CN111398827A - Ambient temperature prediction method, battery temperature prediction method and power calculation method - Google Patents

Abstract

The present disclosure provides an environmental temperature prediction method, including: acquiring the initial moment when the battery is in the current temperature environment and the initial temperature of the battery surface, and the final moment when the battery surface temperature reaches a stable temperature in the current temperature environment and the stable temperature of the battery surface; at least Based on the time length from the initial time to the final time, calculate the average heating power of the internal resistance of the battery within the time length; at least based on the average heating power of the internal resistance of the battery, obtain the battery temperature change caused by the heating of the internal resistance of the battery; The temperature of the current temperature environment is obtained from the temperature, the stable temperature of the battery surface, and the amount of battery temperature change caused by the heating of the internal resistance of the battery. The present disclosure also provides a battery temperature prediction method, a battery power calculation method, a battery management system, and an electronic device.

Description

Ambient temperature prediction method, battery temperature prediction method and power calculation method

technical field

The present disclosure relates to an environmental temperature prediction method, a battery temperature prediction method, an electric quantity calculation method, a battery management system and an electronic device, and is especially suitable for temperature prediction of lithium batteries and electric quantity calculation of lithium batteries.

Background technique

In personal consumer electronic devices, such as mobile phones, wireless headsets and other mobile devices, various chemical energy batteries are usually provided as energy sources. In the process of moving such mobile devices, the working environment of the mobile devices will be in a process of rapid changes, including natural environment such as temperature, humidity, pressure, etc., as well as fluctuations in the load of the mobile devices.

Since temperature has a strong influence on the characteristics of batteries (especially lithium batteries). Therefore, it is very important to accurately predict the temperature change of the battery during operation for the battery power calculation method.

In actual use, for example, in winter, the temperature difference between indoor and outdoor is very large. The indoor temperature is generally 25°C, and the outdoor environment may vary from 0°C to -40°C according to their own conditions. In different temperature environments, the battery temperature is not only affected by its own characteristics and load heating, but also by environmental changes, which will lead to deviations in the prediction of battery temperature by the existing battery model based on the gauge algorithm. Causes a bias in the battery charge calculation. The accurate prediction of the temperature change of the battery is directly related to the accuracy of the battery power calculation method.

Existing battery models based on a gauge algorithm are based on the behavior of the open circuit voltage of the battery itself at different temperatures. In the process of charging and discharging, due to the internal impedance inside the battery, when the current flows inside the battery, heat is generated, which directly affects the change of the characteristics of the battery. The usual power calculation method only considers the temperature rise caused by the heat generated by the charging and discharging current on the internal impedance of the battery, but lacks the influence of the battery temperature change caused by the environmental temperature change. The drastic change of the ambient temperature is much faster than the change of the battery temperature caused by the resistance heating inside the battery. Especially under low temperature conditions, the internal resistance of the battery will also have a very large change with the overall change of temperature.

SUMMARY OF THE INVENTION

In order to solve at least one of the above technical problems, the present disclosure provides an ambient temperature prediction method, a battery temperature prediction method, a power calculation method, a battery management system, and an electronic device.

The environmental temperature prediction method, the battery temperature prediction method, the electric quantity calculation method, the battery management system and the electronic device of the present disclosure are realized by the following technical solutions.

According to one aspect of the present disclosure, there is provided a method for predicting an ambient temperature, including: acquiring an initial moment when a battery is in a current temperature environment and an initial temperature of a battery surface, and a final moment when the battery surface temperature reaches a stable temperature in the current temperature environment and the battery Surface stable temperature; at least based on the time length from the initial time to the final time, calculate the average heating power of the battery internal resistance within the time length; based on at least the average heating power of the battery internal resistance, obtain the battery temperature change caused by the heating of the battery internal resistance; And the temperature of the current temperature environment is obtained based on the initial temperature of the battery surface, the stable temperature of the battery surface, and the amount of battery temperature change caused by the heating of the internal resistance of the battery.

According to the ambient temperature prediction method of at least one embodiment of the present disclosure, the initial temperature of the battery surface and the stable temperature of the battery surface are measured by a temperature sensor.

According to the ambient temperature prediction method of at least one embodiment of the present disclosure, the average heating power of the battery internal resistance within the time period is calculated based on at least the battery internal resistance value within the time period.

According to the environmental temperature prediction method of at least one embodiment of the present disclosure, obtaining the temperature of the current temperature environment based on the initial temperature of the battery surface, the stable temperature of the battery surface, and the amount of battery temperature change caused by the heating of the internal resistance of the battery, including: based on the initial temperature of the battery surface Temperature and battery surface stable temperature Calculate the battery surface temperature change within the time period; calculate the difference between the battery surface temperature change and the battery temperature change caused by the heat generated by the internal resistance of the battery; and obtain the current temperature environment based on at least the difference temperature.

According to the ambient temperature prediction method of at least one embodiment of the present disclosure, the output voltage of the battery and the surface temperature are measured in real time or in a predetermined time period within the time length; The internal resistance of the battery over the length of time that the voltage and surface temperature are calculated.

According to the ambient temperature prediction method of at least one embodiment of the present disclosure, within the time length, the output current of the battery is also measured in real time or in a predetermined time period; the output voltage and output of the battery are measured based on the real time or in a predetermined time period. Current, calculate the average output power of the battery within the time length; at least calculate the output voltage of the battery within the time length based on the average output power of the battery, the output voltage of the battery measured in real time or in a predetermined time period, and the battery internal resistance value within the time length. The average heating power of the internal resistance of the battery.

According to the ambient temperature prediction method of at least one embodiment of the present disclosure, obtaining the temperature of the current temperature environment based on at least the difference includes: obtaining the relationship between the difference and the temperature of the current environment based on the second law of thermodynamics and a heat transfer model of the battery.

According to yet another aspect of the present disclosure, a method for predicting an ambient temperature is provided, comprising: acquiring the time length during which the battery surface temperature changes from a first stable temperature to a second stable temperature; calculating the average heating power of the internal resistance of the battery within the time length ; Based on at least the average heating power of the battery internal resistance, obtain the battery temperature change caused by the heating of the battery internal resistance; and obtain the current temperature based on the first stable temperature, the second stable temperature and the battery temperature change caused by the battery internal resistance heating ambient temperature.

According to the ambient temperature prediction method of at least one embodiment of the present disclosure, the first stable temperature is the stable temperature of the battery surface when the battery is in the first temperature environment, and the second stable temperature is the stable temperature of the battery surface when the battery is in the second temperature environment.

According to the ambient temperature prediction method of at least one embodiment of the present disclosure, the first stable temperature and the second stable temperature are measured by a temperature sensor.

According to the ambient temperature prediction method of at least one embodiment of the present disclosure, the average heating power of the battery internal resistance within the time period is calculated based on at least the battery internal resistance value within the time period.

According to the environmental temperature prediction method of at least one embodiment of the present disclosure, obtaining the temperature of the current temperature environment based on the first stable temperature, the second stable temperature, and the battery temperature change amount caused by the heating of the internal resistance of the battery, includes: based on the first stable temperature Calculate the temperature change of the battery surface within the time length of the calculation of the temperature and the second stable temperature; calculate the difference between the temperature change of the battery surface and the battery temperature change caused by the heat generated by the internal resistance of the battery; and obtain the current temperature environment based on the difference. temperature.

According to the ambient temperature prediction method of at least one embodiment of the present disclosure, the output voltage of the battery and the surface temperature are measured in real time or in a predetermined time period within the time length; The internal resistance of the battery over the length of time that the voltage and surface temperature are calculated.

According to the ambient temperature prediction method of at least one embodiment of the present disclosure, within the time length, the output current of the battery is also measured in real time or in a predetermined time period; the output voltage and output of the battery are measured based on the real time or in a predetermined time period. Current, calculate the average output power of the battery within the time length; at least calculate the output voltage of the battery within the time length based on the average output power of the battery, the output voltage of the battery measured in real time or in a predetermined time period, and the battery internal resistance value within the time length. The average heating power of the internal resistance of the battery.

According to the ambient temperature prediction method of at least one embodiment of the present disclosure, obtaining the temperature of the current temperature environment based on at least the difference includes: obtaining the relationship between the difference and the temperature of the current environment based on the second law of thermodynamics and a heat transfer model of the battery.

According to yet another aspect of the present disclosure, there is provided a battery temperature prediction method, comprising: using any one of the above-mentioned environmental temperature prediction methods to obtain the temperature of the current temperature environment; and calculating a temperature trend of the battery based on at least the temperature of the current temperature environment .

According to yet another aspect of the present disclosure, there is provided a battery power calculation method, comprising: predicting a temperature trend of the battery using the above-mentioned battery temperature prediction method; and calculating the power trend of the battery based on at least the temperature trend of the battery.

According to yet another aspect of the present disclosure, there is provided a battery management system, comprising: a measuring device that measures at least an output voltage of a battery, an output current of the battery, and a surface temperature of the battery; and a processing device based at least on the measuring device The output voltage of the battery, the output current of the battery, and the surface temperature of the battery are measured to perform any one of the above-mentioned ambient temperature prediction method, the above-mentioned battery temperature prediction method and/or the above-mentioned battery power calculation method.

According to yet another aspect of the present disclosure, an electronic device is provided, including the above-mentioned battery management system.

Description of drawings

The accompanying drawings illustrate exemplary embodiments of the present disclosure and, together with the description, serve to explain the principles of the present disclosure, are included to provide a further understanding of the disclosure, and are incorporated in and constitute the present specification part of the manual.

Figure 1 is a schematic diagram of the temperature of two different temperature environments.

FIG. 2 is a schematic diagram of any situation in which the battery may be charged or discharged during the entire process of rapidly moving the mobile device from one temperature environment area to another temperature environment area.

Figure 3 is the temperature change curve of the battery itself during the whole process of moving the mobile device from one temperature environment area to another temperature environment area.

FIG. 4 is a discharge curve of the battery in a state of discharge, and the battery is in a changing temperature environment.

Figure 5 is a graph of battery internal impedance as a function of depth of discharge (DOD) at temperatures of 0°C and 25°C.

FIG. 6 is a schematic structural diagram of a preferred battery management system.

Figure 7 is a simple thermal model of the battery.

Figure 8 is a heat transfer model of the battery.

FIG. 9 is a graph of the temperature change of the battery caused by only considering the internal impedance of the battery when the battery is charged and discharged.

FIG. 10 is a schematic flowchart of an ambient temperature prediction method according to an embodiment of the present disclosure.

FIG. 11 is a schematic flowchart of an ambient temperature prediction method according to still another embodiment of the present disclosure.

Description of reference numerals

100 Battery Management System

10 battery pack

11 Batteries

11A Capacitor

11B Internal resistance

11C external resistance

12 Negative temperature coefficient resistors

20 Analog front-end chip

21 Analog switch

22 Buffer

23 A/D Converter

24 Communication interface

25 coulomb counter

26 switch decoding circuit

27 Controller

28 random volatile memory

29 Non-volatile memory

31 Drive circuit

32 Voltage regulator

41 Sampling resistor

42 Fuses

43 Charge MOSFET

44 Discharge MOSFET

50 Microcontrollers

61 data cable

62 Control lines

63 Control signal

64 Control signals

65 measuring lines

66A differential line

66B differential line

200 mobile devices

300 External environment.

Detailed ways

The present disclosure will be further described in detail below in conjunction with the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are only used to explain the related content, but not to limit the present disclosure. In addition, it should be noted that, for the convenience of description, only the parts related to the present disclosure are shown in the drawings.

It should be noted that the embodiments of the present disclosure and the features of the embodiments may be combined with each other unless there is conflict. The technical solutions of the present disclosure will be described in detail below with reference to the accompanying drawings and in conjunction with the embodiments.

Unless otherwise stated, the illustrated exemplary embodiments/embodiments are to be understood as exemplary features providing various details of some ways in which the technical concept of the present disclosure may be implemented in practice. Therefore, unless otherwise stated, the features of various embodiments/embodiments may be additionally combined, separated, interchanged and/or rearranged without departing from the technical concept of the present disclosure.

The use of cross-hatching and/or hatching in the drawings is generally used to clarify boundaries between adjacent components. As such, unless stated, the presence or absence of cross-hatching or shading does not convey or represent any particular material, material properties, dimensions, proportions, commonalities between the illustrated components and/or any other characteristics of the components, any preferences or requirements for attributes, properties, etc. Furthermore, in the drawings, the size and relative sizes of components may be exaggerated for clarity and/or descriptive purposes. When example embodiments may be implemented differently, the specific process sequence may be performed in a different order than described. For example, two consecutively described processes may be performed substantially concurrently or in the reverse order of that described. In addition, the same reference numerals denote the same components.

When an element is referred to as being "on" or "over", "connected to" or "coupled to" another element, the element can be directly on, directly connected to, the other element Either directly coupled to the other component, or intermediate components may be present. However, when an element is referred to as being "directly on," "directly connected to," or "directly coupled to" another element, there are no intervening elements present. To this end, the term "connected" may refer to a physical connection, electrical connection, etc., with or without intervening components.

For descriptive purposes, the present disclosure may use terms such as "under", "under", "under", "under", "above", "on", "at" Spatially relative terms such as "on", "upper" and "side (eg, in "sidewall")", etc., to describe the relationship between one element and another (other) element as shown in the figures relation. In addition to the orientation depicted in the figures, spatially relative terms are intended to encompass different orientations of the device in use, operation, and/or manufacture. For example, if the device in the figures is turned over, elements described as "below" or "beneath" other elements or features would then be oriented "above" the other elements or features. Thus, the exemplary term "under" can encompass both an orientation of "above" and "below." In addition, the device may be otherwise oriented (eg, rotated 90 degrees or at other orientations) and, as such, the spatially relative descriptors used herein should be interpreted accordingly.

The terminology used herein is for the purpose of describing particular embodiments and is not intended to be limiting. As used herein, the singular forms "a" and "the" are intended to include the plural forms as well, unless the context clearly dictates otherwise. Furthermore, when the terms "comprising" and/or "comprising" and their variants are used in this specification, it is indicated that the stated features, integers, steps, operations, parts, components and/or groups thereof are present, but not excluded One or more other features, integers, steps, operations, parts, components and/or groups thereof are present or additional. Note also that, as used herein, the terms "substantially," "approximately," and other similar terms are used as terms of approximation and not as terms of degree, as they are used to explain what one of ordinary skill in the art would recognize Inherent deviations from measured, calculated and/or provided values.

FIG. 1 is a temperature schematic diagram of two different temperature environments, and FIG. 1 shows a temperature transition region existing between two temperature environment regions (ie, region one and region two).

FIG. 2 is a schematic diagram of any situation in which the battery may be charged or discharged during the entire process of the mobile device rapidly moving from one temperature environment area to another temperature environment area. Curve 1 in Fig. 2 is the change curve of ambient temperature.

As shown in Figures 1 and 2, mobile devices are often moved from place to place due to their portability. In some scenarios, the environment varies greatly from location to location. Such environmental differences may be due to differences in natural environments or artificial temperature control. For example, in winter, in an office, shopping mall or home environment, the indoor temperature can be controlled around 25°C to 26°C through air conditioning. However, the outdoor temperature may be as low as -10°C or even lower depending on the environment and geographical location.

Suppose a mobile device moves from outdoor to indoor or from indoor to outdoor, during this process, the mobile device is being used or is in the process of being charged. Due to the internal resistance of the battery and the heat generated by the operation of the mobile device, the temperature of the battery will rise. There are many factors that affect the temperature change of the battery in the process of the battery temperature rising. If only some of these factors are considered in the battery power calculation method to predict the subsequent battery temperature change (battery temperature trend), the error in the estimation of the battery power trend by the battery power calculation method will be very large.

Figure 3 shows the temperature change curve of the battery itself during the whole process of moving the mobile device from one temperature environment area to another temperature environment area. The curve 1 in FIG. 3 is the change curve of the ambient temperature, and the curve 2 is the change curve of the temperature of the battery itself.

As shown in FIG. 3 , taking a mobile device with a lithium battery as an example, the mobile device moves from area 1 to area 2, and the temperature change of the lithium battery is similar to curve 2 in FIG. 3 .

In the first stage, the temperature of the lithium battery is affected by the sudden change of the ambient temperature and drops rapidly. If the mobile device is in a dormant state and the lithium battery itself is not charged and discharged, after a long enough time, the temperature of the lithium battery will gradually approach the ambient temperature in the second area.

However, it is usually the case that a mobile device with a lithium battery is in the process of being used while on the move. Due to the heating of the mobile device and the heating of the battery caused by the internal resistance of the battery, the temperature of the lithium battery will stabilize above the ambient temperature in area 2 after a certain period of time.

In order to correctly predict the change of lithium battery temperature under complex conditions, the battery power calculation method needs to establish a correct battery thermal model.

FIG. 4 is a discharge curve of the battery in a state of discharge, and the battery is in a changing temperature environment.

Figure 5 is a graph of the internal impedance of the battery as a function of depth of discharge (DOD) at temperatures of 0°C and 25°C.

FIG. 4 shows the discharge voltage curve of a mobile device with a battery (eg, a lithium battery) during movement from zone 1 to zone 2 .

Taking a lithium battery as an example, when the mobile device is in region one, the output voltage of the battery is equal to the battery open circuit voltage (OCV) minus the voltage drop across the battery internal impedance (Ri) due to the discharge current.

In the battery thermal model, both the battery open circuit voltage (OCV) and the battery internal impedance (Ri) are nonlinear functions related to temperature (T) and depth of discharge (DOD).

As shown in FIG. 4 , in the discharge stage 2, since the battery is in the temperature transition region, the temperature of the battery changes, and accordingly, the internal impedance Ri of the battery also changes with the change of the battery temperature.

Assume that the temperature in zone one is 25°C and the temperature in zone two is 0°C. As the ambient temperature drops rapidly, the temperature of the mobile device changes rapidly as the ambient temperature changes, and the internal impedance of the battery also increases rapidly, as shown in Figure 5. And if the battery is in use, the output voltage of the battery drops due to the flow of discharge current and the variation of depth of discharge (DOD).

The change in the battery's internal impedance due to temperature changes dominates the drop in the battery's output voltage over a short period of time.

As the device operates in a new area (in area 2) for a long time, the temperature of the battery will gradually stabilize. Due to the self-heating of the battery, the stable temperature of the battery is usually maintained above the ambient temperature. Eventually, the temperature of the battery in the mobile device reaches a steady state in zone two. After that, the change of the output voltage of the battery is mainly determined by the open-circuit voltage of the battery corresponding to the depth of discharge of the battery, the internal impedance of the battery, and the load current of the mobile device.

The internal impedance of the battery is a nonlinear variable with the parameters of depth of discharge and temperature.

FIG. 6 is a schematic structural diagram of a preferred battery management system.

As shown in FIG. 6 , the battery management system 100 includes an analog front-end chip 20 and a microcontroller 50 . The analog front-end chip 20 is used to measure the output voltage of each cell of the battery pack 10 composed of a single cell 11 in series, and measure the voltage difference across the sampling resistor 41 through the differential lines 66A and 66B through the coulomb counter 25 .

The temperature of the battery pack 10 is measured by a negative temperature coefficient resistor (NTC) 12 or a temperature sensor in other manners arranged inside the battery pack 10 .

The analog front-end chip 20 has the capability of breaking the circuit, such as driving a MOSFET or any form of circuit breaker or relays 43 and 44 connected in series with the output circuit of the battery pack 10 . The driving circuit 31 is integrated inside the analog front-end chip 20 , and controls the external circuit breaking devices 43 and 44 by controlling the control signal 63 and the control signal 64 . The discharge MOSFET 44 is used to prevent the battery pack 10 from discharging externally when an accident occurs. The charging MOSFET 43 is used to prevent the external charger from charging the battery pack 10 when an abnormal situation occurs. The fuse 42 is used for redundant protection in extreme cases, preventing irreversible damage to the equipment and battery.

An analog switch 21 is provided inside the analog front-end chip 20 , and the switch signal is controlled by the switch decoding circuit 26 to measure the voltage of each battery of the battery pack 10 in sequence in a predetermined order. The voltage across the analog switch 21 is used as the input to the buffer 22 . The battery voltage through buffer 22 is used as input to analog-to-digital converter 23 . After conversion by the analog-to-digital converter 23, the digital result is stored in the random volatile memory 28. At the same time, the coulomb counter 25 is used to measure the voltage difference between the two ends of the sampling resistor 41, and enters the measurement port of the coulomb counter 25 through the differential lines 66A and 66B.

The controller 27 inside the analog front-end chip 20 is, for example, a digital state machine, and is used to control the sequence flow of the internal sampling conversion and the execution of other actions. In FIG. 6, the reference numeral 62 is the control line, the reference numeral 65 is the measurement line, and the reference numeral 61 is the data line.

Non-volatile memory 29 is used to store configuration values and factory calibration values to improve measurement accuracy. The external microcontroller 50 writes or reads the internal data of the analog front-end chip 20 through the public or private protocol of the communication interface 24 (preferably a digital communication interface). The voltage regulator 32 draws power from the battery pack 10 . The entire battery management system 100 collects basic battery pack 10 information, including measuring battery output voltage, output current, and/or battery pack temperature, which can be used to perform ambient temperature prediction methods, battery temperature prediction methods, and battery power calculation methods.

In order to correctly predict the temperature change of the battery pack in a complex real environment, a simple thermal model of the battery is shown in Figure 7. It is assumed that at the initial moment, the mobile device 200 is at a temperature of temperature 1 (TEMP1), and the temperature of the external environment 300 of the mobile device 200 is a temperature of 2 (TEMP2).

The heat exchange between the interior and exterior of the mobile device 200 will proceed according to the second law of thermodynamics. The battery 10 may be a single battery, or a battery pack or battery pack including a plurality of batteries.

The current generated by the mobile device 200 during use causes the battery 10 to self-heat. The heating power of the battery 10 is proportional to the square of the current multiplied by the internal impedance of the battery. According to the laws of physics, the heating power of the battery 10 can be obtained based on the internal resistance of the battery 10 , the output voltage of the battery 10 , and the output current of the battery 10 . The internal impedance of the battery is expressed as R _i (DOD, Temp), which is understood by those skilled in the art as a function of the parameters of depth of discharge (DOD) and temperature.

Figure 8 is a heat transfer model of the battery. From the physical meaning of thermal resistance, the relationship between battery surface temperature, battery internal temperature and external ambient temperature and battery heating power can be obtained

In Figure 8, _θis represents the thermal resistance from the inside of the battery to the battery surface, _θsa represents the thermal resistance from the battery surface to the external environment, and _Ts represents the battery surface temperature, which can be measured by a temperature sensor, and T _i Indicates the internal temperature of the battery, and _Ta represents the ambient temperature.

The surface temperature T _s of the battery is a function of time. Figure 9 shows the battery temperature change curve caused by only considering the internal impedance of the battery during charging and discharging (without considering the influence of the external temperature environment).

Based on the understanding of the above content, the following describes the method for predicting the ambient temperature, the method for predicting the battery temperature and the method for calculating the battery power of the present disclosure in detail.

10 is a schematic flowchart of an ambient temperature prediction method according to an embodiment of the present disclosure. The ambient temperature prediction method includes: S11 acquiring the initial moment when the battery is in the current temperature environment and the initial temperature of the battery surface, and when the battery surface temperature reaches the current temperature in the current temperature environment The final time of the stable temperature and the stable temperature of the battery surface; S12 is at least based on the time length from the initial time to the final time, and the average heating power of the battery internal resistance within the time length is calculated; S13 is at least based on the average heating power of the internal resistance of the battery. and S14 to obtain the temperature of the current temperature environment based on the initial temperature of the battery surface, the stable temperature of the battery surface, and the amount of battery temperature change caused by the internal resistance heating of the battery.

For example, the mobile device moves from indoor (first temperature environment) to outdoor (second temperature environment), and the current temperature environment in step S11 is the second temperature environment, for example, the mobile device moves from outdoor (second temperature environment) to indoor (second temperature environment) first temperature environment), the current temperature environment in step S11 is the first temperature environment.

The initial moment when the battery is in the current temperature environment is preferably obtained based on a change curve of the surface temperature of the battery. The final time at which the battery surface temperature reaches a stable temperature in the current temperature environment is preferably also obtained based on a change curve of the battery surface temperature. The surface temperature of the battery can be measured.

Preferably, the initial temperature of the battery surface and the stable temperature of the battery surface are measured by a temperature sensor. The temperature sensor can use the negative temperature coefficient resistor (NTC) 12 shown in FIG. 6 , of course, other types of temperature sensors can also be used.

Preferably, the average heating power of the battery internal resistance within the time period is calculated based on at least the battery internal resistance value within the time period from the initial time to the final time.

The battery internal resistance value R _i (DOD, Temp) can be obtained based on parameters such as the size, shape, and material of the battery, or can be obtained by data fitting with multiple measured values. For example, the change curve of the internal resistance value of the battery in FIG. 5 .

Preferably, the temperature of the current temperature environment is obtained based on the initial temperature of the battery surface, the stable temperature of the battery surface and the amount of battery temperature change caused by the heating of the internal resistance of the battery, including: calculating the time length based on the initial temperature of the battery surface and the stable temperature of the battery surface Calculate the difference between the battery surface temperature change and the battery temperature change caused by the heat generated by the internal resistance of the battery; and obtain the temperature of the current temperature environment based on at least the difference.

The battery surface temperature change can be obtained by measuring the temperature sensor, and the battery temperature change caused by the internal resistance heating of the battery can be obtained based on, for example, the battery heat transfer model shown in FIG. 8 and the heating power of the battery.

Preferably, the battery temperature change amount caused by the heating of the internal resistance of the battery is obtained based on the battery heat transfer model shown in FIG. 8 .

The difference between the battery surface temperature change and the battery temperature change caused by the heat generated by the internal resistance of the battery is caused by the ambient temperature change.

Preferably, within the time length from the initial time to the final time, the output voltage and surface temperature of the battery are measured in real time or in a predetermined time period; at least the output voltage and surface temperature of the battery measured in real time or in a predetermined time period are calculated based on The internal resistance value of the battery over a period of time.

Preferably, within the time length from the initial time to the final time, the output current of the battery is also measured in real time or in a predetermined time period; based on the measurement of the output voltage and output current of the battery in real time or in a predetermined time period, calculate the time The average output power of the battery within the length of time; based on at least the average output power of the battery, the output voltage of the battery measured in real time or in a predetermined time period, and the internal resistance value of the battery within the length of time Calculate the average heating of the internal resistance of the battery within the length of time power.

Wherein, the average output power of the battery can be obtained based on the output voltage and output current of the battery measured in real time or in a predetermined time period.

Preferably, the temperature of the current temperature environment is obtained based on at least the difference between the battery surface temperature change and the battery temperature change caused by the heating of the battery internal resistance, including: obtaining the difference based on the second law of thermodynamics and a heat transfer model of the battery The relationship between the value and the temperature of the current environment. Preferably, based on the second law of thermodynamics and, for example, the heat transfer model of the battery shown in FIG. 8 , the relationship between the temperature of the current environment and the above difference is obtained, so as to obtain the temperature of the current environment.

The ambient temperature prediction method of this embodiment can be executed by the battery management system 100 shown in FIG. 6 .

11 is a schematic flowchart of a method for predicting an ambient temperature according to another embodiment of the present disclosure, including: S21 obtaining the time length for the battery surface temperature to change from the first stable temperature to the second stable temperature; S22 calculating the internal resistance of the battery within the time length The average heating power; S23 is based on at least the average heating power of the internal resistance of the battery to obtain the battery temperature change amount caused by the heating of the internal resistance of the battery; and S24 is based on the first stable temperature, the second stable temperature and the battery temperature change caused by the heating of the internal resistance of the battery amount to obtain the temperature of the current temperature environment.

For example, when the mobile device 200 moves from indoor (first temperature environment) to outdoor (second temperature environment), the first stable temperature in step S21 is the stable temperature reached by the battery surface temperature in the first temperature environment, and the second stable temperature That is, the stable temperature reached by the surface temperature of the battery in the second temperature environment.

Preferably, the first stable temperature is the stable temperature of the battery surface when the battery is in the first temperature environment, and the second stable temperature is the stable temperature of the battery surface when the battery is in the second temperature environment. The first stable temperature and the second stable temperature may be measured by a temperature sensor.

Preferably, the average heating power of the battery internal resistance within the time period is calculated based on at least the battery internal resistance value within the time period from the first stable temperature to the second stable temperature.

Preferably, obtaining the temperature of the current temperature environment based on the first stable temperature, the second stable temperature and the battery temperature change caused by the heating of the internal resistance of the battery includes: calculating the time length based on the first stable temperature and the second stable temperature Calculate the difference between the battery surface temperature change and the battery temperature change caused by the heat generated by the internal resistance of the battery; and obtain the temperature of the current temperature environment based on the difference.

Preferably, within the time length of changing from the first stable temperature to the second stable temperature, the output voltage and the surface temperature of the battery are measured in real time or in a predetermined time period; The output voltage and the internal resistance of the battery over the length of time the surface temperature is calculated.

Preferably, within the time length of changing from the first stable temperature to the second stable temperature, the output current of the battery is also measured in real time or in a predetermined time period; the output voltage of the battery is measured based on the real time or in a predetermined time period, and Output current, calculate the average output power of the battery within the time length; at least based on the average output power of the battery, measure the output voltage of the battery in real time or in a predetermined time period, and the battery internal resistance value within the time length to calculate the time length The average heating power of the battery internal resistance.

Preferably, obtaining the temperature of the current temperature environment based on at least the difference between the battery surface temperature change and the battery temperature change caused by the heating of the battery internal resistance includes: obtaining the difference based on the second law of thermodynamics and a heat transfer model of the battery The relationship between the value and the temperature of the current environment.

The ambient temperature prediction method of this embodiment can be executed by the battery management system 100 shown in FIG. 6 .

According to yet another embodiment of the present disclosure, a battery temperature prediction method includes: using the ambient temperature prediction method of the above embodiment to obtain a temperature _TA of a current temperature environment; and calculating a temperature trend of the battery based on at least the temperature _TA of the current temperature environment.

It will be more accurate to obtain the temperature trend of the battery (or expressed as a predicted battery temperature change curve) through this embodiment.

According to yet another embodiment of the present disclosure, a battery power calculation method includes: using the above-mentioned battery temperature prediction method to predict the temperature trend of the battery; and calculating the power trend of the battery based on at least the temperature trend of the battery.

It will be more accurate to obtain the battery power trend (or expressed as a predicted battery power change curve) through this embodiment.

According to yet another embodiment of the present disclosure, a battery management system includes: a measuring device that measures at least an output voltage of the battery, an output current of the battery, and a surface temperature of the battery; and a processing device that is based on at least the battery's temperature measured by the measuring device. The output voltage, the output current of the battery, and the surface temperature of the battery are used to perform the above-mentioned method for predicting the ambient temperature, the above-mentioned method for predicting the battery temperature and/or the above-mentioned method for calculating the battery power.

Wherein, the measuring device is preferably realized by the temperature sensor and the analog front-end chip in FIG. 6 .

According to yet another embodiment of the present disclosure, there is provided an electronic device including the above-mentioned battery management system.

Wherein, the electronic device may be a mobile phone, a tablet computer or other portable devices. The processing means are preferably implemented by the microcontroller 50 in FIG. 6 .

In the description of this specification, reference to the terms "one embodiment/mode", "some embodiments/modes", "example", "specific example" or "some examples" or the like is meant to be combined with the embodiment/mode or A particular feature, structure, material, or characteristic of the example description is included in at least one embodiment/mode or example of the present disclosure. In this specification, schematic representations of the above terms are not necessarily directed to the same embodiment/mode or example. Furthermore, the particular features, structures, materials or characteristics described may be combined in any suitable manner in any one or more embodiments/means or examples. Furthermore, those skilled in the art may combine and combine the different embodiments/modes or examples described in this specification and the features of the different embodiments/modes or examples without conflicting each other.

In addition, the terms "first" and "second" are only used for descriptive purposes, and should not be construed as indicating or implying relative importance or implying the number of indicated technical features. Thus, a feature delimited with "first", "second" may expressly or implicitly include at least one of that feature. In the description of the present disclosure, "plurality" means at least two, such as two, three, etc., unless expressly and specifically defined otherwise.

Those skilled in the art should understand that the above-mentioned embodiments are only for clearly illustrating the present disclosure, rather than limiting the scope of the present disclosure. For those skilled in the art, other changes or modifications may also be made on the basis of the above disclosure, and these changes or modifications are still within the scope of the present disclosure.

Claims (10)

1. An ambient temperature prediction method, comprising:

acquiring the initial time of the battery in the current temperature environment, the initial temperature of the surface of the battery, the final time when the surface temperature of the battery reaches the stable temperature in the current temperature environment and the stable temperature of the surface of the battery;

calculating the average heating power of the internal resistance of the battery within the time length at least based on the time length from the initial time to the final time;

obtaining the battery temperature variation caused by the heating of the internal resistance of the battery at least based on the average heating power of the internal resistance of the battery; and

and obtaining the temperature of the current temperature environment based on the initial temperature of the surface of the battery, the stable temperature of the surface of the battery and the temperature variation of the battery caused by the heat generation of the internal resistance of the battery.

2. The ambient temperature prediction method according to claim 1, wherein the battery surface initial temperature and the battery surface stable temperature are measured by temperature sensors.

3. The ambient temperature prediction method according to claim 1, characterized in that the average heat generation power of the internal resistance of the battery over the period of time is calculated based on at least the internal resistance value of the battery over the period of time.

4. The method according to claim 1, wherein obtaining the temperature of the current temperature environment based on the battery surface initial temperature, the battery surface stable temperature, and the battery temperature variation amount caused by heat generation of the battery internal resistance comprises:

calculating a battery surface temperature change amount within the time period based on the battery surface initial temperature and the battery surface stable temperature;

calculating the difference value of the battery surface temperature variation and the battery temperature variation caused by the heating of the internal resistance of the battery; and

and obtaining the temperature of the current temperature environment at least based on the difference.

5. The ambient temperature prediction method according to claim 3, characterized in that the output voltage of the battery and the surface temperature are measured in real time or at a predetermined time period within the time length;

calculating the battery internal resistance value within the time length based on at least the output voltage of the battery and the surface temperature measured in real time or at a predetermined time period.

6. The ambient temperature prediction method according to claim 5, characterized in that within the time length, the output current of the battery is also measured in real time or at a predetermined time period;

calculating an average output power of the battery over the length of time based on the output voltage and the output current of the battery measured in real time or at a predetermined time period;

and calculating the average heating power of the internal resistance of the battery within the time length at least based on the average output power of the battery, the output voltage of the battery measured in real time or in a preset time period and the internal resistance value of the battery within the time length.

7. The method of claim 4, wherein obtaining the temperature of the current temperature environment based on at least the difference comprises:

the relationship of the difference value to the temperature of the current environment is obtained based on a second law of thermodynamics and a model of the heat transfer of the battery to the external environment.

8. An ambient temperature prediction method, comprising:

acquiring the time length of the surface temperature of the battery changing from a first stable temperature to a second stable temperature;

calculating the average heating power of the internal resistance of the battery within the time length;

obtaining the battery temperature variation caused by the heating of the internal resistance of the battery at least based on the average heating power of the internal resistance of the battery; and

and obtaining the temperature of the current temperature environment based on the first stable temperature, the second stable temperature and the battery temperature variation caused by the heat generation of the internal resistance of the battery.

9. The ambient temperature prediction method according to claim 8, wherein the first stable temperature is a battery surface stable temperature at which the battery is in a first temperature environment, and the second stable temperature is a battery surface stable temperature at which the battery is in a second temperature environment.

10. The ambient temperature prediction method of claim 8, wherein the first stable temperature and the second stable temperature are measured by a temperature sensor.

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