KR20090129242A - Battery pack circuit and battery pack protection method using the same - Google Patents

Abstract

PURPOSE: A battery pack circuit is provided to prevent the lowering of the lifetime of a battery pack by decompressing a battery voltage to be less than a critical voltage before unbalance in the remaining amount of battery voltage between battery cells occurs at the end of discharge operation of a battery pack. CONSTITUTION: A battery pack circuit(100) comprises a terminal unit(110), a protect circuit module control unit(120), a main charging/discharging switching unit(130), first and second charging/discharging switching units(140,150), a voltage reduction unit(160), and a main control unit(170). The main control unit controls to supply a battery voltage outputted through the charging/discharging switching unit to the terminal unit by turning on a first charging/discharging switching unit.

Description

BATTERY PACK CIRCUIT AND METHOD OF PROTECTING THE BATTERY BY USING THE BATTERY PACK CIRCUIT}

The present invention relates to a battery pack circuit and a battery pack protection method using the same, and more particularly, to a battery pack circuit and a battery pack protection method using the same for preventing the deterioration of the life of the battery pack is used by a high-capacity charger will be.

Recently, compact and lightweight electric / electronic devices such as portable computers have been actively developed and produced. These portable electric / electronic devices have battery packs built in so that they can be operated in a place without a separate power source. The built-in battery pack has a form in which at least one bare battery cells are connected to each other and packaged so as to output a predetermined level of voltage to drive the portable electric / electronic device for a predetermined period of time.

The battery pack has recently adopted a secondary battery capable of charging and discharging in consideration of economic aspects. Secondary batteries include, for example, nickel-cadmium batteries, lead-acid batteries, nickel metal hydride batteries, lithium ion batteries, and the like. Among these, the lithium ion battery has recently been commercialized and mainly employed because of its excellent energy density per weight.

The lithium ion battery may carry various products by miniaturization of electronic products, and portable electronic products are used as power sources. The lithium ion battery is charged using a charger after use.

The advantage of lithium ion batteries is that they have a large capacity and can be used for a long time after being charged. It is also lighter than other batteries. However, it is pointed out as a problem that it is more difficult to make a high power battery which is more dangerous than other batteries and can flow high current due to safety problems.

Therefore, in order to maintain battery performance and to maintain safety, a protection circuit that is not used in other batteries is used. The lithium ion rechargeable battery pack has a structure in which a plurality of series-connected bare battery cells (or unit cells) and pack electrodes are connected by a protection circuit.

On the other hand, when a plurality of lithium ion batteries are connected in series to form a battery pack having a large capacity, excessive discharge of the battery pack has a problem in that the chance of recharging is lost. In order to block such an excessive discharge, the above-described protection circuit is provided to block the discharge operation before the excessive discharge is performed.

However, the discharge rate of each of the lithium ion batteries is different and the capacity after discharge is also different. Therefore, any one of the lithium ion batteries may be excessively discharged, and despite such excessive discharges occurring, the above-mentioned protection circuit may not operate so that a problem arises in that the lithium-ion battery having excessive discharges cannot be recycled. do.

When a battery pack consisting of a plurality of batteries is discharged to be charged and used by a large-capacity charger, in particular, an unbalance may occur in the remaining amount of battery voltage between battery cells during the discharging end operation. The life of the batteries may be shortened.

Accordingly, the technical problem of the present invention is to solve such a conventional problem, and an object of the present invention is to threshold before the unbalance occurs in the remaining amount of battery voltage between battery cells at the end of the discharge operation of a battery pack consisting of a plurality of batteries It is to provide a battery pack circuit for reducing the life of the battery pack by reducing the battery voltage to less than the voltage.

Another object of the present invention is to provide a battery pack protection method using the battery pack circuit described above.

In order to achieve the above object of the present invention, a battery pack circuit according to an embodiment is provided with a power supply supplied from an external device during a charging operation, and a terminal unit connected to a load during a discharge operation to provide charging power, in series A protection circuit module (PCM) control unit for detecting a detected battery voltage in each of the connected batteries, and a main charge / discharge switching on / off based on a switch signal provided from the PCM control unit to output the battery voltage A first charge / discharge switching unit connected to an output terminal of the main charge / discharge switching unit and the terminal unit, and a second charge / discharge switching unit connected to an output terminal of the main charge / discharge switching unit, and the second charge / discharge unit. A pressure reducing unit for reducing the voltage output through the switching unit and providing the terminal unit with the voltage charging unit; and the main charge / discharge switching unit by turning on the first charge / discharge switching unit. In order to control the output battery voltage to be supplied to the terminal unit and to reduce the battery life by preventing unbalanced discharge of the batteries when the voltage detected by the batteries is reduced to a threshold range or less, the first battery life is prevented. And a main controller configured to turn off the charge / discharge switching unit and turn on the second charge / discharge switching unit to reduce the battery voltage output through the main charge / discharge switching unit to be supplied to the terminal unit.

In an embodiment of the present invention, the terminal portion includes a first terminal corresponding to a positive voltage and a second terminal corresponding to a negative voltage, and each of the first and second terminals consists of three metal pieces to form a triangle. It may be arranged in a shape.

In an embodiment of the present disclosure, the terminal unit may further include a third terminal for battery recognition and a fourth terminal for on / off of the main controller. Here, as the fourth terminal contacts the second terminal, power is supplied to the main controller to start the main controller.

In one embodiment of the present invention, the decompression unit includes a level down unit for lowering the level of the battery voltage via the second charge / discharge switching unit, a first transistor for controlling the output of the leveled battery voltage, and the first A turn-on signal by comparing a voltage detector connected to an output terminal of the transistor to detect a level of a battery voltage output through the first transistor, and a voltage detected by the voltage detector and a battery voltage detected by the level down unit; Or an operational amplifier for outputting a turn-off signal to a gate terminal of the first transistor.

In an embodiment of the present disclosure, the main charge / discharge switching unit may include a main discharge transistor, a first diode connected to a source terminal and a drain terminal of the main discharge transistor to block reverse current during a discharge operation, a main charge transistor; And a second diode connected to the source terminal and the drain terminal of the main charging transistor to block reverse current during a charging operation.

In an embodiment of the present disclosure, the first charge / discharge switching unit may include a first discharge transistor, a first diode connected to a source terminal and a drain terminal of the first discharge transistor, and configured to block reverse current during a discharge operation; And a second diode connected to the source terminal and the drain terminal of the first charging transistor and blocking a reverse current during a charging operation.

In an embodiment of the present disclosure, the second charge / discharge switching unit may include: a first diode connected to a second discharge transistor, a source terminal and a drain terminal of the second discharge transistor to block reverse current during a discharge operation; And a second diode connected to the source terminal and the drain terminal of the second charging transistor and blocking a reverse current during a charging operation.

In accordance with another aspect of the present invention, there is provided a method of protecting a battery pack, the method comprising the steps of: (a) checking first the overcharge and the temperature as the battery voltage of the battery pack is supplied to the load; (B) if the battery voltage of the battery pack is lower than the overvoltage voltage threshold and the temperature is lower than the high temperature threshold, checking the discharge current of the battery pack for a second time, and (c) the discharge current is Outputting the battery voltage of the battery pack to the rod through a first path, and checking the temperature of the battery pack, wherein the temperature of the battery pack is greater than a set temperature threshold. Checking the discharge voltage of the battery pack when the temperature of the battery pack is checked to be lower than the temperature threshold when the temperature of the battery pack is checked to be higher than or equal to (e) the discharge; If the current is checked to be lower than the discharge current threshold, in order to prevent the unbalanced discharge of the batteries to block the shortening of the battery life, the output of the battery voltage through the first path is cut off, the battery voltage is reduced Setting a second path to be output to the load.

According to such a battery pack circuit and a method of protecting a battery pack using the same, the battery voltage is reduced to below a threshold voltage in advance before an unbalance occurs in the remaining amount of battery voltage between battery cells at the end of the discharge operation of the battery pack including a plurality of batteries. It is possible to prevent deterioration of the life of the battery pack.

Hereinafter, a battery pack circuit and a battery pack protection method using the same according to an embodiment of the present invention will be described in detail with reference to the accompanying drawings.

As the inventive concept allows for various changes and numerous modifications, the embodiments will be described in detail in the text. However, this is not intended to limit the present invention to a specific disclosed form, it should be understood to include all modifications, equivalents, and substitutes included in the spirit and scope of the present invention. In describing the drawings, similar reference numerals are used for similar elements. Terms such as first and second may be used to describe various components, but the components should not be limited by the terms. The terms are used only for the purpose of distinguishing one component from another. The terminology used herein is for the purpose of describing particular example embodiments only and is not intended to be limiting of the present invention. Singular expressions include plural expressions unless the context clearly indicates otherwise. In the present application, the terms--including--or--consist--are intended to indicate that there is a feature, number, step, operation, component, part, or combination thereof described on the specification, one or It should be understood that no other features or numbers, steps, actions, components, parts, or combinations thereof are excluded in advance.

Unless defined otherwise, all terms used herein, including technical or scientific terms, have the same meaning as commonly understood by one of ordinary skill in the art. Terms such as those defined in the commonly used dictionaries should be construed as having meanings consistent with the meanings in the context of the related art and shall not be construed in ideal or excessively formal meanings unless expressly defined in this application. Do not.

In addition, in order to distinguish that --- first--, --2-2-, --third --- and --fourth --- described in the detailed description and the claims of the present invention are different components, It will be referred to, regardless of the order of manufacture, the name may not coincide in the description and claims.

1 is a block diagram illustrating a battery pack circuit according to an embodiment of the present invention.

Referring to FIG. 1, the battery pack circuit 100 according to an embodiment of the present invention includes a terminal unit 110, a protection circuit module (PCM) control unit 120, and a main charge / discharge switching unit 130. ), The first charge / discharge switching unit 140, the second charge / discharge switching unit 150, the pressure reducing unit 160, the main control unit 170, the discharge current detecting unit 180, and the remaining amount display unit 190. .

The terminal unit 110 includes a first terminal 112 of a kind of positive polarity and a second terminal 114 of a kind of negative polarity. In the charging operation, the terminal unit 110 receives power supplied from the outside and supplies the battery string 50 to the battery string 50 via the first charge / discharge switching unit 140 and the main charge / discharge switching unit 130. In the discharging operation, the battery voltage of the battery string 50 is supplied to the rod (not shown) via the main charge / discharge switching unit 130 and the first charge / discharge switching unit 140.

In addition, when the terminal 110 checks that the battery voltage of the battery string 50 falls below a predetermined level, the terminal voltage 110 sets the battery voltage of the battery string 50 to the main charge / discharge switching unit 130 and the first battery. The charge and discharge switching unit 150 and the decompression unit 160 supplies the reduced voltage of the battery to the rod.

2A to 24F are images illustrating the terminal unit illustrated in FIG. 1. In particular, FIG. 2A is an image for explaining the front of the terminal portion illustrated in FIG. 1, FIG. 2B is an image for explaining a rear surface of the terminal portion illustrated in FIG. 1, and FIG. 2C is a view illustrating a first side of the terminal portion illustrated in FIG. 1. 2D is an image for explaining the second side of the terminal unit illustrated in FIG. 1. FIG. 2E is an image illustrating a first side of the case of the battery pack with the terminal portion illustrated in FIG. 1, and FIG. 2F is an image illustrating the second side of the case of the battery pack with the terminal portion illustrated in FIG. 1. to be.

2A to 2F, the terminal unit includes a first terminal corresponding to the positive voltage and a second terminal corresponding to the negative voltage. Each of the first and second terminals is composed of three metal pieces. Three metal pieces are arranged in a triangular shape. In the charging operation, a space defined by three metal pieces arranged in a triangular shape is connected to a terminal of a charger to provide a charging voltage to the battery string 50. In addition, during the discharge operation, the node is connected to a node in a space defined by three metal pieces arranged in a triangular shape to provide the node with a charging voltage charged in the battery string 50.

Returning to the description of FIG. 1, the PCM controller 120 supplies a switching signal to the main charge / discharge switching unit 130 to control an operation of the main charge / discharge switching unit 130 and the battery string 50. ) Detects the battery voltage detected in each of the series-connected batteries provided to the battery and supplies the detected battery voltage to the discharge current detecting unit 180.

Specifically, the PCM control unit 120 blocks the operation of the main charge / discharge switching unit 130 when the battery voltage level of the battery cell is lower or higher than the threshold range. In addition, the PCM controller 120 blocks the operation of the main charge / discharge switching unit 130 when the threshold current is higher than the threshold current. Substantially, the PCM controller 120 may perform an auxiliary function when the main controller 170 fails to block the operation of the battery pack circuit according to overcharge or overcurrent.

The main charge / discharge switching unit 130 is turned on / off based on a switch signal supplied from the PCM controller 120. That is, a voltage supplied through the terminal unit 110 and the first charge and discharge switching unit 140 during a charging operation is supplied to the battery string 50, and a battery voltage of the battery string 50 is discharged during a discharge operation. The first charge / discharge switching unit 140 or the second charge / discharge switching unit 150 is supplied.

The first charge / discharge switching unit 140 is connected to an output terminal of the main charge / discharge switching unit 130 and the terminal unit 110 and turned on / off according to a switching signal supplied from the main controller 170.

The second charge / discharge switching unit 150 is connected to an output terminal of the main charge / discharge switching unit 130 and the decompression unit 160 and is turned on or off according to a switching signal supplied from the main controller 170.

The decompression unit 160 is turned on according to the switching signal supplied from the main controller 170, the second charge and discharge switching unit 150 is turned on through the main charge and discharge switching unit 130, the battery voltage When supplied, the battery voltage is reduced and supplied to the terminal unit 110.

The main controller 170 turns on the first charge / discharge switching unit 140 to control the battery voltage output through the main charge / discharge switching unit 130 to be supplied to the terminal unit 110.

In addition, the main controller 170 turns off the first charge / discharge switching unit 140 to depressurize the battery voltage in advance when the battery voltage between the battery cells reaches a threshold range during the end-of-discharge operation of the battery pack. The second charge / discharge switching unit 150 is turned on. Accordingly, the battery voltage output through the main charge / discharge switching unit 130 is decompressed by the decompression unit 160 and supplied to the terminal unit 110.

The discharge current detection unit 180 detects the discharge current supplied from the PCM control unit 120 and supplies the discharge current to the main control unit 170.

The remaining amount display unit 190 displays the remaining voltage of the battery string provided by the main controller 170 as the remaining amount display switch (not shown) provided separately. For example, as the signal is supplied to the microcomputer 170 corresponding to the remaining level of the high level by checking at 70% or more of the battery capacity, the remaining amount display unit 190 performs the high level display operation, and the 40 of the battery capacity is maintained. As the signal is supplied to the microcomputer 170 in correspondence with the remaining level of the low level, the remaining amount display unit 190 performs a low level display operation.

3A to 3C are circuit diagrams illustrating the battery pack circuit shown in FIG. 1.

1 to 3C, the battery pack circuit 100 according to an embodiment of the present invention includes a terminal unit 110, a PCM control unit 120, a main charge / discharge switching unit 130, and a first charge / discharge switching unit. 140, the second charge / discharge switching unit 150, the pressure reducing unit 160, the microcomputer 170, the discharge current detecting unit 180, and the remaining amount display unit 190.

The terminal unit 110 includes a first terminal 112 that is a positive terminal (+) and a second terminal 114 that is a negative terminal (-), and is connected to an external battery terminal during a charging operation or a discharge operation. Perform the action. That is, during the charging operation, the first and second terminals 112 and 114 receive power supplied from the outside, for example, power supplied from a charger, and provide the battery pack to the battery pack. In addition, during the discharge operation, the first and second terminals 112 and 114 are connected to a load, for example, a radio, to provide a battery voltage charged in the battery pack to the radio. In FIG. 3B, a temperature fuse TF is further provided between the first terminal 112 and the first charge / discharge switching unit 140.

The terminal unit 110 further includes a third terminal 116 and a fourth terminal 118. The third terminal 116 is used for battery recognition, and as the electric potential of a predetermined level is supplied to the third terminal 116, a charging operation is started.

The fourth terminal 118 is used to turn on / off the microcomputer 170. That is, as the fourth terminal 118 is electrically contacted with the second terminal 114, for example, a ground voltage applied to the second terminal 114 is applied to the gate and the gate of the eighth transistor Q8. The eighth transistor Q8 and the ninth transistor Q9 are turned on by being applied to the gate of the ninth transistor Q9. As the voltage applied to the first terminal 112 is applied to the LDI IC of FIG. 3A according to the turn-on of the eighth transistor Q8, the VCC power applied to the microcomputer 170 is applied to the microcomputer 170. The microcomputer 170 is activated. On the contrary, when the external terminal is removed, the eighth and ninth transistors Q8 and Q9 are turned off so that the VCC power is not output. Accordingly, the microcomputer 170 does not operate, thereby reducing power consumption of the battery. Becomes small, and long time storage is possible.

The first power sensing terminal VC1, the second power sensing terminal VC2, the third power sensing terminal VC3, and the fourth power sensing terminal VC4 of the PCM control unit 120 are connected from four batteries connected in series. Detect battery voltage. The charge control terminal COP and the discharge control terminal DOP of the PCM controller 120 are connected to the main charge / discharge switching unit 130 to control charging and discharging operations of the battery string 50.

The main charge / discharge switching unit 130 includes a first main discharge switch and a first main charge switch connected in series. The first main discharge switch includes a first diode D1 connected between a first transistor Q1 and a source-drain of the first transistor Q1. The first main charge switch includes a second diode D2 connected between a second transistor Q2 and a source-drain of the second transistor Q2. The first and second transistors Q1 and Q2 include a p-channel MOSFET. In this embodiment, one main discharge switch is implemented through one transistor and a diode connected in parallel thereto. However, the diode may be implemented through a body-diode which is an electronic component integrally formed in a transistor. The body-diode is a P-channel Enhancement Mode Field Effect Transistor (FET).

In the charge / discharge operation, when the low signal is applied to the first and second transistors Q1 and Q2 from the PCM controller 120, the first and second transistors Q1 and Q2 are turned on. Accordingly, in the charging operation, the externally supplied power is charged in the battery pack 50 via the second transistor Q2 and the first transistor Q1. The second diode D2 connected in parallel to the second transistor Q2 blocks the charging operation when the voltage of the first to fourth power sensing terminals is higher than the threshold range during the charging operation. In addition, during the discharge operation, power charged in the battery pack 50 is supplied to the load via the first and second transistors Q1 and Q2. The first diode D1 connected in parallel with the first transistor Q1 blocks reverse current when the voltage of the first to fourth power detection terminals is lower than the threshold range during the discharge operation.

The first charge / discharge switching unit 140 includes a first charge switch and a first discharge switch connected in series. The first charging switch includes a third diode D3 connected between the third transistor Q3 and the source-drain of the third transistor Q3. The first discharge switch includes a fourth diode D4 connected between the fourth transistor Q4 and the source-drain of the fourth transistor Q4. The third and fourth transistors Q3 and Q4 include a p-channel MOSFET.

In the charging / discharging operation, when the low signal is applied from the microcomputer 170 to the third and fourth transistors Q3 and Q4, the third and fourth transistors Q3 and Q4 are turned on. Accordingly, in the charging operation, the externally supplied power is charged in the battery pack 50 via the fourth transistor Q4 and the third transistor Q3. The fourth diode D4 connected in parallel to the fourth transistor Q4 blocks the charging operation when the battery voltage is higher than the threshold range during the charging operation. In addition, during the discharge operation, the power charged in the battery pack 50 is supplied to the load via the third transistor Q3 and the fourth transistor Q4. The third diode D3 connected in parallel to the third transistor Q3 blocks the reverse current from flowing when the battery voltage is lower than the threshold range during the discharge operation.

On the other hand, when the battery voltage of the battery string 50 is lower than the threshold value and the high signal is applied to the third and fourth transistors Q3 and Q4 from the microcomputer 170, the third and fourth transistors Q3 and Q4 Is turned off. Accordingly, during the discharge operation, the power charged in the battery pack 50 is blocked from being supplied to the load via the third and fourth transistors Q3 and Q4.

The second charge / discharge switching unit 150 includes a second discharge switch connected between the main charge / discharge switching unit 130 and the pressure reduction unit 160 and a second charge switch connected between the pressure reduction unit 160 and the terminal unit 110. do. The second discharge switch includes a fifth diode D5 connected between the fifth transistor Q5 and the source-drain of the fifth transistor Q5. The second charge / discharge switch includes a sixth diode D6 connected between the sixth transistor Q6 and the source-drain of the sixth transistor Q6. The fifth and sixth transistors Q5 and Q6 include a p-channel MOSFET.

When the high signal from the microcomputer 170 is applied to the fifth and sixth transistors Q5 and Q6, the fifth and sixth transistors Q5 and Q6 are turned off. Accordingly, the power supplied from the outside is not charged in the battery pack 50 via the sixth transistor Q6 and the fifth transistor Q5.

However, in the late discharging operation, when the battery voltage reaches the threshold range, the microcomputer 170 supplies a low signal to the fifth and sixth transistors Q5 and Q6. According to the low signal, the fifth and sixth transistors Q5 and Q6 are turned on to set a discharge path through the decompression unit 160, so that the battery voltage decompressed by the decompression unit 160 is applied to the node. Supplied. As a result, unbalance may occur in the remaining amount of battery voltage, and the battery voltage charged in any battery cell may fall below the threshold voltage, thereby preventing the battery cell from being recycled.

The pressure reduction unit 160 includes a level down unit 162, an operational amplifier OP6, a first transistor Q6Q, a second transistor Q62, and a voltage detector 164. The voltage passing through Q5) is reduced and provided to the terminal unit 110 via the sixth diode D6. The level down part 162 includes a first resistor R61, a second resistor R62, a third resistor R63, and a zener diode (or a reference voltage regulating IC) ZD2. A first diode D61 is connected in parallel between the source and the drain of the first transistor Q6Q, and a second diode D62 is connected in parallel between the source and the drain of the second transistor Q62. The voltage detector 164 includes a fourth resistor R64 and a fifth resistor R65.

In operation, the voltage via transistor Q5 is supplied to transistors Q61 and Q62. At this time, the voltage passing through the transistor Q5 is leveled down and supplied to the negative terminal of the operational amplifier OP6. The operational amplifier OP6 supplies the turn-on signal or the turn-off signal to the transistors Q61 and Q62 by comparing the leveled-down voltage supplied to the negative terminal and the comparison voltage supplied to the positive terminal. . For example, if the leveled-down voltage is higher than the comparison voltage, the operational amplifier OP6 supplies a turn-off signal to the transistors to turn off the transistors Q61 and Q62. On the other hand, if the leveled-down voltage is lower than the comparison voltage, the operational amplifier OP6 supplies the turn-on signal to the transistors Q61 and Q62 to turn on the transistors.

The microcomputer 170 performs an overcharging test and a temperature test of the battery pack, and blocks the charging operation when it is checked as being overcharged, and checks the temperature above the temperature when the temperature is checked, for example, by 70 degrees Celsius or more, to perform the charge / discharge operation. Block it. The temperature test may be performed through a negative temperature coefficient type resistor (NTC) connected to a path through which the power of the microcomputer 170 is supplied.

FIG. 4 is a table for explaining the negative temperature coefficient type resistance NTC shown in FIG. 3A.

Referring to FIG. 4, the negative temperature coefficient type resistance has a characteristic that the resistance value decreases with increasing temperature. For example, when 5 V is applied to a negative temperature coefficient resistor with a resistance of 10 kilo ohms, the resistance is converted to 111 kilo ohms at -25 degrees Celsius, and to 49.772 kilo ohms at -10 degrees Celsius. At 25 degrees Celsius, the resistance is converted to 10 kilo ohms. In this way, by connecting the negative temperature coefficient type resistor to the microcomputer, the operating temperature of the battery pack circuit can be measured.

By reducing the description to FIG. 3B, the microcomputer 170 inspects the discharge current and re-performs the overcharge test and the temperature test when the discharge current is checked to be equal to or less than 0 mA.

In addition, when the microcomputer 170 checks that the discharge current is greater than 0 mA, the microcomputer 170 re-performs the temperature test and performs a series of discharge operations according to the tested temperature. For example, if the temperature is checked to 70 degrees Celsius or more, the microcomputer 170 determines that the temperature is higher than the charge and discharge operation. If the temperature is checked to be more than -25 degrees Celsius, when supplying the battery voltage of the battery pack to the load, the microcomputer 170 adjusts the discharge path so that the discharge operation through the decompression path, not the normal path.

The microcomputer 170 turns on the first charge / discharge switching unit 140 during a charging operation to control power supplied from the outside to the battery string 50.

The discharge current detector 180 includes a fourth resistor R81, a fifth resistor R82, a sixth resistor R83, a seventh resistor R84, and an operational amplifier OP, and the PCM controller The discharge current supplied from the 120 is sensed and supplied to the main controller 170. In operation, the discharge current value voltage provided through the fifth transistor resistor R82 is amplified and provided to the main control unit 170 at the first terminal 112 of the terminal unit 110 via the resistor R83.

The remaining amount display unit 190 includes a first LED 192 connected to the first display terminal LD1 of the microcomputer 170, and a second LED 194 connected to the second display terminal LD2 of the microcomputer 170. And a third LED 196 connected to the third display terminal LD3 of the microcomputer 170. The first to third LEDs LD1, LD2, and LD3 emit light in response to a signal provided from the microcomputer 170.

Next, the operation of the battery pack circuit shown in the embodiment of the present invention, in particular, the operation during discharge will be described.

At the beginning of discharge, the first and second transistors Q1 and Q2 are turned on by the PCM controller 120, and the third and fourth transistors Q3 and Q4 are turned on by the microcomputer 170. Is turned on. Accordingly, the battery voltage of the battery pack 50 is supplied to the load via the first and second transistors Q1 and Q2 and the third and fourth transistors Q3 and Q4. At this time, the fifth transistor Q5 and the sixth transistor Q6 are kept turned off by the microcomputer 170.

The initial recognition of the discharge may be recognized as a terminal (not shown) connected to the gate terminal of each of the eighth and ninth transistors Q8 and Q9 is pressed. That is, as the terminal is pressed, when the low signal is applied, the eighth and ninth transistors Q8 and Q9 are turned on so that the voltage-divided battery voltage is applied to the microcomputer 170.

That is, as the eighth transistor Q8 is turned on, the output voltage of the main charge / discharge switching unit 130 is divided in voltage and applied to the microcomputer 170, and as the ninth transistor Q9 is turned on, the eighth transistor Q8 is turned on. The output voltage of the charge / discharge switching unit is divided by voltage and applied to the microcomputer 170.

In the terminal discharging operation, when the battery voltage between the battery cells reaches the take over range, the fifth and sixth transistors Q5 and Q6 are turned on under the control of the microcomputer 170 such that the battery voltage is reduced in advance. At the same time, the third and fourth transistors Q3 and Q4 are turned off to cut off the battery voltage output through the third and fourth transistors Q3 and Q4. As the fifth transistor Q5 is turned on, the battery voltage via the main charge / discharge switching unit 130 is applied to the decompression unit 160 to be decompressed to a predetermined level, and the decompressed voltage is stored in the sixth transistor ( It is supplied to the rod via Q6).

5A and 5B are flowcharts illustrating a method of protecting a battery pack circuit according to an embodiment of the present invention. In particular, it is a flowchart explaining a series of operations performed in the microcomputer shown in FIG. 3B.

3A to 3C and 5A and 5B, as the battery pack circuit is powered on (step S100), the microcomputer 170 is reset and each port of the microcomputer 170 is initialized (step S100). S102).

Subsequently, the microcomputer 170 performs an overcharge and temperature test (step S104).

Subsequently, the microcomputer 170 checks whether the charging voltage is greater than 16.95V (step S106).

In step S106, if the charging voltage is checked to be greater than 16.95V, the microcomputer 170 controls the charging operation to be turned off (step S108), and then ends.

In step S106, if the charging voltage is checked to be less than or equal to 16.95V, the microcomputer 170 checks whether the temperature is higher than 70 degrees Celsius (step S110).

In step S110, when the temperature is checked to be higher than 70 degrees Celsius, the microcomputer 170 controls the charging and discharging operation to be turned off (step S112). Then, it is checked whether the temperature is lower than 50 degrees Celsius (step S114), if the temperature is checked to be lower than 50 degrees Celsius, it is fed back to step S104, and if the temperature is checked to be higher than or equal to 50 degrees Celsius, to step S112 Feedback.

On the other hand, if the temperature is checked to be lower than or equal to 70 degrees Celsius in step S110, the microcomputer 170 checks the discharge current (step S116).

Subsequently, it is checked whether the remaining amount display switch is on (step S118), and when it is checked to be turned on, the microcomputer 170 controls the remaining voltage to be displayed (step S120).

After checking in step S118 that the remaining amount indicator switch is off or performing step S120, the microcomputer 170 checks whether the temperature is higher than 70 degrees Celsius (step S122).

If it is checked in step S122 that the temperature is higher than 70 degrees Celsius, the microcomputer 170 determines that the temperature is higher than or equal to the charge and discharge operation is controlled (step S124) and ends.

If the temperature is checked to be lower than or equal to 70 degrees Celsius in step S122, the microcomputer 170 checks whether the temperature is higher than -15.4 degrees Celsius (step S128).

If the temperature is checked to be lower than -15.4 degrees Celsius or more than -25 degrees Celsius in step S128, the microcomputer 170 checks whether the output voltage is lower than 9.8V (step S129), and the output voltage is higher than 9.8V. If it is checked to be equal to or greater than, it is fed back to step S128, and if it is checked that the output voltage is less than 9.8V, the discharge operation is controlled to be turned off (step S130). After that, the charge / discharge MOSFET is turned on (step S132).

On the other hand, if the temperature is checked to be higher than or equal to -15.4 degrees Celsius in step S128, the microcomputer 170 checks whether the temperature is in the range of -15.4 degrees Celsius to -10 degrees Celsius (step S134).

If it is checked in step S134 that the temperature is in the range of -15.4 degrees Celsius to -10 degrees Celsius, the microcomputer 170 controls the battery protection operation according to the first mode to be performed (step S136).

On the other hand, if it is checked in step S134 that the temperature does not exist in the range of -15.4 degrees Celsius to -10 degrees Celsius, the microcomputer 170 checks whether the temperature is in the range of -10 degrees Celsius to 0 degrees Celsius. (Step S138).

If it is checked in step S138 that the temperature is in the range of -10 degrees Celsius to 0 degrees Celsius, the microcomputer 170 controls the battery protection operation according to the second mode to be performed (step S140).

On the other hand, if it is checked in step S138 that the temperature does not exist in the range of -10 degrees Celsius to 0 degrees Celsius, the microcomputer 170 checks whether the temperature is in the range of 0 degrees Celsius to 10 degrees Celsius (step S142).

If it is checked in step S142 that the temperature is in the range of 0 degrees Celsius to 10 degrees Celsius, the microcomputer 170 controls the battery protection operation according to the third mode to be performed (step S146).

On the other hand, if it is checked in step S142 that the temperature does not exist in the range of 0 to 10 degrees Celsius, the microcomputer 170 checks whether the temperature is 10 degrees Celsius or more (step S148).

If the temperature is checked to be higher than 10 degrees Celsius in step S148, the microcomputer 170 controls the battery protection operation according to the fourth mode to be performed (step S137).

If the temperature is checked to be lower than or equal to 10 degrees Celsius in step S148, the microcomputer 170 controls the discharge operation to be maintained (step S152).

FIG. 6 is a flowchart illustrating a battery protection operation operation according to the first mode illustrated in FIG. 5B.

5A, 5B and 6, the microcomputer 170 checks whether the discharge current is less than 1.5A (step S200).

If it is checked in step S200 that the discharge current is less than 1.5A, the microcomputer 170 checks whether the battery voltage is higher than 11.8V (step S202).

If it is checked in step S202 that the battery voltage is greater than 11.8V, feedback is sent to step S116.

If the battery voltage is checked to be less than or equal to 11.8V in step S202, the microcomputer 170 controls the decompression circuit (step S204).

Then, it is checked whether the output voltage is greater than 10V or less than 9.7V (step S206). If it is checked in step S206 that the output voltage is greater than 10V or less than 9,7V, the discharge operation is turned off (step S207), and the feedback is fed back to step S104.

If it is checked in step S206 that the output voltage is less than 10V and greater than 9.7V, the microcomputer 170 cuts off the on time of 5 seconds and the off time of 10 seconds after 3 cycles in 1 cycle (step S208).

Subsequently, after 30 seconds off, the microcomputer 170 turns on the charge / discharge MOSFET (step S210) and feeds back to step S104.

On the other hand, if it is checked in step S200 that the discharge current is greater than or equal to 1.5A, the microcomputer 170 checks whether the discharge current exists in the range of 1.5A to 2.7A (step S212).

If it is checked in step S212 that the discharge current does not exist in the range of 1.5A to 2.7A, it feeds back to step S116. In other words, if the discharge current is checked to be larger than 2.7 A, it is fed back to step S116.

If it is checked in step S212 that the discharge current exists in the range of 1.5A to 2.7A, the microcomputer 170 checks whether the voltage is greater than 11.2V (step S214).

In step S214, if the voltage is checked to be greater than 11.2V, it feeds back to step S122, and repeats the process so far. If the microcomputer 170 is checked to be less than or equal to 11.2V, step S204 Feedback to.

FIG. 7 is a flowchart for describing a battery protection operation operation according to the second mode illustrated in FIG. 5B.

3A to 3C, 5A, 5B, and 7, the microcomputer 170 checks whether the discharge current is less than 1.5A (step S300).

If it is checked in step S300 that the discharge current is less than 1.5A, the microcomputer 170 checks whether the battery voltage is higher than 12.2V (step S302).

If it is checked in step S302 that the battery voltage is larger than 12.2V, the flow returns to step S116.

If the battery voltage is checked to be less than or equal to 12.2V in step S302, the microcomputer 170 controls the decompression circuit (step S304).

Then, it is checked whether the output voltage is greater than 10V or less than 9.7V (step S306). If it is checked in step S306 that the output voltage is greater than 10V or less than 9.7V, the discharge operation is turned off (step S307), and the feedback is fed back to step S104.

If it is checked in step S306 that the output voltage is less than 10V and greater than 9.7V, the microcomputer 170 cuts off the on time of 5 seconds and the off time of 10 seconds after 3 cycles in 1 cycle (step S308).

Subsequently, the microcomputer 170 turns on the charge / discharge MOSFET after 30 seconds off (step S310), and feeds back to step S104.

On the other hand, if it is checked in step S300 that the discharge current is greater than or equal to 1.5A, the microcomputer 170 checks whether the discharge current exists in the range of 1.5A to 2.7A (step S312).

In step S312, if it is checked that the discharge current does not exist in the range of 1.5A to 2.7A, it feeds back to step S116. In other words, if the discharge current is checked to be larger than 2.7 A, it is fed back to step S116.

If it is checked in step S312 that the discharge current exists in the range of 1.5A to 2.7A, the microcomputer 170 checks whether the voltage is greater than 11.6V (step S314).

In step S314, if the voltage is checked to be greater than 11.6V, it feeds back to step S122 and the process is repeated so far. The microcomputer 170 feeds back to step S304 when the voltage is checked to be less than or equal to 11.6V.

FIG. 8 is a flowchart illustrating a battery protection operation operation according to a third mode illustrated in FIG. 5B.

3A to 3C, 5A, 5B and 8, the microcomputer 170 checks whether the discharge current is less than 1.5A (step S400).

If it is checked in step S400 that the discharge current is less than 1.5A, the microcomputer 170 checks whether the battery voltage is higher than 12.8V (step S402).

If the battery voltage is checked to be greater than 12.8V in step S402, the flow returns to step S116.

If the battery voltage is checked to be less than or equal to 12.8V in step S402, the microcomputer 170 controls the decompression circuit (step S404).

Then, it is checked whether the output voltage is greater than 10V or less than 9.7V (step S406). If it is checked in step S406 that the output voltage is greater than 10V or less than 9.7V, the discharge operation is turned off (step S407), and the feedback is fed back to step S104.

If it is checked in step S406 that the output voltage is less than 10V and greater than 9.7V, the microcomputer cuts off the on time of 5 seconds and the off time of 10 seconds after 3 cycles in one cycle (step S408).

Subsequently, the microcomputer 170 turns on the charge / discharge MOSFET after 30 seconds off (step S410), and feeds back to step S104.

On the other hand, if it is checked in step S400 that the discharge current is greater than or equal to 1.5A, the microcomputer 170 checks whether the discharge current exists in the range of 1.5A to 2.7A (step S412).

In step S412, if it is checked that the discharge current does not exist in the range of 1.5A to 2.7A, it feeds back to step S116. In other words, if the discharge current is checked to be larger than 2.7 A, it is fed back to step S116.

If it is checked in step S412 that the discharge current exists in the range of 1.5A to 2.7A, it is checked whether the voltage is greater than 12.2V (step S414). If the voltage is greater than 12.2V in step S414, the microcomputer 170 feeds back to step S122 and repeats the process until now. If the voltage is checked to be less than or equal to 12.2V, the flow returns to step S404.

9 is a flowchart for describing a battery protection operation operation according to the fourth mode illustrated in FIG. 5B.

3A to 3C, 5A, 5B, and 9, the microcomputer 170 checks whether the discharge current is less than 1.5A (step S500).

If it is checked in step S500 that the discharge current is smaller than 1.5A, it is checked whether the battery voltage is higher than 13.4V (step S502).

If it is checked in step S502 that the battery voltage is greater than 13.4V, the flow returns to step S116.

If the battery voltage is checked to be less than or equal to 13.4V in step S502, the microcomputer 170 controls the decompression circuit (step S504).

Then, it is checked whether the output voltage is greater than 10V or less than 9.7V (step S506). If it is checked in step S306 506 that the output voltage is greater than 10V or less than 9.7V, the discharge operation is turned off (step S407), and the flow returns to step S104.

If it is checked in step S506 that the output voltage is less than 10V and greater than 9.7V, the microcomputer 170 cuts off the on time of 5 seconds and the off time of 10 seconds after 3 cycles in one cycle (step S508).

Subsequently, the microcomputer 170 turns on the charge / discharge MOSFET after 30 seconds off (step S510), and feeds back to step S104.

On the other hand, if it is checked in step S500 that the discharge current is greater than or equal to 1.5A, the microcomputer 170 checks whether the discharge current exists in the range of 1.5A to 2.7A (step S512).

If it is checked in step S512 that the discharge current does not exist in the range of 1.5A to 2.7A, it feeds back to step S116. In other words, if the discharge current is checked to be larger than 2.7 A, it is fed back to step S116.

If it is checked in step S512 that the discharge current exists in the range of 1.5A to 2.7A, the microcomputer checks whether the voltage is greater than 12.8V (step S514).

In step S514, if the voltage is checked to be greater than 12.8V, it feeds back to step S122 and the process is repeated so far. If the voltage is checked to be less than or equal to 12.8V, the flow returns to step S504.

As described above, the battery voltage is provided in the battery pack by reducing the battery voltage to less than the threshold voltage in advance before unbalance occurs in the remaining battery voltage between the battery cells at the end of the discharge operation of the battery pack consisting of a plurality of batteries It is possible to prevent the deterioration of the life of the battery pack due to unbalanced discharge between them.

Although described above with reference to the embodiments, those skilled in the art can be variously modified and changed within the scope of the invention without departing from the spirit and scope of the invention described in the claims below. I can understand.

1 is a block diagram illustrating a battery pack circuit according to an embodiment of the present invention.

2A to 24F are images illustrating the terminal unit illustrated in FIG. 1.

3A to 3C are circuit diagrams illustrating the battery pack circuit shown in FIG. 1.

FIG. 4 is a table for explaining the negative temperature coefficient type resistance NTC shown in FIG. 3A.

5A and 5B are flowcharts illustrating a method of protecting a battery pack circuit according to an embodiment of the present invention.

FIG. 6 is a flowchart illustrating a battery protection operation operation according to the first mode illustrated in FIG. 5B.

FIG. 7 is a flowchart for describing a battery protection operation operation according to the second mode illustrated in FIG. 5B.

FIG. 8 is a flowchart illustrating a battery protection operation operation according to a third mode illustrated in FIG. 5B.

9 is a flowchart for describing a battery protection operation operation according to the fourth mode illustrated in FIG. 5B.

<Description of the symbols for the main parts of the drawings>

100: battery pack circuit 110: terminal portion

120: PCM control unit 130: main charge and discharge switching unit

140: first charge and discharge switching unit 150: second charge and discharge switching unit

160: decompression unit 170: main control unit

180: discharge current detection unit 190: remaining amount display unit

Claims (16)

A terminal unit receiving power supplied from an external device during a charging operation and connected to a load to provide charging power during a discharge operation; A protection circuit module (PCM) control unit for detecting a detected battery voltage in each of the batteries connected in series; A main charge / discharge switching unit which is turned on / off based on a switch signal provided from the PCM controller to output the battery voltage; A first charge / discharge switching unit connected to an output terminal of the main charge / discharge switching unit and the terminal unit and turned on / off; A second charge / discharge switch connected to an output terminal of the main charge / discharge switch; A pressure reducing unit configured to reduce the voltage output through the second charge / discharge switching unit and provide the reduced voltage to the terminal unit; And When the first charge / discharge switching unit is turned on to control the battery voltage output through the main charge / discharge switching unit to be supplied to the terminal unit, and when the voltage detected by the batteries is reduced to a threshold range or less, the battery is unbalanced. In order to prevent lance discharge and shorten the battery life, the first charge / discharge switching unit is turned off and the second charge / discharge switching unit is turned on to reduce the battery voltage output through the main charge / discharge switching unit. Battery pack circuit comprising a main control unit for controlling to be supplied to the terminal unit. The display device of claim 1, wherein the terminal part comprises a first terminal corresponding to a positive voltage and a second terminal corresponding to a negative voltage. Each of the first and second terminals is composed of three metal pieces arranged in a triangular shape, characterized in that the battery pack circuit. 3. The display device of claim 2, wherein the terminal unit further comprises a third terminal for recognizing the battery and a fourth terminal for on / off of the main controller. And the main controller is activated by supplying power to the main controller as the fourth terminal contacts the second terminal. The method of claim 1, wherein the decompression unit, A level down unit for lowering a level of a battery voltage via the second charge / discharge switching unit; A first transistor controlling an output of the leveled battery voltage; A voltage detector connected to an output terminal of the first transistor to detect a level of a battery voltage output through the first transistor; And And an operational amplifier configured to compare a voltage detected by the voltage detector with a battery voltage detected by the level down unit, and output a turn-on signal or a turn-off signal to a gate terminal of the first transistor. Battery pack circuit. The battery pack circuit of claim 4, further comprising a first diode connected in parallel to the first transistor, wherein the diode blocks a reverse current during a discharge operation. 5. The second circuit of claim 4, further comprising: a source receiving the battery voltage leveled down by the level down unit, a drain connected to the drain and the voltage detector of the first transistor, and a gate connected to an output terminal of the operational amplifier. A battery pack circuit further comprising a transistor. The battery pack circuit of claim 6, further comprising a second diode connected in parallel to the second transistor, wherein the diode blocks a reverse current during a discharge operation. The method of claim 1, wherein the main charge and discharge switching unit, Main discharge transistors; A first diode connected to a source terminal and a drain terminal of the main discharge transistor, the first diode blocking a reverse current during a discharge operation; Main charge transistor; And And a second diode connected to the source terminal and the drain terminal of the main charging transistor, the second diode blocking a reverse current during a charging operation. The battery pack circuit according to claim 7, wherein the main discharge transistor and the main charge transistors are p-channel MOS transistors. The method of claim 1, wherein the first charge and discharge switching unit, A first discharge transistor; A first diode connected to a source terminal and a drain terminal of the first discharge transistor, the first diode blocking a reverse current during a discharge operation; A first charging transistor; And And a second diode connected to the source terminal and the drain terminal of the first charging transistor, the second diode blocking a reverse current during a charging operation. The battery pack circuit of claim 10, wherein the first discharge transistor and the first charging transistors are p-channel MOS transistors. The method of claim 1, wherein the second charge and discharge switching unit, A second discharge transistor; A first diode connected to a source terminal and a drain terminal of the second discharge transistor, the first diode blocking a reverse current during a discharge operation; A second charging transistor; And And a second diode connected to the source terminal and the drain terminal of the second charging transistor, the second diode blocking a reverse current during a charging operation. The battery pack circuit of claim 1, further comprising a discharge current detector configured to detect a discharge current supplied from the PCM controller and provide the discharge current to the main controller. The battery pack circuit of claim 1, further comprising a remaining amount display unit displaying a remaining amount of charge of the battery pack as the remaining amount display switch is activated. The method of claim 1, further comprising a negative temperature coefficient resistance (NTC) resistance decreases with increasing temperature, The main controller performs the above control operation based on the voltage detected by the negative temperature coefficient type resistance (NTC). (a) checking the overcharge and the temperature as the power is turned on to supply the battery voltage of the battery pack to the load; (b) checking a discharge current of the battery pack when the battery voltage of the battery pack is lower than an over battery voltage threshold and the temperature is lower than a high temperature threshold; (c) if the discharge current is greater than 0 mA, outputting a battery voltage of the battery pack to the load through a first path; (d) checking the temperature of the battery pack, and if the temperature of the battery pack is checked to be higher than or equal to a set temperature threshold, the output of the battery voltage is maintained and the temperature of the battery pack is checked to be lower than the temperature threshold. Checking a discharge current of the battery pack, when a third is checked; And (e) if the discharge current is checked to be lower than a discharge current threshold, in order to prevent unbalanced discharge of the batteries to block shortening of the battery life, cut off the output of the battery voltage through the first path, and The battery pack protection method comprising the step of setting a second path to reduce the battery voltage to the output to the load.

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