ESTIMATION OF PARAMETER VALUE(S) OF AN ELECTRIC MODEL REPRESENTING A RECHARGEABLE BATTERY

Abstract

A method estimates parameter values ​​for an electrical model representing a battery associated with a lookup table between battery temperature and state of charge pairs and battery first coefficients, each parameter having known values ​​for pairs with different states of charge and a chosen battery temperature. This method includes a step (10-70) in which second coefficients are determined, equal to ratios between first coefficients corresponding to battery temperature and state of charge pairs and first coefficients corresponding to chosen battery temperature and state of charge pairs. The values ​​of each parameter for given pairs are then estimated as a function of the multiplication of the second coefficient determined for the pair in question and the known value of the parameter for the state of charge of that pair and the chosen battery temperature. Figure 2

Description

Title of the invention: ESTIMATION OF PARAMETER VALUES OF AN ELECTRICAL MODEL REPRESENTING A RECHARGEABLE BATTERY Technical field of the invention

[0001] The invention relates to rechargeable batteries, and more precisely to the estimation of values ​​taken by at least one parameter of an electrical model representing a rechargeable battery. State of the art

[0002] In many fields, such as vehicles (possibly automotive), rechargeable batteries, possibly cellular, are used.

[0003] Before being installed in a system, it is common for a battery to be subject to one or more test phases under the control of at least one computer. Similarly, once installed in a system, a battery is managed by a computer, for example to optimize its lifetime in the system. In both cases, the computers must know the evolution of at least one parameter as a function of the battery temperature and the state of charge of the battery. Each parameter is part of an electrical model representing a rechargeable battery. For example, when the electrical model defines a voltage at the terminals of the battery and is of the RC type, it comprises a first parameter constituting a first resistance (generally designated by R0) and a second parameter constituting a second resistance (generally designated by RI).

[0004] It is important to note that "battery temperature" here means the temperature of the battery within its battery assembly (or "pack").

[0005] Each battery is therefore delivered with information allowing the computer to manage its operation optimally at the time considered, and therefore according to its current battery temperature and its current state of charge.

[0006] Currently, some of this information is battery coefficients which have been previously determined each as a function of a battery temperature and a battery charge state. Generally, these coefficients, which can, for example, be an internal resistance often called DCR ("Direct Current Resistance"), are grouped in a correspondence table (or mapping). Some other of this information is known values ​​of each parameter for pairs comprising different charge states and at least one chosen battery temperature (for example equal to 25°C).

[0007] The calculator managing the battery then uses this correspondence table and these known values ​​to estimate at the time considered the value taken by each parameter of the electrical model, taking into account the current battery temperature and state of charge.

[0008] The known values ​​of each parameter being determined for the same chosen battery temperature (for example equal to 25°C), and in the best case for two chosen battery temperatures (for example equal to 25°C and 45°C), as soon as the battery temperature is relatively far from the (one) chosen battery temperature, the estimated values ​​of the parameters are imprecise, or even very imprecise, and therefore the management of the battery cannot be optimal or the reliability of certain tests cannot be high.

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

[0010] It proposes in particular for this purpose a method for estimating values ​​taken by at least one parameter of an electrical model representing a rechargeable battery and associated with at least one table establishing a correspondence between pairs of battery temperature and state of charge of the battery and first coefficients of this battery, each parameter having known values ​​for pairs comprising different states of charge and at least one same chosen battery temperature.

[0011] This estimation method is characterized by the fact that it comprises a step in which:

[0012] - we determine second coefficients equal respectively to ratios between first coefficients corresponding to pairs containing battery temperatures and states of charge and first coefficients corresponding to pairs containing this chosen battery temperature and these states of charge, then

[0013] - we estimate the values ​​of each parameter, for temperature pairs of given battery and state of charge, depending on the result of a multiplication between the second coefficient determined for the couple considered and the known value of the parameter considered for the state of charge of this couple and the chosen battery temperature.

[0014] Thanks to the invention, we now have estimated values ​​for each parameter which complement the known values, and therefore future management of the battery can be optimal and the reliability of the tests carried out on this battery can be high.

[0015] The estimation method according to the invention may include other characteristics which may be taken separately or in combination, and in particular:

[0016] - in its step, when the couples of the table include charge states su greater than or equal to a first threshold, third coefficients can be determined respectively equal to ratios between first coefficients corresponding to pairs containing the chosen battery temperature and states of charge lower than the first threshold and the first coefficient corresponding to a pair containing this chosen battery temperature and the first threshold, then the values ​​of each parameter can be estimated for pairs containing states of charge lower than the first threshold and the chosen battery temperature as a function of a result of a multiplication between the third coefficient determined for this pair and the known value of the parameter considered for the first threshold and the chosen battery temperature, these estimated values ​​becoming known values;

[0017] - in the presence of the first option, in its step, the first threshold can be understood between a state of charge equal to 15% and another state of charge equal to 25%. For example, this first threshold can be equal to a state of charge of 20%;

[0018] - in its step we can use an electrical model defining a voltage at battery terminals, of RC type, and comprising a first parameter constituting a first resistance and a second parameter constituting a second resistance;

[0019] - in its step, when each parameter has known values ​​for couples comprising different states of charge and first and second selected battery temperatures, first fourth coefficients can be determined respectively equal to ratios between first coefficients corresponding to pairs containing battery temperatures and states of charge and first coefficients corresponding to pairs containing the first selected battery temperature and the states of charge, and second fourth coefficients can be determined respectively equal to ratios between first coefficients corresponding to pairs containing battery temperatures and states of charge and first coefficients corresponding to pairs containing the second selected battery temperature and the states of charge, then each second coefficient corresponding to a pair can be determined by dividing by two a sum between the first and second fourth coefficients corresponding to this pair;

[0020] - in its step, we can compare simulation results of the electrical model with estimated values ​​corresponding to selected stresses on the battery with corresponding real results obtained by actually subjecting the battery to these same stresses, and if a difference between these simulation results and these real results is less than a second threshold, we can consider that the estimated values ​​are usable.

[0021] The invention also provides a computer program product comprising a set of instructions which, when executed by processing means, is capable of implementing an estimation method of the type presented above for estimate values ​​taken by at least one parameter of an electrical model representing a rechargeable battery and associated with at least one table establishing a correspondence between pairs of battery temperature and state of charge of this battery and first coefficients of this battery, each parameter having known values ​​for pairs comprising different states of charge and at least one same chosen battery temperature.

[0022] The invention also proposes an estimation device responsible for estimating values ​​taken by at least one parameter of an electrical model representing a rechargeable battery and associated with at least one table establishing a correspondence between pairs of battery temperature and state of charge of this battery and first coefficients of this battery, each parameter having known values ​​for pairs comprising different states of charge and at least one same chosen battery temperature.

[0023] This estimation device is characterized by the fact that it comprises at least one processor and at least one memory arranged to carry out the operations consisting of:

[0024] - to determine second coefficients respectively equal to ratios between first coefficients corresponding to pairs containing battery temperatures and states of charge and first coefficients corresponding to pairs containing the chosen battery temperature and the states of charge, then

[0025] - to estimate the value of each parameter, for a battery temperature pair and state of charge given, depending on a result of a multiplication between the second coefficient determined for this couple and the known value of the parameter considered for the state of charge of this couple and the chosen battery temperature.

[0026] The invention also proposes electronic equipment with computing capacity comprising an estimation device of the type presented above. Brief description of the figures

[0027] Other characteristics and advantages of the invention will appear on examining the detailed description below, and the appended drawings, in which:

[0028] [Fig-1] schematically and functionally illustrates an example of equipment electronics, comprising a calculator comprising an exemplary embodiment of an estimation device according to the invention, and coupled to a rechargeable battery, and

[0029] [Fig.2] schematically illustrates an example of an algorithm implementing an estimation method according to the invention. Detailed description of the invention

[0030] The invention aims in particular to propose an estimation method, and an associated estimation device DE, intended to allow the estimation of values ​​vpj(ec, te) taken by at least one parameter pj of an electrical model representing a rechargeable BC battery.

[0031] In the following, it is considered, by way of non-limiting example, that the rechargeable battery BC is initially intended to be coupled to electronic equipment EE with computing capacity and responsible for acquiring estimates of values ​​of parameter(s) pj concerning it, then finally intended to be part of a vehicle of the automobile type, such as for example a car. But the invention is not limited to this last application. Indeed the rechargeable battery can be part of any system comprising at least one piece of electronic equipment with computing capacity. Consequently, the system could be a vehicle (land, sea (or river), or air), household appliance (possibly consumer), an electronic device, an installation (possibly industrial), or a building, for example.

[0032] Furthermore, it is considered in the following, by way of non-limiting example, that the rechargeable battery BC is of the cellular type. In this case, it comprises N electrical energy storage cells, with N > 2, possibly grouped into module(s). Each cell (for electrical energy storage) is possibly electrochemical (in this case it may, for example, be of the lithium-ion (or Li-ion) or Ni-Mh or Ni-Cd type).

[0033] [Fig.l] schematically shows an example of electronic equipment EE, comprising at least one calculator CE providing it with its calculation capacity and comprising an example embodiment of an estimation device DE, and coupled to a battery BC (rechargeable).

[0034] For example, this electronic equipment EE can be a computer (possibly portable) or a workstation. But it could also be an electronic tablet, for example.

[0035] As mentioned above, the invention proposes in particular an estimation method intended to allow the estimation of values ​​vpj(ec, te) taken by at least one parameter pj of an electrical model representing the battery BC (rechargeable).

[0036] This (estimation) method can be implemented at least partially by the estimation device DE (illustrated in [Fig.l]) which comprises for this purpose at least one processor PR1, for example a digital signal processor (or DSP ("Digital Signal Processor")), and at least one memory MD. This estimation device DE can therefore be produced in the form of a combination of electrical or electronic circuits or components (or "hardware") and software modules (or "software"). For example, it can be a microcontroller.

[0037] The memory MD is live in order to store instructions for the implementation by the processor PR1 of at least part of the estimation method. The processor PR1 may comprise integrated (or printed) circuits, or several integrated circuits (or printed) connected by wired or wireless connections. An integrated (or printed) circuit is any type of device capable of performing at least one electrical or electronic operation.

[0038] In the example illustrated non-limitingly in [Fig.l], the estimation device DE is part of a calculator CE of electronic equipment EE. But it could be part of a battery calculator coupled to the battery BC and equipping a system (such as for example a vehicle), or could comprise its own dedicated calculator.

[0039] As illustrated non-limitingly in [Fig.2], the (estimation) method, according to the invention, comprises a step 10-70 which is implemented when it is desired to estimate values ​​taken by at least one parameter pj of an electrical model representing the battery BC.

[0040] In the following, it is considered, by way of non-limiting example, that the electrical model defines a voltage across the terminals of the battery BC which is of the RC type, and comprises a first parameter p 1 (j = 1) constituting a first resistance R0 and a second parameter p2 (j = 2) constituting a second resistance RI. It is recalled that in such an electrical model the voltage uBc across the terminals of the battery BC is given by the formula uBc = uv(ec) + R0*I + uRC, where uv(ec) is the no-load voltage, ec is the state of charge, and uRC is the voltage across an RC assembly, comprising a capacitor cl mounted in parallel with the second resistance RI, and mounted in series with the first resistance R0. This electrical model also defines the time derivative of uRC which is given by the formula u'RC = -(uRC / (Rl*cl)) + (I / cl).

[0041] The battery BC is associated with at least one table (or mapping) tl which establishes a correspondence between pairs each comprising a battery temperature te and a state of charge ec of the battery BC and first coefficients cfl(ec, te) of the battery BC. Each parameter pj has known values ​​vcj(ec, teck) for pairs comprising different states of charge ec and at least one same chosen battery temperature teck.

[0042] For example, the first coefficients cfl(ec, te) can be internal resistances called DCR (Direct Current Resistance).

[0043] The table (or mapping) tl and the known values ​​vcj(ec, teck) can, for example, be stored in the estimation device DE or the calculator CE of the electronic equipment EE which comprises it (here).

[0044] Step 10-70 of the method comprises a sub-step 30 in which one (for example the estimation device DE) begins by determining second coefficients cf2(ec, te) which are respectively equal to ratios between first coefficients cfl(ec, te), which correspond to pairs containing battery temperatures te and states of charge ec, and first coefficients cfl(ec, teck), which correspond to pairs containing the chosen battery temperature teck and the states of charge ec. We therefore have cf2(ec, te) = cfl(ec, te) / cfl(ec, teck).

[0045] Step 10-70 of the method also comprises a sub-step 40 in which the values ​​vpj(ec, te) of each parameter pj are estimated (for example the estimation device DE) for given battery temperature te and state of charge ec pairs. Each estimation is made as a function of the result of the multiplication between the second coefficient cf2(ec, te) determined for the pair (ec, te) considered and the known value vcj(ec, teck) of the parameter pj considered for the state of charge ec of this pair and the chosen battery temperature teck. We then have vpj(ec, te) = cf2(ec, te) * vcj(ec, teck).

[0046] Thus, for each parameter pj, we have estimated values ​​vpj(ec, te) which complement the known values ​​vcj(ec, teck) which are usually very few in number because they very generally concern a single chosen battery temperature tecl (for example equal to 25°C) and sometimes two chosen battery temperatures tecl and tec2 (for example equal to 25°C and 45°C respectively). Consequently, the future management of the BC battery can be optimal and the reliability of tests carried out on this BC battery can be high.

[0047] It will be noted that it may happen that the couples of the table tl comprise states of charge ec which are greater than or equal to a first threshold si. In this case, as illustrated non-limitingly in [Fig.2], step 10-70 may comprise a sub-step 20 in which one (for example the estimation device DE) can determine third coefficients cf3(ec, teck) which are respectively equal to ratios between first coefficients cfl(ec, teck) corresponding to couples containing the (one) chosen battery temperature teck and states of charge ec lower than the first threshold si and the first coefficient cfl(sl, teck) corresponding to a couple containing this chosen battery temperature and the first threshold si. We then have cf3(ec, teck) = cfl(ec, teck) / cfl(sl, teck).

[0048] Then, in this sub-step 20 one (for example the estimation device DE) can estimate the values ​​vepj(ec, teck) of each parameter pj for pairs containing states of charge ec lower than the first threshold s 1 and the (one) chosen battery temperature teck as a function of the result of the multiplication between the third coefficient cf3(ec, teck) determined for this pair and the known value vcj(sl, teck) of the parameter pj considered for the first threshold s 1 and this chosen battery temperature teck. We then have vepj(ec, teck) = cf3(ec, teck) * vcj(sl, teck). In this case, the estimated values ​​vepj(ec, teck) become known values ​​complementing the known values ​​vcj(ec, teck), which advantageously makes it possible to have for each parameter pj and for each chosen battery temperature teck known values ​​vcj(ec, teck) for all states of charge ec, whether they are higher or lower than the first threshold si.

[0049] Also for example, in sub-step 20 of step 10-70 the first threshold if can be between a state of charge ec equal to 15% and another state of charge ec' equal to 25%. As an illustrative example, this first threshold si can be equal to a state of charge ec of 20%.

[0050] It will also be noted that in the above it has been considered that known values ​​vcj(ec, teck) are only available for a single chosen battery temperature teck. But it may happen that known values ​​vcj(ec, tecl) are available for a first chosen battery temperature tecl (k = 1) and known values ​​vcj(ec, tec2) are available for a second chosen battery temperature tec2 (k = 2). For example, these first tecl and second tec2 chosen battery temperatures may be respectively equal to 25 °C and 45 °C.

[0051] In this case, in sub-step 30 of step 10-70 one (for example the estimation device DE) can start by determining first cf4i(ec, te) and second cf42(ec, te) fourth coefficients. The first fourth coefficients cf4i(ec, te) are respectively equal to ratios between first coefficients cfl(ec, te) corresponding to pairs containing battery temperatures te and states of charge ec and first coefficients cfl(ec, tecl) corresponding to pairs containing the first chosen battery temperature tecl and the states of charge ec. We then have cf4i(ec, te) = cfl(ec, te) / cfl(ec, tecl).The second fourth coefficients cf42 (ec, te) are respectively equal to ratios between first coefficients cfl(ec, te) corresponding to pairs containing battery temperatures and states of charge ec and first coefficients cfl(ec, tec2) corresponding to pairs containing the second chosen battery temperature tec2 and the states of charge ec. We then have cf42(ec, te) = cfl(ec, te) / cfl(ec, tec2). .

[0052] Then, in this sub-step 30 of step 10-70 one (for example the estimation device DE) can determine each second coefficient cf2(ec, te) corresponding to a pair by dividing by two the sum between the first cf4i(ec, te) and second cf42(ec, te) fourth coefficients corresponding to this pair. We then have cf2(ec, te) = (cf4i(ec, te) + cf42(ec, te)) / 2.

[0053] But one could also use, for example, an Arrhenius law which is representative of the battery temperature dependence of the internal chemical reactions of the BC battery, and often used for battery aging models.

[0054] It will also be noted, as illustrated non-limitingly in [Fig. 2], that step 10-70 of the method may also comprise a sub-step 60 in which one (for example the estimation device DE) checks whether the estimated values ​​vpj(ec, te) have an acceptable estimation error. To this end, one (for example the estimation device DE) can compare simulation results of the electrical model with estimated values ​​vpj(ec, te) corresponding to selected stresses of the battery BC with corresponding real results obtained by actually subjecting the battery BC to these same requests.

[0055] If the difference between the results of the simulations and the actual results is less than a second threshold s2, then one (for example the estimation device DE) can consider that the estimated values ​​vpj(ec, te) are usable. On the other hand, if the difference between the results of the simulations and the actual results is greater than or equal to the second threshold s2, then one (for example the estimation device DE) rejects the estimated values ​​vpj(ec, te), and one will have to proceed differently to obtain usable estimated values ​​vpj(ec, te).

[0056] When such a verification is carried out, step 10-70 of the method may also comprise, as illustrated non-limitingly in [Fig.2], a sub-step 50 in which one (for example the estimation device DE) carries out the simulations of the electrical model with estimated values ​​vpj(ec, te) to obtain the simulation results. But this is not obligatory, because these simulation results could be determined by another computer, possibly external to the electronic equipment EE.

[0057] It will be noted that when known values ​​vcj(ec, teck) are initially available for two chosen battery temperatures tecl and tec2, it is also possible to obtain in sub-steps 10 to 40 a first set of estimated values ​​vpji(ec, te) with the first chosen battery temperature tecl, and a second set of estimated values ​​vpj2(ec, te) with the second chosen battery temperature tec2. Then, in sub-step 60 one (for example the estimation device DE) can determine first and second deviations respectively for the first set of estimated values ​​vpji(ec, te) and the simulation results and the second set of estimated values ​​vpj2(ec, te) and the simulation results.Then, one (for example the estimation device DE) can compare the first and second deviations from the second threshold s2, then decide to retain among the first vpji(ec, te) and second vpj2(ec, te) sets only the one which presents the smallest deviation from the second threshold s2.

[0058] It will also be noted, as illustrated non-limitingly in [Fig. 2], that step 10-70 of the method may also comprise a sub-step 70 in which one (for example the estimation device DE) may estimate at least one other parameter, possibly from the electrical model or characterizing the operation of the battery BC (for example as a function of its internal chemistry), from the known values ​​vcj(ec, teck) and the complementary estimated values ​​vpj(ec, te) retained in sub-step 60. For example, this latter estimation may be done by extrapolation from these known values ​​vcj(ec, teck) and estimated values ​​vpj(ec, te). This makes it possible to approximate the performance of the battery BC as closely as possible in an electrical model approach and to calibrate power maps as accurately as possible, for example useful during real tests of the battery BC or of the system comprising the latter. (here a vehicle).

[0059] It will also be noted, as illustrated non-limitingly in [Fig.l], that the calculator CE of the electronic equipment EE (or the calculator of the estimation device DE) can also comprise a mass memory MM1, in particular for storing the correspondence tables tl and the known values ​​vcj(ec, teck), as well as any intermediate data involved in all its calculations and processing operations. Furthermore, this calculator CE of the electronic equipment EE (or the calculator of the estimation device DE) can also comprise an input interface IE for receiving at least the correspondence tables tl and the known values ​​vcj(ec, teck), to use them in calculations or processing operations, possibly after having formatted and / or demodulated and / or amplified them, in a manner known per se, by means of a digital signal processor PR2.In addition, this calculator CE of the electronic equipment EE (or the calculator of the estimation device DE) can also include an output interface IS, in particular to deliver the estimated values ​​vpj(ec, te) of at least one parameter pj of the electrical model representing the battery BC.

[0060] It will also be noted that the invention also proposes a computer program product (or computer program) comprising a set of instructions which, when executed by processing means of the electronic circuit (or hardware) type, such as for example the processor PR1, is capable of implementing the estimation method described above to estimate values ​​vpj(ec, te) taken by at least one parameter pj of the electrical model representing the battery BC.

[0061] The invention offers several advantages, including:

[0062] - obtaining data defining parameters of the electrical model of the accurate BC battery and following the physics of the latter (BC) as closely as possible, including for (very) low states of charge and low battery temperatures, thus enabling functional validations to be carried out correctly and the performance of the BC battery to be approximated as closely as possible (and in particular its power maps),

[0063] - it allows the schedule of cold tests of the BC battery to be respected in the event of unavailability of data defining parameters of the electrical model of this BC battery,

[0064] - it can allow a verification of the consistency of the model parameters BC battery electric current, including for (very) low states of charge and low battery temperatures.

Claims

Claims

1. Method for estimating values ​​taken by at least one parameter of an electrical model representing a rechargeable battery (BC) and associated with at least one table establishing a correspondence between pairs of battery temperature and state of charge of said battery (BC) and first coefficients of said battery (BC), each parameter having known values ​​for pairs comprising different states of charge and at least one same chosen battery temperature, characterized in that it comprises a step (10-70) in which second coefficients are determined respectively equal to ratios between first coefficients corresponding to pairs containing battery temperatures and states of charge and first coefficients corresponding to pairs containing said chosen battery temperature and said states of charge, then the values ​​of each parameter are estimated,for given battery temperature and state of charge pairs, as a function of a result of a multiplication between the second coefficient determined for the pair considered and the known value of said parameter considered for the state of charge of this pair and said chosen battery temperature.,

2. Method according to claim 1, characterized in that in said step (10-70), when said pairs of said table comprise states of charge greater than or equal to a first threshold, third coefficients are determined respectively equal to ratios between first coefficients corresponding to pairs containing said chosen battery temperature and states of charge lower than said first threshold and said first coefficient corresponding to a pair containing said chosen battery temperature and said first threshold, then the values ​​of each parameter are estimated for pairs containing states of charge lower than said first threshold and said chosen battery temperature as a function of a result of a multiplication between the third coefficient determined for this pair and the known value of said parameter considered for said first threshold and said chosen battery temperature,these estimated values ​​becoming known values.,

3. Method according to claim 2, characterized in that in said step (10-70) said first threshold is between a state of charge equal to 15% and another state of charge equal to 25%.

4. Method according to one of claims 1 to 3, characterized in that in said step (10-70) said electrical model defines a voltage at the terminals of said RC type battery (BC), and comprises a first parameter constituting a first resistance and a second parameter constituting a second resistance.

5. Method according to one of claims 1 to 4, characterized in that in said step (10-70) when each parameter has known values ​​for pairs comprising different states of charge and first and second selected battery temperatures, first fourth coefficients are determined respectively equal to ratios between first coefficients corresponding to pairs containing battery temperatures and states of charge and first coefficients corresponding to pairs containing said first selected battery temperature and said states of charge, and second fourth coefficients respectively equal to ratios between first coefficients corresponding to pairs containing battery temperatures and states of charge and first coefficients corresponding to pairs containing said second selected battery temperature and said states of charge,then we determine each second coefficient corresponding to a pair by dividing by two a sum between the first and second fourth coefficients corresponding to this pair.,

6. Method according to one of claims 1 to 5, characterized in that in said step (10-70) simulation results of said electrical model are compared with estimated values ​​corresponding to selected stresses of said battery (BC) with corresponding real results obtained by actually subjecting said battery (BC) to these same stresses, and if a difference between said simulation results and said real results is less than a second threshold, said estimated values ​​are considered usable.

7. Computer program product comprising a set of instructions which, when executed by processing means, is capable of implementing the estimation method according to one of claims 1 to 6 for estimating values ​​taken by at least one parameter of an electrical model representing a rechargeable battery (BC) and associated with at least one table establishing a correspondence between pairs of battery temperature and state of charge of said battery (BC) and first coefficients of said battery (BC), each parameter having known values ​​for pairs comprising different states of charge and at least one same battery temperature chosen.

8. Estimation device (DE) for estimating values ​​taken by at least one parameter of an electrical model representing a rechargeable battery (BC) and associated with at least one table establishing a correspondence between pairs of battery temperature and state of charge of said battery (BC) and first coefficients of said battery (BC), each parameter having known values ​​for pairs comprising different states of charge and at least one same chosen battery temperature, characterized in that it comprises at least one processor (PR1) and at least one memory (MD) arranged to carry out the operations consisting in determining second coefficients respectively equal to ratios between first coefficients corresponding to pairs containing battery temperatures and states of charge and first coefficients corresponding to pairs containing said chosen battery temperature and said states of charge,then to estimate the values ​​of each parameter, for given battery temperature and state of charge pairs, as a function of a result of a multiplication between the second coefficient determined for the pair considered and the known value of said parameter considered for the state of charge of this pair and said chosen battery temperature.,

9. Electronic equipment (EE) with computing capacity, characterized in that it comprises an estimation device (DE) according to claim 8.

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