CN114771355B - Battery thermal management method, device, computer equipment and storage medium - Google Patents

Abstract

The application relates to a battery thermal management method, a battery thermal management device, a computer device and a storage medium. The method comprises the following steps: acquiring target power required by the vehicle using time and first time length between the vehicle using time and the current time, and determining whether the battery is in a charging state; and under the condition that the battery is in a power-off state, obtaining a first temperature under the influence of the ambient temperature according to a first duration, obtaining a second temperature according to the target power, and starting first thermal management according to the numerical value magnitude relation of the first temperature and the second temperature, wherein the first temperature is the lowest temperature of the battery after the first duration, and the second temperature is the lowest temperature of the battery under the target power. According to the method, the influence of the ambient temperature on the battery temperature is considered, and the battery is subjected to thermal management on the basis, so that the influence of the ambient temperature on the battery temperature is avoided to a certain extent, and the output power of the battery is ensured to enable the power performance to meet the scene requirement when a user is in use.

Description

Battery thermal management method, device, computer equipment and storage medium

Technical Field

The present application relates to the field of new energy vehicle technology, and in particular to a battery thermal management method, device, computer equipment and storage medium.

Background technique

With the advancement of science and technology, new energy vehicles are gradually being widely used. As the core power source of new energy vehicles, power battery packs are used in different environments. When new energy vehicles are placed in a low temperature environment for a long time, the temperature of the battery cells in the power battery pack will become low. If the car is started immediately at this time, the power battery pack may limit the power output, resulting in a decrease in the car's power performance; if the temperature is too low, it may even cause the car to fail to start.

At present, in order to avoid the problem that the battery temperature of the power battery pack is too low when the car is in use, resulting in the inability to use the car normally, the battery management system (BMS) is woken up before the car is used by receiving the car use time set by the user, and the BMS is used to perform thermal management on the battery. For example, it is determined whether heating needs to be turned on. If heating needs to be turned on, the time to turn on heating is calculated. After the battery temperature is heated to the specified temperature, the heating is controlled to be exited.

Since the ambient temperature has a certain impact on the battery temperature, using the above method to perform thermal management on the battery may result in failure to heat to the target temperature, or after heating to the target temperature, there is a possibility that the temperature may drop, thereby affecting the power performance of the vehicle.

Summary of the invention

Based on this, a battery thermal management method, device, computer equipment and storage medium are provided to ensure that when a user uses a car, the output power of the battery makes the power performance meet the scene requirements.

In one aspect, a battery thermal management method is provided, the method comprising:

Obtaining the target power required at the time of using the vehicle and the first time between the time of using the vehicle and the current time, and determining whether the battery is in a charging state;

When the battery is in a power-off state, a first temperature under the influence of ambient temperature is obtained according to the first time period, and a second temperature is obtained according to the target power. According to the numerical relationship between the first temperature and the second temperature, a first thermal management is started, wherein the first temperature is the lowest temperature of the battery after the first time period, and the second temperature is the lowest temperature of the battery at the target power.

In one embodiment, the step of starting the first thermal management according to the numerical relationship between the first temperature and the second temperature includes:

determining whether the first temperature is greater than the second temperature;

If so, do not turn on the heating;

If not, obtaining the heating efficiency of the battery and the amount of heat exchange between the battery and the environment;

Obtaining a second duration for starting heating according to the target power, the heating efficiency and the heat exchange amount;

After the second period of time, heating of the battery is switched on.

In one embodiment, the step of obtaining a second duration for starting heating according to the target power, the heating efficiency and the heat exchange amount comprises:

The specific heat capacity, mass and minimum temperature threshold of the battery are obtained, and a third temperature is set. The second duration is obtained according to the specific heat capacity, the mass, the minimum temperature threshold, the third temperature and the heat exchange amount, wherein the third temperature is the minimum temperature of the battery when heating is turned on. The mathematical expression for obtaining the second duration is:

x＝C*m*(T ₀ −T ₃ )/ΔQ

Wherein, x is the second time length, C is the specific heat capacity, m is the mass, T ₀ is the minimum temperature threshold, T ₃ is the third temperature, and ΔQ is the heat exchange amount;

According to the specific heat capacity, the mass, the heating efficiency, the second temperature, the third temperature and the target power, a third time required to heat the third temperature to the second temperature is obtained, and the mathematical expression for obtaining the third time is:

y＝C*m*η*(T ₂ -T ₃ )/P

Wherein, y is the third duration, C is the specific heat capacity, m is the mass, η is the heating efficiency, _T2 is the second temperature, _T3 is the third temperature, and P is the target power;

According to the sum of the second time duration and the third time duration being equal to the first time duration, obtaining a numerical value of the third temperature;

The numerical value of the second duration is obtained according to the numerical value of the third temperature.

In one embodiment, it also includes:

When the battery is in a charging state, the current charge of the battery is obtained, and based on the current charge, the charging time required to charge the battery to a full charge is obtained, and based on the numerical relationship between the first time and the charging time, the second thermal management is started.

In one embodiment, the step of starting the second thermal management according to the numerical relationship between the first duration and the charging duration includes:

Determining whether the first duration is greater than or equal to the charging duration;

If yes, return to the step of obtaining the first temperature;

If not, look up a table according to the current charge amount and the target power to obtain a fourth temperature, wherein the fourth temperature is the lowest temperature of the battery under the current charge amount and the target power;

Acquire a current minimum temperature of the battery, and determine whether the fourth temperature is less than the current minimum temperature;

If so, do not turn on the heating;

If not, obtaining a fourth time required to heat the current lowest temperature to the fourth temperature according to the fourth temperature and the current lowest temperature;

Determine whether the sum of the charging time and the fourth time is equal to the first time, and start heating the battery when the sum of the charging time and the fourth time is equal to the first time.

In one embodiment, the step of obtaining a fourth time required to heat the current minimum temperature to the fourth temperature according to the fourth temperature and the current minimum temperature comprises:

The specific heat capacity and mass of the battery are obtained, and according to the specific heat capacity, the mass, the fourth temperature, the current minimum temperature, the heating efficiency, and the target power, a mathematical expression for obtaining the fourth duration is obtained as follows:

z＝C*m*(T ₄ −T ₅ )*η/P

Among them, z is the fourth time length, C is the specific heat capacity, m is the mass, _T4 is the fourth temperature, _T5 is the current minimum temperature, η is the heating efficiency, and P is the target power.

In one embodiment, it also includes:

When the exit heating conditions are obtained, the heating operation on the battery is exited, wherein the exit heating conditions include: the current minimum temperature of the battery is greater than or equal to the second temperature, the charge change value of the battery per unit time is greater than or equal to a preset charge change threshold, and the vehicle is in a start state.

In another aspect, a battery thermal management device is provided, the device comprising:

A preprocessing module, the preprocessing module is used to obtain the target power required at the time of using the vehicle and the first time between the time of using the vehicle and the current time, and determine whether the battery is in a charging state;

A first thermal management module, wherein the first thermal management module is used to obtain, when the battery is in a power-off state, a first temperature under the influence of ambient temperature according to the first duration, and a second temperature according to the target power, and to start a first thermal management according to a numerical relationship between the first temperature and the second temperature, wherein the first temperature is the lowest temperature of the battery after the first duration, and the second temperature is the lowest temperature of the battery at the target power.

In another aspect, a computer device is provided, comprising a memory, a processor, and a computer program stored in the memory and executable on the processor, wherein when the processor executes the computer program, the following steps are implemented:

Obtaining the target power required at the time of using the vehicle and the first time between the time of using the vehicle and the current time, and confirming whether the battery is in a charging state;

When the battery is in a power-off state, a first temperature under the influence of ambient temperature is obtained according to the first time period, and a second temperature is obtained according to the target power. According to the numerical relationship between the first temperature and the second temperature, a first thermal management is started, wherein the first temperature is the lowest temperature of the battery after the first time period, and the second temperature is the lowest temperature of the battery at the target power.

In another aspect, a computer-readable storage medium is provided, on which a computer program is stored, and when the computer program is executed by a processor, the following steps are implemented:

Obtaining the target power required at the time of using the vehicle and the first time between the time of using the vehicle and the current time, and confirming whether the battery is in a charging state;

When the battery is in a power-off state, a first temperature under the influence of ambient temperature is obtained according to the first time period, and a second temperature is obtained according to the target power. According to the numerical relationship between the first temperature and the second temperature, a first thermal management is started, wherein the first temperature is the lowest temperature of the battery after the first time period, and the second temperature is the lowest temperature of the battery at the target power.

The above-mentioned battery thermal management method, device, computer equipment and storage medium obtain the target power that needs to be met at the time of using the vehicle set by the user, as well as the first time between the time of using the vehicle and the current time, and determine whether the battery is in a charging state; when the battery is in a power-off state, according to the first time, a first temperature under the influence of ambient temperature is obtained, and according to the target power, a second temperature is obtained, and according to the numerical relationship between the first temperature and the second temperature, the first thermal management is started, wherein the first temperature is the lowest temperature of the battery after the first time, and the second temperature is the lowest temperature of the battery at the target power; since the lowest temperature of the battery will be affected by the ambient temperature, that is, the first temperature will be affected by the ambient temperature, for example, compared with a higher ambient temperature, a lower ambient temperature will cause the battery temperature to drop faster, so the first thermal management takes into account the influence of the ambient temperature on the battery temperature, and on this basis, the battery is thermally managed, thereby avoiding the influence of the ambient temperature on the battery temperature to a certain extent, so as to ensure that when the user uses the vehicle, the output power of the battery makes the power performance meet the scene requirements.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG1 is a schematic diagram of a process of a battery thermal management method in one embodiment;

FIG2 is a schematic flow chart of a battery thermal management method in another embodiment;

FIG3 is a schematic diagram of the overall process of a battery thermal management method in one embodiment;

FIG4 is a structural block diagram of a battery thermal management device in one embodiment;

FIG5 is a structural block diagram of a battery thermal management device in another embodiment;

FIG. 6 is a diagram showing the internal structure of a computer device in one embodiment.

Detailed ways

In order to make the purpose, technical solution and advantages of the present application more clearly understood, the present application is 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 present application and are not used to limit the present application.

It should be noted that the diagram provided in the present embodiment only illustrates the basic concept of the present invention in a schematic manner, and the diagram only shows the components related to the present invention rather than drawing according to the number, shape and size of the components during actual implementation. The type, quantity and ratio of each component during actual implementation can be changed at will, and the component layout type may also be more complicated. At the same time, the terms such as "upper", "lower", "left", "right", "front", "back", "middle" and "one" cited in this specification are only for the convenience of narration, rather than for limiting the scope of the present invention. The change or adjustment of the relative relationship shall also be regarded as the scope of the present invention without substantial change in the technical content. In addition, the terms "first" and "second" are only used for descriptive purposes and cannot be understood as indicating or implying relative importance.

Since new energy vehicles are in a low temperature environment, the temperature of their power battery packs will become lower due to the ambient temperature, resulting in the output power of the power battery pack being limited when the user's vehicle is in the starting state, causing the vehicle's power performance to weaken or even fail to start. At present, in order to overcome the above problems, the battery management system (BMS) will be awakened in advance to heat the battery when heating is required. Considering that the battery temperature will be affected by the ambient temperature, therefore, using the above method to heat the battery may fail to reach the target temperature, or the temperature may drop after reaching the target temperature, resulting in the vehicle's power performance being affected.

To this end, the present application provides a battery thermal management method, device, computer equipment and storage medium. The battery thermal management device can be implemented by communicating with the battery management system or embedded in the battery management system to implement the method described in the present application, such as obtaining a target power and a first duration, and based on the target power and the first duration, starting a first thermal management, etc., to achieve thermal management of the battery. The present application will not go into details about this.

The method is described by taking the battery thermal management device as an example of the execution subject. Specifically, the battery thermal management device includes a preprocessing module and a first thermal management module, wherein the preprocessing module is used to obtain the target power that needs to be met at the time of using the vehicle set by the user, as well as the first time between the time of using the vehicle and the current time, and determine whether the battery is in a charging state; the first thermal management module is used to obtain the first temperature under the influence of the ambient temperature according to the first time when the battery is in a power-off state, wherein the first temperature is the lowest temperature of the battery after the first time.

The first thermal management module also looks up a table according to the target power to obtain a second temperature, wherein the second temperature is the lowest temperature of the battery at the target power. It should be noted that the table looked up is a two-dimensional table with charge as the horizontal coordinate, temperature as the vertical coordinate, and the value is power; the first thermal management is started according to the numerical relationship between the first temperature and the second temperature.

Since the lowest temperature of the battery will be affected by the ambient temperature, that is, the first temperature will be affected by the ambient temperature. For example, compared with a higher ambient temperature, a lower ambient temperature will cause the battery temperature to drop faster. Therefore, the first thermal management takes into account the impact of the ambient temperature on the battery temperature. On this basis, the battery is thermally managed to avoid the impact of the ambient temperature on the battery temperature to a certain extent, so as to ensure that when the user uses the car, the battery output power makes the power performance meet the scene requirements.

In one embodiment, as shown in FIG1 , a battery thermal management method is provided, comprising the following steps:

S101: Obtain the target power required for the vehicle use time and the first time between the vehicle use time and the current time, and determine whether the battery is in a charging state.

It should be noted that in order to preheat the battery of the vehicle so that the battery can reach the target temperature to a certain extent when the user uses the vehicle, and the vehicle's power performance can meet the needs, the vehicle use time and target power set by the user through the vehicle system or remote application can be obtained; and based on the current time, the first time distance from the current time to the vehicle use time is calculated, wherein the target power is the output power that the vehicle needs to meet when the vehicle is used. In addition, considering that the battery temperature and the battery charge are different when the battery is in the two states of charging or not charging, the battery is confirmed to be in the charging state, so that corresponding measures are taken in the two states respectively to improve the efficiency of heating or preheating the battery.

S102: When the battery is in a power-off state, a first temperature under the influence of ambient temperature is obtained according to the first duration, and a second temperature is obtained according to the target power. According to the numerical relationship between the first temperature and the second temperature, a first thermal management is started, wherein the first temperature is the lowest temperature of the battery after the first duration, and the second temperature is the lowest temperature of the battery at the target power.

It should be noted that, since the battery temperature is more affected by the ambient temperature when not charging, thermal management is more required. Therefore, the thermal management method of the battery when the battery is in a power-off state will be described below.

According to the first duration, a first temperature under the influence of the ambient temperature is obtained, wherein the first temperature is the lowest temperature of the battery after the first duration. Specifically, the mass, specific heat capacity, and heat exchange between the battery and the environment can be obtained according to the data published when the battery leaves the factory, and the first temperature can be obtained according to the mass, specific heat capacity, heat exchange, and the first duration. The mathematical expression for obtaining the first temperature is:

T ₁ = ΔQ*Δt/(C*m)

Wherein, _T1 is the first temperature, ΔQ is the heat exchange amount, Δt is the first time duration, C is the specific heat capacity of the battery, and m is the mass of the battery.

According to the target power, the second temperature is obtained. Specifically, the second temperature can be obtained by looking up a table. In a two-dimensional table in which the horizontal axis is the charge of the battery, the vertical axis is the temperature of the battery, and the value is the power, when the value is the target power, the corresponding minimum temperature of the battery is the second temperature.

Compare the numerical values of the first temperature and the second temperature to obtain a comparison result, and start the first thermal management according to the comparison result. Specifically, compare the numerical values of the first temperature and the second temperature to determine whether the first temperature is greater than the second temperature; if so, that is, the lowest temperature of the battery after the first time period is higher than the lowest temperature at the target power, the power performance of the vehicle at the time of use will not be affected by the battery temperature, so there is no need to heat the battery at this time, and the output power of the battery of the vehicle can be effectively guaranteed so that the power performance meets the scene requirements.

If not, that is, the lowest temperature of the battery after the first period of time is lower than the lowest temperature at the target power, in order to ensure the output power of the battery when the vehicle is used so that the power performance meets the scene requirements, the battery needs to be heated, and the second period of time for turning on the heating needs to be calculated, and the heating of the battery is turned on after the second period of time.

To further illustrate, the step of calculating the time to start heating may include: obtaining the specific heat capacity, mass and minimum temperature threshold of the battery according to the data published when the battery leaves the factory; and setting the minimum temperature of the battery when the heating is turned on to the third temperature; based on the specific heat capacity, the mass, the minimum temperature threshold, the third temperature and the heat exchange amount, obtaining the second duration through the following mathematical expression, which is mathematically expressed as follows:

x＝C*m*(T ₀ −T ₃ )/ΔQ

Wherein, x is the second time length, C is the specific heat capacity, m is the mass, _T0 is the minimum temperature threshold, _T3 is the third temperature, and ΔQ is the heat exchange amount.

Since the second time duration and the third temperature are both unknown, this embodiment calculates the second time duration by obtaining the third time duration required to heat the third temperature to the second temperature and the first time duration obtained based on the vehicle use time set by the user.

Specifically, according to the specific heat capacity, the mass, the heating efficiency, the second temperature, the third temperature and the target power, the third duration is obtained by using the following mathematical expression, which is:

y＝C*m*η*(T ₂ -T ₃ )/P

Wherein, y is the third duration, C is the specific heat capacity, m is the mass, η is the heating efficiency, _T2 is the second temperature, _T3 is the third temperature, and P is the target power.

According to the mathematical relationship that the sum of the second duration and the third duration is equal to the first duration, the numerical value of the third temperature can be calculated; then the numerical value of the third temperature is substituted into the mathematical expression for obtaining the second duration to obtain the numerical value of the second duration.

It should be noted that the above description of the order of calculation is an exemplary description, and the timing of the calculation can be adjusted arbitrarily. In order to make the description concise, not all possible calculation timings and processes are described. The mathematical expression of the second duration, the mathematical expression of the third duration, and the mathematical relationship that the sum of the second duration and the third duration is equal to the first duration are combined, and the timing and process of the calculation are not limited. As long as there is no contradiction in the order and process of the calculation and the requirement of calculating the numerical value of the second duration is met, it should be considered to be within the scope of this specification.

After the second time period, the battery is heated, and as the heating progresses, the battery temperature gradually rises. When it rises to a certain level, the heating needs to be turned off. Therefore, in this embodiment, it also includes: collecting the current minimum temperature of the battery, the change in charge within a unit time period, and whether the vehicle is in a startup state; when the collected current minimum temperature is greater than or equal to the second temperature, or the charge change value is greater than or equal to the preset charge change threshold, or the vehicle is in a startup state, the exit heating condition is obtained, and at this time, it means that the battery temperature can make the output power of the battery of the vehicle reach the target power, so that the power performance meets the scene requirements, and the heating operation of the battery is exited.

In the above-mentioned battery thermal management method, since the first temperature obtained through the above-mentioned steps is obtained based on the heat exchange between the battery and the environment, in other words, the numerical value of the first temperature is related to the ambient temperature. Therefore, on this basis, according to the numerical value relationship between the first temperature and the second temperature, starting the first thermal management can eliminate the influence of the ambient temperature on the temperature of the battery to a certain extent. By taking the ambient temperature into consideration as an influencing factor in the battery thermal management method, the battery in a low temperature environment can be preheated more efficiently, thereby effectively ensuring that the user starts the vehicle at the time of use and the vehicle's power performance meets the scene requirements.

In one embodiment, as shown in FIG2 , the following steps are included:

S201: Obtain the target power required for the vehicle use time and the first time between the vehicle use time and the current time, and determine whether the battery is in a charging state.

It should be noted that in order to preheat the vehicle's battery so that the output power of the user at the time of using the vehicle can reach the target power to a certain extent and the vehicle's power performance can meet the demand, the vehicle use time and target power set by the user through the vehicle system or remote application can be obtained; and based on the current time, the first time distance from the current time to the vehicle use time is calculated, wherein the target power is the power that the vehicle needs to meet at the time of using the vehicle. In addition, considering that the battery temperature and the battery charge are different when the battery is in the two states of charging or not charging, the battery's charging state is confirmed, and corresponding measures are taken in the two states to improve the efficiency of heating or preheating the battery.

S202: When the battery is in a charging state, obtain the current charge of the battery, and based on the current charge, obtain the charging time required to charge the battery to a full charge, and start the second thermal management based on the numerical relationship between the first time and the charging time.

It should be noted that, although the battery temperature is more affected by the ambient temperature when not charging, and thermal management is more needed; when the battery is in a charging state, even if the battery temperature increases as charging proceeds, when the charge in the battery reaches a certain value, its temperature will slowly drop to room temperature. If it is in a low temperature environment, its battery temperature may also be affected by the low temperature environment. Therefore, in order to adapt to the battery in a charging state, there may be a phenomenon that the battery needs to be heated. Next, the battery thermal management method when the battery is in a charging state will be described.

The current charge of the battery is obtained, and based on the current charge, the charging time required for charging the battery to a full charge is obtained. Specifically, the charging time of the battery can be obtained according to the charging time required for a unit charge and the current charge of the battery; or the charging time can be obtained according to the charge reference information preset before the battery leaves the factory and the current charge of the battery. Since the present application does not make improvements to the method for obtaining the charging time, it is not limited here.

After the charging time is obtained, the second thermal management is started according to the numerical relationship between the first time and the charging time. Specifically, the numerical relationship between the first time and the second time is compared to determine whether the first time is greater than or equal to the charging time; if so, that is, before the vehicle is used, the battery can be fully charged. At this time, return to the step of obtaining the first temperature described in S102 above, and execute according to the steps after obtaining the first temperature. Since the above has been described in detail, the above related description can be referred to here and will not be repeated here.

If not, that is, the battery cannot be fully charged before the vehicle is used, a table is looked up according to the current charge and the target power to obtain a fourth temperature, wherein the fourth temperature is the lowest temperature of the battery under the current charge and the target power. It should be noted that in a two-dimensional table where the horizontal axis is the battery charge, the vertical axis is the battery temperature, and the value is power, when the horizontal axis is the current charge and the value is the target power, the corresponding lowest temperature of the battery is the fourth temperature.

Obtain the current minimum temperature of the battery, and compare the fourth temperature with the current minimum temperature to determine whether the fourth temperature is less than the current minimum temperature; if so, the output power of the battery at the current temperature meets the power performance requirements, and the battery does not need to be heated; if not, the output power of the battery at the current temperature cannot meet the power performance requirements, and the battery needs to be heated.

Further, according to the fourth temperature and the current minimum temperature, a fourth time required to heat the current minimum temperature to the fourth temperature is obtained. Specifically, the specific heat capacity and mass of the battery are obtained, and according to the specific heat capacity, the mass, the fourth temperature, the current minimum temperature, the heating efficiency and the target power, the fourth time is obtained through the following mathematical expression, and the mathematical expression is:

z＝C*m*(T ₄ −T ₅ )*η/P

Among them, z is the fourth time length, C is the specific heat capacity, m is the mass, _T4 is the fourth temperature, _T5 is the current minimum temperature, η is the heating efficiency, and P is the target power.

After obtaining the fourth duration, determine whether the sum of the charging duration and the fourth duration is equal to the first duration. When the sum of the charging duration and the fourth duration is equal to the first duration, turn on heating for the battery, thereby performing thermal management of the battery when the battery is in a charging state and the battery needs to be heated to ensure that the output power meets the power performance requirements, thereby improving the scenario adaptability of the method.

It should be noted that, considering the existence of various errors, for example, there are errors in the process of obtaining the charging time, so that the sum of the charging time and the fourth time may not be completely equal to the first time, therefore, in this embodiment, an allowable deviation is set. By adding the first time and the allowable deviation, a time interval including the first time can be obtained. When the sum of the charging time and the fourth time is within the time interval, it is determined that the sum of the charging time and the fourth time is equal to the first time. By setting the allowable deviation, the phenomenon of missing the need for heating can be effectively avoided, and the output power of the battery can be further ensured to meet the requirements of power performance.

As the heating progresses, the temperature of the battery gradually increases, and when it increases to a certain degree, the heating needs to be turned off. Therefore, in this embodiment, it also includes: collecting the current minimum temperature of the battery, the change in charge within a unit time, and whether the vehicle is in a startup state; when the collected current minimum temperature is greater than or equal to the second temperature, or the charge change value is greater than or equal to the preset charge change threshold, or the vehicle is in a startup state, the exit heating condition is obtained, and at this time, it means that the output power of the battery at the current temperature can make the power performance of the vehicle meet the scene requirements, and the heating operation of the battery is exited.

In combination with the above two embodiments, as shown in FIG3 , the battery thermal management method is further described. The target power set by the user and the first time from the current moment to the time of using the vehicle are obtained, and it is determined whether the battery is in a charging state, and corresponding thermal management methods are adopted for the battery in the charging state and the battery in the non-charging state. Specifically:

When the battery is not in a charging state, the first temperature is obtained according to the first time period, and the second temperature is obtained according to the target power; it is determined whether the first temperature is greater than the second temperature, and if so, heating is not turned on; if not, the heating efficiency of the battery and the heat exchange amount between the battery and the environment are obtained; according to the target power, the heating efficiency and the heat exchange amount, a second time period for turning on heating is obtained; after the second time period, heating is turned on for the battery; as heating progresses, when the condition for exiting heating is obtained, heating is exited.

When the battery is not in a charging state, obtain the current charge of the battery, and obtain the charging time required to charge the battery to a full charge according to the current charge; determine whether the first time is greater than or equal to the charging time, and if so, return to the step of obtaining the first temperature, and execute according to the steps after obtaining the first temperature; if not, look up a table according to the current charge and the target power to obtain a fourth temperature, and obtain the current minimum temperature of the battery; determine whether the fourth temperature is less than the current minimum temperature, and if so, do not turn on heating; if not, obtain a fourth time according to the fourth temperature and the current minimum temperature; and determine whether the sum of the charging time and the fourth time is equal to the first time, and if not, do not turn on heating; if so, turn on heating, and as heating progresses, exit heating when the exit heating condition is obtained.

It should be noted that the battery thermal management steps shown in FIG. 3 are for the purpose of providing a general description of the two situations in which the battery is in a charged state or an uncharged state. The specific calculations, table lookups or processing methods involved have been described in detail in the above description, and the above-mentioned related descriptions may be referred to, and will not be repeated here.

It should be understood that, although the various steps in the flowcharts of Figures 1-3 are displayed in sequence according to the indication of the arrows, these steps are not necessarily executed in sequence according to the order indicated by the arrows. Unless there is a clear explanation in this article, the execution of these steps is not strictly limited in order, and these steps can be executed in other orders. Moreover, at least a portion of the steps in Figures 1-3 may include multiple sub-steps or multiple stages, and these sub-steps or stages are not necessarily executed at the same time, but can be executed at different times, and the execution order of these sub-steps or stages is not necessarily to be carried out in sequence, but can be executed in turn or alternately with other steps or at least a portion of the sub-steps or stages of other steps.

In one embodiment, as shown in FIG4 , a battery thermal management device is provided, comprising: a preprocessing module and a first thermal management module, wherein:

A preprocessing module, the preprocessing module is used to obtain the target power required at the time of using the vehicle and the first time between the time of using the vehicle and the current time, and determine whether the battery is in a charging state;

A first thermal management module, wherein the first thermal management module is used to obtain, when the battery is in a power-off state, a first temperature under the influence of ambient temperature according to the first duration, and a second temperature according to the target power, and to start a first thermal management according to a numerical relationship between the first temperature and the second temperature, wherein the first temperature is the lowest temperature of the battery after the first duration, and the second temperature is the lowest temperature of the battery at the target power.

It should be noted that the battery thermal management device can communicate with the battery management system or be embedded in the battery management system. Here, the battery thermal management system and the battery management system communicate as an example. Since the user can set the vehicle use time and target power through the vehicle system or remote application, the preprocessing module can communicate with the vehicle system or the terminal with the remote application installed to obtain the vehicle use time and target power set by the user, and then obtain the first time length between the current time and the vehicle use time based on the current time.

By communicating with the battery management system, the preprocessing module determines whether the battery is in a charging state through the battery management system. Since the battery temperature and the amount of charge of the battery are different when the battery is in the charging state or not, by confirming whether the battery is in the charging state or not, corresponding measures are taken in the two states respectively to improve the efficiency of heating or preheating the battery.

When the battery is in a power-off state, the preprocessing module communicates with the first thermal management module and sends the acquired target power and the first duration to the first thermal management module, so that the first thermal management module performs thermal management on the battery according to the target power and the first duration. The specific thermal management method performed by the first thermal management can refer to the definition of the first thermal management method for battery startup above, which will not be repeated here.

In one embodiment, as shown in FIG. 5 , the first thermal management module starts the first thermal management step according to the numerical relationship between the first temperature and the second temperature, including:

determining whether the first temperature is greater than the second temperature;

If so, do not turn on the heating;

If not, obtaining the heating efficiency of the battery and the amount of heat exchange between the battery and the environment;

Obtaining a second duration for starting heating according to the target power, the heating efficiency and the heat exchange amount;

After the second period of time, heating of the battery is switched on.

In one embodiment, the first thermal management module obtains a second duration for starting heating according to the target power, the heating efficiency and the heat exchange amount, comprising:

The specific heat capacity, mass and minimum temperature threshold of the battery are obtained, and a third temperature is set. The second duration is obtained according to the specific heat capacity, the mass, the minimum temperature threshold, the third temperature and the heat exchange amount, wherein the third temperature is the minimum temperature of the battery when heating is turned on. The mathematical expression for obtaining the second duration is:

x＝C*m*(T ₀ −T ₃ )/ΔQ

Wherein, x is the second time length, C is the specific heat capacity, m is the mass, T ₀ is the minimum temperature threshold, T ₃ is the third temperature, and ΔQ is the heat exchange amount;

According to the specific heat capacity, the mass, the heating efficiency, the second temperature, the third temperature and the target power, a third time required to heat the third temperature to the second temperature is obtained, and the mathematical expression for obtaining the third time is:

y＝C*m*η*(T ₂ -T ₃ )/P

Wherein, y is the third duration, C is the specific heat capacity, m is the mass, η is the heating efficiency, _T2 is the second temperature, _T3 is the third temperature, and P is the target power;

According to the sum of the second time duration and the third time duration being equal to the first time duration, obtaining a numerical value of the third temperature;

The numerical value of the second duration is obtained according to the numerical value of the third temperature.

In one embodiment, the battery thermal management device further includes a second thermal management module, the second thermal management module communicates with the preprocessing module and the first thermal management module, and the second thermal management module is used to:

When the battery is in a charging state, the current charge of the battery is obtained, and based on the current charge, the charging time required to charge the battery to a full charge is obtained, and based on the numerical relationship between the first time and the charging time, the second thermal management is started.

In one embodiment, the second thermal management module starts the second thermal management step according to the numerical relationship between the first duration and the charging duration, including:

Determining whether the first duration is greater than or equal to the charging duration;

If yes, return to the step of obtaining the first temperature;

If not, look up a table according to the current charge amount and the target power to obtain a fourth temperature, wherein the fourth temperature is the lowest temperature of the battery under the current charge amount and the target power;

Acquire a current minimum temperature of the battery, and determine whether the fourth temperature is less than the current minimum temperature;

If so, do not turn on the heating;

If not, obtaining a fourth time required to heat the current lowest temperature to the fourth temperature according to the fourth temperature and the current lowest temperature;

Determine whether the sum of the charging time and the fourth time is equal to the first time, and start heating the battery when the sum of the charging time and the fourth time is equal to the first time.

In one embodiment, the second thermal management step of obtaining a fourth time required to heat the current lowest temperature to the fourth temperature according to the fourth temperature and the current lowest temperature includes:

The specific heat capacity and mass of the battery are obtained, and according to the specific heat capacity, the mass, the fourth temperature, the current minimum temperature, the heating efficiency, and the target power, a mathematical expression for obtaining the fourth duration is obtained as follows:

z＝C*m*(T ₄ −T ₅ )*η/P

Among them, z is the fourth time length, C is the specific heat capacity, m is the mass, _T4 is the fourth temperature, _T5 is the current minimum temperature, η is the heating efficiency, and P is the target power.

In one embodiment, after the first thermal management module starts the first thermal management to heat the battery, or after the second thermal management module starts the second thermal management to heat the battery, it is further used to:

When the exit heating conditions are obtained, the heating operation on the battery is exited, wherein the exit heating conditions include: the current minimum temperature of the battery is greater than or equal to the second temperature, the charge change value of the battery per unit time is greater than or equal to a preset charge change threshold, and the vehicle is in a start state.

For the specific definition of the battery thermal management device, please refer to the definition of the battery thermal management method above, which will not be repeated here. Each module in the above-mentioned battery thermal management device can be implemented in whole or in part by software, hardware and a combination thereof. The above-mentioned modules can be embedded in or independent of the processor in the computer device in the form of hardware, or can be stored in the memory of the computer device in the form of software, so that the processor can call and execute the operations corresponding to the above modules.

In one embodiment, a computer device is provided, which may be a terminal, and its internal structure diagram may be shown in FIG6. The computer device includes a processor, a memory, a network interface, a display screen, and an input device connected via a system bus. Among them, the processor of the computer device is used to provide computing and control capabilities. The memory of the computer device includes a non-volatile storage medium and an internal memory. The non-volatile storage medium stores an operating system and a computer program. The internal memory provides an environment for the operation of the operating system and the computer program in the non-volatile storage medium. The network interface of the computer device is used to communicate with an external terminal via a network connection. When the computer program is executed by the processor, a battery thermal management method is implemented. The display screen of the computer device may be a liquid crystal display screen or an electronic ink display screen, and the input device of the computer device may be a touch layer covered on the display screen, or a key, trackball or touchpad provided on the housing of the computer device, or an external keyboard, touchpad or mouse, etc.

Those skilled in the art will understand that the structure shown in FIG. 6 is merely a block diagram of a partial structure related to the solution of the present application, and does not constitute a limitation on the computer device to which the solution of the present application is applied. The specific computer device may include more or fewer components than those shown in the figure, or combine certain components, or have a different arrangement of components.

In one embodiment, a computer device is provided, including a memory, a processor, and a computer program stored in the memory and executable on the processor, wherein the processor implements the following steps when executing the computer program:

Obtaining the target power required at the time of using the vehicle and the first time between the time of using the vehicle and the current time, and determining whether the battery is in a charging state;

When the battery is in a power-off state, a first temperature under the influence of ambient temperature is obtained according to the first time period, and a second temperature is obtained according to the target power. According to the numerical relationship between the first temperature and the second temperature, a first thermal management is started, wherein the first temperature is the lowest temperature of the battery after the first time period, and the second temperature is the lowest temperature of the battery at the target power.

In one embodiment, when the processor executes the computer program, the following steps are also implemented:

determining whether the first temperature is greater than the second temperature;

If so, do not turn on the heating;

If not, obtaining the heating efficiency of the battery and the amount of heat exchange between the battery and the environment;

Obtaining a second duration for starting heating according to the target power, the heating efficiency and the heat exchange amount;

After the second period of time, heating of the battery is switched on.

In one embodiment, when the processor executes the computer program, the following steps are also implemented:

The specific heat capacity, mass and minimum temperature threshold of the battery are obtained, and a third temperature is set. The second duration is obtained according to the specific heat capacity, the mass, the minimum temperature threshold, the third temperature and the heat exchange amount, wherein the third temperature is the minimum temperature of the battery when heating is turned on. The mathematical expression for obtaining the second duration is:

x＝C*m*(T ₀ −T ₃ )/ΔQ

Wherein, x is the second time length, C is the specific heat capacity, m is the mass, T ₀ is the minimum temperature threshold, T ₃ is the third temperature, and ΔQ is the heat exchange amount;

According to the specific heat capacity, the mass, the heating efficiency, the second temperature, the third temperature and the target power, a third time required to heat the third temperature to the second temperature is obtained, and the mathematical expression for obtaining the third time is:

y＝C*m*η*(T ₂ -T ₃ )/P

Wherein, y is the third duration, C is the specific heat capacity, m is the mass, η is the heating efficiency, _T2 is the second temperature, _T3 is the third temperature, and P is the target power;

According to the sum of the second time duration and the third time duration being equal to the first time duration, obtaining a numerical value of the third temperature;

The numerical value of the second duration is obtained according to the numerical value of the third temperature.

In one embodiment, when the processor executes the computer program, the following steps are also implemented:

When the battery is in a charging state, the current charge of the battery is obtained, and based on the current charge, the charging time required to charge the battery to a full charge is obtained, and based on the numerical relationship between the first time and the charging time, the second thermal management is started.

In one embodiment, when the processor executes the computer program, the following steps are also implemented:

Determining whether the first duration is greater than or equal to the charging duration;

If yes, return to the step of obtaining the first temperature;

If not, look up a table according to the current charge amount and the target power to obtain a fourth temperature, wherein the fourth temperature is the lowest temperature of the battery under the current charge amount and the target power;

Acquire a current minimum temperature of the battery, and determine whether the fourth temperature is less than the current minimum temperature;

If so, do not turn on the heating;

If not, obtaining a fourth time required to heat the current lowest temperature to the fourth temperature according to the fourth temperature and the current lowest temperature;

Determine whether the sum of the charging time and the fourth time is equal to the first time, and start heating the battery when the sum of the charging time and the fourth time is equal to the first time.

In one embodiment, when the processor executes the computer program, the following steps are also implemented:

The specific heat capacity and mass of the battery are obtained, and according to the specific heat capacity, the mass, the fourth temperature, the current minimum temperature, the heating efficiency, and the target power, a mathematical expression for obtaining the fourth duration is obtained as follows:

z＝C*m*(T ₄ −T ₅ )*η/P

Among them, z is the fourth time length, C is the specific heat capacity, m is the mass, _T4 is the fourth temperature, _T5 is the current minimum temperature, η is the heating efficiency, and P is the target power.

In one embodiment, when the processor executes the computer program, the following steps are also implemented:

When the exit heating conditions are obtained, the heating operation on the battery is exited, wherein the exit heating conditions include: the current minimum temperature of the battery is greater than or equal to the second temperature, the charge change value of the battery per unit time is greater than or equal to a preset charge change threshold, and the vehicle is in a start state.

In one embodiment, a computer readable storage medium is provided, on which a computer program is stored, and when the computer program is executed by a processor, the following steps are implemented:

Obtaining the target power required at the time of using the vehicle and the first time between the time of using the vehicle and the current time, and determining whether the battery is in a charging state;

When the battery is in a power-off state, a first temperature under the influence of ambient temperature is obtained according to the first time period, and a second temperature is obtained according to the target power. According to the numerical relationship between the first temperature and the second temperature, a first thermal management is started, wherein the first temperature is the lowest temperature of the battery after the first time period, and the second temperature is the lowest temperature of the battery at the target power.

In one embodiment, when the computer program is executed by a processor, the following steps are also implemented:

determining whether the first temperature is greater than the second temperature;

If so, do not turn on the heating;

If not, obtaining the heating efficiency of the battery and the amount of heat exchange between the battery and the environment;

Obtaining a second duration for starting heating according to the target power, the heating efficiency and the heat exchange amount;

After the second period of time, heating of the battery is switched on.

The specific heat capacity, mass and minimum temperature threshold of the battery are obtained, and a third temperature is set. The second duration is obtained according to the specific heat capacity, the mass, the minimum temperature threshold, the third temperature and the heat exchange amount, wherein the third temperature is the minimum temperature of the battery when heating is turned on. The mathematical expression for obtaining the second duration is:

x＝C*m*(T ₀ −T ₃ )/ΔQ

Wherein, x is the second time length, C is the specific heat capacity, m is the mass, T ₀ is the minimum temperature threshold, T ₃ is the third temperature, and ΔQ is the heat exchange amount;

According to the specific heat capacity, the mass, the heating efficiency, the second temperature, the third temperature and the target power, a third time required to heat the third temperature to the second temperature is obtained, and the mathematical expression for obtaining the third time is:

y＝C*m*η*(T ₂ -T ₃ )/P

Wherein, y is the third duration, C is the specific heat capacity, m is the mass, η is the heating efficiency, _T2 is the second temperature, _T3 is the third temperature, and P is the target power;

According to the sum of the second time duration and the third time duration being equal to the first time duration, obtaining a numerical value of the third temperature;

The numerical value of the second duration is obtained according to the numerical value of the third temperature.

In one embodiment, when the computer program is executed by a processor, the following steps are also implemented:

When the battery is in a charging state, the current charge of the battery is obtained, and based on the current charge, the charging time required to charge the battery to a full charge is obtained, and based on the numerical relationship between the first time and the charging time, the second thermal management is started.

In one embodiment, when the computer program is executed by a processor, the following steps are also implemented:

Determining whether the first duration is greater than or equal to the charging duration;

If yes, return to the step of obtaining the first temperature;

If not, look up a table according to the current charge amount and the target power to obtain a fourth temperature, wherein the fourth temperature is the lowest temperature of the battery under the current charge amount and the target power;

Acquire a current minimum temperature of the battery, and determine whether the fourth temperature is less than the current minimum temperature;

If so, do not turn on the heating;

If not, obtaining a fourth time required to heat the current lowest temperature to the fourth temperature according to the fourth temperature and the current lowest temperature;

Determine whether the sum of the charging time and the fourth time is equal to the first time, and start heating the battery when the sum of the charging time and the fourth time is equal to the first time.

In one embodiment, when the computer program is executed by a processor, the following steps are also implemented:

The specific heat capacity and mass of the battery are obtained, and according to the specific heat capacity, the mass, the fourth temperature, the current minimum temperature, the heating efficiency, and the target power, a mathematical expression for obtaining the fourth duration is obtained as follows:

z＝C*m*(T ₄ −T ₅ )*η/P

Among them, z is the fourth time length, C is the specific heat capacity, m is the mass, _T4 is the fourth temperature, _T5 is the current minimum temperature, η is the heating efficiency, and P is the target power.

In one embodiment, when the computer program is executed by a processor, the following steps are also implemented:

When the exit heating conditions are obtained, the heating operation on the battery is exited, wherein the exit heating conditions include: the current minimum temperature of the battery is greater than or equal to the second temperature, the charge change value of the battery per unit time is greater than or equal to a preset charge change threshold, and the vehicle is in a start state.

Those skilled in the art can understand that all or part of the processes in the above-mentioned embodiment methods can be completed by instructing the relevant hardware through a computer program, and the computer program can be stored in a non-volatile computer-readable storage medium. When the computer program is executed, it can include the processes of the embodiments of the above-mentioned methods. Among them, any reference to memory, storage, database or other media used in the embodiments provided in the present application can include non-volatile and/or volatile memory. Non-volatile memory can include read-only memory (ROM), programmable ROM (PROM), electrically programmable ROM (EPROM), electrically erasable programmable ROM (EEPROM) or flash memory. Volatile memory can include random access memory (RAM) or external cache memory. As an illustration and not limitation, RAM is available in many forms, such as static RAM (SRAM), dynamic RAM (DRAM), synchronous DRAM (SDRAM), double data rate SDRAM (DDRSDRAM), enhanced SDRAM (ESDRAM), synchronous link (Synchlink) DRAM (SLDRAM), memory bus (Rambus) direct RAM (RDRAM), direct memory bus dynamic RAM (DRDRAM), and memory bus dynamic RAM (RDRAM).

The technical features of the above embodiments may be arbitrarily combined. To make the description concise, not all possible combinations of the technical features in the above embodiments are described. However, as long as there is no contradiction in the combination of these technical features, they should be considered to be within the scope of this specification.

The above-mentioned embodiments only express several implementation methods of the present application, and the descriptions thereof are relatively specific and detailed, but they cannot be understood as limiting the scope of the invention patent. It should be pointed out that, for a person of ordinary skill in the art, several variations and improvements can be made without departing from the concept of the present application, and these all belong to the protection scope of the present application. Therefore, the protection scope of the patent of the present application shall be subject to the attached claims.

Claims (8)

1. A method of thermal management of a battery, comprising:

Acquiring target power required by the vehicle using moment and first time length between the vehicle using moment and the current moment, and determining whether the battery is in a charging state or not;

when the battery is in a power-off state, a first temperature under the influence of ambient temperature is obtained according to the first duration, a second temperature is obtained according to the target power, and a first thermal management is started according to the numerical value magnitude relation between the first temperature and the second temperature, wherein the first temperature is the lowest temperature of the battery after the first duration, and the second temperature is the lowest temperature of the battery under the target power;

The step of starting a first thermal management according to the magnitude relation between the first temperature and the second temperature comprises the following steps:

Determining whether the first temperature is greater than the second temperature;

if yes, heating is not started;

If not, obtaining the heating efficiency of the battery and the heat exchange quantity between the battery and the environment;

obtaining a second duration for starting heating according to the target power, the heating efficiency and the heat exchange amount;

after the second time period, starting heating the battery;

The step of obtaining a second duration for turning on heating according to the target power, the heating efficiency and the heat exchange amount includes:

Acquiring specific heat capacity, mass and a lowest temperature threshold of the battery, setting a third temperature, and acquiring a second duration according to the specific heat capacity, the mass, the lowest temperature threshold, the third temperature and the heat exchange amount, wherein the third temperature is the lowest temperature of the battery when heating is started, and acquiring mathematical expression of the second duration is as follows:

；

wherein x is the second duration, C is the specific heat capacity, m is the mass, For the lowest temperature threshold,/>For the third temperature,/>Is the heat exchange amount;

Obtaining a third time period required for heating the third temperature to the second temperature according to the specific heat capacity, the mass, the heating efficiency, the second temperature, the third temperature and the target power, wherein the mathematical expression for obtaining the third time period is as follows:

；

Wherein y is the third duration, C is the specific heat capacity, m is the mass, For the heating efficiency,/>For the second temperature,/>P is the target power for the third temperature;

Obtaining the value of the third temperature according to the sum of the second time length and the third time length being equal to the first time length;

and obtaining the value of the second duration according to the value of the third temperature.

2. The battery thermal management method of claim 1, further comprising:

And when the battery is in a charging state, acquiring the current charge quantity of the battery, acquiring the charging time length required by the battery to be charged to the full charge quantity according to the current charge quantity, and starting a second thermal management according to the numerical value size relation between the first time length and the charging time length.

3. The battery thermal management method according to claim 2, wherein the step of initiating a second thermal management according to a numerical magnitude relation of the first time period and the charging time period includes:

determining whether the first time period is greater than or equal to the charging time period;

If yes, returning to the step of obtaining the first temperature;

If not, looking up a table according to the current charge quantity and the target power to obtain a fourth temperature, wherein the fourth temperature is the lowest temperature of the battery under the current charge quantity and the target power;

Acquiring the current lowest temperature of the battery, and determining whether the fourth temperature is less than the current lowest temperature;

if yes, heating is not started;

If not, obtaining a fourth time length required for heating the current minimum temperature to the fourth temperature according to the fourth temperature and the current minimum temperature;

Determining whether the sum of the charging time period and the fourth time period is equal to the first time period, and starting heating of the battery under the condition that the sum of the charging time period and the fourth time period is equal to the first time period.

4. A battery thermal management method according to claim 3, wherein the step of obtaining a fourth time period required to heat the current minimum temperature to the fourth temperature from the fourth temperature and the current minimum temperature comprises:

acquiring the specific heat capacity and the mass of the battery, and acquiring mathematical expressions of the fourth duration according to the specific heat capacity, the mass, the fourth temperature, the current lowest temperature, the heating efficiency and the target power, wherein the mathematical expressions are as follows:

；

Wherein z is the fourth duration, C is the specific heat capacity, m is the mass, For the fourth temperature,/>For the current minimum temperature,/>For the heating efficiency, P is the target power.

5. The battery thermal management method of claim 1, further comprising:

and when an exit heating condition is acquired, exiting the heating operation of the battery, wherein the exit heating condition comprises: the current lowest temperature of the battery is larger than or equal to the second temperature, the charge quantity change value of the battery in unit time is larger than or equal to a preset charge quantity change threshold, and the vehicle is in a starting state.

6. A battery thermal management device, comprising:

The pretreatment module is used for obtaining target power required by the vehicle using moment and first duration between the vehicle using moment and the current moment and determining whether the battery is in a charging state or not;

the first thermal management module is used for obtaining a first temperature under the influence of the ambient temperature according to the first duration when the battery is in a power-off state, obtaining a second temperature according to the target power, and starting first thermal management according to the numerical value magnitude relation between the first temperature and the second temperature, wherein the first temperature is the lowest temperature of the battery after the first duration, and the second temperature is the lowest temperature of the battery under the target power;

The first thermal management module starts a first thermal management step according to the numerical value magnitude relation between the first temperature and the second temperature, and the first thermal management step comprises the following steps:

Determining whether the first temperature is greater than the second temperature;

if yes, heating is not started;

If not, obtaining the heating efficiency of the battery and the heat exchange quantity between the battery and the environment;

obtaining a second duration for starting heating according to the target power, the heating efficiency and the heat exchange amount;

after the second time period, starting heating the battery;

the first thermal management module obtains a second duration for turning on heating according to the target power, the heating efficiency and the heat exchange amount, and the method comprises the following steps:

Acquiring specific heat capacity, mass and a lowest temperature threshold of the battery, setting a third temperature, and acquiring a second duration according to the specific heat capacity, the mass, the lowest temperature threshold, the third temperature and the heat exchange amount, wherein the third temperature is the lowest temperature of the battery when heating is started, and acquiring mathematical expression of the second duration is as follows:

；

wherein x is the second duration, C is the specific heat capacity, m is the mass, For the lowest temperature threshold,/>For the third temperature,/>Is the heat exchange amount;

Obtaining a third time period required for heating the third temperature to the second temperature according to the specific heat capacity, the mass, the heating efficiency, the second temperature, the third temperature and the target power, wherein the mathematical expression for obtaining the third time period is as follows:

；

Wherein y is the third duration, C is the specific heat capacity, m is the mass, For the heating efficiency,/>For the second temperature,/>P is the target power for the third temperature;

Obtaining the value of the third temperature according to the sum of the second time length and the third time length being equal to the first time length;

and obtaining the value of the second duration according to the value of the third temperature.

7. A computer device comprising a memory, a processor and a computer program stored on the memory and executable on the processor, characterized in that the processor implements the steps of the battery thermal management method of any one of claims 1 to 5 when the computer program is executed by the processor.

8. A computer readable storage medium having stored thereon a computer program, characterized in that the computer program, when executed by a processor, implements the steps of the battery thermal management method of any of claims 1 to 5.