BATTERY PACK

CROSS-REFERENCE TO RELATED APPLICATION This application claims priority to and benefit of Chinese Patent Application

Serial No. 200910105109.0, filed on Jan. 16, 2009 to the State Intellectual Property Office of the P. R. China, the entire content of which is incorporated herein by reference.

FIELD OF THE INVENTION

The present invention relates to the field of battery, more particularly, to a battery managing device, a method of using the battery managing device and a charging management method of a battery pack.

BACKGROUND OF THE RELATED ART

With advancement of the society and development of economy, people pay more attention to hybrid power vehicles and electric vehicles which can save energy and reduce emission of carbon dioxide. But charging of a battery in such vehicle is difficult because of huge capacity of the battery. There is much work to do to improve the technique of charging. The present charging device has a disadvantage that a charging controlling curve reserved in advance in a charging curve library and read out from the curve library to control the charging device during charging process has an inferior correlation with a battery.

SUMMARY OF THE INVENTION

In viewing thereof, the present invention is directed to solve at least one of the problems existing in the prior art. Accordingly, a battery managing device is provided which correlates a charging device with a battery more closely so that the charging device may be efficiently controlled. Further, a battery managing method may need to be provided.

According to an embodiment of the invention, a battery managing device is provided, which may comprise a single-chip for determining a charging voltage and a charging current according to a remaining capacity of the battery and controlling a charging device coupled to the battery managing device to charge the battery pack with the charging voltage and charging current determined by the single-chip.

Further, according to another embodiment of the invention, a method of using a battery managing device as described above may be provided, which may comprise the following steps: (1) determining the charging voltage and the charging current according to a remaining capacity of the battery by the single-chip; (2) controlling the charging device coupled to the battery managing device by the single-chip to charge the battery pack with said charging voltage and charging current.

Still, according to a further embodiment of the invention, a charging management method of a battery pack may be provided, which may comprise the following steps: obtaining an initial remaining capacity of a battery to be charged before charging; determining an initial charging voltage and an initial charging current according to the initial remaining capacity of the battery pack; charging the battery pack to be charged according to the initial charging voltage and the initial charging current; obtaining a current remaining capacity of the battery pack during charging; determining a current charging voltage and a current charging current according to the current remaining capacity; and charging the battery pack to be charged according to the current charging voltage and the current charging current.

According to the battery managing device of the present invention, the corresponding charging voltage and the charging current may be determined by the current remaining capacity of each battery pack, and the charging device coupled to the battery managing device may be controlled to charge the battery pack based on the determined charging voltage and the charging current, so that the charging voltage, the charging current correlate to the current state of the battery pack, which may enhance battery power management.

Additional aspects and advantages of the embodiments of present invention will be given in part in the following descriptions, become apparent in part from the following descriptions, or be learned from the practice of the embodiments present invention.

BRIEF DESCRIPTION OF THE DRAWINGS

The aforementioned features and advantages of the invention as well as additional features and advantages thereof will be more clearly understood hereinafter as a result of a detailed description of embodiments when taken in conjunction with the drawings, in which:

Fig. l shows a graph illustrating the relationships between charging amount, charging voltage, charging current and time in prior art.

Fig.2 shows a schematic view of a connection relationship among a charging device, a battery managing device and a battery pack according to an embodiment of the invention.

Fig.3 shows a structural schematic view of a battery managing device according to an embodiment of the invention.

DETAILED DESCRIPTION OF THE EMBODIMENT

Reference will be made in detail to embodiments of the present invention. The embodiments described herein with reference to drawings are explanatory, illustrative, and used to generally understand the present invention. The embodiments shall not be construed to limit the present invention. The same or similar elements and the elements having same or similar functions are denoted by like reference numerals throughout the descriptions.

Fig. l shows a graph illustrating the relationships between charging amount, charging voltage, charging current and time in prior art. Through experiments, the technicians can draw an optimal mating curve between a remaining capacity of the battery pack 3 and the charging voltage and the charging current. For example, the battery may be discharged completely. Then the battery is charged with different charging voltages and charging currents according to the battery characteristic curve to draw the curve among the remaining capacity, the charging voltage and the charging current. Then the appropriate relationship curve among the remaining capacity, the charging voltage and the charging current may be built up by experiment. When the remaining capacity is detected, the battery can be charged with the charging voltage and charging current determined by the relationship curve. Due to the different type of the battery, the relationship curve thereof is different as well. And the characteristic information of the battery may be stored into different types of storage modules. During charging process, related data may be read out therefrom directly so that the charging process may be completed.

According to an embodiment of the invention, as shown in Fig.2, the battery managing device 2 may include a single-chip 25 for determining a charging voltage and a charging current according to a remaining capacity of the battery pack 3 and controlling the charging device 1 coupled to the battery managing device 2 to charge the battery pack 3 in the determined charging voltage and charging current. It should be noted that here the single-chip is described for illustration purpose rather than limitation. Any central processor may be used as the single-chip instead. The charging device 1 is commonly used in the art. The charging device 1 may include an AC/DC voltage converting module or DC/DC voltage converting module for converting the voltage of the power grid into the voltage needed by the battery. Further, the charging device 1 may further comprise a hardware protecting circuit for protecting the hardware and a charging interface for charging. The battery managing device may further include a capacity detecting module

(not shown) and an AfD converting module (not shown). The capacity detecting module may be coupled to the AfD converting module. The AID converting module may be coupled to the single-chip 25. The capacity detecting module is used for detecting the remaining capacity of the battery pack 3. The capacity detecting module may be known in the art.

The charging device normally runs in a status of high voltage and current, which may bring great impact to the detection of small signals due to electromagnetic interference generated therefrom. It is difficult to detect these signals. In order to overcome the difficulty, the battery managing device according to an embodiment of the present invention may include a current detecting module 21, a voltage detecting module 22, a temperature detecting module 23, an A/D converting module 24, a single-chip 25 and a storage module 26. The current detecting module 21, the voltage detecting module 22 and the temperature detecting module 23 are respectively coupled to the A/D converting module 24. The A/D converting module 24 is coupled to the single-chip 25. The storage module 26 is coupled to the single-chip 25.

The battery pack 3 may include a single cell or a plurality of single cells. According to an embodiment of the invention, the battery pack 3 may include a plurality of single cells connected in series.

For convenience of installation, the plurality of single cells connected in series can be divided into a plurality of battery groups. The battery groups may have the same or different number of the single cells. According to an embodiment of the invention, the battery groups may have the same number of the single cells. The temperature detecting module 23 detects the temperature of each single cell and battery group respectively.

The current detecting module 21 is used for detecting the discharging current of the battery pack 3 during usage. The voltage detecting module 22 is used for detecting the voltage of a single cell when the battery pack 3 is charged. The current detecting module 21, the voltage detecting module 22 and the temperature detecting module 23 are respectively coupled to the A/D converting module 24. The A/D converting module 24 is used for converting the current detected by the current detecting module 21, the voltage detected by the voltage detecting module 22 and the temperature detected by the temperature detecting module 23 into digital signals and transferring thereof to the single-chip 25.

The storage module 26 stores information of the total capacity of the battery pack 3, the remaining capacity of the battery pack 3, the rated voltage of the single cell and the rated voltage of the battery pack 3. The storage module 26 may further record the information when the battery pack 3 is discharged or charged, such as the discharging current, the discharging or charging time etc. The storage module 26 also record how many times the battery pack 3 has been charged. The information can be used in the research and development of the battery pack and single cell. The battery managing device 2 can be coupled to the charging device 1 in any known manner. According to an embodiment of the invention, both the battery managing device 2 and the charging device 1 may both have a CAN communicating module. The charging device 1 may further comprise a single-chip. The battery managing device 2 is coupled to the charging device 1 by a CAN bus so that they can communicate conveniently. The battery managing device 2 can be coupled to the charging device 1 in other ways as long as the information of the charging voltage and charging current generated by the battery managing device 2 can be sent to the charging device 1. And then the charging device can charge the battery according to the information of the charging voltage and charging current. According to an embodiment of the invention, a method of using the battery managing device 2 as described above including a single-chip 25 may be further provided, comprising: (1) determining a charging voltage and a charging current according to a remaining capacity of the battery by the single-chip; (2) controlling the charging device coupled to the battery managing device to charge the battery in the charging voltage and charging current by the single-chip.

The battery managing device may further include a capacity detecting module (not shown in figures) and an A/D converting module (not shown in figures). The capacity detecting module is coupled to the A/D converting module. The A/D converting module is coupled to the single-chip 25. The capacity detecting module is used for detecting the remaining capacity of the battery pack 3. The capacity detecting module is known in the art.

The charging device runs with high voltage and current. The detecting information may be influenced by the electromagnetic interference which is generated by the charging device. It is difficult to detect the battery information. In order to overcome the difficulty, the battery managing device according to an embodiment of the present invention may include a current detecting module 21, a voltage detecting module 22, a temperature detecting module 23, an A/D converting module 24, a single-chip 25 and a storage module 26. The current detecting module 21, the voltage detecting module 22 and the temperature detecting module 23 are respectively coupled to the A/D converting module 24. The A/D converting module 24 may be coupled to the single-chip 25. The storage module 26 may be coupled to the single-chip 25.

The battery pack 3 may include a single cell or a plurality of single cells. According to an embodiment of the invention, the battery pack 3 may comprise a plurality of single cells connected in series.

The single cells connected in series can be divided into several battery groups. The battery groups may have the same or different number of the single cells. According to an embodiment of the invention, the battery groups may have the same number of the single cells. The temperature detecting module 23 may detect the temperature of each single cell and battery group.

The current detecting module 21 may detect the current of the battery pack 3 when the battery pack 3 is discharged. The voltage detecting module 22 may detect the voltage of the single cell when the battery pack 3 is charged. The current detecting module 21, the voltage detecting module 22 and the temperature detecting module 23 are respectively coupled to the A/D converting module 24. The A/D converting module 24 may converts the current detected by the current detecting module 21, the voltage detected by the voltage detecting module 22 and the temperature detected by the temperature detecting module 23 into corresponding digital signals and delivering thereof to the single-chip 25 coupled thereto.

The storage module 26 may store the information of the total capacity of the battery pack 3, the remaining capacity of the battery pack 3, the rated voltage of the single cell and the rated voltage of the battery pack 3. The storage module 26 may further record the information when the battery pack 3 is discharged or charged, such as the current, the time of being discharged or charged. The storage module 26 also record how many times the battery pack 3 has been charged. The information can be used in the research and development of the battery pack 3 and the single cell.

The battery managing device 2 may be coupled to the charging device 1 in any known manners. As a preferred embodiment of the invention, both the battery managing device 2 and the charging device 1 may have a CAN communicating module. The charging device 1 may further have a single-chip. The battery managing device 2 may be coupled to the charging device 1 by a CAN bus so that they may communicate conveniently. The battery managing device 2 may be coupled to the charging device 1 in other ways as long as the information of the charging voltage and charging current generated by the battery managing device 2 may be sent to the charging device 1. And then the charging device may charge the battery according to the information of the charging voltage and charging current.

As a preferred embodiment of the invention, the step (1) may comprise: (1-1) obtaining an initial remaining capacity of the battery from the storage module and determining an initial charging voltage and an initial charging current according to the initial remaining capacity by the single-chip; (1-2) determining a current charging voltage and a current charging current according to the present remaining capacity of the battery by the single-chip.

The initial remaining capacity in step (1-1) may be calculated by following steps: (1-1-1) obtaining an used capacity by integrating a discharging voltage with a discharging current by the single-chip during the usage of the battery pack, in which the battery managing device is connected with the battery pack; (1-1-2) subtracting the used capacity from the total capacity of the battery pack to obtain the initial remaining capacity by the single-chip; (1-1-3) storing the initial remaining capacity in the storage module by the single-chip; and/or (1-1-4) obtaining the initial remaining capacity from the storage module by the single-chip during charging.

In the step (1-1-1), the battery managing device 2 may be coupled to the battery pack 3. For example, the battery managing device 2 may be integrated with the battery pack 3 to record the information of the battery pack 3. The present remaining capacity in step (1-2) is calculated by following steps:

(1-2-1) obtaining the charged capacity by integrating the charging voltage with the charging current by the single-chip during charging; (1-2-2) obtaining the present remaining capacity by adding the initial remaining capacity and the amount of the capacity which has been stored in the battery when the battery is charged by the single-chip. The amount of electricity which has been stored in the battery is the integral value of the charging voltage and the charging current.

Further, the method of the invention may comprise: (3) determining whether the battery pack 3 is fully charged by the charging device via the single-chip 25. The single-chip 25 determines whether the remaining capacity of the battery pack 3 is as much as the total capacity or whether the voltage of one of the single cells is as much as the rated voltage to determine whether the battery pack 3 is fully charged or not. According to an embodiment of the invention, the single-chip 25 determines whether the voltage of one of the single cells is as much as the rated voltage to determine whether the battery pack 3 is fully charged. Thus, with the present invention, the life-span of the battery pack 3 may be prolonged.

The step (3) may comprise: (3-1) controlling the charging device 1 to stop charging the battery pack 3 by the single-chip when the battery pack 3 is fully charged; (3-2) controlling the charging device 1 to continue charging the battery 2 by the single-chip when the battery 1 is not fully charged. In order to protect the single cell of the battery pack 3, the battery managing device may further include a temperature detecting module coupled to the A/D converting module, the step (1) and step (2) may further include: (s-1) dividing the plurality of single cells connected in series into a plurality of battery groups and detecting the temperature of every single cell and battery group by the temperature detecting module 23; (s-2) determining whether the temperature of one of the single cells and battery groups reaches the predetermined temperature threshold by the temperature detecting module 23; (s-3) alarming and stopping charging the battery pack 3 if the temperature of one of the single cells and battery groups reaches the predetermined temperature threshold; (s-4) keeping on charging the battery pack 3 if the temperature of any single cell and battery group does not reach the predetermined temperature threshold.

The predetermined temperature threshold may be preset by the type of the battery pack 3. For example, it may be 65 centigrade degree. An alarming device which is used for alarming can be positioned on the charging device 1 or the battery managing device 2. The alarming device may be a buzzer or beeper etc. And accidental explosion of the battery pack 3 may be avoided accordingly.

According to the battery managing device and the method of using the same, the high voltage and large current in the charging device 1 may bring less influence so that data may be better detected to enhance data detection accuracy.

Further, the present invention discloses a charging management method of a battery pack, which may comprise: obtaining an initial remaining capacity of a battery to be charged before charging; determining an initial charging voltage and an initial charging current according to the initial remaining capacity of the battery pack; charging the battery pack to be charged according to the initial charging voltage and the initial charging current; obtaining a current remaining capacity of the battery pack during charging; determining a current charging voltage and a current charging current according to the current remaining capacity; and charging the battery pack to be charged according to the current charging voltage and the current charging current. According to an embodiment of the invention, the initial remaining capacity and the current remaining capacity are detected by a capacity detecting module, the initial remaining capacity may be obtained by the following steps: obtaining an used capacity by integrating the discharging voltage and the discharging current during the use of the battery pack to be charged; and obtaining the initial remaining capacity based on a total capacity of the battery pack to be charged and the used capacity.

Further, in the charging management method of the invention, the current remaining capacity may be obtained by the following steps: obtaining a charged capacity by integrating the charging voltage and the charging current during charging; and obtaining a current remaining capacity based on the initial remaining capacity and the charged capacity. The method may further comprise: determining whether the battery pack is completely charged or not according to the current remaining capacity; and stopping charging if it is completely charged. According to an embodiment of the invention, whether the battery pack is completely charged or not may be determined by follows: detecting a temperature fore each single cell in the battery pack; determining whether the temperature of any one of the single cell reaches a predetermined threshold or not; and alarming and stopping charging if the temperature of any one of the single cell has reached the predetermined threshold. According to another embodiment of the invention, whether the battery pack is completely charged or not may be determined by follows: detecting a voltage for each single cell in the battery pack; determining whether any one of the single cells is completely charged or not based on the voltage of each single cell; and stopping charging if any one of the single cells is completely charged. The principles of the preferred embodiment described herein is therefore illustrative and not restrictive, the scope of the invention being indicated in the appended claims and all variations which come within the spirit and meaning of the claims may be intended be embraced therein.