Method and system for determining the final health status of a battery in an electric or hybrid motor vehicle.

Abstract

- Method and system for determining the final health state of a battery in an electric or hybrid motor vehicle. - The determination system (1) comprises a receiving unit (4) configured to receive discharged energy (X1) during a first cycle and an i-th discharged energy (Xi) during an i-th cycle, a calculation unit (6) configured to determine a final health state (SoH1b) at the end of the first cycle and to determine the final health state (SoH1N) by assuming that the initial i-th health state (SoHia) is equal to the (i-1)-th final health state (SoH(i-1)b) at the end of the (i-1)-th cycle, and a transmission unit (7) configured to transmit the final health state (SoH1N) of the battery (2) to a user device (8). Figure for the abstract: Fig. 1

Description

Title of the invention: Method and system for determining the final health status of a battery of an electric or hybrid motor vehicle. technical field

[0001] The present invention relates to a method and a system for determining the final state of health of a battery of an electric or hybrid motor vehicle subjected to a plurality of successive use cycles, two consecutive cycles having distinct degradation profiles from each other. State of the art

[0002] During its use, a traction battery in an electric or hybrid motor vehicle will age. The battery may be subjected to at least one usage cycle, also called cycling. A cycling cycle corresponds to a specific use of the battery in terms of charging and discharging.

[0003] The state of health (SoH) of a battery is generally defined at a given time t as the ratio between, on the one hand, the total energy or capacity that can be extracted from the battery at that time t and, on the other hand, the total energy or capacity that can be extracted from the battery before any use, i.e., when the battery is new. The state of health of a battery, often expressed as a percentage, thus provides an indicator that reflects a percentage of the battery's residual energy, a portion of which is irreversibly lost due to use and associated battery degradation.

[0004] Understanding the health and aging of a battery is a crucial technical issue for automotive and battery manufacturers. Knowing the State of Health (SoH) allows them to determine a battery's lifespan. For example, when the SoH indicates that the battery is nearing the end of its life, it may need to be replaced. This knowledge of the battery's health is also important from an economic perspective. Maximizing the SoH makes it possible, for instance, to consider giving the battery a second life. This knowledge is also important from a regulatory standpoint. Regulations define the accuracy of the SoH.

[0005] Several methods already exist for determining the SoH of a battery.

[0006] The SoH can be determined by direct measurement, either outside the vehicle (battery removed) of the vehicle), or during its use requiring a dedicated phase of vehicle use.

[0007] The SoH can also be determined by prediction using semi-empirical models. This predictive method is capable of estimating the vehicle's SoH at any given time and informing the customer in real time.

[0008] However, currently, faced with the increasing number of customer uses, we are witnessing a diversification of the types of battery cycling stresses. Indeed, in addition to conventional driving associated with traditional charging at charging stations generally limited to low power levels (between 7 kW and 11 kW, for example), there are now uses with fast charging (with power levels exceeding 100 kW), or new uses such as Vehicle-to-Grid (V2G) or Vehicle-to-Load (V2L), in which the battery is used to power an electrical grid or an electrical device. This diversity of uses can result in different degradation profiles, that is to say, different kinetics or, in other words, different rates of degradation depending on the type of cycling.

[0009] Thus, from a historically simple situation in which only one type of cycling is carried out, we have moved to a more complex situation in which several very different types of cycling and uses are carried out. We can distinguish in particular a cycling profile specific to driving the vehicle (i.e.: at non-zero speed); a profile linked to slow charging of the vehicle; a profile linked to fast charging of the vehicle; a profile linked to using the battery to recharge an electrical network external to the vehicle, of the so-called V2G type; etc.

[0010] However, there are methods for determining the SoH by taking into account the number of different uses or cycles.

[0011] A process is based on a model that relies on a single degradation law. In other words, if the battery is subjected to at least two types of cycling with different degradation kinetics, then an "averaged" aging kinetics law is determined to consider a single degradation law for cycling. However, finding an averaged kinetics law can prove practically difficult, either because it is analytically challenging to construct, or because it would require numerous costly and time-consuming tests.

[0012] Another method involves summing cycling degradations independently. In other words, it is as if the SoH degradations of a battery subjected sometimes to cycling A and sometimes to cycling B were equal to the SoH degradations calculated independently according to cycling A on the one hand and cycling B on the other, according to an "additivity law" of SoH degradation. However, it is known that this law is not mathematically correct and that its use leads to inaccuracies in SoH estimation. Moreover, this method does not take into account battery aging. Indeed, the degradation is determined at each cycle. of the SoH by taking as a starting point the SoH of a new battery without taking into account the aging of the battery for the previous cycle(s).

[0013] The methods for determining the SoH of batteries are therefore not fully satisfactory. Description of the invention

[0014] The present invention aims to provide a method for determining the state of health of a battery in an electric or hybrid motor vehicle which takes into account the aging of the battery.

[0015] For this purpose, it relates to a method for determining the final state of health of a battery of an electric or hybrid motor vehicle that is likely to be subjected to N successive cycles, N being at least equal to two, each cycle being associated with a degradation curve indicating the state of health of the battery as a function of energy discharged by the battery, the degradation curves of two consecutive cycles being distinct from each other.

[0016] According to the invention, the determination method comprises the following steps: - a first reception step, implemented by a receiving unit, to receive from an energy meter a signal representative of a first energy discharged during the first cycle; - a first determination step, implemented by a computing unit, to determine a first final state of health at the end of a first cycle from a first degradation curve associated with the first cycle and the first energy discharged during the first cycle; - the following sequence of steps repeated dei = 2ài = N: • an i-th reception step, implemented by the receiving unit, to receive from the energy meter a signal representing an i-th energy discharged during the i-th cycle, • an i-th determination step, implemented by the calculation unit, to determine the final health state, an i-th final health state at the end of the i-th cycle being determined from an i-th degradation curve associated with the i-th cycle and by setting that the i-th initial health state is equal to the (il)-th final health state at the end of the (il)-th cycle; - a transmission step, implemented by a transmission unit, to transmit a signal representative of the final health state of the battery to a user device.

[0017] Thus, thanks to the process in which the i-th initial health state is equal to the (il)-th final health state at the end of the (il)-th cycle, the SoH can be determined much more precisely.

[0018] Advantageously, the first reception step El is implemented by the receiving unit 4 to receive, in addition, from the battery management system (BMS), a start signal and an end signal for battery operation according to a particular cycle corresponding to a degradation curve specific to the first cycle Cp

[0019] Similarly, for i = 2 to i = N, the i-th reception step Eh is implemented by the receiving unit 4 to receive further from the battery management system BMS a start signal and then an end signal of battery operation according to a particular cycle corresponding to a degradation curve specific to the i-th cycle C;.

[0020] Advantageously, the i-th determination step comprises: - a sub-step of determining an i-th initial energy at the beginning of the i-th cycle from an i-th initial health state and an i-th degradation curve, the i-th initial health state being equal to the (il)-th final health state at the end of the (il)-th cycle, - a sub-step for determining an i-th final health state at the end of the i-th cycle from the i-th degradation curve associated with the i-th cycle and a sum of the i-th initial energy and an i-th energy discharged during the i-th cycle, - a sub-step of determining a battery health state, the battery health state being equal to the difference between the i-th initial health state and the i-th final health state.

[0021] Moreover, the first cycle presents an initial state of health corresponding to the state of health of a new battery.

[0022] Furthermore, the first reception step is implemented by the receiving unit in addition to receiving initial operating data characteristic of the first cycling, the first degradation curve being chosen by the calculation unit according to the operating data;

[0023] the i-th reception step being implemented by the receiving unit further to receive i-th operating data, the i-th degradation curve being chosen by the calculation unit as a function of the i-th operating data.

[0024] The invention also relates to a system for determining the final state of health of a battery of an electric or hybrid motor vehicle that is likely to be subjected to N successive cycles, N being at least equal to two, each cycle being associated with a degradation curve indicating the state of health of the battery as a function of energy discharged by the battery, the degradation curves of two consecutive cycles being distinct from each other.

[0025] According to the invention, the determination system comprises: - a receiving unit configured to receive from an energy meter a signal representative of the first energy discharged during the first cycle, - a computing unit configured to determine a first final health state at the end of a first cycle from a first degradation curve associated with the first cycle and the first energy discharged during the first cycle;

[0026] for i = 2 to i = N: - the receiving unit being configured to receive from the energy meter a signal representing the i-th energy discharged during the i-th cycle, - the computing unit being configured to determine the final health state, an i-th final health state at the end of the i-th cycle being determined at each iteration i from an i-th degradation curve associated with the i-th cycle and by setting that the i-th initial health state is equal to the (il)-th final health state at the end of the (il)-th cycle;

[0027] the system further comprising a transmission unit configured to transmit a signal representative of the final health state of the battery to a user device.

[0028] Advantageously, the receiving unit is configured to receive in addition from the battery management system BMS a start signal and an end signal of battery operation according to a particular cycle corresponding to a degradation curve specific to the first cycle.

[0029] Furthermore, for i = 2 to i = N, the receiving unit 4 is configured to receive in addition from the battery management system BMS a start signal and then an end signal of battery operation according to a particular cycle corresponding to a degradation curve specific to the i-th cycle Q.

[0030] Advantageously, the calculation unit is configured with i = 2 to i = N for: - determine an i-th initial energy at the beginning of the i-th cycle from an i-th initial health state and an i-th degradation curve, the i-th initial health state being equal to the (il)-th final health state at the end of the (il)-th cycle, - determine an i-th final health state at the end of the i-th cycle from the i-th degradation curve associated with the i-th cycle and a sum of the i-th initial energy and an i-th energy discharged during the i-th cycle, - determine a battery health state, the battery health state being equal to the difference between the i-th initial health state and the i-th final health state.

[0031] Moreover, the first cycle presents an initial state of health corresponding to the state of health of a new battery.

[0032] Furthermore, the receiving unit is also configured to: - receive initial operating data characteristic of the first cycling, the first degradation curve being chosen by the calculation unit based on the operating data; - receive i-th operating data with i = 2 to i = N, the i-th degradation curve being chosen by the calculation unit as a function of the i-th operating data.

[0033] The invention also relates to an electric or hybrid motor vehicle comprising at least one battery capable of being subjected to N successive cycles, N being at least equal to two,

[0034] comprising a system for determining the final health status of a battery, as specified above. Brief description of the figures

[0035] The accompanying figures will clearly illustrate how the invention can be implemented. In these figures, identical reference numerals designate similar elements.

[0036] Fig. 1 schematically represents the determination system.

[0037] Fig. 2 schematically represents the determination process.

[0038] Fig. 3 schematically represents the i-th step in determining the determination process.

[0039] Figure 4 represents a graph of degradation curves indicating the state of health of a battery as a function of the energy discharged by the battery.

[0040] Figure [Fig. 5] represents an electric or hybrid motor vehicle comprising the determination system. Detailed description

[0041] The system for determining 1 a final state of health SoHiN of a battery 2 of an electric or hybrid motor vehicle 3 capable of being subjected to a plurality of N successive cycles is schematically represented in [Fig. 1]. It is referred to as "determination system 1" in the following description.

[0042] The parameter N, which corresponds to the number of successive cycles to which the battery 2 is subjected, is a natural integer at least equal to two.

[0043] Each cycle is associated with a degradation curve Ci, ..., CN indicating the state of health of battery 2 as a function of energy discharged by battery 2.

[0044] Two consecutive cycles exhibit distinct degradation profiles. In other words, two consecutive degradation curves Ci and Ci+i are distinct from each other. However, it is possible that some degradation curves from two non-consecutive cycles may be identical, for example, if the type of vehicle use returns to the same state.

[0045] A degradation curve Ci, ..., CN can depend, among other things, on the type of battery use during the cycle to which it is associated, on operating conditions such as ambient temperature, and / or on the state of charge (SoC) of the battery 2. The SoC corresponds to a relative measure of the amount of energy stored in a battery. It is defined as the ratio between the cell's charge at a certain time and its total capacity.

[0046] A degradation curve can also be linked to the type of vehicle use. In particular, but not limited to, the following can be distinguished: -a degradation curve corresponding to the vehicle's movement (speed strictly greater than 0 km / h); -a degradation curve linked to a slow vehicle charge; -a degradation curve linked to a rapid vehicle charge; -a degradation curve linked to the use of the vehicle according to a so-called V2G (“Vehicle-to-Grid”) profile which consists of charging an external electrical network by the vehicle's battery; -etc.

[0047] The determination system comprises at least one receiving unit 4, one computing unit 6 and one transmission unit 7.

[0048] The calculation unit 6 may correspond to a software or electronic module of an on-board computer embedded in the motor vehicle 3. The calculation unit 6 may also correspond to a software or electronic module of the battery management system (BMS) of the motor vehicle 3. The degradation curves Ci, ..., CN may be stored in a storage module (not shown) of the battery management system. The parameter N may be limited by the storage capacity of the battery management system.

[0049] The degradation curves Ci, ..., CN can be stored in a storage module (not shown). The parameter N can be limited by the storage capacity of the storage module containing the degradation curves Ci, ..., CN.

[0050] The receiving unit 4 is configured to receive from an energy meter 5 a signal representing the first discharged energy Xi during the first cycle. The energy meter 5 of a battery measures the amount of energy charged or discharged by the battery 2. For example, this amount of energy is expressed in kWh.

[0051] The receiving unit 4 can be configured to receive, in addition to the battery management system (BMS), a start signal and an end signal for battery operation according to a particular cycle corresponding to a degradation curve specific to the first cycle Cp

[0052] The first cycle may present an initial health state SoHia corresponding to a health state of a new battery 2.

[0053] Fig. 4 illustrates the implementation of the system with N = 2. It represents two degradation curves Ci and C2 in a coordinate system showing the battery health state SoH (in percentage) as a function of the amount of energy charged or discharged X (in kWh for example).

[0054] The computing unit 6 is configured to determine a first final health state SoHib at the end of a first cycle based on a first degradation curve Ci associated with the first cycle and the first energy discharged Xi during the first cycle. In [Fig. 4], the first final health state SoHib is determined at point A (see [Fig. 4]) of the degradation curve Ci. This shows a degradation DA of the SoH of battery 2.

[0055] For i = 2 to i = N, the receiving unit 4 is further configured to receive from the energy meter 5 an i-th discharged energy X; during the i-th cycle.

[0056] Furthermore, for i = 2 to i = N, the receiving unit 4 can be configured to receive in addition from the battery management system BMS a start signal and then an end signal of battery operation according to a particular cycle corresponding to a degradation curve specific to the i-th cycle Ci.

[0057] For i = 2 to i = N, the calculation unit 6 is further configured to determine the final health state SoHiN.

[0058] An i-th final health state SoHib at the end of an i-th cycle is determined at each iteration i from an i-th degradation curve Ci associated with the i-th cycle. It is further assumed that the i-th initial health state SoHia is equal to the (il)-th final health state SoH(ii)b at the end of the (il)-th cycle.

[0059] The determination system 1 further includes a transmission unit 7 configured to transmit a signal representative of the final health state SoHiN of the battery 2 to a user device 8.

[0060] The user device 8 may include a display unit configured to display the SoH of battery 2.

[0061] Advantageously, with i = 2 to i = N, the calculation unit 6 can be configured to: - determine an i-th initial energy Xia at the beginning of the i-th cycle from an i-th initial health state SoHia and an i-th degradation curve Ci , the i-th initial health state SoHia being equal to the (il)-th final health state SoH(i_i)b at the end of the (il)-th cycle, - determine an i-th final health state SoHib at the end of the i-th cycle from the i-th degradation curve Ci associated with the i-th cycle and a sum of the i-th initial energy Xia and an i-th discharged energy X; during the i-th cycle, - determine a battery health state, the battery health state being equal to the difference between the i-th initial health state SoHia and the i-th final health state SoHib.

[0062] In [Fig.4], the second initial energy X2a at the beginning of the second cycle is determined from a second initial health state SoH2a and a second degradation curve C2 (point B in [Fig. 4]). The second initial health state SoH2a is equal to the first final health state SoHib at the end of the first cycle. The second final health state SoH2b at the end of the second cycle is determined from the second degradation curve C2 associated with the second cycle and a sum of the second initial energy X2a and a second discharged energy X2 during the second cycle (point C in [Fig. 4]). Thus, a degradation DB of the SoH of battery 2 is observed, which is added to the degradation DA of the SoH of battery 2.

[0063] The health state of the battery being equal to the difference between the second initial health state SoH2a and the second final health state SoH2b.

[0064] Furthermore, the receiving unit 4 can also be configured to receive initial operating data characteristic of the first cycle. The first degradation curve Ci is then selected by the calculation unit 6 based on the operating data.

[0065] Similarly, for i = 2 to i = N, the receiving unit 4 can be configured to receive i-th operating data with i = 2 to i = N. The i-th degradation curve Ci is then chosen by the calculation unit 6 as a function of the i-th operating data.

[0066] By way of non-limitation, the operating data may include at least one of the following parameters: the temperature of the environment in which battery 2 operates, the SoC of battery 2, the type of operation of battery 2.

[0067] The degradation curves Ci, ..., CN may include coefficients dependent on these operating data.

[0068] The degradation curves can also correspond to the recognition of a specific type of battery operation (vehicle driving, fast charging, slow charging, V2G type use, etc.).

[0069] The invention also relates to a method for determining a final state of health SoHin of a battery 2 of an electric or hybrid motor vehicle 3 subjected to N successive cycles ([Fig.2]).

[0070] The determination process comprises the following steps: - a first reception stage El, implemented by the receiving unit 4, to receive from an energy meter 5 a signal representative of a first energy discharged Xi during the first cycle; - a first determination step E2, implemented by the computing unit 6, to determine a first final health state SoHib at the end of a first cycle from a first degradation curve Ci associated with the first cycle and the first energy discharged Xi during the first cycle; - the following sequence of steps repeated dei = 2ài = N: • an i-th reception step El;, implemented by the receiving unit 4, to receive from the energy meter 5 a signal representing an i-th energy discharged X; during the i-th cycling, • an i-th determination step E2;, implemented by the calculation unit 6, to determine the final health state SoHiN, an i-th final health state SoHib at the end of the i-th cycle being determined from an i-th degradation curve C; associated with the i-th cycle and by setting that the i-th initial health state SoHia is equal to the (il)-th final health state SoH(i_1)b at the end of the (il)-th cycle.

[0071] The sequence of steps is followed by a transmission step E3, implemented by the transmission unit 7, to transmit a signal representative of the final health state SoHin of the battery 2 to a user device 8.

[0072] Furthermore, the first reception step El can be implemented by the receiving unit 4 to also receive from the battery management system BMS a start signal and an end signal for battery operation according to a particular cycle corresponding to a degradation curve specific to the first cycle Cb

[0073] Similarly, the i-th reception step El; can be implemented by the receiving unit 4 to receive in addition from the battery management system BMS a start signal and then an end signal of battery operation according to a particular cycle corresponding to a degradation curve specific to the i-th cycle Ci.

[0074] Advantageously, the i-th determination step E2; ([Fig.3]) comprises: - a sub-step of determination E21; of an i-th initial energy Xia at the beginning of the i-th cycle from an i-th initial health state SoHia and a i-th degradation curve Ci, the i-th initial health state SoHia being equal to the (il)-th final health state SoH(bi)b at the end of the (il)-th cycling, - a substep of determining E22; of an i-th final health state SoHib at the end of the i-th cycle from the i-th degradation curve Ci associated with the i-th cycle and a sum of the i-th initial energy Xia and an i-th discharged energy X; during the i-th cycle, - a sub-step of determination E23; of a battery health state, the battery health state being equal to the difference between the i-th initial health state SoHia and the i-th final health state SoHib.

[0075] Furthermore, the first reception step El can be implemented by the reception unit 4 in addition to receive the first operating data characteristic of the first cycling, the first degradation curve Ci being chosen by the calculation unit 6 according to the operating data.

[0076] Similarly, the i-th reception step El; can be implemented by the reception unit 4 further to receive i-th operating data, the i-th degradation curve C; being chosen by the calculation unit 6 as a function of the i-th operating data.

Claims

Demands

1. A method for determining the final state of health (SoHiN) of a battery (2) of an electric or hybrid motor vehicle (3) capable of being subjected to N successive cycles, N being at least equal to two, each cycle being associated with a degradation curve (Ci, ..., CN) indicating the state of health of the battery (2) as a function of energy discharged by the battery (2), the degradation curves of two consecutive cycles being distinct from each other, characterized in that it comprises the following steps: a first reception stage (El), implemented by a receiving unit (4), to receive from an energy meter (5) a signal representative of a first energy discharged (Xi) during the first cycle; a first determination step (E2), implemented by a computing unit (6), to determine a first final health state (SoHlb) at the end of a first cycle from a first degradation curve (Ci) associated with the first cycle and the first energy discharged (XJ during the first cycle; the following sequence of steps repeated dei = 2ài = N: • an i-th reception step (El;), implemented by the receiving unit (4), to receive from the energy meter (5) a signal representative of an i-th energy discharged (Xi) during the i-th cycle, • an i-th determination step (E2;), implemented by the calculation unit (6), to determine the final health state (SoHiN), an i-th final health state (SoHib) at the end of the i-th cycle being determined from an i-th degradation curve (Ci) associated with the i-th cycle and by setting that the i-th initial health state (SoHia) is equal to the (il)-th final health state (SoH(bi)b) at the end of the (il)-th cycle;

2.

3.

4. - a transmission step (E3), implemented by a transmission unit (7), to transmit a signal representative of the final health state (SoHiN) of the battery (2) to a user device (8). Method according to claim 1, characterized in that the i-th determination step (E2;) comprises: - a substep of determining (E21;) an i-th initial energy (Xia) at the beginning of the i-th cycle from an i-th initial health state (SoHia) and an i-th degradation curve (Ci), the i-th initial health state (SoHia) being equal to the (il)-th final health state (SoH, 1)b) at the end of the (il)-th cycle, - a substep for determining (E22;) an i-th final health state (SoHib) at the end of the i-th cycle from the i-th degradation curve (Ci) associated with the i-th cycle and a sum of the i-th initial energy (Xia) and an i-th discharged energy (Xj) during the i-th cycle, - a substep of determining (E23i) a health state of the battery, the health state of the battery being equal to the difference between the i-th initial health state (SoHia) and the i-th final health state (SoHib). A method according to any one of claims 1 and 2, characterized in that the first cycle exhibits an initial state of health (SoHia) corresponding to the state of health of a new battery. A method according to any one of claims 1 to 3, characterized in that the first acceptance step (El) is implemented by the receiving unit (4) further to receive initial operating data characteristic of the first cycle, the first degradation curve (Ci) being selected by the calculation unit (6) based on the operating data; the i-th acceptance step (El) being implemented by the receiving unit (4) further to receive i-th operating data, the i-th degradation curve (Ci) being selected by the calculation unit (6) based on the i-th operating data.

5. System for determining the final state of health (SoHiN) of a battery (2) of an electric or hybrid motor vehicle (3) capable of undergoing N successive cycles, N being at least equal to two, each cycle being associated with a degradation curve (Ci, ..., CN) indicating the state of health of the battery (2) as a function of energy discharged by the battery (2), the degradation curves of two consecutive cycles being distinct from each other, characterized in that it comprises: - a receiving unit (4) configured to receive from an energy meter (5) a signal representative of a first energy discharged (XJ during the first cycle, - a computing unit (6) configured to determine a first final state of health (SoHiN) at the end of a first cycle from a first degradation curve (Ci) associated with the first cycle and the first energy discharged (Xi) during the first cycle;for i = 2 to i = N: - the receiving unit (4) being configured to receive from the energy meter (5) a signal representative of an i-th energy discharged (Xj) during the i-th cycle, - the calculation unit (6) being configured to determine the final health state (SoHiN), an i-th final health state (SoHib) at the end of the i-th cycle being determined at each iteration i from an i-th degradation curve (Ci) associated with the i-th cycle and by setting that the i-th initial health state (SoHia) is equal to the (il)-th final health state (SoH(bi)b) at the end of the (il)-th cycle; the system further comprising a transmission unit (7) configured to transmit a signal representative of the final health state (SoHiN) of the battery (2) to a user device (8).

6. System according to claim 5, characterized in that the computing unit (6) is configured with i = 2 to i = N for: - determine an i-th initial energy (Xia) at the beginning of the i-th cycle from an i-th initial health state (SoHia) and an i-th degradation curve (Ci), the i-th initial health state (SoHia) being equal to the (il)-th final health state (SoH(i_i)b) at the end of the (il)-th cycle, - determine an i-th final health state (SoHib) at the end of the i-th cycle from the i-th degradation curve (Ci) associated with the i-th cycle and a sum of the i-th initial energy (Xia) and an i-th discharged energy (X;) during the i-th cycle, - determine a battery health state, the battery health state being equal to the difference between the i-th initial health state (SoHia) and the i-th final health state (SoHib).

7. System according to any one of claims 5 and 6, characterized in that the first cycle exhibits an initial state of health (SoHia) corresponding to a state of health of a new battery.

8. System according to any one of claims 5 to 7, characterized in that the receiving unit (4) is further configured to: - receive first operating data characteristic of the first cycle, the first degradation curve (Ci) being chosen by the calculation unit (6) according to the operating data; - receive i-th operating data with i = 2 to i = N, the i-th degradation curve (Ci) being chosen by the calculation unit (6) according to the i-th operating data.

9. Electric or hybrid motor vehicle comprising at least one battery capable of being subjected to N successive cycles, N being at least equal to two, characterized in that it comprises a system for determining (1) a final state of health of a battery (2), as specified under any one of claims 5 to 8.

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