 , the (supervision) method, according to the invention, comprises a step 10-110.

[0046] This step 10-110 firstly comprises a sub-step 10 in which, in the event of a test request, it (the supervision device DS) determines whether the isolation device DI is capable of ensuring (total) isolation.

[0047] For example, this determination can be made by testing the operation of the isolation device DI, that is to say by checking whether it can move from its closed state to its fully open state, and vice versa. It will be noted that this operating test is not necessarily carried out in sub-step 10. It can in fact be carried out previously, for example just after (each) wake-up of the vehicle V, and in this case the determination consists of obtaining the result of the last operating test carried out.

[0048] If the test is negative (isolation device DI cannot ensure total isolation), the (supervision device DS) signals in a sub-step 20 to the computer that requested the test (for example the supervision computer CS) that this test cannot be carried out. The supervision process then ends.

[0049] If so (isolation device DI capable of ensuring total isolation), step 10-110 comprises a sub-step 70 in which one (the supervision device DS) orders isolation by the isolation device DI (placement in the open state), then a sub-step 80 in which one (the supervision device DS) orders the performance of the test requested by the test device DT. The test is then performed in a sub-step 90 by the test device DT.

[0050] Thanks to this verification of the capacity of the DI isolation device to ensure total isolation, we are certain that when this capacity is effective the result of the test to be carried out will not be distorted and therefore can be used without risk by the calculator which requested this test.

[0051] It will be understood that it is the processor PR1 and memory MD which are arranged to carry out the operations consisting, in the event of a test request, of determining whether the isolation device DI is suitable for ensuring isolation, and if so, of ordering this isolation and then ordering the performance of the requested test.

[0052] For example, and as illustrated without limitation on the figure 3 , step 10-110 may comprise a sub-step 30 in which one (the supervision device DS) can determine whether the test device DT is capable of carrying out the requested test.

[0053] For example, this determination can be made by testing the operation of the test device DT, that is to say by checking whether it can go from its fully open state to its closed state, and vice versa. It will be noted that this operating test is not necessarily done in sub-step 30. It can in fact be carried out previously, for example just after (each) wake-up of the vehicle V, and in this case the determination consists of obtaining the result of the last operating test carried out. When this operating test is done in sub-step 30 it is preferable to first place the isolation device DI in its open state to isolate the service battery BS and thus prevent it from discharging when the on-board network RB is supplied, which would modify its state of charge.

[0054] If not (test device DT cannot perform the test), we (the supervision device DS) signal in a sub-step 40 to the computer which requested the test (for example the supervision computer CS) that this test cannot be performed. The supervision process then ends.

[0055] If so (test device DT capable of performing the test) and when, in addition, the isolation device DI is capable of providing isolation, the isolation is ordered (sub-step 70) by the supervision device DS, then the test is ordered (sub-step 80) by the supervision device DS.

[0056] Thanks to this additional verification of the DT test device's ability to perform a test before ordering it to be performed, unnecessary time is avoided when performing an unfeasible test, which allows the computer that requested this test to make its decision more quickly (almost immediately).

[0057] Also for example, and as illustrated without limitation on the figure 3 , step 10-110 may comprise a sub-step 50 in which, when the isolation device DI is capable of ensuring isolation and the test device DT is capable of carrying out the requested test, one (the supervision device DS) may determine whether the test device DT is already carrying out a test.

[0058] If so (test device DT already performing a test), the computer that requested the test (for example the supervision computer CS) is signaled in a substep 60 by the supervision device DS that this test cannot be performed because another test is in progress. The supervision process then ends.

[0059] If not (test device DT not performing a test), we (the supervision device DS) order isolation (sub-step 70), then we (the supervision device DS) order the test to be performed (sub-step 80).

[0060] It will be noted that in step 10-110 there may be a need for coupling between the CV converter and the service battery BS during the performance of a test (for example in the event of a failure occurring in the CV converter or the main battery BP or the monitoring battery BS, or a safety maneuver in progress or to be performed and requiring immediate interruption of the test). In this case, one (the supervision device DS) can order in a sub-step 100 the coupling of the monitoring battery BS to the CV converter by the isolation device DI (transition to its closed state), and one (the supervision device DS) can order in a sub-step 110 an interruption of the test by the test device DT (transition to its open state).

[0061] It will also be noted that in sub-step 90 of step 10-110 the test device DT can carry out the test by causing at least two predefined current draws by the service battery BS, for example by placing itself in its closed state to put the electrical load CE and the service battery BS in series. In this case, during each current draw the test device DT determines a minimum intermediate voltage across the terminals of the service battery BS and an intermediate internal resistance of the latter (BS). Then, the test device DT can determine the minimum voltage from these determined minimum intermediate voltages and the internal resistance from these determined intermediate internal resistances.

[0062] For example, the number of current draws in each test can be three. But this number can take any value greater than or equal to two.

[0063] Also for example, each current draw of a test can be at least 60 A (it depends on the electrical load CE). Thus, it can, for example, be equal to 100 A. Furthermore, each current draw of a test can, for example, have a duration of 200 ms, and can be carried out according to a period which is, for example, equal to 400 ms (200 ms of current draw by placing the test device DT in its closed state, then 200 ms of "rest" (without current draw) by placing the test device DT in its open state). All the preceding durations are given as an illustrative example and are all configurable.

[0064] Also for example, the minimum voltage determined during a test may be equal to the average of the intermediate minimum voltages determined during each of the current draws of that test, and the internal resistance determined during a test may be equal to the average of the intermediate internal resistances determined during each of the current draws of that test.

[0065] The determinations of the minimum intermediate voltages and intermediate internal resistance can, for example, be carried out after the expiry of a configurable duration after the appearance (or the start) of the variation of the current leaving the service battery BS (the voltage dynamics is lower than the current dynamics). For example, this configurable duration can be chosen equal to 5 ms. Preferably, each determination of an intermediate internal resistance is carried out just after the expiry of the configurable duration, while each determination of an intermediate minimum voltage is carried out at the expiry of a time interval starting just after the expiry of the configurable duration and having a duration strictly less than the duration of the current demand, and for example equal to 100 ms.In this case, the intermediate internal resistance is determined immediately after the end of the variation in the current leaving the service battery BS (i.e. 5 ms or 6 ms after the start of this variation) and the minimum intermediate voltage 100 ms after the end of the variation in the current leaving the service battery BS (i.e. 105 ms after the start of this variation).

[0066] Each intermediate internal resistance can be deduced from the variation of voltage Δu during the variation of current Δi and from this variation of current Δi determined (r = Δu / Δi).

[0067] Preferably, during each current call, the determinations of the minimum intermediate voltage at the terminals of the service battery BS and of the intermediate internal resistance of the latter (BS) are only made when at least one predefined condition is satisfied.

[0068] A first condition may, for example, consist of having a current leaving the service battery BS which is lower than a (configurable) threshold. For example, this threshold may be chosen equal to -50 A.

[0069] A second condition may, for example, consist of only carrying out the aforementioned determinations when the current leaving the service battery BS increases by a value which is greater than the aforementioned threshold for a configurable duration (for example equal to 5 ms) which begins at the same time as the current draw begins.

[0070] A third condition may, for example, be that current / voltage sensors do not report any failure during their measurements.

[0071] Satisfaction of these conditions makes it possible to meet minimum requirements in terms of representativeness of the current profile and accuracy of the calculation of the internal resistance.

[0072] When at least one of the above conditions is not satisfied, the minimum intermediate voltages and intermediate internal resistance are not determined.

[0073] It will also be noted that in sub-step 90 of step 10-110, at the end of carrying out a (complete) test, one (the supervision device DS) can determine a state of the service battery BS as a function of the minimum voltage and internal resistance determined, then one (the supervision device DS) can determine reliability information for the test as a function of at least the minimum voltage and internal resistance.

[0074] This reliability information is likely to reinforce the interest offered by knowing the current state of the BS service battery, since it guarantees that this state is consistent with reality at the time considered.

[0075] For example, reliability information is representative of a reliably reliable test when the determined internal resistance and minimum voltage are considered reliable due to their normal values.

[0076] Also, for example, reliability information representative of an unreliable test may result from the fact that the determined internal resistance and minimum voltage are considered unreliable due to their abnormal values, or from non-optimal conditions for passing the test, or from an interruption of the test required by a computer of the vehicle V (possibly the master computer).

[0077] The test reliability information is transmitted with the status of the BS service battery to the computer that requested the test (for example the CS supervision computer).

[0078] It will also be noted, as illustrated without limitation on the figure 2, that the supervision calculator CS (or the possible calculator of the supervision device DS) can also include, in addition to the RAM MD and processor PR1, a mass memory MM2, in particular for the storage of the state of the service battery BS and any reliability information and intermediate data involved in all its calculations and processing.Furthermore, this supervision calculator CS (or the possible calculator of the supervision device DS) can also comprise an input interface IE for receiving at least the message signaling whether the isolation device DI is suitable (or not) for ensuring (total) isolation, the possible message signaling whether the test device DT is suitable (or not) for carrying out a test, and the possible message signaling whether the test device DT is (or not) already carrying out a test, the state of the service battery BS and the possible reliability information for use 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 supervision computer CS (or the possible computer of the supervision device DS) can also include an output interface IS, in particular for delivering the isolation, coupling or test performance messages or orders, and the requests for obtaining the capacity of the isolation device DI to ensure (total) isolation, the possible requests for obtaining the capacity of the test device DT to perform a test.

[0079] 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 supervision method described above to supervise the performance of the tests of the service battery BS.

Claims

1. Supervision method for a vehicle (V) comprising an on-board network (RB) supplied with electrical energy by a service battery (BS) and a converter (CV), an isolation device (DI) capable of isolating the latter (BS, CV) from each other or of coupling the latter (BS, CV), and a test device (DT) capable of carrying out a test of said service battery (BS) to determine a minimum voltage at the terminals of the latter (BS) and an internal resistance of said service battery (BS) , characterized in that it comprises a step (10-110) in which, in the event of a test request, it is determined whether said isolation device (DI) is capable of ensuring isolation, and if so, said isolation is ordered and then said test is ordered to be carried out.

2. Method according to claim 1, characterized in that in said step (10-110) it is also determined whether said test device (DT) is suitable for carrying out said test, and if so and when said isolation device (DI) is suitable for ensuring said isolation, the latter is ordered and then the carrying out of said test is ordered.

3. Method according to claim 2, characterized in that in said step (10-110), when said isolation device (DI) is suitable for ensuring said isolation and said test device (DT) is suitable for carrying out said test, it is determined whether said test device (DT) is already carrying out a test, and if not, said isolation is ordered and then said carrying out of the test is ordered.

4. Method according to one of claims 1 to 3, characterized in that in said step (10-110) , in the event of a need for coupling between said converter (CV) and service battery (BS) during the performance of said test, said coupling is ordered and an interruption of said test is ordered.

5. Method according to one of claims 1 to 4, characterized in that in said step (10-110) , at the end of carrying out said test, a state of said service battery (BS) is determined as a function of said minimum voltage and internal resistance determined, then reliability information of said test is determined as a function of at least said minimum voltage and internal resistance .

6. Method according to one of claims 1 to 5, characterized in that in said step (10-110) said test is carried out by causing at least two predefined current draws by said service battery (BS), during each of which a minimum intermediate voltage at the terminals of said service battery (BS) and an intermediate internal resistance of the latter (BS) are determined, and said minimum voltage is determined from said determined minimum intermediate voltages and said internal resistance from said determined intermediate internal resistances.

7. Computer program product comprising a set of instructions which, when executed by processing means, is capable of implementing the supervision method according to one of the preceding claims for supervising the performance of tests of a service battery (BS) equipping a vehicle (V) comprising an on-board network (RB) supplied with electrical energy by said service battery (BS) and a converter (CV), an isolation device (DI) capable of isolating the latter (BS, CV) from each other or of coupling the latter (BS, CV), and a test device (DT) capable of performing said tests of said service battery (BS) to determine a minimum voltage at the terminals of the latter (BS) and an internal resistance of said service battery (BS).

8. Supervision device (DS) for a vehicle (V) comprising an on-board network (RB) supplied with electrical energy by a service battery (BS) and a converter (CV), an isolation device (DI) capable of isolating the latter (BS, CV) from each other or of coupling the latter (BS, CV), and a test device (DT) capable of carrying out a test of said service battery (BS) to determine a minimum voltage at the terminals of the latter (BS) and an internal resistance of said service battery (BS) , 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 event of a test request, of determining whether said isolation device (DI) is capable of ensuring isolation, and if so, of ordering said isolation and then ordering the carrying out of said test.

9. Vehicle (V) comprising an on-board network (RB) supplied with electrical energy by a service battery (BS) and a converter (CV), an isolation device (DI) capable of isolating the latter (BS, CV) from each other or of coupling the latter (BS, CV), and a test device (DT) capable of carrying out a test of said service battery (BS) to determine a minimum voltage at the terminals of the latter (BS) and an internal resistance of said service battery (BS) , characterized in that it further comprises a supervision device (DS) according to claim 8.

10. Vehicle according to claim 9, characterized in that it is of the automobile type.