KR20080000390A - Multi battery cell control method and potable equipment with the same - Google Patents

Abstract

A multi battery cell control method and portable equipment with the same are provided to extend the use time of portable equipment by independently charging and discharging a plurality of battery cells according to the status information of a battery. A multi battery cell control method includes the steps of: detecting the status information of a battery for more than two battery cells(S10); and independently charging and discharging the battery cells based on the status information of the battery according to a predetermined order. The charging and discharging step includes the steps of: checking the abnormality of battery cells(S12); and controlling the charging and discharging of battery cells according to the result of checking. The checking step includes the steps of: supplying charging current to each battery cell; detecting the charging voltage of each battery cell; and determining the battery cell, whose charging voltage is changed, as the normal battery cell.

Description

Multi battery cell control method and portable device using same {Multi Battery Cell Control Method and Potable Equipment with the same}

1 is a block diagram of a portable device to which a conventional parallel-connected battery cell is applied.

2 is a block diagram of a portable device according to an embodiment of the present invention.

3 is a flowchart illustrating a step-by-step method of charging multiple battery cells according to an embodiment of the present invention.

4 is a flowchart illustrating a step-by-step method of discharging multiple battery cells according to an exemplary embodiment of the present invention.

`` Explanation of symbols for main parts of drawings ''

110: path control circuit 120: charging circuit

130: micom 210: main switch

220: charge and discharge switch 230: current detection unit

240: battery cell 250: voltage detector

260: temperature detector 270: protection IC

The present invention relates to a battery of a portable device, and more particularly, to a multi-battery cell control method for independently controlling a plurality of battery cells and a portable device using the same.

In general, a battery used in a portable device uses one battery cell having a large capacity or two battery cells connected in parallel. However, since there is a limit on the capacity of the battery cells at the current level, there is an increasing demand for connecting and using a plurality of battery cells in parallel.

For example, FIG. 1 is a block diagram of a portable device using a conventional parallel connected battery cell. As shown, a conventional portable device includes a battery pack 20 having two battery cells 21a and 21b connected in parallel, a charging circuit 12 for charging the battery cells 21, an entire system and It consists of a MICOM 11 which controls charging / discharging of a battery cell. The microcomputer 11 refers to a central processing unit (CPU) such as an embedded controller of a portable computer or a portable communication device. The charging circuit 12 charges the battery cell 21 by using a DC power supplied from an AC-DC adapter 30 that converts an external commercial AC power.

In addition, the battery pack 20 is provided with a protection circuit 22 to prevent an accident such as explosion of the battery cell 21. The protection circuit 22 includes a detector 24 for detecting a current charged in the battery cell 21, a voltage charged in the battery cell 21, and a temperature inside the battery pack 20, and the AC-DC adapter. A charge / discharge switch 23 for intermittently discharging the power supplied to the battery cell 21 from the 30 or intermittently discharging when the voltage of the battery cell 21 falls below a predetermined voltage is provided.

The protection circuit 22 includes a protection IC 25 for controlling the charge / discharge switch 23 based on the data detected by the detection unit 24. The protection IC 25 compares the voltage charged in the battery cell 21 with a predetermined voltage during charging to prevent overcharging. In addition, the protection IC 25 may prevent over discharge by comparing the voltage of the battery cell 21 with the system threshold voltage during discharge.

The conventional portable device having two battery cells connected in parallel has the following problems.

First, there is a demand to use three or more battery cells due to the limitation of the battery cell capacity. Thus, when three or more battery cells are connected in parallel, impedance matching of each battery cell is required, but impedance matching is difficult, and even impedance matching is often caused by impedance matching.

In addition, deterioration problems and accidents occur in a specific battery cell due to a loop path difference between the parallel connected battery cells.

In addition, when an internal short circuit occurs in the battery cell, an accident such as an explosion or fire due to concentration of current occurs.

In addition, in the conventional portable device, since the battery cells are connected in parallel and integratedly controlled, even if an error occurs in only one battery cell, the entire battery cell cannot be used.

Accordingly, an object of the present invention is to provide a multi-battery cell control method for independently controlling a plurality of battery cells and a portable device using the same.

Another object of the present invention is to provide a multiple battery cell control method for extending the battery usage time of a portable device using a plurality of battery cells and a portable device using the same.

According to an aspect of the present invention, there is provided a method of controlling a multiple battery cell, the method comprising: detecting battery state information of two or more battery cells, and performing a predetermined order of the battery cells according to the detected battery state information. It characterized in that it comprises a step of independently charging and discharging.

Preferably, the charging and discharging step includes a step of checking whether the battery cell is normal and controlling the charging and discharging operation of the battery cell according to the test result.

The checking may include supplying a charging current to each of the battery cells, detecting a charging voltage of each of the battery cells, and determining a battery cell in which the charging voltage is changed by the charging current as a normal state. It is preferably configured to include the step.

The charging and discharging operations include charging and discharging the battery cells according to the predetermined order when all of the battery cells are normal, and charging and discharging the battery cells when one of the battery cells is defective. Blocking and charging and discharging the remaining battery cells, and if the predetermined number or more of the battery cells is defective, it is preferable to include a step of stopping all the charging and discharging operations.

Preferably, the predetermined number is a number that is randomly set according to the number of battery cells.

The charging operation is preferably performed in order from the battery cells having a low charging voltage among the battery cells.

In the charging, when the battery cell being charged is fully charged, it is preferable to stop charging the battery cell and charge another battery cell.

The fully charged state is preferably a state in which the charging voltage is higher than the predetermined voltage and the charging current is lower than the predetermined current.

The predetermined voltage is 4.2V ± 1%, and the predetermined current is preferably within 10% of the current supplied at the beginning of the battery cell charging operation.

Preferably, the charging current decreases as the battery cell is charged.

In the discharging operation, when the charging voltage is lower than the system threshold voltage, it is preferable to stop the discharge of the battery cell and to switch to the sleep mode.

The system threshold voltage is preferably a voltage arbitrarily set between 3.1V and 3.5V.

Preferably, the discharging operation is performed in order from the battery cells with the high charging voltage.

Preferably, the discharge discharges a battery cell having a higher charging voltage than a booting proper voltage when the system is booted.

It is preferable that the boot voltage is 3.6V.

In the discharge, when the booting is completed, it is preferable to discharge a battery cell whose charging voltage is higher than the system threshold voltage.

When the charge voltage of the battery cell being discharged is lower than the system threshold voltage, it is preferable to stop discharging the battery cell being discharged and discharge another battery cell.

A portable device using the multi-battery cell control method according to the present invention for achieving the above object is a battery pack including two or more battery cells, and charging the battery cell or the power using an externally supplied power And a microcomputer for controlling the charging and discharging operation of the charging and discharging unit according to the battery state information detected from the battery cell, and the battery cell is independent in a predetermined order. It is characterized in that the charging and discharging.

The battery state information may include the number of battery cells, a charging voltage, a charging current, an internal temperature of a battery pack, and a number of defective battery cells.

The charging and discharging unit may be configured to include a charging circuit for charging the battery cells in order from a low charging voltage, and a discharge circuit for discharging the battery cells in order from a high charging voltage.

The battery pack may include a charge / discharge switching unit connected to each of the battery cells in series to control the charge / discharge power of the battery cell, a detector for detecting battery state information of the battery cell, and the battery state information according to the battery state information. It is preferably configured to include a protection IC for controlling the charge-discharge switching unit to control the charge and discharge of the battery cell.

The protection IC may be configured to include a data transmission terminal for transmitting the battery state information to the microcomputer.

The detector may include a temperature detector configured to detect a temperature inside the battery pack, a current detector configured to detect the charging current supplied to the battery cell and a discharge current discharged from the battery cell to charge the battery cell, It is preferably configured to include a voltage detector for detecting the charge voltage charged in the battery cell.

Preferably, the current detector is a sensing resistor connected in series to each of the battery cells.

The battery pack may further include a main switch for shutting off the charge / discharge power of all the battery cells under the control of the protection IC when the number of battery cells in an abnormal state among the battery cells is more than a predetermined number.

Preferably, the predetermined number is set according to the number of battery cells.

The present invention preferably further comprises a path control circuit for controlling a path to which power supplied from the outside and power discharged from the battery pack are supplied.

The present invention having the configuration as described above, the charging and discharging switch is provided for each battery cell to independently control the charging and discharging operation of a plurality of battery cells.

Hereinafter, a method of controlling a multiple battery cell and a portable device using the same will be described in detail with reference to the accompanying drawings.

2 is a block diagram of a portable device to which multiple battery cells are applied according to an exemplary embodiment of the present invention.

As shown in FIG. 2, the present invention provides a battery pack 200 connected to a main body 100 and a main body 100 of a portable device to supply power or to be charged by power supplied from an AC-DC adapter. Is provided.

The main body 100 includes a path control circuit 110 for controlling a path to supply power to the system and the battery pack 200. The path control circuit 110 supplies power to the charging circuit 120 to supply power from the AC-DC adapter 300 to the system or to charge the battery cell 240 under the control of the microcomputer 130. Control the path as much as possible. In contrast, when the power is not supplied from the AC-DC adapter 300, the path control circuit 110 controls the path to supply the power charged in the battery cell 240 to the system.

The charging circuit 120 charges the battery cell 240 using power supplied from the AC-DC adapter 300 via the path control circuit 110 under the control of the microcomputer 130. The charging circuit 120 charges from a battery cell having a low voltage according to the charging voltage of the battery cell 240.

The microcomputer 130 controls the overall system, the path control circuit 110 and the charging circuit 120. The microcomputer 110 controls the charging and discharging of the battery pack 200 by checking whether the battery cell 240 is charged and normal according to the battery state information transmitted from the protection IC 270 of the battery pack 200. do. To this end, the microcomputer 110 supplies the charging current to each of the battery cells 240 through the charging circuit 120 and determines that the battery cells whose charging voltage changes are normal.

Accordingly, the protection IC 270 and the microcomputer 130 communicate using the data transmission terminals 271 and 131 provided, respectively. That is, according to the number of pulses output from the data transmission terminal 271 of the protection IC 270, the microcomputer 130 receives the battery state information to check the charge and discharge state and normal status of the battery cell 240, The signal for controlling the protection IC 270 is transmitted.

Next, in the present embodiment, the battery pack 200 includes three battery cells 240 and a charge / discharge switch 220 for intermitting charge / discharge of each battery cell. Although the battery cells 240 are configured to be connected in parallel, the charging / discharging operation may be independently performed by the intermittent charge / discharge switches 220 provided. For example, when the first charge / discharge switch 221 of the charge / discharge switch 230 is turned on, the remaining charge / discharge switches 222 and 223 are turned off to be turned off. Only cell 241 is independently charged or discharged.

The charge / discharge switch 220 is controlled by a protection IC 270 that protects the battery cell 240 to maintain an electrically stable state. The protection IC 270 controls the charge / discharge switch 220 according to the battery state information applied from the detectors 230, 250, and 260 for detecting the voltage, current, and temperature of the battery cell 240. The battery state information may include a charging voltage which is a voltage charged in the battery cell 240, a charging current which is a current charged in the battery cell 240, a temperature inside the battery pack 200, the number of battery cells 240, And the number of bad battery cells 240. Among such battery state information, the charging current is a taper current that is supplied higher than the rated current of the battery cell in order to shorten the charging time at the beginning of the charging operation, but gradually decreases as the battery cell is charged after a predetermined time.

The detector includes a current detector 230 that detects the charging current, a voltage detector 250 that detects the charging voltage, and a temperature detector 260 that detects a temperature inside the battery pack 200. In this case, the current detection unit 230 is preferably a sensing resistor that is connected in series between the charge and discharge switch 220 and the battery cell 240 to sense the charging current. The battery state information detected by the detector is transmitted to the protection IC 270.

The protection IC 270 stops charging and discharging when the number of the defective battery cells 240 is two or more according to the battery state information transmitted from the detectors 230, 250, and 260, and charging the defective battery cells when the protection IC 270 is one or more. The charge and discharge switch 220 is controlled to block the discharge. In addition, the protection IC 270 controls to charge from a cell with a low charge voltage and discharge from a cell with a high charge voltage. In other words, in the charging operation, the protection IC 270 has a charging voltage of the battery cell 240 of more than a full charging voltage (for example, 4.2V ± 1%) and a charging current within 10% of the initial charging current. Judged as fully charged. Accordingly, the protection IC 270 controls the charge / discharge switch 220 to charge the battery cells having a low charging voltage among the remaining battery cells 240.

 In the discharging operation, the protection IC 270 discharges the battery cell whose charging voltage of the battery cell 240 is higher than the system threshold voltage (for example, a voltage arbitrarily set between 3.1V and 3.5V). In particular, in order to drive the system, during a booting operation with a large power consumption, only the battery cell whose charging voltage is higher than the boot proper voltage (for example, 3.6V) is discharged.

In addition, the battery pack 100 includes a main switch 210 for blocking charge and discharge of the entire battery pack 200 when two or more battery cells 240 are defective. The main switch 22 performs a secondary protection function to protect the battery cell by blocking overcharge and overdischarge of the battery cell 240 under the control of the protection IC 270.

According to the present invention, a battery cell is supplied by a power supplied from the path control circuit 110 via the charging circuit 120, the main switch 210, the charge / discharge switch 220, and the current detector 230 during the charging operation. A charging path through which 240 is filled is formed. In the discharging operation, the discharge circuit in which the charge / discharge switch 240 is turned on and the power discharged from the battery cell 240 is supplied to the system via the main switch 210 and the path control circuit 110 is provided. It is formed.

According to an embodiment of the present invention, the battery pack including two or more battery cells is configured to control and charge and discharge each battery cell independently, and the charging voltage and the charging current, the temperature inside the battery pack, and the battery cell are configured as described above. Detect the number and whether the number of normal to deliver to the microcomputer 130 of the main body 100.

Hereinafter, a method of controlling multiple battery cells according to an exemplary embodiment of the present invention will be described in detail with reference to FIGS. 3 and 4. In the present embodiment, a description will be made of the charging method and the discharge method for convenience.

3 is a flowchart illustrating a method of charging a multiple battery cell according to an exemplary embodiment of the present invention, and FIG. 4 is a flowchart illustrating a method of discharging a multiple battery cell according to an exemplary embodiment of the present disclosure.

First, the multi-battery cell charging method according to the present invention will be described in detail with reference to FIG. 3. When the AC-DC adapter 300 for converting and supplying a commercial AC power supplied from the outside into DC power is connected, in the tenth step S10 of FIG. 3, the microcomputer 130 detects the battery state through the detection unit. Information is received from the protection IC 270. In an eleventh step S11, the microcomputer 130 checks the number of battery cells 240 and the charging voltage of each battery cell. Subsequently, in a twelfth step S12, the microcomputer 130 checks whether all battery cells 240 are normal. In other words, the microcomputer 130 controls the charging circuit 120 and the charge / discharge switch 220 to supply power to each of the battery cells 240 to charge the battery, and determines that the battery cells whose charging voltage changes are normal. .

If all of the battery cells 240 are in the normal state in the twelfth step S12, the microcomputer 130 starts the charging operation in the thirteenth step S13. At this time, the microcomputer 130 charges one by one from the lowest battery cell 240 by comparing the charging voltage among the battery state information received from the protection IC (270). For example, when the charging voltage of the second battery cell 242 is lower than the charging voltage of the third battery cell 243, the second battery cell 242 is first charged. Subsequently, it is checked whether the charged battery cell 242 is fully charged in the fifteenth step S15. Accordingly, when the second battery cell 242 is in a fully charged state (for example, the charging voltage is 4.2V ± 1% and the charging current is 10% or less of the initial charging current), the second battery cell 242 is fully charged. Diagnose with (full charging) and stop charging.

In a sixteenth step (S16), the microcomputer 130 checks whether all the battery cells 240 are charged and repeats the twelfth steps (S12) to the fifteenth step (S15) until all the battery cells 240 are charged. Perform. Accordingly, the remaining battery cells are charged in order from the low charging voltage.

On the other hand, when the bad battery cell is identified in the twelfth step (S12), in the twelfth step (S20), the microcomputer 130, if there is only one bad battery cell, the charge and discharge switch 220 to not charge the bad battery cell Control to block. For example, when the first battery cell 241 is defective, the microcomputer 130 may turn off the first charge / discharge switch 221 to prevent the first battery cell 240 from being charged.

In addition, when the number of defective battery cells 240 is two or more in the twentieth step S20, the microcomputer 130 controls the protection IC 270 to block the charge / discharge switch 220 and the main switch 210. The charging of the battery pack 200 is stopped (S22).

Through the above process, the multi-battery cell charging method according to an embodiment of the present invention checks whether or not normal according to the battery state information, and charges a plurality of battery cells independently from the low charging voltage.

Next, a multi-battery cell discharge method according to an embodiment of the present invention will be described in detail with reference to FIG. 4. When the AC-DC adapter 300 is not connected, when the power button is operated in operation 30 (S30) of FIG. 4, the microcomputer 130 may protect the protection IC 270 in operation 31 (S31). The battery state information is received from the battery cell 240 to check the number and the charging voltage (S32).

Subsequently, in a thirty-third step S33, the microcomputer 130 checks whether all battery cells 240 are normal in the same manner as the charging operation. If all of the battery cells 240 are in a normal state, the microcomputer 130 checks whether all of the battery cells 240 are lower than the bootable voltage (for example, 3.6 V) in a 34 th step S34. Thus, when the charging voltage of the at least one battery cell 240 is higher than the boot suitable voltage, in operation 35 (S35), the microcomputer 130 discharges the battery cells 240 sequentially from the battery cells having the highest charging voltage. To control. When the booting is finished (S36), in operation 37, the microcomputer 130 uses a battery cell having a charging voltage higher than a system threshold voltage (for example, a voltage arbitrarily set between 3.1 V and 3.5 V). Control to perform discharge. That is, the microcomputer 130 drives the system by using only the battery cells 240 having a charge voltage higher than the boot proper voltage in consideration of the large power consumption during the booting operation, and when the booting ends, the system threshold voltage. The battery cell 240 is controlled to use a higher charging voltage.

In operation 38, the microcomputer 130 stops discharging when the charging voltage of the discharging battery cell 240 reaches the system threshold voltage. In operation 39 (S39), steps 37 through 38 are performed repeatedly until all battery cells 240 are discharged to the system threshold voltage.

In operation 40, when all battery cells 240 are discharged to the system threshold voltage, the microcomputer 130 enters the sleep mode and ends the discharge operation.

On the other hand, when the number of defective battery cells 240 is one in step 33 (S33) (S51), the microcomputer 130 is connected to the defective battery cells (for example, the first battery cell, 241) the charge and discharge switch ( The controller 221 turns off the battery cell 241 to block the discharge (S52). In operation 51, when the number of defective battery cells is two or more, the microcomputer 130 ends the discharge (S53) and switches to the sleep mode in which the power is cut off in the system (S40). . At this time, the main switch 210 is also turned off together, all the power discharged from the battery cell 240 is preferably cut off.

In addition, when the charging voltages of all the battery cells 240 are lower than the bootable voltage in step 34 (S34), the microcomputer 130 determines that the discharge has failed (S53) and switches to the sleep mode (S40). .

Through the above process, the multiple battery cell control method and the portable device using the same according to an embodiment of the present invention charges and discharges a plurality of battery cells by determining the charge and discharge and priority according to the battery state information.

In the above embodiment, three battery cells have been described, but in the present invention, when four or more battery cells are provided, the number of battery cells determining failure of charging and discharging may be changed to three or more.

As described above, the present invention has been described with reference to the embodiments shown in the drawings, which are merely exemplary, and a person of ordinary skill in the art without departing from the spirit and scope of the present invention. It will be apparent that various modifications, changes, and equivalent other embodiments are possible. Therefore, the true technical protection scope of the present invention will be defined by the technical spirit of the appended claims.

As described above, the present invention independently charges and discharges a plurality of battery cells according to priorities according to battery state information. Accordingly, the present invention can extend the use time of the portable device using a plurality of battery cells. In addition, the present invention may use a portable device using the remaining battery cells even if one battery cell is defective.

Claims (27)

Detecting battery state information of at least two battery cells; And independently charging and discharging the battery cells in a predetermined order according to the detected battery state information. The method of claim 1, wherein the charging and discharging step, Checking whether the battery cell is normal; And controlling the charging and discharging operations of the battery cells according to the test result. The method of claim 2, wherein the inspecting step, Supplying a charging current to each of the battery cells; Detecting a charging voltage of each of the battery cells; And determining a battery cell in which the charging voltage is changed by the charging current as a normal state. The method of claim 2, wherein the charging and discharging operation, Charging and discharging the battery cells according to the predetermined order when all of the battery cells are normal; If one of the battery cells is defective, blocking charging and discharging of the battery cells and charging and discharging the remaining battery cells; And stopping all of the charging and discharging operations when a predetermined number or more of battery cells are defective. The method of claim 4, wherein And the predetermined number is a number set arbitrarily according to the number of battery cells. The method of claim 2, wherein the charging operation, The method of claim 1, wherein the battery cells are charged in order from the battery cells having the lowest charging voltage. The method of claim 6, wherein the filling, When the battery cell being charged is in a fully charged state, the method of controlling a multiple battery cell, characterized in that to stop charging the battery cell and to charge another battery cell. The method of claim 7, wherein the full state of charge, And the charging voltage is higher than a predetermined voltage and the charging current is lower than a predetermined current. The method of claim 8, The predetermined voltage is 4.2V ± 1% or more, and the predetermined current is within 10% of the current supplied at the beginning of the battery cell charging operation. The method of claim 8, wherein the charging current, And the battery cell decreases as it is charged. The method of claim 2, wherein the discharge operation, When the charging voltage is lower than a system threshold voltage, stopping the discharge of the battery cell and switching to a sleep mode. The method of claim 11, wherein the system threshold voltage, A method for controlling multiple battery cells, wherein the voltage is arbitrarily set between 3.1V and 3.5V. The method of claim 2, wherein the discharge operation, And discharging the battery cells in order from the battery cells with high charging voltage. The method of claim 13, wherein the discharge, The method of controlling a multi-battery cell according to claim 1, wherein the battery cell discharges a battery cell whose charging voltage is higher than a booting voltage. 15. The method of claim 14, wherein the boot voltage, Multiple battery cell control method characterized in that the 3.6V. The method of claim 11 or 13, wherein the discharge, And discharging a battery cell having the charging voltage higher than the system threshold voltage when the booting is completed. The method according to claim 11 or 13, And when the charging voltage of the battery cell being discharged is lower than the system threshold voltage, discharging the battery cell being discharged and discharging another battery cell. A battery pack including two or more battery cells, A charging and discharging unit for charging the battery cell or discharging the power charged in the battery cell using power supplied from an outside; And a microcomputer controlling the charging / discharging operation of the charging / discharging unit according to the battery state information detected from the battery cell. The battery cell is a portable device using a multiple battery cell control method, characterized in that for independently charging and discharging in a predetermined order. The method of claim 18, The battery state information may include the number of battery cells, a charging voltage, a charging current, a battery pack internal temperature, and a number of defective battery cells. The method of claim 18, wherein the charging and discharging unit, A charging circuit for charging the battery cells in order from a low charging voltage; And a discharging circuit for discharging the battery cells in order from a high charging voltage. The method of claim 18, wherein the battery pack, Charge and discharge switching unit for intermittent charge and discharge power of the battery cells are connected in series for each of the battery cells; A detector which detects battery state information of the battery cell; And a protection IC configured to control the charge / discharge switching unit to control charging and discharging of the battery cell in accordance with the battery state information. The method of claim 21, wherein the protection IC, And a data transmission terminal for transmitting the battery state information to the microcomputer. The method of claim 21, wherein the detection unit, A temperature detector detecting a temperature of the battery pack; A current detector for detecting the charge current supplied to the battery cell and the discharge current discharged from the battery cell to charge the battery cell; And a voltage detector for detecting the charging voltage charged in the battery cell. The method of claim 23, wherein The current detection unit is a portable device using a multiple battery cell control method, characterized in that the sensing resistor is connected in series to each of the battery cells. The method of claim 21, wherein the battery pack, And a main switch for shutting off the charge / discharge power of all the battery cells under the control of the protection IC when the number of battery cells in an abnormal state among the battery cells is more than a predetermined number. Portable device using.  The method of claim 25, And the predetermined number is set according to the number of battery cells. The method of claim 18, And a path control circuit for controlling a path through which power supplied from the outside and power discharged from the battery pack are supplied.

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