KR100802912B1 - Method and apparatus of correcting full charge capacity and end of discharge voltage - Google Patents

Abstract

The present invention relates to a battery charging capacity and discharge limitation voltage correcting method and apparatus for correcting a discharge limiting voltage of a battery in accordance with a charged capacity of a battery in consideration of characteristics such as a temperature and a degree of deterioration depending on the number of times of charging and discharging, And to provide the above-mentioned objects.

A method for correcting a battery charging capacity according to the present invention includes the steps of: measuring a remaining capacity from a low-charged state of the battery to a shutdown; and determining a remaining capacity of the battery from the full- And correcting the first value by adding the first value to the charge capacity of the battery.

A method for correcting a discharge limitation voltage of a battery according to the present invention includes the steps of: measuring a remaining capacity from a low-charged state of the battery to a shutdown; and determining a discharge limit voltage And a step of correcting the correction value.

Battery pack, charge capacity, discharge limiting voltage

Description

METHOD AND APPARATUS OF CORRECTING FULL CHARGE CAPACITY AND END OF DISCHARGE VOLTAGE BACKGROUND OF THE INVENTION 1. Field of the Invention [0001]

1 is a configuration diagram of a battery management apparatus according to a preferred embodiment of the present invention;

FIG. 2 and FIG. 3 are flow charts of a method for correcting a battery charging capacity and a discharge limiting voltage according to a preferred embodiment of the present invention.

Description of the Related Art

100: Battery management device

102:

104:

106: clock generator

108: Voltage sensing unit

110:

112: Current sensing unit

114: sensing resistance

BACKGROUND OF THE INVENTION 1. Field of the Invention [0002] The present invention relates to a battery management method and apparatus, and more particularly, to a method and apparatus for correcting a charging capacity and a discharge limiting voltage of a battery.

Generally, a portable electronic device enters a power saving mode to protect data that is being operated through a portable electronic device when the remaining capacity of the battery is less than a predetermined value, or to prevent abnormal operation due to a battery having a low remaining capacity, Allow the device to operate reliably.

Incidentally, the charging capacity of the battery is often erroneously measured due to the number of times of charging the battery, a sudden change in the ambient temperature, and the like.

More specifically, a battery pack (secondary battery) including a lithium ion battery has a characteristic that the charging capacity is determined for each battery pack, but the charging capacity varies depending on the temperature to be used.

For example, when the battery pack is used at a low temperature, the internal impedance of the battery cell is increased. Therefore, when the same current value is to be supplied, the voltage drop increases and the charging capacity of the battery pack decreases.

In addition, the battery pack is characterized in that the charging capacity is reduced even when the number of charging / discharging is increased. This is because battery cells deteriorate due to repetition of charging and discharging and the usable capacity decreases, which is referred to as cycle deterioration.

Since the charging capacity of the battery changes depending on the cycle deterioration caused by repetition of charging and discharging and the temperature at the time of use, an error occurs between the calculated remaining capacity of the battery and the remaining capacity of the actual battery.

In order to solve this problem, various methods have been proposed in the past.

For example, Patent No. 10-2004-0092389, filed by the Korean Intellectual Property Office on the basis of a battery pack and a method for calculating the remaining battery charge, includes temperature measuring means for measuring the temperature of the battery cell, A correction value storing means for storing a correction value which is changed every predetermined number of times of charging and discharging and for calculating a battery remaining amount according to the temperature and a correction value storage means for storing the correction value storage means on the basis of the measured temperature and the counted number of charge / And remaining amount calculating means for calculating the remaining amount of battery in accordance with the correction value by searching the means for determining the correction value. This conventional technique makes it possible to correct the error of the residual capacity caused by the number of charge reversals and the temperature.

In addition, Patent No. 10-2001-0029768, filed by the Korean Intellectual Property Office with the name of the method for calibrating the residual capacity of a smart battery, is used as a parameter of current, charge / discharge frequency, and temperature in measuring the residual capacity of a smart battery used in a portable electronic device A residual capacity correction method for a smart battery is disclosed in which a voltage of a specific capacity is calculated, and the residual capacity is corrected by the calculated voltage of the specific capacity, thereby improving accuracy in the residual capacity correction. This conventional technique makes it possible to correct the error of the residual capacity caused by the current, the number of charging / discharging times, the temperature, and the like.

As described above, various methods for correcting the error of the residual capacity of the battery have been proposed. However, since characteristics such as the temperature and the degree of deterioration according to the number of times of charge and discharge differ for each battery cell, the residual capacity of the battery can not be accurately corrected only by the conventional method described above.

Accordingly, development of a technology for accurately detecting the remaining capacity of the battery in consideration of characteristics such as deterioration degree depending on different temperatures and the number of times of charge and discharge for each battery cell has been urgently required.

SUMMARY OF THE INVENTION The present invention has been made to overcome the above-mentioned conventional problems, and it is an object of the present invention to provide a battery charging capacity correcting method and apparatus for correcting a charging capacity of a battery in consideration of characteristics such as a temperature and a degree of deterioration depending on the number of charge / .

Another object of the present invention is to provide a battery discharge limiting voltage correcting method for correcting a discharge limiting voltage of a battery in accordance with a charged capacity of the battery in consideration of characteristics such as a temperature and a deterioration degree depending on the number of charge / Device.

According to another aspect of the present invention, there is provided a method for correcting a charge capacity of a battery, comprising the steps of: measuring a remaining capacity from a low charge state to a shutdown state of the battery; And correcting the first value obtained by adding the remaining capacity to the capacity before reaching the low-charge state with the charge capacity of the battery.

A method for correcting a discharge limitation voltage of a battery according to the present invention comprises the steps of: measuring a remaining capacity from a low battery charge state to a shutdown state; and measuring a discharge limit voltage And a step of correcting the correction value.

The present invention corrects the charge capacity (FCC) of the battery on the basis of the actual remaining capacity (shut-SOC) from the low-charge state to the shutdown state, which determines the entry into the power-saving mode, It is possible to accurately calculate the charging capacity even if the characteristics such as the degree of deterioration are different.

Also, by correcting the discharge limiting voltage (C-EDV) according to the charging capacity (FCC), the battery can be protected and the device receiving power from the battery can operate normally.

The configuration of a battery management apparatus according to a preferred embodiment of the present invention will be described with reference to FIG.

The battery management apparatus 100 is an MCU generally referred to as a fuel gauging IC. The control unit 102 of the battery management apparatus 100 controls the overall operation of the battery management apparatus 100 and controls the charging of the battery V based on the actual remaining capacity shut-SOC according to a preferred embodiment of the present invention. The capacitance (FCC) and the discharge limitation voltage (C-EDV) are corrected.

The memory unit 104 stores various information including a processing program of the control unit 102, and particularly includes a discharge limitation voltage correction table according to a preferred embodiment of the present invention. The discharge limitation voltage correction table stores the discharge limit voltage (C-EDV) corresponding to each of a plurality of actual remaining capacities (shut-SOC) in correspondence with each other. (C-EDV) according to the remaining capacity (shut-SOC) and interpolates the actual remaining capacity (shut-SOC) between the level intervals to obtain the discharge restricting voltage do.

The memory unit 104 stores the discharge limitation voltage (C-EDV), the residual capacity (FCC) of the battery (V), the shutdown voltage, the capacity discharged from the full charge state to the low charge state (DCR), a value (FCC_BEFORE) before the charge capacity (FCC) is updated, and a correction flag. Here, the correction flag is a flag indicating whether the discharge has been sustained in the power saving mode to reach shutdown.

The clock generator 106 generates a clock for operation of the battery management device 100 and provides the generated clock to each part.

The voltage sensing unit 108 senses the voltages V +, V-, VH and VL of the battery V and supplies the result to the control unit 100.

The communication unit 110 communicates with the portable electronic device provided with the battery V and the control unit 102 and is provided with a clock and data terminal for communication with the portable electronic device.

The current sensing unit 112 senses the current of the battery V through the sensing resistor 114 and provides the result to the control unit 100.

The sensing resistor 114 is connected in series to the power output path of the battery V. [

Now, a battery charge capacity and a discharge limitation voltage correction method according to a preferred embodiment of the present invention applicable to the above-described battery management apparatus will be described in detail with reference to FIGS. 2 and 3. FIG.

The control unit 102 checks whether the portable electronic device incorporating the battery V enters the power saving mode (step 200).

If the voltage of the battery V corresponds to the discharge limitation voltage C-EDV stored in the memory unit 104, the control unit 102 transmits a power saving mode entering command to the portable electronic device. Upon receiving the power saving mode entry command, the portable electronic device enters the power saving mode in accordance with the power saving mode entry command, thereby protecting the portable electronic device and the battery (V).

If the voltage of the battery V corresponds to the discharge limitation voltage C-EDV, the controller 102 counts the shutdown time (step 202). Here, the shutdown time is for calculating the actual remaining capacity (shut-SOC) of the battery V, and the shutdown refers to power-off.

More specifically, the present invention counts a shutdown time from the time of entering the power saving mode, that is, from the low charge state until the battery (V) is shut down. The shutdown time, the current sensing value provided by the current sensing unit (122) (Shut-SOC) of the battery (V) by multiplying the voltage sensing value provided by the sensing unit (108).

When the counting of the shutdown time starts, the control unit 102 checks whether the voltage of the battery V is a predetermined shutdown voltage. If the voltage of the battery V is a shutdown voltage, the control unit 102 checks whether or not the battery is in a power saving mode. That is, the control unit 102 checks whether the power saving mode is maintained without starting charging until the shutdown voltage is reached (steps 206 and 208).

If the power saving mode is maintained until the shutdown voltage is reached, the control unit 102 sets the correction flag to 1, stores the counted shutdown time, and then performs shutdown (step 210).

When charging is performed in the power saving mode different from the above, the control unit 102 resets the correction flag to 0 (step 212).

As described above, the control unit 102 counts the shutdown time for calculating the actual remaining capacity (shut-SOC) each time the voltage of the battery V arrives at the discharge limitation voltage C-EDV and enters the power saving mode , And the correction flag is reset or set depending on whether charging is performed in the power saving mode or shutdown is performed.

Now, a method for correcting the battery charge capacity and the discharge limit voltage using the shutdown time and the correction flag will be described with reference to FIG.

The control unit 102 checks whether charging is started as the external power source is turned on (step 300). When the charging is started, the control unit 102 calculates an actual remaining capacity (shut-SOC) from the low-charge state to the shutdown state (step 302). The actual remaining capacity (shut-SOC) is calculated by multiplying the shutdown time, the current sensing value provided by the current sensing unit 122, and the voltage sensing value provided by the voltage sensing unit 108.

When the actual remaining capacity (shut-SOC) is calculated, the control unit 102 checks whether the correction flag is set (step 304). That is, it is checked whether or not shutdown is performed in the power saving mode. If the correction flag is reset, the control unit 102 calculates the first and second charge capacities FCC1 and FCC2 according to the following equations (1) and (2).

Equation 1 is for calculating a first charge capacity FCC1 that does not take into account the actual remaining capacity (shut-SOC) according to the characteristics of the battery V, and the DCR is a state in which the full charge BATTERY LOW% represents the ratio of the charge capacity discharged from the low charge state to the shutdown state in relation to the charge capacity (FCC), and FCC_BEFORE represents the value before the charge capacity (FCC) is updated.

Equation (1) is a formula for a general charge capacity calculation in which the actual remaining capacity (shut-SOC) according to the characteristics of the battery V is not taken into account, and is a capacity discharged from the fully charged state to the low- (BATTERY LOW% * FCC_BEFORE) discharged from the low-charge state to the shutdown state is added to the first charge capacity (DCR) to calculate the first charge capacity (FCC1).

(2) is calculated by adding the actual remaining capacity (shut-SOC) discharged from the low-charge state to the shutdown state to the discharged capacity DCR from the fully charged state to the low-charged state to calculate the second charged capacity FCC2 , Which is an applied value of the actual remaining capacity (shut-SOC) according to the characteristics of the battery (V).

When the first and second charge capacities FCC1 and FCC2 are calculated, the control unit 102 checks whether the second charge capacity FCC2 is greater than the first charge capacity FCC1. It is determined that there is no need to correct the charge capacity of the battery V according to the actual remaining capacity shut-SOC if the second charge capacity FCC2 is not greater than the first charge capacity FCC1, And corrects the charging capacity (FCC) of the battery in accordance with the charging capacity (FCC1).

After correcting the above-described charge capacity (FCC), the control unit 102 refers to the discharge limitation voltage correction table to extract a discharge limit voltage corresponding to the actual remaining capacity (shut-SOC) Correct the discharge limitation voltage accordingly.

It is determined that it is necessary to correct the charging capacity of the battery V according to the actual remaining capacity (shut-SOC) if the second charging capacity FCC2 is larger than the first charging capacity FCC1 And corrects the charging capacity (FCC) of the battery according to the second charging capacity (FCC2).

After correcting the above-described charge capacity (FCC), the control unit 102 refers to the discharge limitation voltage correction table to extract a discharge limit voltage corresponding to the actual remaining capacity (shut-SOC) Correct the discharge limitation voltage accordingly.

On the other hand, if the correction flag is set in step 304, the controller 102 calculates the second charge capacity FCC2 according to equation (2) (step 312). When the second charge capacity FCC2 is calculated, the controller 102 corrects the charge capacity FCC of the battery according to the second charge capacity FCC2.

After correcting the charge capacity FCC, the controller 102 refers to the discharge limit voltage correction table to extract a discharge limit voltage corresponding to the actual remaining capacity (shut-SOC), and the extracted discharge limit voltage To compensate the discharge limitation voltage.

In the preferred embodiment of the present invention described above, only the discharge limiting voltage corresponding to the actual remaining capacity from the low-charge state to the shutdown state is determined using the discharge limitation voltage correction table. However, It is possible to calculate the discharge restricting voltage corresponding to the actual remaining capacity by using a function according to the correspondence relationship between the voltages.

The above-described embodiments of the invention include a computer readable medium having program instructions for performing various computer implemented operations. The computer-readable medium may include program instructions, data files, data structures, and the like, alone or in combination. The program instructions of the medium may be those specially designed and constructed for the present invention or may be available to those skilled in the art of computer software. The computer-readable recording medium may be any one of a magnetic medium such as a hard disk, a floppy disk and a magnetic tape, an optical medium such as a CD-ROM and a DVD, a floppy disk, Magneto-optical media, and ROM, RAM, flash memory, etc. may be employed and may include hardware devices specifically configured to store and execute program instructions. The medium may also be a transmission medium such as an optical or metal line, a wave guide, or the like, including a carrier wave for transmitting a signal designating a program command, a data structure, and the like. And the program instructions include high level language code that can be executed by a computer using an interpreter or the like as well as machine language code such as that produced by a compiler.

As described above, the present invention corrects the charging capacity of the battery in consideration of characteristics such as the temperature and the degree of deterioration depending on the number of charge / discharge cycles for each battery cell, so that the portable electronic device including the battery and the battery operates stably There is an advantage to be able to.

The present invention also provides a portable battery having the battery and the battery by compensating the discharge limitation voltage of the battery in correspondence with the detected charge capacity of the battery in consideration of characteristics such as the temperature and the degree of deterioration according to the number of charge / There is an advantage that the electronic device can be stably operated.

While the present invention has been particularly shown and described with reference to exemplary embodiments thereof, it is to be understood that the invention is not limited to the disclosed exemplary embodiments, but, on the contrary, Modification is possible.

Accordingly, the spirit of the present invention should be understood only in accordance with the following claims, and all equivalents or equivalent variations thereof are included in the scope of the present invention.

Claims (10)

A battery charge capacity correction method comprising: Measuring a remaining capacity from a low-charged state of the battery to shutdown; And Correcting a first value obtained by adding the remaining capacity to a capacity from the full charge state of the battery to the low charge state to the charge capacity of the battery Wherein the battery charging capacity correction method comprises: The method according to claim 1, The remaining capacity, Counting the time from the low-charge state of the battery to the shutdown; And calculating the battery charging capacity by multiplying the counted time by the voltage and current of the battery. The method according to claim 1, When the battery starts charging without reaching shutdown in a low charge state, a ratio of a remaining capacity ratio from a low charge state to shutdown and a previous battery charge capacity multiplied by a value obtained by multiplying the battery charge capacity by the remaining capacity ratio, And correcting the second value by adding the capacity of the battery to the charge capacity of the battery. The method of claim 3, And correcting the charge capacity of the battery according to the first value when the first value is greater than the second value. A battery charge capacity correcting device comprising: A current sensing unit for sensing a current of the battery; A voltage sensing unit for sensing a voltage of the battery; A memory unit for storing a capacity from the full charge state of the battery to the low charge state; Counting the time from the low-charged state of the battery to the shutdown, calculating the remaining capacity by multiplying the counted time by the current and voltage sensed by the current and voltage sensing unit, A control unit for correcting a first value obtained by adding the remaining capacity to a capacity from the full charge state of the battery to the low charge state stored in the memory unit to the charge capacity of the battery, Wherein the battery charging capacity correcting device comprises: 6. The method of claim 5, The control unit, When the battery starts charging without reaching shutdown in a low charge state, a ratio of a remaining capacity ratio from a low charge state to shutdown and a previous battery charge capacity multiplied by a value obtained by multiplying the battery charge capacity by the remaining capacity ratio, And a second value obtained by adding the capacity up to the capacity of the battery is corrected to the charging capacity of the battery. The method according to claim 6, The control unit, And corrects the charge capacity of the battery according to the first value when the first value is greater than the second value. In a battery discharge limiting voltage correction method, Measuring a remaining capacity from a low-charged state of the battery to shutdown; And Correcting a discharge limitation voltage of the battery with a discharge limitation voltage stored in advance corresponding to the remaining capacity Wherein the battery discharge limiting voltage correcting method comprises: A battery discharge limit voltage correcting device comprising: A current sensing unit for sensing a current of the battery; A voltage sensing unit for sensing a voltage of the battery; A memory unit storing a discharge limitation voltage correction table in which a discharge limiting voltage corresponding to a capacity from the full charge state of the battery to the low charge state and a plurality of remaining capacitances are associated with each other; Wherein the control unit counts the time from the low-charged state of the battery to the shutdown, calculates the remaining capacity by multiplying the counted time by the current and voltage sensed by the current and voltage sensing unit, A control unit for reading the discharge limit voltage corresponding to the calculated remaining capacity and correcting the discharge limit voltage of the battery with the discharge limit voltage, Wherein the battery discharge limiting voltage correcting device comprises: 10. The method of claim 9, The control unit, And obtaining the discharge limitation voltage corresponding to the remaining capacity by interpolating if the remaining capacity does not exist in the discharge limitation voltage correction table.

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