FR3122260A1 - METHOD FOR DIAGNOSING THE OPERATING STATE OF A MOTOR VEHICLE ELECTRIC ENERGY STORAGE - Google Patents

Abstract

The invention relates to a method for diagnosing the operating state of an electrical energy storer (10) of a motor vehicle (11) comprising: - a step of selecting a diagnostic (Sel_diag) of the operating state of the electric energy storer (10), - a step for retrieving characteristics (Typ_batt, Tech_batt) of the electric energy storer (10) and data (Soc_batt, Rint_norm) relating to operation of the electric energy storer ( 10) containing in particular a measured state of charge (Soc_batt) and a measured internal resistance (Rint_norm) of the electrical energy store (10), - a step of determining an internal resistance threshold (S_res_int) from the characteristics ( Typ_batt, Tech_batt) of the electrical energy store (10), - a step for comparing the measured internal resistance (Rint_norm) with at least one threshold depending on the previously determined internal resistance threshold (S_res_int), - a step for comparing the state measured load (Soc_batt) with at least one load threshold, and - a step of establishing a diagnosis (Diag_batt) of the operating state of the electrical energy store (10) according to the comparisons previously made. Figure 1

Description

METHOD FOR DIAGNOSING THE OPERATING STATE OF A MOTOR VEHICLE ELECTRIC ENERGY STORAGE

The present invention relates to a method for diagnosing the operating state of a motor vehicle electrical energy store.

In a manner known per se, during the preparation of new vehicles before delivery to the end user, it is necessary to ensure that a low voltage electrical energy storage device, in particular a storage device having an operating voltage of 12V , is in a state which allows the driver, on the one hand to start his vehicle in complete safety, and on the other hand not to quickly encounter a battery failure thereafter.

To do this, a test of the electrical energy storage device is systematically carried out before delivery by an external operator using an off-board tester. However, the results show that the use of the dismounted tester is not always mastered, which can lead to incorrect diagnoses. Indeed, a storage unit can be falsely declared to be in good working order or falsely declared defective, which generates warranty costs. A dismounted tester also has a high cost of several hundred to several thousand euros.

The invention aims to effectively remedy the aforementioned drawbacks by proposing a method for diagnosing the operating state of a motor vehicle electrical energy store comprising:

- a step of selecting a diagnosis of the operating state of the electrical energy storer,

- a step of recovering characteristics of the electric energy storer and data relating to an operation of the electric energy storer containing in particular a measured state of charge and a measured internal resistance of the electric energy storer,

- a step of determining an internal resistance threshold from the characteristics of the electrical energy storer,

- a step of comparing the internal resistance measured with at least one threshold depending on the previously determined internal resistance threshold,

- a step of comparing the measured state of charge with at least one charge threshold, and

- a step of establishing a diagnosis of the operating state of the electrical energy store according to the comparisons previously made.

The invention thus makes it possible to carry out a diagnosis of the operating state of the electrical energy storage device without having to use a land-based tester, which represents an economic gain. The diagnostic strategy according to the invention may be integrated into an already existing after-sales diagnostic tool allowing automation of the storage tank test process. The invention thus makes it possible to reduce the risk of misdiagnosis, which is a guarantee of safety for the operator. The invention also has the advantage of being able to easily adapt to the type of electrical energy storage device on board the vehicle.

According to one implementation, the diagnosis of the operating state generates the request for an action to be carried out on the electric energy storer, in particular a recharging action of said electric energy storer, the duration of which varies according to the diagnosis established.

According to one implementation, the method comprises a step of selecting a second diagnosis in the case where a first diagnosis has generated the performance of a recharging of the electrical energy store and then the launching of said second diagnosis.

According to one implementation, the characteristics of the electric energy storer are retrieved from a computer associated with the electric energy storer.

According to one implementation, the data relating to an operation of the electric energy storer are retrieved from a computer of the motor vehicle.

According to one implementation, the data relating to an operation of the electric energy storer are stored by the computer of the motor vehicle over the last N runs of said motor vehicle.

According to one implementation, the characteristics of the electric energy storer and the data relating to an operation of the electric energy storer are recovered in the form of hexadecimal frames intended to be decoded to allow their exploitation.

According to one implementation, the data relating to an operation of the electric energy storer also contains data representative of a level of reliability of a measurement of the state of charge of the electric energy storer also taken into account for establishing the diagnosis.

According to one implementation, the internal resistance threshold is determined by means of a map establishing a correspondence between the characteristics of the electric energy storer and an associated internal resistance threshold of the electric energy storer.

The invention also relates to a computer comprising a memory storing software instructions for implementing the method as defined above.

The invention will be better understood on reading the following description and on examining the accompanying figures. These figures are given only by way of illustration but in no way limit the invention.

There is a schematic representation of the system implementing the method according to the invention for diagnosing the operating state of an electrical energy store;

There is a diagrammatic representation of a menu offered to an operator for choosing the operating state diagnosis of the electrical energy store;

There is a diagram of the different steps of the method according to the invention for diagnosing the operating state of the electrical energy store.

There shows a system 20 implementing a method according to the invention for diagnosing the operating state of a low-voltage electrical energy storer 10 in preparation for a new motor vehicle 11. The electrical energy storer 10, which can also be called a "battery" in the remainder of the description, has for example an operating voltage of 12V.

The system 20 comprises a Man-Machine interface (or MMI) 15 allowing an operator 12 to launch a test procedure for the storer 10 and to read the result, with the actions to be carried out on the storer 10, if necessary.

It should be noted that to reduce misuse, the management of the diagnosis via the HMI 15 can be substituted for an automated procedure consisting of an automated launch of the test and supply of the result to the operator 12 with the required actions.

During a diagnostic request from the store 10, the system 20 being connected to the vehicle 11 by wire, via a diagnostic socket, it will send a request to the vehicle 11 to retrieve recorded and stored data, each time the vehicle is driven. 11. These data are mainly the measurement of the state of charge Soc_batt of the storer 10 during travel, Stat_soc information on the reliability of the state of charge measurement while travelling, the standardized internal resistance Rint_norm of the storer 10 while travelling. , as well as the Typ_batt, Tech_batt characteristics of the storer 10 used on the vehicle 11.

The method determines from the characteristics of the storer 10 (type of storer Typ_batt, storer technology Tech_batt), an internal resistance threshold S_res_int which can be used subsequently to determine the state of the storer 10.

Depending on all the data on the storer 10, retrieved by the system 20 via an interaction with the vehicle 11, the method synthesizes a state of the storer 10 and, if necessary, provides the operator 12 directly with instructions on the actions to be carried out on Storer 10 (replacement or recharging for a specific duration).

System 20 mainly implements four functions F1-F4. The function F1 provides management of a diagnostic interface of the storer 10. This function F1 communicates with the operator 12, to allow him to initiate a diagnostic session of the storer 10 and communicate to him the result of the diagnosis of the storer 10. This function F1 consumes as input a selection of a diagnostic Sel_diag of the operating state of the electrical energy store 10 and a diagnostic Diag_batt of the battery 10. The function F1 provides as output the diagnostic request information Dem_diag_batt of the battery 10, a diagnosis type Typ_diag and a diagnosis result message Mess_res_diag.

The data recovery and decoding function F2 communicates with the vehicle 11 to recover raw data on the use and state of the storer 10. The function F2 decodes and translates the information received from the vehicle 11 into useful data that can be used to carry out a diagnosis of the state of the storer 10. The function F2 consumes as input the diagnostic request Dem_diag_batt, raw data Raw_data relating to the operation of the storer 10 coming from the computer of the vehicle 14 and the Carac_batt characteristics of the battery 10. The function F2 outputs a request for retrieval Data_req of data relating to the operation of the storer 10, a request for retrieval of the characteristics data of the storer 10 Data_batt_req, a level of reliability Stat_soc of the state of charge measurement of the storer 10 ( nominal/non-nominal), a state of charge in percentage Soc_batt of the battery 10 during the last drive or during the measurement of pr 11 new vehicle, a Rint_norm standardized internal resistance measurement in mOhm of the 10 storer, a Typ-batt battery type (size L0/L1/L2/L3 and capacity in AH) and a Tech_batt technology of the 10 battery (Liquid , Waterproof_VRLA, etc.).

The function F3 for determining an internal resistance threshold of the battery 10 determines for the storer 10 identified on the vehicle 11, an internal resistance threshold S_res_int from the characteristics Typ_batt, Tech_batt of the electrical energy storer 10. The threshold internal resistance threshold S_res_int can be used to diagnose storage device 10. This function F3 consumes the type of battery Typ-batt and the Tech_batt technology of battery 10 as input. Function F3 supplies an internal resistance threshold S_res_int of battery 10 as output. 10.

The diagnostic determination function F4 provides a result on the state of the storer 10, depending on the type of diagnostic requested and the parameters and measurements characteristic of the state of the storer 10. The function F4 consumes the reliability level Stat_soc as input. of the measurement of the state of charge of the storer 10, the state of charge Soc_batt of the battery 10 during the last run or during the measurement of preparation of the new vehicle 11, the measurement of standardized internal resistance Rint_norm of the storer 10, the threshold of internal resistance S_res_int of battery 10 and the type of diagnosis Typ_diag. Function F4 outputs the Diag_batt diagnosis of battery 10.

The various stages of the method according to the invention for diagnosing the operating state of the storer 10 are described below, with reference to FIGS. 1 to 3. A computer internal or external to the vehicle comprises for this purpose a memory storing software instructions for implementing this method.

During a step 100, the function F1 makes it possible to manage the HMI 15 authorizing the operator 12 to launch a diagnosis of the storer 10 and to read the result of the diagnosis as well as the actions to be carried out on the storer 10, before declare the vehicle 11 ready for delivery.

Two types of diagnosis are possible. A first diagnosis Diag_1 makes it possible to test the storer 10 for the first time. A second diagnosis Diag_2 is used in addition to the first, only in the case where the result of the first diagnosis Diag_1 imposes actions to be carried out on the storer 10.

There illustrates a non-limiting diagram of the menu that can be offered to the operator 12 for the choice of diagnosis.

By clicking on a diagnostic selection option Sel_diag, the operator 12 has the choice between a touch button “Diag_1” and another “Diag_2”.

When operator 12 wishes to launch a first Diag_1 diagnosis of storer 10, operator 12 presses the "Diag_1" touch button.

The need for diagnosis will be confirmed: Dem_diag_batt = TRUE

The type of diagnosis will be chosen: Typ_diag = Diag_1

When the operator 12 launches a second Diag_2 diagnosis of the storer 10 (because the first Diag_1 diagnosis will have imposed additional actions to be carried out before a second Diag_2 diagnosis of the storer 10), the operator 12 presses the "Diag_2" touch button.

The need for diagnosis will be confirmed: Dem_diag_batt = TRUE

The type of diagnosis will be chosen: Typ_diag = Diag_2

When the operator 12 does not carry out a diagnostic session or when the first diagnostic Diag_1 or the second diagnostic Diag_2 is finished (result of the diagnostic displayed), then there is no need for diagnostics so that Dem_diag_batt = FALSE.

When the diagnosis is finished, the HMI 15 translates the result of the diagnosis of the improvement Diag_batt into information usable by the operator Mess_res_diag.

The different types of messages that can be displayed by the HMI 15 are detailed below:

- Replace the service battery according to the recommended battery replacement recommendations.

- Recharge the service battery for 3 hours according to the recommended recharging recommendations. Then carry out a second test after starting the vehicle again via the Diag_2 menu. And if it is impossible to activate the vehicle after 10 successive attempts, carry out the diagnosis of the battery via a dismounted tester.

- Recharge the service battery for 6 hours according to the recommended recharging recommendations. Then carry out a second test after starting the vehicle again via the Diag_2 menu. And if it is impossible to activate the vehicle after 10 successive attempts, carry out the diagnosis of the battery via a dismounted tester.

- Recharge the service battery for 9 hours according to the recommended recharging recommendations. Then carry out a second test after starting the vehicle again via the Diag_2 menu. And if it is impossible to activate the vehicle after 10 successive attempts, carry out the diagnosis of the battery via a dismounted tester.

- Recharge the service battery for 12 hours according to the recommended recharging recommendations. Then carry out a second test after starting the vehicle again via the Diag_2 menu. And if it is impossible to activate the vehicle after 10 successive attempts, carry out the diagnosis of the battery via a dismounted tester.

- Recharge the service battery for 16 hours according to the recommended recharging recommendations. Then carry out a second test after starting the vehicle again via the Diag_2 menu. And if it is impossible to activate the vehicle after 10 successive attempts, carry out the diagnosis of the battery via a dismounted tester.

- Service battery good.

- If the electrical architecture of the vehicle is different from AEE2010_V2 then carry out the diagnosis of the battery via a dismounted tester. Otherwise, make a maximum of 10 attempts to activate the vehicle, with the vehicle stationary. If the vehicle is successfully activated, carry out a new diagnosis under the Diag_1 menu. If the vehicle is not activated, carry out diagnostics of the battery using an off-board tester.

The management of the display of these messages will be carried out as follows.

When Diag_batt = REPLACER_BATTERY, the HMI 15 displays the message "Replace the service battery according to the recommended battery replacement recommendations".

When Diag_batt = CHARGER_3H_ET_RETEST_APRES_REDEM, the HMI 15 displays the message "Recharge the service battery for 3 hours according to the recommended charging recommendations and carry out a second test after restarting the vehicle via the Diag_2 menu".

When Diag_batt = CHARGER_6H_ET_RETEST_APRES_REDEM, the HMI 15 displays the message "Recharge the service battery for 6 hours according to the recommended charging recommendations and carry out a second test after restarting the vehicle via the Diag_2 menu".

When Diag_batt = CHARGER_9H_ET_RETEST_APRES_REDEM, the HMI 15 displays the message "Recharge the service battery for 9 hours according to the recommended charging recommendations and carry out a second test after restarting the vehicle via the Diag_2 menu".

When Diag_batt = CHARGER_12H_ET_RETEST_APRES_REDEM, the HMI 15 displays the message "Recharge the service battery for 12 hours according to the recommended charging recommendations and carry out a second test after restarting the vehicle via the Diag_2 menu".

When Diag_batt = CHARGER_16H_ET_RETEST_APRES_REDEM, the HMI 15 displays the message "Recharge the service battery for 16 hours according to the recommended charging recommendations and carry out a second test after restarting the vehicle via the Diag_2 menu".

When Diag_batt = BATTERY_GOOD, the HMI 15 displays the message “Service battery good”.

In the event that the vehicle 11 is not compatible with the method, because it is too old for example, the method still makes it possible to direct the operator by indicating to him to use another means to test the storer 10. Thus:

When Diag_batt = DIAG_UNAVAILABLE, the HMI 15 displays the message "Carry out battery diagnostics via an off-board tester".

In a step 101, the function F2 exploits the capacity of the vehicle 11 to record, on each run, relevant data on the use of the vehicle 11 and on the state of the storer 10 during the run, such as the state of charge of the storer 10, the reliability Stat_soc of this state of charge, or the normalized internal resistance Rint_norm. The vehicle 11 can store this information on the last N runs (for example N=10).

These data recorded on each run are stored by the vehicle 11 and can then be transmitted to the method in the form of hexadecimal frames.

An example of frames that can be provided by the vehicle 11 is given below:

«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

75E1FF0000010CFE7CFEFE00037CFEFE0014004262

7F2231, 7F2231, 7F2231, 7F2231, 7F2231, 7F2231, 7F2231, 7F2231, 7F2231, 7F2231, 7F2231, 7F2231, 7F2231, 7F2231, 7F2231

7F2231 »

Furthermore, a computer 13 linked to the storer 10 makes it possible to provide the Carac_batt characteristics of the storer 10, such as its type of technology or even its size (60AH, 70AH etc.).

When the operator 12 requests a diagnosis from the storer 10, that is to say when Dem_diag_batt = TRUE, the method sends a Data_req request to the vehicle 11, to retrieve the data stored during the last N runs (for example 10), so that we have Data_req = REQUEST. The vehicle 11 then sends a Raw_data frame to the process, in hexadecimal form containing the data stored by the vehicle 11.

The method sends a second Data_batt_req request to the vehicle 11, to retrieve the Carac_batt characteristics of the storer 10, so that we have Data_batt_req=REQUEST. The vehicle 11 then transmits a Carac_batt frame to the function F2 in hexadecimal form containing the characteristics of the storer 10.

Once the raw data Raw_data and Carac_batt have been recovered by the function F2, the system 20 decodes them and translates them into data that can be used directly by the method. These data are as follows:

- Stat_soc corresponding to the level of reliability of the state of charge measurement of storer 10 (nominal/non-nominal),

- Soc_batt corresponding to the state of charge of the storer 10 in percentage during the last drive, or during the preparation measurement of the new vehicle 11,

- Rint_norm corresponding to the standardized internal resistance measurement in mOhm of storer 10,

- Typ-batt corresponding to battery type 10 (size L0/L1/L2/L3 and capacity in AH),

- Tech_batt corresponding to battery technology 10 (Liquid, Sealed_VRLA etc.).

In a step 102, the function F3 defines, as a function of the Typ_batt and Tech_batt characteristics of the storer 10, an internal resistance threshold S_res_int which will be used for the diagnosis of the storer 10 in the subsequent step 103. To this end, a mapping establishes a correspondence between the characteristics Typ_batt, Tech_batt of the electrical energy storer 10 and an associated internal resistance threshold S_res_int, i.e. S_res_int = Mapping (Typ_batt, Tech_batt)

A non-limiting example of mapping that can be used is defined below: If Typ_batt = 0b00001: L0 250/ 390 (EN)/ 42 (Ah) OR
0b00111: L0 200/ 300 (EN)/ 35 (Ah) OR
0b00011: L1 250/ 390 (EN)/ 44 (Ah) 0b00010: L1 300/ 480 (EN)/ 50 (Ah) If Tech_batt = 0b0011: Liquid 0b0011: Liquid So S_res_int
(mOhms) = 10 9 If Typ_batt = 0b00100: L2 400/ 640 (EN)/ 60 (Ah) OR
0b00101: L2 400+/ 640+ (EN)/ 64 (Ah) OR
0b00110: L2 300/ 480 (EN)/ 50 (Ah) 0b01100: L3/ 500/ 800 (EN)/ 75 (Ah) If Tech_batt = 0b0011: Liquid 0b0100: Liquid_Cyclable 0b0011: Liquid So S_res_int
(mOhms) = 6.7 6.7 5.4 If Typ_batt = 0b01000: L3 450/ 720 (EN) or 760 (EN)/ 70 (Ah) 0b01101: L4/ 800/ 80 (Ah) 0b10000: L5/ 600/ 950 (EN)/ 95 (Ah) If Tech_batt = 0b0011: Liquid 0b0100: Liquid_Cyclable 0b0010: EFR 0b0001: Waterproof_VRLA 0b0001: Waterproof_VRLA 0b0011: Liquid So S_res_int
(mOhms) = 6 6 5.7 5.7 5.4 4.5

During step 103, function F4 supplies a result of the Diag_batt diagnosis of storage unit 10 for compatible vehicles 11.

In the case where the vehicle 11 does not have an electrical architecture making it possible to store the necessary data while driving, the diagnosis will not be possible and the method will signal this. There is then in this case Diag_batt = DIAG_UNAVAILABLE.

In the case where the vehicle 11 is compatible, the diagnosis result will depend on the type of diagnosis to be performed (“Diag_1” or “Diag_2”).

In the case of a first diagnosis Diag_1, that is to say when Typ_diag=Diag_1, the method synthesizes a diagnosis result depending on the information available on the storer 10, i.e. Diag_batt=Resultat_1er_Diagnostic (Stat_soc, Soc_batt, Rint_norm, S_res_int) where “Resultat_1er_Diagnostic” is a result matrix depending on the characteristics and measurements linked to the storer 10.

A non-limiting example of such a matrix is given in the diagram below: AND Rint_norm < 0.7 S_res_int AND 0.7 S_res_int ≤ Rint_norm < 0.87 S_res_int If Stat_soc ≠ NOMINAL Then Diag_batt = CHARGER_16H_ET_RETEST_APRES_REDEM If Stat_soc = NOMINAL AND Soc_batt ≤ S_diag_batt_1 Then Diag_batt = CHARGER_12H_ET_RETEST_APRES_REDEM AND S_diag_batt_1 < Soc_batt ≤ S_diag_batt_2 Then Diag_batt = CHARGER_9H_ET_RETEST_APRES_REDEM AND S_diag_batt_2 < Soc_batt ≤ S_diag_batt_3 Then Diag_batt = CHARGER_6H_ET_RETEST_APRES_REDEM AND S_diag_batt_3 < Soc_batt ≤ S_diag_batt_4 Then Diag_batt = CHARGER_3H_ET_RETEST_APRES_REDEM AND Soc_batt > S_diag_batt_4 Then Diag_batt = BATTERY_GOOD AND 0.87 S_res_int ≤ Rint_norm < S_res_int AND Rint_norm ≥ S_res_int AND Rint_norm = UNAVAILABLE Then Diag_batt = CHARGER_16H_ET_RETEST_APRES_REDEM Then Diag_batt = REPLACE_BATTERY Then Diag_batt = CHARGER_16H_ET_RETEST_APRES_REDEM Then Diag_batt = CHARGER_16H_ET_RETEST_APRES_REDEM Then Diag_batt = CHARGER_16H_ET_RETEST_APRES_REDEM Then Diag_batt = CHARGER_12H_ET_RETEST_APRES_REDEM Then Diag_batt = CHARGER_12H_ET_RETEST_APRES_REDEM Then Diag_batt = CHARGER_9H_ET_RETEST_APRES_REDEM Then Diag_batt = CHARGER_9H_ET_RETEST_APRES_REDEM Then Diag_batt = CHARGER_6H_ET_RETEST_APRES_REDEM Then Diag_batt = CHARGER_6H_ET_RETEST_APRES_REDEM Then Diag_batt = CHARGER_3H_ET_RETEST_APRES_REDEM Then Diag_batt = CHARGER_3H_ET_RETEST_APRES_REDEM

With :

S_diag_batt_1 = 10% of maximum battery state of charge 10.

S_diag_batt_2 = 30% of maximum battery state of charge 10.

S_diag_batt_3 = 50% of maximum battery state of charge 10.

S_diag_batt_4 = 75% of maximum battery state of charge 10.

In the event that the result of the first Diag_1 diagnosis requires a charging phase of the storer 10, followed by a new test of the storer 10, a second test must be carried out, after the recommended maintenance operation.

In this case, the second final Diag_2 diagnosis will be requested and Typ_diag = Diag_2.

In this second case, the method synthesizes a diagnostic result depending on the information available on the storage device 10, i.e. Diag_batt = Result_2e_Diagnostic (Stat_soc, Soc_batt, Rint_norm, S_res_int) where “Resultat_2e_Diagnostic” is a second (final) result matrix dependent characteristics and measures related to the storer 10.

A non-limiting example of such a matrix is given in the diagram below: AND Rint_norm < 0.7 S_res_int AND 0.7 S_res_int ≤ Rint_norm < 0.87 S_res_int If Stat_soc ≠ NOMINAL Then Diag_batt = BATTERY_GOOD If Stat_soc = NOMINAL AND Soc_batt ≤ S_diag_batt_1 AND S_diag_batt_1 < Soc_batt ≤ S_diag_batt_2 AND S_diag_batt_2 < Soc_batt ≤ S_diag_batt_3 AND S_diag_batt_3 < Soc_batt ≤ S_diag_batt_4 AND Soc_batt > S_diag_batt_4 AND 0.87 S_res_int ≤ Rint_norm < S_res_int AND Rint_norm ≥ S_res_int AND Rint_norm = UNAVAILABLE Then Diag_batt = REPLACE_BATTERY Then Diag_batt = DIAG_UNAVAILABLE Then Diag_batt = REPLACE_BATTERY

With :

S_diag_batt_1 = 10% of maximum battery state of charge 10.

S_diag_batt_2 = 30% of maximum battery state of charge 10.

S_diag_batt_3 = 50% of maximum battery state of charge 10.

S_diag_batt_4 = 75% of maximum battery state of charge 10.

The characteristic of this second diagnosis Diag_2, compared to the first diagnosis Diag_1 is that it is final, that is to say that the battery 10 will either be declared good or to be replaced, the charging step having been conclusive or not. .

Claims (10)

Method for diagnosing the operating state of an electric energy storer (10) of a motor vehicle (11) comprising:
- a step for selecting a diagnosis (Sel_diag) of the operating state of the electrical energy store (10),
- a step for retrieving characteristics (Typ_batt, Tech_batt) of the electrical energy store (10) and data (Soc_batt, Rint_norm) relating to operation of the electrical energy store (10) containing a measured state of charge (Soc_batt ) and a measured internal resistance (Rint_norm) of the electrical energy store (10),
- a step of determining an internal resistance threshold (S_res_int) from the characteristics (Typ_batt, Tech_batt) of the electrical energy store (10),
- a step of comparing the internal resistance measured (Rint_norm) with at least one threshold depending on the internal resistance threshold (S_res_int) previously determined,
- a step of comparing the measured state of charge (Soc_batt) with at least one charge threshold (S_diag_batt_1, S_diag_batt_2, S_diag_batt_3), and
- a step of establishing a diagnosis (Diag_batt) of the operating state of the electrical energy store (10) according to the comparisons previously made. Method according to Claim 1, characterized in that the diagnosis (Diag_batt) of the operating state generates the request for an action to be carried out (Mess_res_diag) on the electrical energy storer (10), in particular an action of recharging said electrical energy storer (10) whose duration varies according to the established diagnosis. Method according to claim 1 or 2, characterized in that it comprises a step of selecting a second diagnosis (Diag_2) in the case where a first diagnosis (Diag_1) has generated the performance of a recharging of the energy store electric (10) then the launch of said second diagnosis (Diag_2). Method according to any one of Claims 1 to 3, characterized in that the characteristics (Typ_batt, Tech_batt) of the electric energy storer (10) are retrieved from a computer (13) associated with the electric energy storer ( 10). Method according to any one of Claims 1 to 3, characterized in that the data (Soc_batt, Rint_norm) relating to operation of the electrical energy store (10) are recovered from a computer (14) of the motor vehicle ( 11). Method according to Claim 5, characterized in that the data (Soc_batt, Rint_norm) relating to an operation of the electric energy storer (10) are stored by the computer (14) of the motor vehicle (11) over the N last runs of said motor vehicle (11). Method according to any one of Claims 1 to 6, characterized in that the characteristics (Typ_batt, Tech_batt) of the electric energy storer (10) and the data (Soc_batt, Rint_norm) relating to an operation of the electric energy storer (10) are recovered in the form of hexadecimal frames intended to be decoded to enable their use. Method according to any one of Claims 1 to 7, characterized in that the data (Soc_batt, Rint_norm) relating to operation of the electrical energy store (10) also contain data representative of a level of reliability (Stat_soc) a measurement of the state of charge of the electrical energy store (10) also taken into account for establishing the diagnosis. Method according to any one of Claims 1 to 8, characterized in that the internal resistance threshold (S_res_int) is determined by means of a map establishing a correspondence between the characteristics (Typ_batt, Tech_batt) of the electrical energy storer ( 10) and an internal resistance threshold (S_res_int) associated with the electrical energy storer (10). Computer comprising a memory storing software instructions for implementing the method as defined according to any one of the preceding claims.