Improving battery life based on sensor data

Abstract

The invention relates to a system for controlling the energy supply of a device (104). The device may be a power retention device that requires permanent power supply. To this end, it may alternatively be powered by a power supply (140) in a first mode or by a battery (102) in a second mode. At least one sensor (110‑114; 105) of the system acquires data related to the battery, such as environmental data, the voltage of the battery or the discharge current of the battery. Based on the data and at least one characteristic curve of the battery, a battery monitoring module is configured to switch between the first mode and the second mode to improve the life of the battery.

Description

Technical Field

[0001] The present invention relates to the monitoring of battery life cycle and, in particular, but not exclusively, to the monitoring of battery life cycle in the context of solid-state batteries. Background Art

[0002] Batteries or supercapacitors are often used to provide power to devices when no other power source is available. In particular, power retention devices such as real-time clocks (RTCs) need to be continuously powered even when the power is off. For this reason, traditional backup systems integrate supercapacitors or chemical batteries to provide power in any situation. For example, a backup battery can be used to power a data retention device when the output voltage of the power supply drops below a threshold.

[0003] The expression "power retention device" refers to any device (such as a memory or an RTC) that embeds critical functions that should not be interrupted even when the power supply is turned off or defective.

[0004] RTC is used in many applications, especially in industrial automation control processing unit (CPU) or remote terminal unit (RTU) modules.

[0005] Once fully or partially discharged, the battery can be recharged by supplying power from a power source. However, the number of recharge cycles for a battery is limited and depends on the battery technology (e.g. conventional or solid-state), the depth of discharge, and many other factors.

[0006] Furthermore, batteries are very sensitive to operating conditions and the battery life cycle strongly depends on these operating conditions.

[0007] In a 10-year period, within a given temperature range, the RTC retention time is typically guaranteed to be 40 days. To achieve this, the life of the battery used to power a data retention device such as an RTC needs to be extended. Summary of the invention

[0008] It is an object of the present invention to alleviate at least some of the above disadvantages.

[0009] A first aspect of the present invention relates to a system for controlling energy supply to a device, comprising:

[0010] Battery;

[0011] power supply;

[0012] Equipment, powered alternately by batteries or a mains supply;

[0013] at least one sensor configured to sense battery-related data;

[0014] A battery monitoring module is operably coupled to the switch and configured to control the switch based at least on the data and at least one predefined curve to switch between a first mode in which the load and the battery are powered by the power source and a second mode in which the device is powered by the battery, wherein the predefined curve is a characteristic curve of the battery.

[0015] The battery monitoring module thus enables alternation between the first mode and the second mode to improve the battery life, since the characteristic curve of the battery and the environmental data acquired by the sensor are taken into account.

[0016] According to some embodiments, the at least one sensor may include one or more of the following:

[0017] - a temperature sensor arranged to sense the temperature of the battery;

[0018] - a humidity sensor arranged to sense the humidity ratio of the environment of the battery,

[0019] - a pressure sensor arranged to sense the pressure of the environment of the battery;

[0020] - a vibration sensor arranged to sense vibrations around the battery; and

[0021] - A shunt and an ammeter arranged to determine the value of the load applied to the battery.

[0022] Therefore, the data acquired by the sensor is data that affects the operation and life of the battery.

[0023] According to some embodiments, the at least one predefined curve may represent the voltage of the battery depending on the discharge of the battery for several temperature values, and the at least one sensor may include a temperature sensor arranged for sensing the temperature of the battery.

[0024] Therefore, the discharge of the battery can be managed by the battery monitoring module for different temperature conditions.

[0025] Alternatively or in addition, the at least one predefined curve may represent the voltage of the battery depending on discharge of the battery for several load values, and the at least one sensor may comprise a shunt and an ammeter arranged for measuring the load value applied to the battery.

[0026] Therefore, the discharge of the battery can be managed by the battery monitoring module for different load conditions.

[0027] Alternatively or in addition, the battery monitoring module may determine a minimum voltage value of the battery based on at least one predefined curve and based on the maximum discharge rate, and when in the second mode, if the voltage of the battery reaches the minimum voltage value, the battery monitoring module switches to the first mode.

[0028] Therefore, the battery monitoring module ensures that the battery's discharge rate remains below the maximum discharge rate, thereby improving the battery's life.

[0029] Alternatively or as a supplement, the battery monitoring module can control a load-shedding system in the event of a current overload. In particular, when the battery is responsible for powering equipment other than the device, some of the other equipment can be released and disconnected from the power supply battery so that the device can be powered uninterruptedly.

[0030] According to some embodiments, the switch may have a controllable switching rate, and the switching rate of the switch may be lower than a predefined value.

[0031] The controllable switching rate enables peaks in the current in the battery to be avoided when switching to the second mode, thus extending the battery life.

[0032] As a supplement, the switching speed of the switch can be greater than 10kHz.

[0033] According to some embodiments, in the first mode, the battery may be powered by a voltage regulator between the battery and a power source.

[0034] The voltage regulator regulates the voltage delivered by the power source to charge the battery.

[0035] According to some embodiments, the system may further include a current limiter between the voltage regulator and the battery, and the current limiter may be configured to limit a charging current delivered to the battery in the first mode.

[0036] The current limiter enables the battery to be charged slowly, which extends the life of the battery.

[0037] According to some embodiments, the battery monitoring module may also be configured to control environmental conditions of the battery based on the data.

[0038] For example, the battery monitoring module can control temperature, humidity, and pressure to avoid battery degradation and thus extend its life.

[0039] According to some embodiments, the battery monitoring module may include a counter, and the counter may be configured to start when the battery monitoring module is switched to the first mode, and if the counter reaches a preset counter value, the battery monitoring module may switch to the second mode.

[0040] This makes it possible to extend the life of the battery.

[0041] According to some embodiments, at least one characteristic curve may represent a change in battery capacity depending on the number of charging cycles.

[0042] Managing the number of charging cycles enables the life of the battery to be extended.

[0043] According to some embodiments, the battery may be a solid-state battery.

[0044] Solid-state batteries have an average lifespan longer than batteries using liquid electrolytes.

[0045] According to some embodiments, the device may be a real time clock.

[0046] A real-time clock needs to be permanently powered, so the system according to the invention is very suitable for this application.

[0047] According to some embodiments, the battery monitoring module may further include an interface configured to increase the voltage delivered by the power source.

[0048] This makes it possible to store more power in the battery. Correspondingly, it limits the life cycle of the battery, which, however, is compensated by the above-mentioned technical features of the invention. Thus, even when the power stored in the battery exceeds the nominal power of the battery, a minimum autonomy (e.g. 40 days) during a minimum life cycle (e.g. 10 years) can be ensured. Thus, this embodiment makes it possible to use the same battery architecture with different RTCs consuming different power levels.

[0049] A second aspect of the present invention relates to a method for controlling the power supply of a device in a system, the system comprising a device alternately powered by a battery or a power source, the method comprising the following operations:

[0050] -Sensing battery-related data;

[0051] - controlling the switch based at least on the data and at least one predefined curve, which is a characteristic curve of the battery, to switch between a first mode in which the load and the battery are powered by the power source and a second mode in which the device is powered by the battery.

[0052] Other objects, aspects, effects and details of the present invention are described in the following detailed description of various exemplary embodiments with reference to the accompanying drawings. BRIEF DESCRIPTION OF THE DRAWINGS

[0053] By way of example only, embodiments of the present disclosure will be described with reference to the accompanying drawings, in which:

[0054] Figure 1 A system according to some embodiments of the present invention is shown;

[0055] Figure 2 shows a first characteristic curve of a battery in a system according to some embodiments of the present invention;

[0056] Figure 3 shows a second characteristic curve of a battery in a system according to some embodiments of the present invention;

[0057] Figure 4 is a graph showing discharge current values ​​of a battery and pulse power values ​​based on pulse length in a system according to some embodiments of the present invention;

[0058] Figure 5 shows different curves in a system with switches with controlled slew rates and in a system with switches with uncontrolled slew rates;

[0059] Figure 6 is a curve showing the variation of battery capacity depending on the number of cycles; and

[0060] Figure 7 is a flow chart illustrating steps or operations of a method according to some embodiments of the present invention. DETAILED DESCRIPTION

[0061] refer to Figure 1 , showing a system according to some embodiments of the present invention.

[0062] The system includes a device 104, in particular a power retention device in the context of the present invention, which is alternately powered by a battery 102 or a power supply 140. In the following, the device 104 is considered to be a real-time clock RTC. However, there is no limitation on the device 104, and the device 104 can be any device that requires power retention, such as a memory or a low power (LP), a remote terminal unit (RTU) or any device with a function that requires permanent power supply. Since the device 104 can be powered by the battery 102, the device 104 can be referred to as a "battery load" in the following.

[0063] The RTC 104 may be integrated into a larger entity, such as other modules of the larger entity that synchronize based on the RTC signal.

[0064] The power supply 140 may be an external power supply, or may be a common power supply of a larger entity. The RTC 104 may be connected to the power supply 140 via the backplane 130. The backplane 130 is a board to which components of the larger entity are connected.

[0065] The power source 140 may be a voltage source that provides 24 volts (V). However, there is no limitation on the voltage / current level delivered by the power source 140.

[0066] The system includes a battery monitoring module 101 operably coupled to a switch 103 via a first interface 120. The battery monitoring module 101 may be a microcontroller, such as a microcontroller STM32 F301. A microcontroller refers to any computing unit on a single integrated circuit. However, there is no limitation on the battery monitoring module 101, which may alternatively include separate components, such as a processor running software for executing the steps of the method according to the present invention, a memory storing instructions (such as a random access memory RAM and a read-only memory ROM), and an input / output interface. At least some components of the battery monitoring module 101 may also be virtualized in the cloud. In this case, the system according to the present invention also includes a network interface for accessing a network (such as an IP network for accessing virtualized components).

[0067] The battery monitoring module 101 is configured to open or close a switch to disconnect / connect the battery from the RTC 104 and switch between the first mode and the second mode. There is no limitation on the switch 103, which encompasses any entity configured to open and close a circuit (or more generally, significantly change the resistance value between two points of a circuit).

[0068] According to a first mode, the device 104 and the battery 102 are powered by the power source 140, and the switch 103 is open. According to a second mode, the device 104 is powered by the battery 102, and the switch 103 is closed.

[0069] The battery monitoring module 101 can also measure the current flowing through the battery 102 and the voltage of the battery 102 via the second interface 121 by means of the shunt resistor 105 between the battery 102 and the switch 103. The discharge current corresponds to the load value of the battery. The load value can be expressed as a multiple of the nominal discharge current of the battery. For example, if the nominal discharge current of the battery is 100 μA, a load value of 500 μA is recorded as 5C.

[0070] The second interface 121 may be an analog-to-digital converter (ADC) interface.

[0071] According to the present invention, the battery monitoring module 101 is also connected to at least one sensor 110. Figure 1 , for illustration purposes only, four sensors 111 to 114 are shown:

[0072] A temperature sensor 111 is arranged to sense the temperature of the battery 102 or the temperature around (near) the battery 102;

[0073] a humidity sensor 112 arranged to sense the humidity ratio of the environment of the battery 102 ;

[0074] - a pressure sensor 113 arranged to sense the air pressure around the battery 102;

[0075] A vibration sensor 114 arranged to sense vibrations around the battery 102 .

[0076] The system may include Figure 1 The shunt resistor 105 coupled to the interface 121 can also be regarded as a sensor for obtaining the discharge current of the battery supplied to the load.

[0077] Indeed, in the context of the present invention, the wording “sensor” encompasses any device configured to acquire data related to the battery 102 .

[0078] The battery monitoring module 101 may be connected to the sensor(s) 110 via a dual master bus (DualMaster Bus) on the I2C1 pins I2C1-SDA and I2C1-SCL.

[0079] As described below, the battery monitoring module 101 is configured to manage the charging and discharging of the battery using the switch 103 taking into account data emitted from at least one sensor. The battery monitoring module 101 also takes into account at least one predefined curve, which is a characteristic curve of the battery 102. The characteristic curve can be provided by the battery manufacturer. The characteristic curve can also be derived from manufacturer data. For example, it can be obtained by updating the manufacturing data. Figures 2 to 4 To describe an example of a characteristic curve.

[0080] The switch 103 is preferably selected to have a controllable switching rate and a high speed, such as above 10 kHz. This enables the inrush current to be minimized when switching from powering the device 104 with the power supply 140 to powering the device 104 with the battery 102, see Figure 5 It will be better understood. Inrush current is a momentary high input current generated when a power supply or device is turned on. The controllable switching rate makes it possible to limit the damage to the normalized capacity over the entire temperature range (for example from -20°C to 80°C). In particular, it limits the speed variation of the switch 103.

[0081] According to some embodiments, the battery may be a solid-state battery. A solid-state battery is a battery in which the electrolyte is in a solid phase. Compared to liquid batteries, solid-state batteries have the advantage of higher energy density due to their tolerance to higher temperatures. In addition, solid-state batteries are safer because liquid electrolytes are generally flammable. Solid-state batteries are also more compact because fewer safety systems are required.

[0082] There is no limitation on the type of solid-state battery used. For example, the solid-state battery can be a ceramic battery. Ceramic batteries are small enough to be implemented on a printed circuit board (PCB).

[0083] According to some embodiments, the system may include a voltage regulator 107 that receives power from a power source 140 .

[0084] The voltage regulator 107 may be a low drop out (LDO) regulator that can regulate the output voltage when the supply voltage (from the power supply 140) is very close to the output voltage. This enables the battery 102 to be charged with a constant voltage source and the RTC 104 to be powered with a constant voltage.

[0085] The system may also include a current limiter 106 between the battery 102 and the voltage regulator 107, which makes it possible to limit the charging current to a maximum value, thus limiting the impact of the current on the battery capacity. In fact, the slower the charging, the higher the charging capacity of the battery. Therefore, the current limiter 106 can improve the life of the battery.

[0086] Examples of characteristic curves are given below. Some characteristic curves may represent the voltage of a battery depending on the discharge rate of the battery for several environmental data values. The environmental data values ​​may include, for example, temperature values ​​or load values.

[0087] In the following, for illustration purposes only, the following general technical data of the battery 102 are considered:

[0088] - Nominal voltage: 1.4V;

[0089] -Operating voltage Vop: 0 to 1.6V;

[0090] - Nominal capacity: 100μAh;

[0091] - Nominal discharge current: 100μA;

[0092] - Operating temperature: between -20℃ and +80℃;

[0093] - Initial internal resistance: <200Ω;

[0094] - Weight of battery 102: 0.04 g.

[0095] However, the present invention can be applied to any battery regardless of its general technical data.The battery monitoring module may also take into account the general technical data of the battery 102 when deciding to switch between the first mode and the second mode.

[0096] Battery manufacturers typically define the charge and discharge profiles for their batteries based on temperature, load, and normalized capacity.

[0097] refer to Figure 2 , shows a first characteristic curve of the battery 102 according to some embodiments of the present invention.

[0098] The first characteristic curve shows the voltage of the battery 102 depending on the discharge capacity for different load values ​​(0.2C, 1C, 2C, 5C and 10C) for a given battery. Assuming that the battery 102 has a nominal discharge current of 100 μA as described above, the different load values ​​correspond to 20 μA, 100 μA, 200 μA, 500 μA and 1000 μA, respectively.

[0099] The first characteristic curve may also correspond to a given temperature, such as 25° C., and a given charge, such as a constant voltage charge at 1.6 V for 3 hours. Similar curves may be obtained (from the manufacturer or by experimentation) for other temperature values.

[0100] The first characteristic curve enables predicting a rapid discharge of the battery when in the second mode and switching to the first mode before the rapid discharge begins. To achieve this, the battery monitoring module can check whether the voltage of the battery is above a given threshold or minimum voltage value at a given load value. The threshold value can be determined to ensure that the discharge speed does not exceed the maximum discharge speed. The threshold value can vary depending on the load value, or can be common to all load values ​​(e.g., 1.4V).

[0101] Then, when in the second mode, if the voltage of the battery 102 is below the threshold, the battery monitoring module 101 opens the switch 130 to switch to the first mode.

[0102] refer to Figure 3 , shows a second characteristic curve of the battery 102 according to some embodiments of the present invention.

[0103] The second characteristic curve shows the voltage of the battery 102 as a function of the discharge capacity for different temperature values ​​(TA=-20° C.; 0° C.; 25° C. and 80° C.) for a given battery.

[0104] The second characteristic curve may also correspond to a constant discharge current of 20 μA at 0 V and a given charge, such as a constant voltage charge for 3 hours at 1.6 V. Similar curves may be obtained (from the manufacturer or by experiment) for other constant discharge currents.

[0105] The second characteristic curve enables predicting a rapid discharge of the battery when in the second mode and switching to the first mode before the rapid discharge begins. To achieve this, the battery monitoring module can check whether the voltage of the battery is above a given threshold or minimum voltage value at a given temperature value. The threshold value can be determined to ensure that the discharge speed does not exceed the maximum discharge speed. The threshold value can vary depending on the temperature value, or can be common to all temperature values ​​(e.g. 1.4V).

[0106] Then, when in the second mode, if the voltage of the battery 102 is below the threshold, the battery monitoring module 101 opens the switch 130 to switch to the first mode.

[0107] According to some embodiments, for example, the battery monitoring module 101 considers both the first characteristic curve and the second characteristic curve to define a voltage threshold applicable to all load and temperature values. Figure 2 and Figure 3 From the characteristic curve, it can be considered that the discharge voltage that does not affect the normalized discharge capacity is equal to or greater than 1.5V. Therefore, the threshold can be set to 1.5V.

[0108] One or several criteria may be defined for the battery monitoring module 101 , which then controls the switches based on the characteristic curve and environmental data to ensure that the criteria are met.

[0109] These standards are as follows:

[0110] - limiting the rapid discharge of the battery by taking into account data from sensors, such as load, temperature and humidity values. To this end, a voltage threshold can be set as described above;

[0111] - Use load and temperature values ​​to limit the depth of discharge of the battery. For example, a maximum depth of discharge value can be set. Based on this value and the load value and / or temperature value, a corresponding voltage threshold can be determined, and the switch 103 is controlled based on a comparison between the voltage value of the battery 102 and the voltage threshold;

[0112] - Discharge is limited to 20% of the normalized capacity by monitoring the charging curve of the battery (limiting the charging current) and also based on the analysis of the discharge current. In fact, knowing the discharge current enables the charge or discharge capacity of the battery 102 to be obtained.

[0113] As described above, the slew rate of the switch 103 is controllable, which enables the inrush current to be managed.

[0114] Figure 4 The values ​​of pulse power (in mW) based on the value of discharge current and pulse length are shown. These data are provided by the battery manufacturer and represent the pulse power that the battery 102 can support without damaging the battery 102.

[0115] The following table can be provided for this figure, which indicates the time interval for each pulse length:

[0116]

[0117] These data may correspond to a fixed temperature value of 25°C.

[0118] Controlling the switching rate of the switch 103 enables limiting the inrush current and enabling avoiding damage to the battery. In fact, a strong inrush current can rapidly discharge the battery 103 and / or degrade it.

[0119] Figure 5 Included are curves showing the difference between a controlled slew rate (left curve) and an uncontrolled slew rate (right curve) of switch 103.

[0120] Referring to the right curve, the bottom curve represents the command of the switch 103. It can be observed that the switch is closed suddenly. The current delivered by the power supply 140 to the RTC also decreases suddenly until it becomes zero. Regarding the current delivered by the battery, because the change in current is sudden, it produces a current peak above the target current value. The current peak is likely to damage the battery 103 and shorten its life.

[0121] This peak is avoided by controlling the slew rate according to the left curve, where the slope of the switching command is reduced compared to the right curve.

[0122] It should also be noted that the battery monitoring module 101 can only switch between the first mode and the second mode when the power supply 140 is available. Even when the power supply 140 is available, switching to the second mode is useful because the battery will not be permanently (or for a long time) disconnected. In fact, the battery monitoring module 101 also takes into account that in order to avoid damaging the battery and reducing its capacity, the battery will be used regularly. To this end, the battery monitoring module 101 can be forced to switch to the second mode after a given period in the first mode exceeds a threshold. For this purpose, the battery monitoring module 101 may include a counter that is started when the switch 103 is switched to the first mode. If the counter reaches a preset counter value, the battery monitoring module 101 can switch to the second mode to avoid long disconnection time.

[0123] The battery monitoring module 101 also attempts to reduce the number of charging cycles of the battery 103 because Figure 6 As shown, after a certain number of charging cycles, the capacity of the battery decreases. Therefore, the battery monitoring module 101 ensures a compromise between battery aging due to the number of charging cycles and degradation due to long periods of disconnection.

[0124] By managing the battery (limiting charging current, controlling the switching rate of the switch, and optimally switching between the first mode and the second mode) based on the sensor values ​​and the characteristic curve, the life of the battery 103 can be increased by approximately 15%.

[0125] like Figure 1 As shown, the battery monitoring module 101 may further include a fourth interface 123, such as a digital to analog converter (DAC). Through the DAC 123, the battery monitoring module 101 is configured to increase the voltage applied to the battery 102 and the RTC 104. This enables more power to be stored in the battery. Correspondingly, it limits the life cycle of the battery, however, this is compensated by the above-mentioned technical features of the present invention. Therefore, even when the power stored in the battery 103 exceeds the nominal power of the battery, the minimum autonomy (e.g., 40 days) during the minimum life cycle (e.g., 10 years) can be ensured. Therefore, this embodiment enables the use of the same battery architecture with different RTCs consuming different power levels.

[0126] The battery monitoring module 101 may also include an internal clock, such as a real-time clock RTC, or may access an external clock, such as the device 104, in order to measure time and manage the timing of the operations described below.

[0127] The battery monitoring module may include and control a load shedding system (not shown in the figure). In particular, in the case of a current overload, and in the case where the battery is responsible for powering equipment other than the device 104, some of the other equipment may be released and disconnected from the battery by the load shedding system so that the device 104 can be powered uninterruptedly.

[0128] Figure 7 is a flow chart illustrating steps or operations of a method according to some embodiments of the present invention.

[0129] In step 700, the system according to the present invention is in a current mode among the first mode or the second mode.

[0130] In step 701, data related to the battery is sensed by one of the sensors. As described above, the data may be the voltage, discharge current and / or temperature / humidity / pressure / vibration of the battery 102.

[0131] In step 702 , the battery monitoring module 101 determines whether to switch the switch 103 based on the current mode, the sensed data, and a predefined characteristic curve of the battery.

[0132] If it is determined in step 702 to switch the switch 103, then in step 703, the battery monitoring module 101 switches from the current mode to another mode. Then in step 700, the other mode is considered as the current mode.

[0133] Otherwise, the method returns to step 700 and the battery monitoring module 101 remains in the current mode.

[0134] Although the present invention has been described above with reference to specific embodiments, the present invention is not intended to be limited to the specific forms set forth herein. On the contrary, the present invention is limited only by the appended claims, and within the scope of these appended claims, other embodiments besides the specific embodiments described above are also possible.

[0135] In addition, although exemplary embodiments have been described above with some exemplary combinations of components and / or functions, it should be understood that alternative embodiments may be provided by different combinations of components and / or functions without departing from the scope of the present disclosure. In addition, it is specifically contemplated that specific features described separately or as part of an embodiment may be combined with other separately described features or parts of other embodiments.

Claims

1. A system for controlling power supply of a device, comprising: Battery (102); Power supply (140); Switch(103); The device (104) is powered alternately by the battery or the power source; At least one sensor (110-114; 105), configured to sense data affecting the operation and life of the battery; a battery monitoring module (101) operably coupled to the switch (103) and configured to control the switch based at least on the data and at least one predefined curve to switch between a first mode in which the power source supplies power to the load and the battery and a second mode in which the battery supplies power to the device, wherein the predefined curve is a characteristic curve of the battery, Wherein, the at least one sensor (110-114; 105) includes at least one of the following: - a temperature sensor (111) arranged to sense the temperature of the battery; - a humidity sensor (112) arranged to sense the humidity ratio of the environment of the battery, - a pressure sensor (113) arranged to sense the pressure of the environment of the battery; - a vibration sensor (114) arranged to sense vibrations around the battery; or - a shunt (105) and an ammeter arranged to determine the value of the load applied to the battery.

2. The system according to claim 1, wherein: the at least one predefined curve representing the voltage of the battery as a function of the discharge of the battery for several temperature values; The at least one sensor comprises a temperature sensor (111), wherein the temperature sensor (111) is arranged to sense the temperature of the battery (102).

3. The system according to claim 1, wherein: The at least one predefined curve represents the voltage of the battery (102) depending on the discharge of the battery for several load values; and The at least one sensor comprises a shunt (105) and an ammeter, wherein the shunt (105) and the ammeter are arranged to measure a load value applied to the battery.

4. The system according to claim 2, wherein: The battery monitoring module (101) determines a minimum voltage value of the battery based on the at least one predefined curve and based on the maximum discharge rate, and when in the second mode, if the voltage of the battery reaches the minimum voltage value, the battery monitoring module switches to the first mode.

5. The system according to any one of claims 1 to 4, wherein: The switch (103) has a controllable switching rate, and wherein the switching rate of the switch is lower than a predefined value.

6. The system according to claim 5, wherein: The switch (103) has a switching speed greater than 10 kHz.

7. The system according to any one of claims 1 to 4, wherein: In a first mode, the battery is powered by a voltage regulator (107) between the battery (102) and the power source (140).

8. The system according to claim 7, further comprising a current limiter (106) between the voltage regulator (107) and the battery (102), wherein: The current limiter is configured to limit a charging current delivered to the battery in a first mode.

9. The system according to one of claims 1 to 4, wherein: The battery monitoring module (101) is also configured to control the environmental conditions of the battery (102) based on the data.

10. The system according to one of claims 1 to 4, wherein: The battery monitoring module (101) comprises a counter, wherein the counter is configured to start when the battery monitoring module is switched to a first mode, and wherein if the counter reaches a preset counter value, the battery monitoring module switches to a second mode.

11. The system according to one of claims 1 to 4, wherein: The at least one characteristic curve represents the change in the battery capacity as a function of the number of charging cycles.

12. The system according to one of claims 1 to 4, wherein: The battery (102) is a solid-state battery.

13. The system according to any one of claims 1 to 4, wherein: The device (104) is a real time clock.

14. The system according to one of claims 1 to 4, wherein: The battery monitoring module (101) also includes an interface configured to increase the voltage delivered by the power source (140).

15. A method for controlling power supply of a device in a system, the system comprising a device, a battery, a power supply, a switch and at least one sensor, the device being powered alternately by the battery or the power supply, the method comprising the following operations: - sensing data affecting the operation and life of the battery by means of the at least one sensor (701); - controlling (702; 703) the switch to switch between a first mode in which the load and the battery are powered by the power source and a second mode in which the device is powered by the battery, based at least on the data and at least one predefined curve, the predefined curve being a characteristic curve of the battery, The at least one sensor includes at least one of the following: - a temperature sensor arranged to sense the temperature of the battery; - a humidity sensor arranged to sense the humidity ratio of the environment of the battery, - a pressure sensor arranged to sense the pressure of the environment of the battery; - a vibration sensor arranged to sense vibrations around the battery; or - a shunt and an ammeter arranged to determine the value of the load applied to the battery.

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