Method and system for determining a representative data point for the maximum autonomy of a battery in an electrical device

Abstract

The invention relates to a method for determining a measurement value, expressed in a unit of service, representing the maximum autonomy of a battery (BATT) of an electrical device, the maximum battery autonomy being defined by the following relationship: Where: corresponds to the maximum battery autonomy; corresponds to the electrical energy supplied for a full charge of the battery during a first charging stage; corresponds to the electrical energy supplied to charge the battery during a second charging stage; corresponds to the number of units of service of a standardized discharge cycle applied; corresponds to the number of standardized discharge cycles applied; Figure to be published with the abbreviation: Figure 1

Description

Title of the invention: Method and system for determining data representative of the maximum autonomy of a battery of an electrical device Technical field of the invention

[0001] The present invention relates to a method and a system for determining data representative of the maximum autonomy of a battery of an electrical device. The battery may in particular be that of an electric or rechargeable hybrid vehicle. State of the art

[0002] The number of electrical appliances has increased significantly in recent years and many of these devices are often resold on the second-hand market. This is particularly the case for electric or hybrid vehicles which operate using an electric battery.

[0003] When the device is new, the maximum battery life for a complete discharge from 100% to 0% is often indicated by the manufacturer. For an electric vehicle, it is for example indicated in number of kilometers that the vehicle is capable of traveling with its battery charged to 100%. For other electrical devices, the autonomy may be indicated in number of hours, in number of service units that the device will be capable of carrying out in a standardized framework.

[0004] It is known that the maximum autonomy of an electric battery tends to decrease over time. However, knowing this maximum autonomy is of real interest when it comes to evaluating the condition of an electrical device and its battery.

[0005] There are different methods for determining the maximum battery life of an electrical device.

[0006] In the case of an electric vehicle, we distinguish the three methods described below.

[0007] A first method consists of working only on the battery by doing a charge / discharge cycle. The first charging phase is used to place the battery at a maximum state of charge. To perfect the state of charge, this charging phase can be completed with a balancing phase of the battery accumulators. This ensures that the battery is at the highest level of charge.

[0008] Then the battery is discharged with an established current regime (for example C / 2).

[0009] During this discharge phase, the energy (or capacity) restored by the battery is measured.

[0010] By comparing the energy (or capacity) restored with the initial energy (or capacity) of the battery, we can deduce an aging (expressed in %). We can then deduces the autonomy of the system.

[0011] Let's take the example of an electric vehicle capable of traveling 425 km when it leaves the factory and having a battery with an initial capacity of 59 kWh. After several years of operation, the described charge / discharge cycle is applied to it and an energy of 57 kWh is measured. This means that the battery is at 96.6% of its initial energy. We deduce that the vehicle can only travel 411 km instead of the initial 425 km.

[0012] A second method consists of reproducing exactly the same test sequence as that carried out when the system left the factory to measure the initial maximum autonomy.

[0013] For electric vehicles, a standardization of the autonomy measurement process has been implemented worldwide (the WLTC cycle for "Worldwide harmonized Light vehicles Test Cycles"). The vehicle is first charged to 100%, then it is placed on a roller test bench and a rolling profile (WLTC) is applied to the vehicle. The roller test bench is used to reproduce the road force that the vehicle would have to counter when driving on a real road (force due to the mass of the vehicle and friction among other things).

[0014] There are four standard cycles (Class 1, Class 2, Class 3a and Class 3b). The cycle to be applied to the vehicle depends on the power (W), the mass of the vehicle (kg) and its maximum speed (km / h). Most conventional city vehicles must follow the "Class 3a" cycle corresponding to a power / mass ratio greater than 34 and a maximum speed greater than 120 km / h.

[0015] This cycle is applied to the vehicle and repeated until the vehicle stops by itself. The distance (in km) traveled by the vehicle is then directly measured.

[0016] It should be noted that:

[0017] By "autonomy in pure electric mode", in the case of an externally rechargeable hybrid electric vehicle (RE-HEV), is meant the total distance travelled from the start of the test, until the moment when the combustion engine begins to consume fuel, after having travelled a certain number of complete or partial WLTC cycles (for the last cycle).

[0018] By "autonomy in pure electric mode", we mean, in the case of a pure electric vehicle (PEV), the total distance traveled from the start of the test until the moment when the automatic disconnection criterion is reached, after having traveled a certain number of complete or partial WLTC cycles (for the last cycle).

[0019] A third method consists of integrating electronics into the system so that it estimates the remaining autonomy in real time based on the previous states of the system. Based on predictive models and knowing the history of the conditions seen by the system (temperature, charge / discharge regime, time spent in calendar, etc.), it is possible to give an estimate of the maximum autonomy remaining.

[0020] The first method allows to measure the storage capacity of the actual energy remaining in the system battery. But it does not allow to measure the actual autonomy of the complete system (in particular the mechanical part of the vehicle).

[0021] The second method allows the entire system to be characterized, but it can be very time-consuming to implement. The second method also requires monopolizing the test bench for the entire battery discharge time, which is not very compatible with profitability requirements.

[0022] The third method is based solely on modeling, which only provides an estimate of battery life and is in no way a measure of actual battery life.

[0023] The aim of the invention is to propose a method which makes it possible to determine measurement data representative of the autonomy of a battery of an electrical device and which is capable of overcoming the drawbacks of previous solutions. This method is suitable for application to the complete system including the battery and its entire environment. It makes it possible to characterize the battery and its system in a reduced time, without monopolizing a test bench. It makes it possible to carry out a real measurement of the autonomy of the battery. Statement of the invention

[0024] This aim is achieved by a method for determining a measurement datum, expressed in a service unit, representative of the maximum autonomy of a battery of an electrical device, said battery requiring the application of a number N of standardized discharge cycles to be completely discharged from 100% to 0%, N being strictly greater than 1, the standardized discharge cycle being applied to the battery to partially discharge it by a determined number of service units,

[0025] On an initially completely discharged battery, said method comprising: - A first step of completely charging the battery from a state of charge of 0% to a state of charge of 100%, - A first step of determining the electrical energy provided for the complete charge of the battery, - A step of partial discharge of the battery, by application of a discharge profile, said discharge profile being chosen to comprise at least one standardized discharge cycle and at most Nl standardized discharge cycles when N is an integer strictly greater than 1, - A second charging stage up to 100% state of charge of the battery previously partially discharged by applying the discharge profile, - A second step of determining the electrical energy supplied for the second stage of battery charging, - A step of determining in service unit the data representative of the maximum autonomy of the battery of the electrical device, from: • The electrical energy supplied to the battery for the first stage of battery charging, • The electrical energy supplied to the battery for the second stage of battery charging, • The number of service units of a standardized discharge cycle, • The number of standardized discharge cycles when applying the discharge profile.

[0026] According to a particularity, the maximum autonomy of the battery is defined by the following relation:

[0027] Autonomy_batt = -f——■ x Nbus cvele xn

[0028] In which: - Autonomie_batt corresponds to the maximum battery life; - ^al_cha corresponds to the electrical energy supplied for the complete charge of the battery during the first charging stage; - ECy■cle__cha corresponds to the electrical energy supplied to charge the battery during the second stage of battery charging; - N b us cycle corresponds to the number of service units of the discharge cycle standardized applied; - n corresponds to the number of standardized discharge cycles applied;

[0029] According to another particularity, the method comprises a step of determining the electrical energy delivered by the battery during the application of the discharge profile, during the step of partial discharge of the battery.

[0030] According to another particularity, the method comprises a step of determining the electrical efficiency of the battery from the electrical energy delivered by the battery during the application of the discharge profile and the electrical energy supplied for the second step of partial charging of the battery.

[0031] According to another feature, the method comprises an initial step of completely discharging the battery, to bring it to a state of charge of 0%.

[0032] According to another feature, the electrical device is an electric or rechargeable hybrid vehicle and the measurement data is expressed in kilometers.

[0033] According to another feature, the method comprises an initial step of completely discharging the battery of the electric or hybrid vehicle, to bring it to a state of charge of 0%, by applying the most energy-restricting phase of a standardized driving cycle of the vehicle.

[0034] The invention also relates to a system for determining a measurement datum, expressed in a service unit, representative of the maximum autonomy of a battery of an electrical device, said battery requiring the application of a number N of standardized discharge cycles to be completely discharged from 100% to 0%, N being an integer strictly greater than 1, the standardized discharge cycle being applied to the battery to partially discharge it by a determined number of service units,

[0035] On an initially fully discharged battery, a system control and processing unit being configured to: Command a full charge of the battery from a state of charge of 0% to a state of charge of 100%, Determine the electrical energy supplied for the full charge of the battery, Control a partial discharge of the battery, by applying a discharge profile, said discharge profile being chosen to include at least one standardized discharge cycle and at most N1 standardized discharge cycles when N is strictly greater than 1, Order a partial charge up to 100% state of charge of the battery previously partially discharged by applying the discharge profile, Determine the electrical energy supplied during the partial charge, Determine in service unit the data representative of the maximum autonomy of the battery of the electrical device, from: The electrical energy supplied to the battery for full charge, The electrical energy supplied to the battery for partial charge, The number of service units of a standardized discharge cycle, The number of standardized discharge cycles when applying the discharge profile.

[0036] According to a particularity, the maximum autonomy of the battery is defined by the following relation:

[0037] E Battery life = x Number of cycles xn — ec^le_cfla

[0038] In which: Autonomy _batt corresponds to the maximum autonomy of the battery; E reul_çha corresponds to the electrical energy supplied for the complete charge of the battery during the first charging stage; Ecycle_cha corresponds to the electrical energy supplied to charge the battery during the second stage of battery charging; Nbus cycie corresponds to the number of service units of the discharge cycle standardized applied; - n corresponds to the number of standardized discharge cycles applied;

[0039] According to another feature, the control and processing unit is configured to determine the electrical energy delivered by the battery when applying the discharge profile.

[0040] According to another feature, the control and processing unit is configured to determine the electrical efficiency of the battery from the electrical energy delivered by the battery during the application of the discharge profile and the electrical energy supplied for the partial charge of the battery.

[0041] According to another feature, the electrical device is an electric or rechargeable hybrid vehicle and in that the measurement data is expressed in kilometers.

[0042] According to another feature, the system comprises a roller test bench on which the vehicle is placed for the application of the discharge profile.

[0043] According to another feature, the system comprises means for controlling a complete initial discharge of the battery, by applying the most energy-restricting phase of a standardized discharge cycle.

[0044] According to another feature, the system comprises a charging terminal used for each charge of the battery. Brief description of the figures

[0045] Other characteristics and advantages will appear in the detailed description which follows, given with reference to the appended drawings in which: - [Fig.l] schematically represents the system of the invention; - [Fig.2] represents a diagram illustrating the different stages of the method of the invention;

[0046] Detailed description of at least one embodiment

[0047] The invention applies to a BATT battery of an electrical device.

[0048] The term "battery" means a rechargeable energy source, allowing an electrical device to temporarily free itself from a power supply. An electrochemical type battery may be composed of one or more electrochemical cells. In the context of the invention, the term "battery" also encompasses what is called a battery pack used in an electric or rechargeable hybrid vehicle.

[0049] The invention is of particular interest for batteries of electric or rechargeable hybrid vehicles. But it should be understood that it can be adapted for any electrical device.

[0050] As is known, the autonomy of a battery is often indicated using a service unit. For an electric vehicle, this is the number of kilometers that the vehicle can still travel with its battery. But for other devices electric, the battery life could be indicated in number of hours of use under given conditions, in number of maneuvers for a moving part powered by the battery...

[0051] Another indicator of the state of the battery is the electrical efficiency between charging and discharging thereof. As the battery ages, its internal resistance tends to increase, which generates a decrease in the charge / discharge electrical efficiency. This second indicator is an optional indicator that can easily be derived from the implementation of the invention, and can provide additional information on the state of the battery.

[0052] With reference to [Fig. 1], the system responsible for implementing the method of the invention comprises a test bench 2 on which the electrical device 1 whose battery BATT is to be tested is fitted.

[0053] The test bench 2 comprises an installation adapted to allow the electrical device whose BATT battery is to be characterized to simulate its mechanical / electrical operation.

[0054] For an electric vehicle, this installation may comprise rollers on which the vehicle's wheels rest. These rollers are rotated by the vehicle's wheels (driven by the motor) and make it possible to simulate the operation of the car on a road. A rolling profile is applied, this profile reproducing in particular the resistance of the road. As already indicated above, the installation makes it possible to apply standardized cycles (WLTC), taking into account the size of the vehicle and its technical characteristics.

[0055] The system may also include a charging terminal 3, to which the BATT battery is connected when it needs to be charged. The system also includes means 4 for measuring the electrical quantities of charge, and optionally of discharge of the battery.

[0056] These measuring means can be, as shown in [Fig.l], at the level of the battery BATT, such as current I_batt during charging / discharging and voltage U_batt during charging / discharging. This is necessary when it is desired to measure the discharge energy of the battery, in order to evaluate the charging / discharging efficiency thereof (see step E9 of the method below).

[0057] In the case of calculating only the autonomy, the measuring means 4 can also be located at the charging terminal, or alternatively on the electrical circuit supplying the charging terminal, to measure the voltage and intensity characteristics of the battery charge. These means can also be part of the charging terminal itself, the latter providing the voltage, current, or even directly the power and / or energy values ​​used during the charging phases. This then considerably simplifies the implementation of the invention.

[0058] The system also includes a control and processing unit UC, responsible for: - Order test bench 2 suitable for the electrical device whose BATT battery is to be characterized. - Control the electrical device whose BATT battery is to be characterized; when applying a standardized cycle, it should be noted that it is the vehicle that drives the rollers of the test bench when its engine is running and that it is the rollers that allow the behavior of a road to be simulated; - Order charging station 3 to charge the BATT battery. - Acquire measurements (voltage, current) taken at the BATT battery, or upstream of the battery, for example at the charging station, during execution of the process, via the measuring means 4. - Determine data related to the implementation of each step of the process, in particular the maximum autonomy of the BATT battery of the electrical device, expressed in the chosen service unit.

[0059] The control and processing unit UC can be located in the electrical appliance, at the charging terminal 3 or remotely, using suitable communication means.

[0060] With reference to [Fig.2] and considering that the electrical device is for example an electric vehicle, the method of the invention is as follows:

[0061] Step E0: The battery BATT is initially in a state of charge SOC_tO. This state of charge SOC_tO can be zero (X=0 in [Fig.2]) or non-zero (X different from 0). If the battery is already completely discharged, the next step El is optional.

[0062] Step El: This step consists of completely discharging the BATT battery of the electric vehicle, so that it is at a state of charge SOC_tl=0%. For this, different methods can be considered. This initial step of completely discharging the battery of the electric or hybrid vehicle, can be carried out by applying the most energetically restrictive part of the standardized driving cycle of the vehicle. The vehicle can for example be placed on the installation of test bench 2 to simulate driving at high speed (for example 130 km / h) in order to discharge the battery as quickly as possible. To accelerate the process, it is also possible to turn on the vehicle's auxiliaries (air conditioning / heating, lights or any other consumption unit). Of course, other methods could be considered, for example outside of test bench 2, this step having the sole purpose of obtaining a complete discharge of the battery.

[0063] This step E1 is optional if it turns out that the vehicle battery is already completely discharged (see step E0).

[0064] Step E2: This step consists of activating the charging terminal 3 to carry out a full battery charge BATT, i.e. charging the battery from a state of charge of 0% to a state of charge SOC_t2 of 100%. Activation of charging station 3 can be controlled by the control and processing unit UC. Charging is preferably carried out slowly.

[0065] Step E3: During step E2 of fully charging the BATT battery, the control and processing unit UC acquires current and voltage measurements at the BATT battery, or upstream of the battery, for example at the charging terminal 3, via the measuring means 4. The control and processing unit can thus calculate the actual charging energy of the battery: Ereal_cha

[0066] This complete charge can possibly be carried out outside the test bench 2, because its installation is not useful, only the charging terminal 3, the measuring means 4 and the control and processing unit UC being used.

[0067] Step E4: Apply one or more discharge cycles to the BATT battery using the test bench 2 setup. This will be called the battery discharge profile.

[0068] As indicated above, there are standardized discharge cycles that can be applied to the battery of an electric vehicle (there are WLTC cycles for class 1, class 2, class 3A, class 3B vehicles). For an electric vehicle, a standardized discharge cycle is particularly suitable for making the vehicle travel a determined number of km over a determined period. For example, the standardized cycle for a class 3A vehicle is as follows: A starting temperature of 14°C; An average speed of 46 km / h; A test duration of 30 minutes; A distance covered during the test of 23 km; A top speed of 130 km / h; A stopping time which represents 13% of the total cycle time;

[0069] Currently, in the methods in force, a number N of discharge cycles is applied which is sufficient for the BATT battery to be completely discharged. In the context of the invention, the objective is to apply only one discharge cycle and at most N1 discharge cycles when N is strictly greater than 1. Therefore, ideally, only one standardized discharge cycle is applied and a partial discharge of the battery is then obtained to a state of charge S0C_t3 equal to Y% (Y then being non-zero).

[0070] Step E5: During step E4 of discharging the battery, by applying the standardized discharge cycle, the control and processing unit can acquire current and voltage measurements at the level of the battery BATT, via the measuring means 4.

[0071] The control and processing unit can thus calculate the actual energy to do the discharge profile (e.g. a single standardized discharge cycle) of the battery: Ecycle_dch

[0072] It should be noted that this step is optional because this quantity Ecycle_dch is not necessarily useful in determining the maximum autonomy of the battery (see formula below). If it is available, it could however be used in calculating the electrical efficiency of the battery (see step E9 below).

[0073] Step E6: The charging station 3 is activated to recharge the battery BATT again to a state of charge SOC_t4 equal to 100%. The activation of the charging station 3 can be controlled by the control and processing unit UC. This recharging can be carried out outside the test bench, provided that no energy is consumed to move the vehicle.

[0074] Step E7: During step E6 of recharging the battery, the control and processing unit UC acquires current and voltage measurements at the battery BATT, or upstream of the battery, for example at the charging terminal, via the measuring means 4.

[0075] The control and processing unit UC can thus calculate the actual energy to recharge the battery up to 100%: Ecycle_cha

[0076] Step E8: The control and processing unit UC can thus determine the maximum autonomy of the BATT battery, referenced Autonomie_batt. The formula is as follows:

[0077] Battery autonomy = ■ x Nbl!S cvde xn w.ie_eha —

[0078] In which: - Nbus cycle corresponds to the number of service units of the standardized discharge cycle applied; - n corresponds to the number of standardized discharge cycles applied in step E4;

[0079] For an electric vehicle, the formula will be more specifically the following:

[0080] Autonomy_batt = x Nb^ cvc]exn ^cycle_cho — •

[0081] In which: - Nbkm cvcie corresponds to the number of kilometers of the standardized discharge cycle applied;

[0082] Step E9: As indicated above, it is also possible to deduce the electrical efficiency of the battery, using the following formula: [°°831 R_batt = f^ ^cyde^dia

[0084] In which: - Ecycle_dch was determined during step E5 described above; - Ecycle_cha was determined during step E7 described above;

[0085] However, it is understood that calculating the electrical efficiency of the battery requires knowing the quantity Ecycle_dch, which implies the presence of means for measuring the voltage and current parameters, as close as possible to the battery, ideally in the electrical device whose battery is to be characterized.

[0086] It should be noted that as a battery ages, it loses capacity and its internal electrical resistance increases. The method described allows the capacity loss to be measured, but does not take into account the increase in the internal resistance of the BATT battery.

[0087] Increasing the internal resistance of the BATT battery will impact the system's ability to respond to a power demand. Typically on the WLTC Class 3a cycle, the vehicle will struggle to pass the 130 km / h phase when the battery is almost empty.

[0088] To take this phenomenon into account, it is advantageous to carry out the initial discharge step E1 with a discharge rate corresponding to 130 km / h, so that the discharge system stops when the rate requested from the battery is the highest in the profile.

[0089] Concretely, the vehicle could be placed on test bench 2 for the time required to completely discharge the battery at 130 km / h. Or, alternatively, to minimize the time spent monopolizing test bench 2, it would be useful to simply finalize the discharge on test bench 2. For example, starting from a state of charge at 10% SOC for a vehicle with a range of 425 km, this corresponds to 20 minutes of monopolization of the test bench.

[0090] Furthermore, when for example only one standardized discharge cycle is carried out, the charge / service unit efficiency calculation (steps E4 to E7) is only carried out over a small state of charge amplitude. However, the efficiency of a BATT battery changes depending on the state of charge of the BATT battery and it is known that the efficiency is less good between 90% and 100% state of charge and between 0 and 10% state of charge, and that it is better between 10% and 90% charge.

[0091] It follows that if we want to improve the measurement of the yield, it is advantageous to carry out several cycles in succession (n>1). The more successive cycles we carry out (during step E4), the more precise the measurement will be, but in return it will be necessary to spend more time on test bench 2.

[0092] The invention thus has the advantage of only monopolizing a test bench 2 for a short period of time (for example the time of a single cycle, i.e. 30 minutes for a WLTC Class 3a cycle). All the other steps of the method described above can be done off the test bench, or even in hidden time for the longest recharging step (Step E2). It is thus possible to pass around ten vehicles per day, which can improve the profitability of such an installation.

[0093] With this method, it is also easy to compare the determined autonomy with the autonomy announced by the manufacturer at the start of life.

Claims

Claims

1. Method for determining a measurement datum, expressed in a service unit, representative of the maximum autonomy of a battery (BATT) of an electrical device, said battery requiring the application of a number N of standardized discharge cycles to be completely discharged from 100% to 0%, N being strictly greater than 1, the standardized discharge cycle being applied to the battery to partially discharge it by a determined number of service units, On an initially completely discharged battery, said method being characterized in that it comprises: A first stage (E2) of complete charging of the battery (BATT) from a state of charge of 0% to a state of charge of 100%, A first step (E3) of determining the electrical energy (Ereal_cha) provided for the complete charge of the battery (BATT), A step (E4) of partial discharge of the battery, by application of a discharge profile, said discharge profile being chosen to comprise at least one standardized discharge cycle and at most Nl standardized discharge cycles when N is an integer strictly greater than 1, A second step of charging (E6) up to 100% state of charge of the battery (BATT) previously partially discharged by the application of the discharge profile, A second step of determining (E7) the electrical energy (Ecycle_cha) provided for the second step of charging the battery, A step (E8) of determining in service unit the data representative of the maximum autonomy (Autonomie_batt) of the battery of the electrical device, from: • The electrical energy supplied to the battery for the first stage of battery charging, • The electrical energy supplied to the battery for the second stage of battery charging, • The number of service units of a standardized discharge cycle, • The number of standardized discharge cycles when applying the discharge profile.

2. Method according to claim 1, characterized in that the maximum autonomy of the battery is defined by the following relation: £ Autonomie _batt = - *Nbus „ciexn Lcyde._cha — - In which: - Autonomie_batt corresponds to the maximum autonomy of the battery; - Corresponds to the electrical energy supplied for the complete charge of the battery during the first charging step; - Ecycie cha corresponds to the electrical energy supplied to charge the battery during the second charging step of the battery; - Nb[j$ cycie corresponds to the number of service units of the standardized discharge cycle applied; - n corresponds to the number of standardized discharge cycles applied;

3. Method according to claim 1 or 2, characterized in that it comprises a step of determining (E5) the electrical energy (Ecycle_dch) delivered by the battery during the application of the discharge profile, during the step (E4) of partial discharge of the battery.

4. Method according to claim 3, characterized in that it comprises a step of determining (E9) the electrical efficiency of the battery from the electrical energy (Ecycle_dch) delivered by the battery during the application of the discharge profile and the electrical energy (Ecycle_cha) provided for the second step of partial charging of the battery (BATT).

5. Method according to one of claims 1 to 4, characterized in that it comprises an initial step of complete discharge of the battery, to bring it to a state of charge of 0%.

6. Method according to one of claims 1 to 5, characterized in that the electrical device is an electric or rechargeable hybrid vehicle and in that the measurement data is expressed in kilometers.

7. Method according to claim 6, characterized in that it comprises an initial step of complete discharge of the battery of the electric or hybrid vehicle, to bring it to a state of charge of 0%, by application of the most energy-restricting phase of a standardized driving cycle of the vehicle.

8. System for determining a measurement datum, expressed in a service unit, representative of the maximum autonomy of a battery (BATT) of an electrical device, said battery requiring the application of a number N of standardized discharge cycles to be completely discharged from 100% to 0%, N being an integer strictly greater than 1, the standardized discharge cycle being applied to the battery to partially discharge it by a determined number of service units, On an initially completely discharged battery, said system being characterized in that it comprises a control and processing unit configured to: - Command a full battery charge (BATT) from 0% state of charge to 100% state of charge, - Determine the electrical energy (Ereal_cha) provided for the complete charge of the battery (BATT), - Control a partial discharge of the battery, by applying a discharge profile, said discharge profile being chosen to include at least one standardized discharge cycle and at most N1 standardized discharge cycles when N is strictly greater than 1, - Order a partial charge up to 100% state of charge of the battery (BATT) previously partially discharged by applying the discharge profile, - Determine the electrical energy (Ecycle_cha) provided during partial charging, - Determine in service unit the data representative of the maximum autonomy (Autonomie_batt) of the battery of the electrical device, from: • The electrical energy supplied to the battery for full charge, • The electrical energy supplied to the battery for partial charging, • The number of service units of a standardized discharge cycle, • The number of standardized discharge cycles when applying the discharge profile.

9. System according to claim 8, characterized in that the maximum autonomy of the battery is defined by the following relation: Autonomie_batt = x Nbus cvcle xn In which: - Autonomie _batt corresponds to the maximum autonomy of the battery; - Erea] cha corresponds to the electrical energy supplied for the complete charge of the battery during the first charging step; - Ecycie cha corresponds to the electrical energy supplied to charge the battery during the second charging step of the battery; - Nbjjs cycie corresponds to the number of service units of the standardized discharge cycle applied; - n corresponds to the number of standardized discharge cycles applied;

10. System according to claim 8 or 9, characterized in that the control and processing unit (UC) is configured to determine the electrical energy (Ecycle_dch) delivered by the battery when applying the discharge profile.

11. System according to claim 10, characterized in that the control and processing unit (UC) is configured to determine the electrical efficiency of the battery from the electrical energy (Ecycle_dch) delivered by the battery during the application of the discharge profile and the electrical energy (Ecycle_cha) provided for the partial charge of the battery (BATT).

12. System according to one of claims 8 to 11, characterized in that the electrical device is an electric or rechargeable hybrid vehicle and in that the measurement data is expressed in kilometers.

13. System according to claim 12, characterized in that it comprises a roller test bench (2) on which the vehicle is placed for the application of the discharge profile.

14. System according to claim 13, characterized in that it comprises means for controlling a complete initial discharge of the battery, by applying the most energetically restrictive phase of a standardized discharge cycle.

15. System according to one of claims 8 to 14, characterized in that it comprises a charging terminal (3) used for each charge of the battery.

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