MANAGING THE RECHARGE OF A CELLULAR BATTERY IN A SYSTEM ACCORDING TO THE DESIRED STATE OF CHARGE

Abstract

A method for managing the charging of a cellular battery in a system includes a step (10-100) in which: - if a partial charge is requested to obtain a desired state of charge strictly below a maximum state of charge, this charge is allowed until an estimated state of charge equal to this desired state of charge is reached, and - if a full charge is requested to obtain a desired state of charge equal to the maximum state of charge, the use of a maximum charging current is enforced until a maximum cellular voltage greater than or equal to a first threshold is reached, then a multi-step charging process is performed in each step, the use of a charging current strictly lower than the previous charging current, until the charging current used is below a second threshold. Figure 3

Description

Title of the invention: MANAGEMENT OF THE RECHARGES OF A CELLULAR BATTERY OF A SYSTEM BASED ON THE DESIRED STATE OF CHARGE Technical field of the invention

[0001] The invention relates to cellular batteries, and more specifically to the management of recharging of such cellular batteries. State of the art

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

[0003] During a recharging phase, a computer, called a cellular battery computer because it is associated with the cellular battery, is responsible for controlling the recharging so that it is done without risk and with a stable current (and therefore without oscillation), so as to guarantee the performance of this cellular battery for a predefined duration.

[0004] Currently, this control is carried out on the basis of end-of-recharge criteria which are based on obtaining a state of charge (or SOC (“State Of Charge”)) of the cellular battery. As those skilled in the art know, this state of charge is a parameter which is estimated, and which can therefore be subject to deviations from reality. It will be noted that the more partial the recharge, the greater the deviation from reality can be because the voltage at the terminals of the cellular battery often varies very quickly and strongly during the first fifty minutes of recharge.

[0005] Due to these differences, during a complete recharge it often happens that the user is made to wait longer than necessary (when the maximum state of charge is difficult to achieve) but above all an overcharging of the cellular battery can occur, which is potentially dangerous because it can lead to internal damage and / or heating likely to trigger a fire in the event of thermal runaway.

[0006] Furthermore, during recharging the voltage at the terminals of the cellular battery may be subject to oscillations which may induce an accumulation effect of a chemical species around the anode (or "plating") which may cause a short circuit or heating likely to trigger a fire in the event of thermal runaway.

[0007] The invention therefore aims in particular to improve the situation. Presentation of the invention

[0008] It proposes in particular for this purpose a management method intended to enable the management of recharges of a cellular battery having an estimated current state of charge and a maximum state of charge and equipping a system.

[0009] This management method is characterized by the fact that it comprises a step in which:

[0010] - in case of request for partial recharging of the cellular battery to obtain a state desired charge strictly lower than the maximum state of charge, this recharge is authorized until an estimated state of charge equal to this desired state of charge is obtained, and

[0011] - in case of request for complete recharging of the cellular battery to obtain a desired state of charge equal to the maximum state of charge, we impose the use of a maximum recharge current until obtaining a maximum cell voltage greater than or equal to a first threshold, then we carry out a recharge in multiple steps in each of which we impose the use of a recharge current strictly lower than the previous recharge current until the recharge current used is lower than a second threshold.

[0012] Thanks to the invention, the duration of complete recharges is reduced and the occurrence of overcharges of the cellular battery BC is avoided, which makes it possible to increase the safety of the system and its users and the lifespan of the cellular battery.

[0013] The management method according to the invention may include other characteristics which may be taken separately or in combination, and in particular:

[0014] - in a first embodiment, in its step, when the recharging current used is greater than the second threshold, multi-step recharging can be interrupted when a number of steps taken is equal to a maximum number of steps;

[0015] - in a second embodiment, in its step, when the recharging current used is greater than the second threshold, the multi-step recharge can be interrupted when the latter has been carried out for a duration equal to a chosen duration;

[0016] - in its step, the second threshold can be a function of a recharge current minimum that can be delivered by a power source external to the system, temporarily coupled to the latter and ensuring recharging;

[0017] - in its step, during each step of the multi-step recharge it is possible to impose the use of a recharge current equal to the previous recharge current multiplied by a coefficient chosen strictly less than one;

[0018] - in the presence of the last option, in its step, the chosen coefficient can be between 0.6 and 0.95;

[0019] - in its step, we can analyze the maximum cellular voltage at least as long as that it is lower than the first threshold so that in the event of a drop in this maximum cellular voltage, following the use of a new recharge current strictly lower than a previous recharge current, this must be maintained new recharge current until the maximum cell voltage returns above a value it had reached before this drop.

[0020] The invention also proposes a computer program product comprising a set of instructions which, when executed by processing means, is capable of implementing a management method of the type presented above for managing recharges of a cellular battery, having an estimated current state of charge and a maximum state of charge and equipping a system.

[0021] The invention also proposes a management device intended to manage recharges of a cellular battery having an estimated current state of charge and a maximum state of charge and equipping a system.

[0022] This management 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:

[0023] - in case of request for partial recharging of the cellular battery to obtain a state desired charge state strictly lower than the maximum charge state, to authorize recharging until obtaining an estimated charge state equal to the desired charge state, and

[0024] - in case of request for complete recharging of the cellular battery to obtain a desired state of charge equal to the maximum state of charge, to trigger an imposition of the use of a maximum recharge current until a maximum cell voltage greater than or equal to a first threshold is obtained, then to trigger the performance of a recharge in multiple steps in each of which an imposition of a recharge current strictly lower than the previous recharge current is triggered until the recharge current used is lower than a second threshold.

[0025] The invention also proposes a system comprising a cellular battery, having an estimated current state of charge and a maximum state of charge, and a management device of the type presented above. Brief description of the figures

[0026] Other characteristics and advantages of the invention will appear on examining the detailed description below, and the appended drawings, in which:

[0027] [Fig-1] schematically and functionally illustrates an example of the embodiment of a vehicle comprising a management device according to the invention and a GMP with an electric motor powered by a cellular battery associated with a battery computer,

[0028] [Fig.2] schematically and functionally illustrates an exemplary embodiment of a battery calculator comprising a management device according to the invention,

[0029] [Fig.3] schematically illustrates an example of an algorithm implementing a management method according to the invention, and

[0030] [Fig.4] schematically illustrates first and second examples of diagrams of temporal evolution respectively of the recharge current (lower part) and of the maximum cellular voltage (upper part), during a recharge carried out by the implementation of the management method according to the invention. Detailed description of the invention

[0031] The invention aims in particular to propose a management method, and an associated management device DG, intended to allow the management of the recharges of a cellular battery BC equipping a system S according to the state of charge ecd desired by the user of this system S.

[0032] In the following, it is considered, by way of non-limiting example, that the system S is a motor vehicle, such as for example a car, as illustrated in [Fig.l]. But the invention is not limited to this type of system. It in fact relates to any type of system comprising at least one cellular battery (rechargeable) by an external power source temporarily coupled to this system. Thus, it relates to vehicles (land, sea (or river), and air), electronic devices (possibly household appliances), installations (possibly industrial), and buildings, for example.

[0033] Furthermore, it is considered in the following, by way of non-limiting example, that the vehicle S comprises a transmission chain with a powertrain (or GMP) of the all-electric type (and therefore comprising at least one electric motor associated with a cellular battery). But the GMP could be of the hybrid type (and in this case the drive of the vehicle S is provided by at least one thermal motor and one electric motor).

[0034] [Fig.l] schematically shows a system S (here a vehicle) comprising an all-electric GMP transmission chain (and therefore comprising at least one electric MME motor machine), a supervision computer CS, a service battery BS, a cellular battery BC, a converter CV, and a management device DG according to the invention.

[0035] The service battery BS is responsible for supplying electrical energy to the on-board network RB of the vehicle S, in addition to that supplied by the converter CV powered by the cellular battery BC via a main electrical circuit, and sometimes instead of this converter CV. For example, this service battery BS can be arranged in the form of a very low voltage type battery (typically 12 V, 24 V or 48 V). It is rechargeable at least by the converter CV. It is considered in the following, by way of non-limiting example, that the service battery BS is of the 12 V Lithium-ion type.

[0036] The on-board network RB is an electrical power supply network to which electrical (or electronic) equipment (or components) that consume energy are coupled. electric.

[0037] The main electrical circuit (or "high voltage" or "power") is connected, on the one hand, to the cellular battery BC via an interface device, and, on the other hand, to electronic equipment, such as for example the converter CV and the driving machine MME. It also allows the recharging of the cellular battery BC by an external power source SA and temporarily coupled to the vehicle S for example via a recharging connector CN of the latter (S).

[0038] The transmission chain has a GMP which is, here, purely electric, and therefore which comprises, in particular, in addition to its (electric) driving machine MME, a motor shaft, and a transmission shaft. Here, the term "electric driving machine" means an electric machine arranged so as to provide torque to move the system S (here a vehicle), as well as possibly to recover regenerative braking torque. The operation of the GMP is supervised by a supervision computer CS.

[0039] The driving machine MME (here an electric motor) is coupled to the cellular battery BC via the main electrical circuit, in order to be supplied with electrical energy, as well as possibly to supply this cellular battery BC with electrical energy during a regenerative braking phase. It is coupled to the motor shaft, to provide it with torque by rotational drive. This motor shaft is here coupled to a reducer RD which is also coupled to the transmission shaft, itself coupled to a first train T1 (here of wheels), preferably via a differential DF.

[0040] This first train T1 is here located in the front part PVV of the vehicle S. But in a variant this first train T1 could be the one which is here referenced T2 and which is located in the rear part PRV of the vehicle S.

[0041] The operation of the driving machine MME is controlled by a machine computer CM, and supervised by the supervision computer CS.

[0042] The CV converter is also responsible, here, during the driving phases of the vehicle S for converting part of the electric current stored in the cellular battery BC to supply converted electric current to the on-board network RB and the service battery BS (to recharge it). It is also, here, electrically coupled, via the main electrical circuit, to the charging connector CN of the vehicle S. During a charging phase of the cellular battery BC, this charging connector CN is, here, intended to be temporarily coupled to a power source SA external to the vehicle S, via a charging cable CR.

[0043] It will be noted, as illustrated non-limitingly in [Fig.l], that the converter CV can be part of an internal charger CH also comprising a computer CA responsible, at least, for controlling the recharges of the cellular battery BC.

[0044] The BC cell battery comprises at least one CE cell, and preferably several. For example, each CE cell can be electrochemical, possibly lithium-ion (or Li-ion) or Ni-Mh or Ni-Cd type. Also for example, the BC cell battery can be low voltage type (typically 450 V for illustration). But it could be medium voltage or high voltage type.

[0045] It will be noted, as illustrated non-limitingly in [Fig. 1], that when the cellular battery BC comprises several cells CE, they can be part of modules MC which are coupled together, for example in series. Here, the term “module MC” means a group of at least one cell CE. When an MC module comprises several cells CE, the latter (CE) can be coupled together in series and / or in parallel.

[0046] It will be noted that the cellular battery BC is associated with a battery box BB which notably comprises means for measuring voltage, current and internal temperature (not illustrated) and a battery calculator CB. This battery calculator CB centralizes the current measurements, the voltage measurements and the internal temperature measurements (notably those which individually concern each of the N cells CE), and estimates parameters of the cellular battery BC as a function of these measurements, and notably its internal resistance, its minimum voltage, its charge, its current state of charge (or SOC) ece and its maximum state of charge ecm. It is recalled that the maximum state of charge ecm varies over time, and notably as a function of the aging of the cellular battery BC and the temperature of the air surrounding the latter (BC).

[0047] It will also be noted that in the example illustrated non-limitingly in [Fig. 1] the vehicle S also comprises a distribution box BD to which the service battery BS, the converter CV and the on-board network RB are coupled. This distribution box BD is responsible for distributing in the on-board network RB the electrical energy which is produced by the converter CV or stored in the service battery BS, for the supply of the electrical components (or equipment) coupled to the on-board network RB, according to power supply requests received (in particular from the supervision computer CS of the GMP).

[0048] As mentioned above, the invention proposes in particular a management method intended to enable the management of the recharges of the cellular battery BC according to the state of charge ecd desired by the user of the system S (here a vehicle).

[0049] This (management) method can be implemented at least partially by the management device DG (illustrated in [Fig.2]) 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 management device DG can therefore be produced in the form of a combination of electrical or electronic circuits or components (or "hardware") and software modules (or "software"). As For example, it could be a microcontroller.

[0050] The memory MD is live in order to store instructions for the implementation by the processor PR1 of at least part of the management method. The processor PR1 may comprise integrated (or printed) circuits, or several integrated (or printed) circuits connected by wired or wireless connections. An integrated (or printed) circuit is understood to mean any type of device capable of carrying out at least one electrical or electronic operation.

[0051] In the example illustrated non-limitingly in Figures 1 and 2, the management device DG is part of the battery calculator CB. But it could be part of another calculator embedded in the system S (such as for example the calculator CA of the internal charger CH), or could comprise its own dedicated calculator.

[0052] As illustrated non-limitingly in [Fig. 2], the (management) method, according to the invention, comprises a step 10-100 which is implemented each time a user of the system S wants to recharge the cellular battery BC (and therefore, here, once the recharging connector CN has been temporarily coupled to a power source SA external to the vehicle S, via a recharging cable CR).

[0053] Step 10-100 of the method comprises a sub-step 10 in which one (for example the management device DG) begins by determining whether the user of the system S has requested a partial recharge of the cellular battery BC to obtain a desired state of charge ecd strictly lower than the maximum state of charge ecm, or a complete recharge of the cellular battery BC to obtain a desired state of charge ecd equal to the maximum state of charge ecm.

[0054] If the determination made in sub-step 10 indicates that the user wants to obtain a desired state of charge ecd strictly lower than the maximum state of charge ecm, in a sub-step 20 of step 10-100 one (for example the management device DG) authorizes the requested partial recharge until an estimated state of charge ece equal to this desired state of charge ecd is obtained.

[0055] To do this, one (for example the management device DG) imposes the use by the power source SA of a recharge current ir which is less than or equal to a maximum recharge current irmax which depends in particular on the current state of the cellular battery BC and the temperature of the air surrounding the latter (BC).

[0056] On the other hand, if the determination made in sub-step 10 indicates that the user wants to obtain a desired state of charge ecd equal to the maximum state of charge ecm, in a sub-step 30 of step 10-100 the use of the maximum recharge current irmax is imposed (for example the management device DG triggers the imposition of) until a maximum cellular voltage ucmax greater than or equal to a first threshold si is obtained.

[0057] It should be noted that the first threshold si can depend on the chemistry and aging of the BC cell battery, as well as possibly the temperature of the air surrounding the latter (BC). In this case, the first threshold si is determined by the DG management device according to the variable parameters of the BC cell battery. But it could also be predefined according to the chemistry of the BC cell battery.

[0058] Then, once ucmax > si is reached, in sub-steps 80 to 100 of step 10-100 a multiple step charge is performed (for example the management device DG triggers the performance of a) multiple step charge. Here, the term "multiple step charge" means a charging phase comprising a multiplicity of successive replacement steps prn. In each step prn, the use by the power source SA of a charging current irn is imposed (for example the management device DG triggers the imposition of) which is strictly lower than the previous charging current irn i (used during the previous step prn J- until the charging current irn used during the current step prn (with n' > n) is lower than a second threshold s2.

[0059] [Fig.4] schematically illustrates first and second examples of time evolution diagrams respectively of the recharge current ir (lower part) and of the maximum cellular voltage ucmax (upper part), during a recharge carried out by the implementation of the management method according to the invention.

[0060] The invention therefore makes it possible to reduce the duration of complete recharges while avoiding the occurrence of overcharging of the cellular battery BC, and therefore to increase the safety of the system S and its users and the lifespan of the cellular battery BC.

[0061] For example, and as illustrated non-limitingly in [Fig.3], step 10-100 of the method may comprise a sub-step 40 in which one (for example the management device DG) may compare the maximum cellular voltage ucmax to the first threshold si after the imposition of a recharge current ir.

[0062] If the maximum cell voltage ucmax is lower than the first threshold si, it can be determined (for example the management device DG) in a sub-step 50 of step 10-100 whether the multi-step recharge phase has started. If not, in a sub-step 60 of step 10-100 the current recharge current ir is maintained (for example the management device DG orders the maintenance of the) current recharge current ir (which is then equal to the maximum recharge current irmax), then sub-step 40 is carried out again. On the other hand, if the answer is yes (multi-step recharge phase started), in a sub-step 70 of step 10-100 the current recharge current ir is maintained (for example the management device DG orders the maintenance of the) current recharge current ir (which is then equal to the recharge current irn of the current step prn), then sub-step 40 is carried out again.

[0063] If the maximum cellular voltage ucmax is greater than or equal to the first threshold if, in a sub-step 80 of step 10-100 on (for example the management device DG) can increment by one the current value vp of a step counter prn (vp then becomes vp+1, and prn becomes prn+i), then can impose the use of a recharge current irn+i which is strictly lower than the previous recharge current irn (used during the previous step prn). Then, in a sub-step 90 of step 10-100 one (for example the management device DG) can compare the recharge current irn+i used during the current step prn+i to the second threshold s2.

[0064] If the recharge current irn+i is greater than or equal to the second threshold s2, this means that the multi-step recharge phase is not finished and therefore one (for example the management device DG) can carry out the sub-step 40 again to possibly start the following step prn+2 with the imposition of a new recharge current irn+2 strictly lower than the previous recharge current irn+i, and so on until the last recharge current irn„ used is lower than the second threshold s2.

[0065] On the other hand, if the recharge current irn+[ is lower than the second threshold s2, this means that the multi-step recharge phase is finished (and therefore more generally that the recharge of the cellular battery BC is finished), and consequently the management method ends in a sub-step 100 of step 10-100.

[0066] At least two different embodiments of the multi-step recharging phase can be envisaged.

[0067] For example, in a first embodiment, in step 10-100, when the recharge current used irn is greater than the second threshold s2, it is possible to interrupt (for example the management device DG can trigger an interruption of) the multi-step recharge when the number vp of steps prn performed is equal to a maximum number of steps npmax. It will be understood that this interruption is decided even though the last recharge current irn used is still greater than the second threshold s2, because it is considered that performing at least one additional step prn+i would not make it possible to significantly increase the current state of charge of the cellular battery BC.

[0068] Also for example, the maximum number of steps npmax can be between 8 and 12. As an illustrative example, the maximum number of steps npmax can be equal to 10. But other values ​​of the maximum number of steps npmax can be used. For example, the value of the maximum number of steps npmax can be chosen during the development phase of the cell battery BC.

[0069] Alternatively, in a second embodiment, in step 10-100, when the used recharge current irn is greater than the second threshold s2, it is possible to interrupt (for example the management device DG can trigger an interruption of) the multi-step recharge when the latter has been carried out for a duration which is equal to a chosen duration of. It will be understood that this interruption is decided even though the last recharge current irn used is still greater than the second threshold s2, because considers that continuing the multi-step charging phase would not significantly increase the current state of charge of the cellular battery BC.

[0070] For example, the chosen duration of can be between 1 hour and 12 hours. As an illustrative example, the chosen duration of can be equal to 5 hours. But other values ​​of the chosen duration of can be used. For example, the value of the chosen duration of can be chosen during the development phase of the cellular battery BC. It will be noted that this chosen duration of can possibly be variable depending on the type of the power source SA used (fast charging or slow charging).

[0071] It will also be noted that in step 10-100 the second threshold s2 may be a function of the minimum recharge current that can be delivered by the power source SA (external to the system S, temporarily coupled to the latter (S) and ensuring the recharge). As an illustrative example, the second threshold s2 may be equal to the minimum recharge current. It will be understood that it is pointless to continue a multi-step recharge phase by imposing the use of a new recharge current irn- lower than the minimum recharge current that can be delivered by the power source SA because this would not make it possible to increase the current state of charge of the cellular battery BC. But other values ​​of the second threshold s2 may be used, and in particular a value slightly higher than the minimum recharge current. For example, the value of the second threshold s2 may be chosen during the phase of fine-tuning the cellular battery BC.

[0072] It will also be noted that in step 10-100, during each step prn of the multi-step recharge it is possible to impose (for example the management device DG can trigger the imposition of) the use of a recharge current irn which is equal to the previous recharge current irn i multiplied by a chosen coefficient cc which is strictly less than one (i.e. irn = irn4*cc, with cc < 1).

[0073] For example, in step 10-100 the chosen coefficient cc may be between 0.6 and 0.95. As an illustrative example, the chosen coefficient cc may be equal to 0.85. But other values ​​of the chosen coefficient cc may be used. For example, the value of the chosen coefficient cc may be chosen during the development phase of the cellular battery BC.

[0074] It will also be noted that in step 10-100, one (for example the management device DG) can analyze (or monitor) the maximum cellular voltage ucmax at least as long as it is lower than the first threshold if, in order to detect as quickly as possible each drop in this maximum cellular voltage ucmax, following the use of a new recharge current ir strictly lower than the previous recharge current ir. Thus, in the event of a drop in the maximum cellular voltage ucmax, one can impose (for example the management device DG can impose the triggering of) a maintenance of this new recharge current until the maximum cell voltage ucmax returns above the value it had reached before this drop.

[0075] This “anti-oscillation” mechanism in fact advantageously makes it possible to prevent a drop in the maximum cell voltage ucmax, caused by a reduction in the recharge current ir, from automatically causing the recharge current to rise to the value it previously had, which would unnecessarily cause an oscillation of the recharge current and therefore an increase in the duration of the recharge as well as an accumulation of a chemical species around the anode (or plating) which is potentially dangerous. In addition, this anti-oscillation mechanism constitutes a closed feedback loop in real time which makes it possible to overcome the disadvantages of the open-loop time delays of the prior art (which require significant calibration phases due to the dependence of the variations in recharge current on temperature and voltage). In addition, this anti-oscillation mechanism makes it possible to increase the durability of the electronic components concerned.

[0076] It should be noted that it is not mandatory to continue the anti-oscillation mechanism during the multi-step recharging phase. However, such continuation can nevertheless be considered.

[0077] It will also be noted, as illustrated non-limitingly in [Fig.l], that the battery calculator CB (or the calculator of the management device DG) can also comprise a mass memory MM1, in particular for storing the maximum state of charge ecm, the desired state of charge ecd, the minimum recharge current that can be delivered by the power source SA, the possible aging state of the cellular battery BC and the possible temperature of the air surrounding the latter (BC), as well as possible intermediate data involved in all its calculations and processing.Furthermore, this battery calculator CB (or the calculator of the management device DG) can also comprise an input interface IE for receiving at least the maximum state of charge ecm, the desired state of charge ecd, the minimum recharge current that can be delivered by the power source SA, the possible aging state of the cellular battery BC, the possible temperature of the air surrounding the latter (BC), to use them in calculations or processing, possibly after having shaped and / or demodulated and / or amplified them, in a manner known per se, by means of a digital signal processor PR2. In addition, this battery calculator CB (or the calculator of the management device DG) can also comprise an output interface IS, in particular for delivering each message (or order) containing the definition of the imposed recharge current, and each message (or order) to stop the recharge.

[0078] It will also be noted that the invention also provides a program product computer (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 management method described above to manage the recharges of the cellular battery BC equipping the system S.

Claims

Claims

1. Method for managing recharges of a cellular battery (BC) having an estimated current state of charge and a maximum state of charge and equipping a system (S), characterized in that it comprises a step (10-100) in which, i) in the event of a request for partial recharging of said cellular battery (BC) to obtain a desired state of charge strictly lower than said maximum state of charge, said recharging is authorized until an estimated state of charge equal to said desired state of charge is obtained, and, ii) in the event of a request for complete recharging of said cellular battery (BC) to obtain a desired state of charge equal to said maximum state of charge, the use of a maximum recharging current is imposed until a maximum cellular voltage greater than or equal to a first threshold is obtained,then a multiple-step recharge is carried out in each of which the use of a recharge current strictly lower than the previous recharge current is imposed until said recharge current used is lower than a second threshold.,

2. Method according to claim 1, characterized in that in said step (10-100), when said recharge current used is greater than said second threshold, said multi-step recharge is interrupted when a number of steps taken is equal to a maximum number of steps.

3. Method according to claim 1, characterized in that in said step (10-100), when said recharge current used is greater than said second threshold, said multi-step recharge is interrupted when the latter has been carried out for a duration equal to a chosen duration.

4. Method according to one of claims 1 to 3, characterized in that in said step (10-100) said second threshold is a function of a minimum recharge current which can be delivered by a power source (SA) external to said system (S), temporarily coupled to the latter (S) and ensuring said recharge.

5. Method according to one of claims 1 to 4, characterized in that in said step (10-100) during each step of said multi-step recharge, the use of a recharge current equal to the previous recharge current multiplied by a chosen coefficient strictly less than one is imposed.

6. Method according to claim 5, characterized in that in said step (10-100) said chosen coefficient is between 0.6 and 0.

95.

7. Method according to one of claims 1 to 6, characterized in that in said step (10-100) analyzes said maximum cell voltage at least as long as it is lower than said first threshold so that in the event of a drop in said maximum cell voltage, following the use of a new recharge current strictly lower than a previous recharge current, a maintenance of said new recharge current is imposed until said maximum cell voltage returns above a value that it had reached before said drop.

8. Computer program product comprising a set of instructions which, when executed by processing means, is capable of implementing the management method according to one of claims 1 to 7 for managing recharges of a cellular battery (BC), having an estimated current state of charge and a maximum state of charge and equipping a system (S).

9. Management device (DG) for managing recharges of a cellular battery (BC) having an estimated current state of charge and a maximum state of charge and equipping a system (S), characterized in that it comprises at least one processor (PR1) and at least one memory (MD) arranged to carry out the operations consisting, i) in the event of a request for partial recharging of said cellular battery (BC) to obtain a desired state of charge strictly lower than said maximum state of charge, in authorizing said recharging until an estimated state of charge equal to said desired state of charge is obtained, and, ii) in the event of a request for complete recharging of said cellular battery (BC) to obtain a desired state of charge equal to said maximum state of charge, in triggering an imposition of the use of a maximum recharging current until a maximum cell voltage greater than or equal to a first threshold is obtained,then to trigger the carrying out of a multi-step recharge in each of which an imposition of a recharge current strictly lower than the previous recharge current is triggered until said recharge current used is lower than a second threshold.,

10. System (S) comprising a cellular battery (BC) having an estimated current state of charge and a maximum state of charge, characterized in that it further comprises a management device (DG) according to claim 9.

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