WO2015078200A1

WO2015078200A1 - Charging method and device

Info

Publication number: WO2015078200A1
Application number: PCT/CN2014/084009
Authority: WO
Inventors: 陈勇
Original assignee: 华为技术有限公司
Priority date: 2013-11-30
Filing date: 2014-08-08
Publication date: 2015-06-04
Also published as: CN103606716A; CN103606716B

Abstract

A charging method, comprising: detecting the capacity of a lithium battery; according to the required electric quantity and the capacity of the lithium battery, calculating a required charging state, and acquiring a charging cut-off voltage via a mapping relationship between the required charging state and an open-circuit voltage; and according to the charging cut-off voltage, charging the lithium battery so as to guarantee that the charging electric quantity is greater than or equal to the required electric quantity; alternatively, detecting the real-time electric quantity of the lithium battery; according to the real-time electric quantity and the required electric quantity, calculating to obtain the remaining charging electric quantity; according to the remaining charging electric quantity and a charging current, calculating to obtain a charging cut-off time; and according to the charging cut-off time, charging the lithium battery so as to guarantee that the charging electric quantity is greater than or equal to the required electric quantity. Therefore, the utilization rate of the capacity of a lithium battery and the service life of the lithium battery can be increased.

Description

Charging method and device

The present invention relates to the field of energy technologies, and in particular, to a charging method and device. Background technique

Lithium batteries are widely used in various fields due to their high energy density and maintenance-free advantages. However, due to the limitations of some characteristics of lithium batteries, users need to charge them when using lithium batteries. Characteristics Make a reasonable charging method to fully utilize the advantages of lithium batteries and ensure their service life. Several common lithium battery characteristics are as follows:

a. The state of charge (SOC) of a lithium battery has a stable mapping relationship with its Open Circuit Voltage (OCV). Generally, it does not change with the capacity decay of the lithium battery.

b. Under the same SOC, the discharge capacity of the same lithium battery is positively correlated with the ambient temperature. The ambient temperature is high, the discharge capacity will increase, the ambient temperature will be low, and the discharge capacity will decrease.

c The life of a lithium battery is inversely related to the ambient temperature. The higher the ambient temperature, the shorter the life of the lithium battery.

d. Under the same conditions of charge and discharge, the service life of lithium battery is negatively related to its SOC, that is, the fuller the lithium battery is charged during charging, the shorter the service life of the lithium battery.

In the prior art, most lithium batteries are charged by charging to a fully charged state, i.e., when SOC = 100%. It is characterized in that the lithium battery charging cut-off voltage is fixed to the highest charging voltage allowed by the lithium battery. Depending on the d characteristics of the lithium battery, this charging method will speed up the capacity decay of the lithium battery and shorten the service life. Another method of charging is to charge the lithium battery to a fixed and lower SOC, such as when SOC=80% instead of 100%, which is characterized by a fixed charge cut-off voltage that is lower than the maximum allowable for the lithium battery. A charging voltage of the charging voltage, which can reduce the decay speed of the lithium battery capacity and prolong the service life of the lithium battery, but the capacity of the lithium battery that is not full is not utilized, if the lithium with SOC=100% is to be achieved. The same discharge capacity of the battery requires an increase in the initial design capacity of the lithium battery, and the implementation cost will increase. Summary of the invention

A technical problem to be solved by embodiments of the present invention is to provide a charging method. Can upgrade lithium battery The utilization of the pool capacity and the service life of the lithium battery.

A first aspect of the embodiments of the present invention provides a charging method, including:

Detecting the capacity of a lithium battery;

Calculating a required charging state according to the required power and the capacity of the lithium battery, and obtaining a charging cutoff voltage by a mapping relationship between the required charging state and the open circuit voltage;

The lithium battery is charged according to the charge cutoff voltage to ensure that the charge amount is greater than or equal to the required amount of power.

In a first possible implementation manner of the first aspect, the required charging state is calculated according to the required power amount and the capacity of the lithium battery, and before the charging cutoff voltage is obtained by the mapping relationship between the required charging state and the open circuit voltage, Also includes:

The temperature of the lithium battery is detected.

With reference to the first possible implementation manner of the first aspect, in a second possible implementation manner, the calculating a required charging state according to the required power quantity and the capacity of the lithium battery, by the required charging state and the open circuit voltage The mapping relationship obtains the charging cutoff voltage, including:

Obtaining a coefficient of the capacity of the lithium battery as a function of temperature;

Calculating the corrected demand power according to the coefficient and the required power amount;

And calculating a required charging state according to the corrected required power amount and the capacity of the lithium battery, and obtaining a charging cutoff voltage by a mapping relationship between the required charging state and the open circuit voltage.

A second aspect of the present invention provides a charging method, including:

Detecting the real-time power of the lithium battery;

Calculating a remaining charging power according to the real-time power and the required power, and calculating a charging cut-off time according to the remaining charging power and the charging current;

The lithium battery is charged according to the charge cut-off time to ensure that the charge amount is greater than or equal to the required amount of power.

In a first possible implementation manner of the second aspect, before the detecting the real-time power of the lithium battery, the method further includes:

The temperature of the lithium battery is detected.

With reference to the first possible implementation manner of the second aspect, in a second possible implementation, the calculating the remaining charging power according to the real-time power and the required power, and calculating the remaining charging power and the charging current Charging deadline, including: Obtaining a coefficient of the capacity of the lithium battery as a function of temperature;

Correcting the real-time power according to the coefficient and the real-time power calculation;

The remaining charging power is calculated according to the corrected real-time power and the required power, and the charging cut-off time is calculated according to the remaining charging power and the charging current.

A third aspect of the present invention provides a charging apparatus, including:

a detection module for detecting the capacity of the lithium battery;

a calculation module, configured to calculate a required charging state according to the required power and the capacity of the lithium battery, and obtain a charging cutoff voltage by the mapping relationship between the required charging state and the open circuit voltage;

And a charging module, configured to charge the lithium battery according to the charging cutoff voltage to ensure that the charging power is greater than or equal to the required power.

In a first possible implementation manner of the third aspect, the detecting module is further configured to detect a temperature of the lithium battery.

In conjunction with the first possible implementation of the third aspect, in a second possible implementation, the calculating module is further configured to obtain a coefficient of a capacity of the lithium battery as a function of temperature; Calculating the corrected required power; calculating the required charging state according to the corrected required power and the capacity of the lithium battery, and obtaining the charging cutoff voltage by the mapping relationship between the required charging state and the open circuit voltage.

A fourth aspect of the embodiments of the present invention provides a charging apparatus, including:

a detecting module, configured to detect a real-time power of the lithium battery;

a calculation module, configured to calculate a remaining charging power according to the real-time power and the required power, and calculate a charging cut-off time according to the remaining charging power and the charging current;

And a charging module, configured to charge the lithium battery according to the charging cut-off time to ensure that the charging power is greater than or equal to the required power.

In a first possible implementation manner of the fourth aspect, the detecting module is further configured to detect a temperature of the lithium battery.

With reference to the first possible implementation manner of the fourth aspect, in a second possible implementation manner, the calculating module is further configured to acquire a coefficient of a capacity of the lithium battery as a function of temperature; Calculating the corrected real-time power; calculating the remaining charging power according to the corrected real-time power and the required power, and calculating the charging cut-off time according to the remaining charging power and the charging current.

Embodiments of the present invention have the following beneficial effects: By dynamically adjusting the charging parameters such as the charge cut-off voltage or the charge cut-off time throughout the life cycle of the lithium battery, the charge capacity of the lithium battery can satisfy the demanded power of the user and its equipment, and maintain the lithium battery at a lower state of charge. , thus extending the life of the lithium battery. DRAWINGS

In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the drawings used in the embodiments or the description of the prior art will be briefly described below. Obviously, the drawings in the following description are only It is a certain embodiment of the present invention, and other drawings can be obtained from those skilled in the art without any creative work.

1 is a schematic flow chart of a first embodiment of a charging method of the present invention;

2 is a schematic flow chart of a second embodiment of a charging method of the present invention;

3 is a schematic flow chart of a third embodiment of the charging method of the present invention;

4 is a schematic flow chart of a fourth embodiment of a charging method of the present invention;

Figure 5 is a schematic view showing the composition of a first embodiment of the charging device of the present invention;

Figure 6 is a schematic view showing the composition of a second embodiment of the charging device of the present invention. detailed description

BRIEF DESCRIPTION OF THE DRAWINGS The technical solutions in the embodiments of the present invention will be described in detail with reference to the accompanying drawings. All other embodiments obtained by a person of ordinary skill in the art based on the embodiments of the present invention without creative work are within the scope of the present invention.

1 is a schematic flowchart of a first embodiment of a charging method according to the present invention. In this embodiment, the method includes the following steps:

5101, detecting the capacity of the lithium battery.

5102. Calculate a required charging state according to the required power and the capacity of the lithium battery, and obtain a charging cutoff voltage by a mapping relationship between the required charging state and the open circuit voltage.

Specifically, the required power amount may be a fixed value or a changed value. H does not require the amount of electricity to be Qi, and the capacity of the battery is Qmax, then the required state of charge SOCi=Qi/Qmax, and the open circuit voltage, that is, the charge cutoff voltage Vchar, can be obtained according to the mapping relationship between the required state of charge SOCi and the open circuit voltage OCV. Wherein, the mapping relationship between the required charging state SOCi and the open circuit voltage Vchar is one of the characteristics of the lithium battery, and no longer here. Said.

S103, charging the lithium battery according to the charge cutoff voltage to ensure that the charge amount is greater than or equal to the required amount of power.

Specifically, after the charging cutoff voltage is obtained, the voltage across the lithium battery can be monitored in real time during charging, and the lithium battery is charged with the charging cutoff voltage as a charging control parameter to ensure that the charging capacity of the lithium battery is greater than or equal to the required amount of electricity. In this way, there is no problem that the lithium battery life is reduced due to the high state of charge, and the power demand of the user and its equipment can be fully satisfied.

Since the capacity of the lithium battery is continuously attenuated during use, it is necessary to continuously adjust the charging parameter such as the charging cut-off voltage to ensure that the charged power meets the required power; in this embodiment, by dynamically adjusting the charging cut-off voltage throughout the life cycle of the lithium battery, The charging capacity of the lithium battery can satisfy the demand of the user and its equipment, and maintain the lithium battery in a lower state of charge, thereby prolonging the service life of the lithium battery.

Preferably, in addition to dynamically adjusting the charge cut-off voltage during the entire macro life cycle of the lithium battery, steps S101-S102 may be periodically performed during a single micro-charge process of the lithium battery, thereby achieving finer adjustment of the charge cut-off voltage. The execution period can be determined according to factors such as the condition of the battery, such as temperature and overall usage time.

2 is a schematic flowchart of a second embodiment of a charging method according to the present invention. In this embodiment, the method includes the following steps:

5201, detecting the capacity and temperature of the lithium battery.

Specifically, since some characteristics of the lithium battery are temperature dependent, the step of detecting the temperature of the lithium battery is added in the present embodiment.

5202. Obtain a coefficient of the capacity of the lithium battery as a function of temperature.

Wherein, the coefficient of the capacity change of the lithium battery with temperature is an inherent characteristic of the lithium battery, and the corresponding relationship and coefficient of the lithium battery can be obtained through prior testing, and the coefficient of capacity and temperature can be stored, and when needed, Only need to carry out the corresponding search work, such as using the software look-up table method can get the corresponding coefficient.

5203. Calculate the corrected required power according to the coefficient and the required power.

Specifically, since the temperature and the capacity are positively correlated, that is, when the temperature is increased, the capacity is increased, and when the temperature is lowered, the capacity is decreased, and if the temperature is increased at this time, the capacity is increased, and if the required amount of electricity is divided by the increase The SOC obtained by the capacity has a certain deviation, and the charge cutoff voltage obtained according to the SOC is also inaccurate. As a result, the final charge level does not match the demand level. Therefore, in the present embodiment, the required power amount can be multiplied by the coefficient to obtain the corrected required power amount. By correcting the required demand by dividing the current capacity of the lithium battery, an accurate soc can be obtained.

S204: Calculate a required charging state according to the corrected required power amount and a capacity of the lithium battery, and obtain a charging cutoff voltage by a mapping relationship between the required charging state and an open circuit voltage.

5205. Charge the lithium battery according to the charge cutoff voltage to ensure that the charge amount is greater than or equal to the required power.

In this embodiment, the consideration of the temperature factor is added to ensure that the calculated charge cutoff voltage is an accurate value, thereby ensuring that the final charge amount is equal to or slightly larger than the required amount of power.

Referring to FIG. 3, it is a schematic flowchart of a third embodiment of a charging method according to the present invention. In this embodiment, the method includes the following steps:

5301, detecting the real-time power of the lithium battery.

Wherein, if the charging current is constant, the detection of the real-time power can be obtained according to the product of the current charging current and the charging time plus the initial amount of the lithium battery; if the charging current changes, the detection of the real-time power can be based on the charging current and the charging time. The result of the integration is added to the initial charge of the lithium battery.

5302. Calculate a remaining charging power according to the real-time power and the required power, and calculate a charging cut-off time according to the remaining charging power and the charging current.

Specifically, the remaining power can be obtained by subtracting the real-time power from the required power, and the charging cut-off time can be obtained by dividing the remaining charging power by the charging current. The charging current can be obtained by various detection methods. Narration.

5303. Charge the lithium battery according to the charging cut-off time to ensure that the charging power is greater than or equal to the required power.

Specifically, after calculating the charging cut-off time, it is only necessary to keep the current charging current unchanged, and then continue charging until the charging cut-off time arrives. At this time, the charged electric quantity is the required electric quantity.

Since the capacity of the lithium battery is continuously attenuated during use, it is necessary to continuously adjust the charging parameters such as the charging cut-off time to ensure that the charged power meets the required power; in this embodiment, by dynamically adjusting the charging cut-off time throughout the life cycle of the lithium battery, The charging capacity of the lithium battery can satisfy the demand of the user and its equipment, and maintain the lithium battery in a lower state of charge, thereby prolonging the service life of the lithium battery.

Preferably, in addition to dynamically adjusting the charge cut-off time over the entire macro life cycle of the lithium battery, Steps S301-S302 can be periodically performed during a single micro-charge process of the lithium battery, thereby achieving finer adjustment of the charge cut-off time, and the execution cycle can be determined according to factors such as temperature of the battery, overall use time, and the like.

Referring to FIG. 4, it is a schematic flowchart of a fourth embodiment of a charging method according to the present invention. In this embodiment, the method includes the following steps:

5401, detecting the real-time power and temperature of the lithium battery.

5402. Obtain a coefficient of the capacity of the lithium battery as a function of temperature.

S403. Calculate the corrected real-time power according to the coefficient and the real-time power amount.

S404, calculating a remaining charging power according to the corrected real-time power and the required power, and calculating a charging cut-off time according to the remaining charging power and the charging current.

5405. Charge the lithium battery according to the charging cut-off time to ensure that the charging power is greater than or equal to the required power.

In this embodiment, the consideration of the temperature factor is added to ensure that the calculated charge cut-off time is an accurate value, thereby ensuring that the final charge amount is greater than or equal to the required amount of power.

It should be noted that, in various embodiments of the present invention, the calculation of the charge cutoff voltage and the charge cutoff time can be performed simultaneously, and the final charging process is completed to ensure accurate control according to different charge cutoff parameters in different charging stages of the lithium battery. .

In addition, you can directly poll the real-time and demanded power of the lithium battery until the real-time power is greater than or equal to the required power. For example, every preset period, such as 2 seconds, performs real-time power detection, and then compares with the required power. If the real-time power is lower than the required power, continue charging until the next cycle is detected and compared again.

Please refer to FIG. 5 , which is a schematic diagram of the composition of the first embodiment of the charging device of the present invention. In this embodiment, the device includes:

The detecting module 100 is configured to detect a capacity of the lithium battery; The calculation module 200 is configured to calculate a required charging state according to the required power and the capacity of the lithium battery, and obtain a charging cutoff voltage by the mapping relationship between the required charging state and the open circuit voltage;

The charging module 300 is configured to charge the lithium battery according to the charge cutoff voltage to ensure that the charge amount is greater than or equal to the required power.

The detecting module 100 is further configured to detect a temperature of the lithium battery.

The calculation module 200 is further configured to obtain a coefficient of the capacity of the lithium battery as a function of temperature; calculate a corrected required power according to the coefficient and the required power; and calculate a required charging according to the corrected required power and the capacity of the lithium battery. The state is obtained by the mapping relationship between the required charging state and the open circuit voltage.

It should be noted that the above inspection module, the calculation module, and the charging module may be set together or may exist independently, and the inspection module, the calculation module, and the charging module in the above charging device embodiment may be independent of the processor of the charging device in hardware form. Separately arranged, and the setting form may be in the form of a microprocessor; it may also be embedded in the processor of the charging device in hardware form, or may be stored in the memory of the charging device in software, so as to be called by the processor of the charging device. Perform the operations corresponding to the above inspection module, calculation module, and charging module.

In another implementation, the charging device can include: an interface circuit, a memory, and a processor coupled to the interface circuit and the memory. The memory is for storing a set of program codes, and the processor is configured to call the program code stored in the memory to perform the operations described in any one of the first to second embodiments of the charging method of the present invention.

Please refer to FIG. 6, which is a schematic diagram of the composition of a second embodiment of the charging device of the present invention. In this embodiment, the device includes:

The detecting module 400 is configured to detect a real-time power of the lithium battery;

The calculating module 500 is configured to calculate a remaining charging power according to the real-time power and the required power, and calculate a charging cut-off time according to the remaining charging power and the charging current;

The charging module 600 is configured to charge the lithium battery according to the charging cut-off time to ensure that the charging power is greater than or equal to the required power.

The detection module 400 is further configured to detect a temperature of the lithium battery.

The calculation module 500 is further configured to obtain a coefficient of the capacity of the lithium battery as a function of temperature; calculate a corrected real-time power according to the coefficient and the real-time power; and calculate a remaining charge according to the corrected real-time power and the required power, according to The remaining charging power and charging current are calculated to be charged Stop time.

In another implementation, the charging device can include: an interface circuit, a memory, and a processor coupled to the interface circuit and the memory. The memory is for storing a set of program codes, and the processor is configured to call the program code stored in the memory to perform the operations described in any of the third to fourth embodiments of the charging method of the present invention.

It should be noted that the various embodiments in the present specification are described in a progressive manner, and each embodiment focuses on differences from other embodiments, and the same similar parts between the embodiments are referred to each other. Just fine. For the device embodiment, since it is basically similar to the method embodiment, the description is relatively simple, and the relevant parts can be referred to the description of the method embodiment.

Through the description of the above embodiments, the present invention has the following advantages:

By dynamically adjusting the charging parameters such as the charge cut-off voltage or the charge cut-off time throughout the life cycle of the lithium battery, the charge capacity of the lithium battery can satisfy the demanded power of the user and its equipment, and maintain the lithium battery at a lower state of charge. , thus extending the life of the lithium battery.

A person skilled in the art can understand that all or part of the process of implementing the above embodiment method can be completed by a computer program to instruct related hardware, and the program can be stored in a computer readable storage medium. When executed, the flow of an embodiment of the methods as described above may be included. The storage medium may be a magnetic disk, an optical disk, a read-only memory (ROM), or a random access memory (RAM).

The above is only the preferred embodiment of the present invention, and the scope of the present invention is not limited thereto, and the equivalent changes made by the claims of the present invention are still within the scope of the present invention.

Claims

Rights request

A charging method, comprising:

Detecting the capacity of a lithium battery;

2. The method according to claim 1, wherein the required charging state is calculated according to the required amount of electricity and the capacity of the lithium battery, and the charging cutoff voltage is obtained before the charging cutoff voltage is obtained by the mapping relationship between the required charging state and the open circuit voltage. , Also includes:

The temperature of the lithium battery is detected.

The method according to claim 2, wherein the calculating the required charging state according to the required power amount and the capacity of the lithium battery, and obtaining the charging cutoff voltage by the mapping relationship between the required charging state and the open circuit voltage, including :

Calculating the corrected demanded power according to the coefficient and the required power;

4. A charging method, comprising:

Detecting the real-time power of the lithium battery;

The lithium battery is charged according to the charge cut-off time to ensure that the charge amount is greater than or equal to the required amount of power. The method according to claim 4, wherein said detecting the real-time power of the lithium battery Previously, it also included:

The temperature of the lithium battery is detected.

The method according to claim 5, wherein the calculating the remaining charging power according to the real-time power and the required power, and calculating the charging deadline according to the remaining charging power and the charging current, comprising:

7. A charging device, comprising:

a detection module for detecting the capacity of the lithium battery;

8. The apparatus according to claim 7, wherein the detecting module is further configured to detect a temperature of the lithium battery.

The device according to claim 8, wherein the calculation module is further configured to acquire a coefficient of a capacity change of the lithium battery according to a temperature; and calculate a corrected required power according to the coefficient and the required power amount; Calculating the required charging state by correcting the required power amount and the capacity of the lithium battery, and obtaining a charging cutoff voltage by a mapping relationship between the required charging state and the open circuit voltage.

10. A charging device, comprising:

a calculation module, configured to calculate a remaining charging power according to the real-time power and the required power, and calculate a charging cut-off time according to the remaining charging power and the charging current; And a charging module, configured to charge the lithium battery according to the charging cut-off time to ensure that the charging power is greater than or equal to the required power.

11. The apparatus according to claim 10, wherein the detecting module is further configured to detect a temperature of the lithium battery.

The device of claim 11, wherein the calculation module is further configured to acquire a coefficient of the capacity of the lithium battery as a function of temperature; and calculate a corrected real-time power according to the coefficient and the real-time power amount; The corrected real-time power and the required power are calculated to obtain the remaining charging power, and the charging cut-off time is calculated according to the remaining charging power and the charging current.