JP2013005561A - Secondary battery discharge method and pack battery - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a secondary battery discharge method and a pack battery, enabling discharge of the secondary battery of which discharge is suspended, even when power is not supplied to an electric apparatus on which the pack battery is mounted.SOLUTION: When a shipping mode is set, MOSFETs 71, 72 for charging and discharging are switched off. On detection that the secondary battery is mounted on an electric apparatus 20 on which the self-secondary battery is to supply power, the MOSFETs 71, 72 for charging and discharging are switched on, and after a predetermined time, switched off. Further, on detection that the secondary battery is mounted on the electric apparatus 20, the MOSFETs 71, 72 for charging and discharging are switched on, and thereafter, if an instruction is given to cancel the shipping mode by the transmission of a predetermined communication command from a control and power unit 21 of the electric apparatus 20, or if the charge and discharge current of the secondary battery 1 is detected by a current detector 2, the on state of the MOSFETs 71, 72 for charging and discharging is retained irrespective of an elapsed time after being switched on.

Description

  The present invention relates to a method of discharging a secondary battery in a battery pack in which a switching element that cuts off a charging current of the secondary battery is turned off, and the battery pack.

  In battery packs that are installed in electrical equipment and shipped from the factory, secondary batteries may become over-discharged due to leakage current in the electrical equipment before it is delivered to the user and used. The battery is often shipped in a state (so-called shipping mode) in which charging / discharging is forcibly prohibited by turning off the switching element interposed in the charging / discharging path in the battery pack.

  For example, in Patent Document 1, when a battery voltage becomes lower than a sleep mode (corresponding to a shipping mode) switching voltage, a test for forcibly switching to a sleep mode with a battery pack that is switched to a sleep mode that reduces power consumption. A technique for providing points is disclosed. Further, in Patent Document 2, when a predetermined low power consumption transition command is received through communication with an external electric device and the potential of the communication terminal is held at a low level for a predetermined time longer, the mode is switched to the low power consumption mode. A battery pack is disclosed.

JP 11-339862 A Japanese Patent Laid-Open No. 2002-300731

  However, in the technique disclosed in Patent Document 1, the battery pack must be charged in order to cancel the sleep mode of the battery pack, and a charger connected to a commercial AC power source needs to be connected to the battery pack. was there. In order to switch the battery pack disclosed in Patent Document 2 from the low power consumption mode to the normal operation mode, the battery pack must be mounted on an external electric device and the potential of the communication terminal must be set to a high level. Specifically, it is necessary to connect an electric device that operates with an AC power source and the battery pack.

  The present invention has been made in view of such circumstances, and an object of the present invention is to provide a secondary in which discharge is stopped even when power is not supplied to an electric device to which a battery pack is attached. An object of the present invention is to provide a secondary battery discharging method and a battery pack capable of discharging the battery.

  The secondary battery discharge method according to the present invention includes a secondary battery and a switching element that cuts off a discharge current of the secondary battery, and discharges the secondary battery in a pack battery in which the switching element is turned off. In the method, it is detected whether or not the electric device to be fed is attached, and when the attachment is detected, the switching element is turned on, the elapsed time since turning on is counted, and when the predetermined time is counted, The switching element is turned off.

  In the secondary battery discharging method according to the present invention, a communication unit capable of communicating with the electrical device is prepared, and when the communication unit communicates predetermined data with the electrical device, the elapsed time measured Regardless, the switching element is turned on.

  The method for discharging a secondary battery according to the present invention provides a current detection unit for detecting the charge / discharge current of the secondary battery, and when the current detection unit detects the charge / discharge current, regardless of the elapsed time measured. The switching element is turned on.

  The battery pack according to the present invention includes a secondary battery and a switching element that cuts off a discharge current of the secondary battery, and is installed in an electric device to be fed in the battery pack with the switching element turned off. A mounting detection unit for detecting whether or not, a means for turning on the switching element when the mounting detection unit detects the mounting, a time measuring unit for measuring an elapsed time since the unit was turned on, and the unit And a means for turning off the switching element when the predetermined time is measured.

  The battery pack according to the present invention includes a communication unit capable of communicating with the electrical device, and when the communication unit communicates predetermined data with the electrical device, regardless of the elapsed time measured by the timing unit. And means for turning on the switching element.

  The battery pack according to the present invention includes a current detection unit that detects a charge / discharge current of the secondary battery, and when the current detection unit detects a charge / discharge current, regardless of the elapsed time counted by the timing unit, And a means for turning on the switching element.

In the present invention, the switching element that cuts off the discharge current is turned off in advance, and when it is detected that the switching element is attached to an electrical device to be supplied with power, the switching element is turned on and turned off after a predetermined time. .
Thereby, for example, when the switching element for discharge is set off in the shipping mode, even when it is attached to an electrical device that is not connected to the AC adapter and is not turned on, The switching element is temporarily turned on for a predetermined time.

In the present invention, when a predetermined data communication is performed with the electrical device after detecting that the electrical device is mounted and turning on the switching element for discharge, the elapsed time after turning on is detected. Regardless, the switching element is kept on.
That is, the switching element is always turned on after predetermined data communication is performed, and the on state of the switching element is continued even when a predetermined time has elapsed since the switching element was first turned on. For this reason, the switching element is not turned off thereafter.

In the present invention, after detecting that it is mounted on an electrical device and turning on the switching element for discharge, when detecting the charge / discharge current of the secondary battery, regardless of the elapsed time after turning on, The switching element is kept on.
In other words, the switching element is always turned on from the time when the charging / discharging current of the secondary battery is detected, and the switching element is kept on even when a predetermined time has elapsed since the switching element was turned on first. . For this reason, the switching element is not turned off thereafter.

According to the present invention, when mounted on an electrical device, the discharge switching element that has been turned off until then is turned on for a predetermined time. Also, the switching element is temporarily turned on.
Therefore, even when power is not supplied to the electric device to which the battery pack is attached, the secondary battery whose discharge has been stopped can be discharged.

It is a block diagram which shows the structural example of the battery pack which concerns on this invention. It is a flowchart which shows the process sequence of CPU which discharges the secondary battery in the pack battery which concerns on this invention temporarily. It is a flowchart which shows the process sequence of CPU which concerns on the subroutine of shipping mode determination. It is a flowchart which shows the process sequence of CPU which concerns on the subroutine of electrical equipment mounting | wearing determination.

Hereinafter, the present invention will be described in detail with reference to the drawings illustrating embodiments thereof.
FIG. 1 is a block diagram showing a configuration example of a battery pack according to the present invention. In the figure, reference numeral 10 denotes a battery pack. The battery pack 10 is configured to be detachable from an electric device 20 such as a personal computer (PC) or a portable terminal, and is attached to the electric device 20 at the time of shipment. The battery pack 10 includes, for example, battery blocks 11, 12, and 13 that are formed by connecting three battery cells 111, 112, 113, 121, 122, 123, 131, 132, and 133, which are made of, for example, lithium ion batteries. A secondary battery 1 that is connected in series in order is provided. The secondary battery 1 is configured such that the positive electrode of the battery block 13 and the negative electrode of the battery block 11 become a positive electrode terminal and a negative electrode terminal, respectively.

  The voltages of the battery blocks 11, 12, and 13 are each independently applied to the analog input terminal of the A / D conversion unit 4, converted into a digital voltage value, and from the digital output terminal of the A / D conversion unit 4 It is given to the control unit 5 comprising a computer. The analog input terminal of the A / D conversion unit 4 is arranged in close contact with the secondary battery 1, and the detection output of the temperature detector 3 that detects the battery temperature of the secondary battery 1 by a circuit including a thermistor, A detection output of a current detector 2 including a resistor for detecting a charging current and a discharging current of the secondary battery 1 is given. These detection outputs are converted into digital detection values and given to the control unit 5 from the digital output terminal of the A / D conversion unit 4.

  The charge / discharge path on the positive electrode terminal side of the secondary battery 1 is provided with a circuit breaker 7 composed of P-channel type MOSFETs 71 and 72 that block the charge current and the discharge current, respectively. The charge / discharge MOSFETs 71 and 72 are connected in series with their drain electrodes facing each other, and the source electrode of the charge MOSFET 71 is connected to the plus (+) terminal 83 of the battery pack 10. A diode connected in parallel between the drain electrode and the source electrode of each of the MOSFETs 71 and 72 is a parasitic diode (body diode).

  The above-described current detector 2 is interposed in the charge / discharge path on the negative electrode terminal side of the secondary battery 1, and one end of the current detector 2 is connected to the minus (−) terminal 84 of the battery pack 10. Yes. Connected to the minus (−) terminal 84 is a source electrode of an N-channel type MOSFET 61 for detecting that the battery pack 10 is attached to the electric device 20. The gate electrode of the MOSFET 61 is connected to one end of a resistor 62 pulled up to the power supply voltage (Vcc) of the control unit 5 and a B / I (Battery In) terminal 85 of the battery pack 10.

  The control unit 5 includes a CPU 51, which includes a ROM 52 that stores information such as programs, a RAM 53 that stores temporarily generated information, a timer 54 that measures various times in parallel, and a battery pack 10. The I / O port 55 for inputting / outputting each unit is connected to each other by a bus. The I / O port 55 is connected to the digital output terminal of the A / D conversion unit 4, the gate electrodes of the MOSFETs 71 and 72, the drain electrode of the MOSFET 61, and the communication unit 9. The communication unit 9 communicates with a control / power supply unit (charging unit) 21 included in the electrical device 20. The ROM 52 is a nonvolatile memory composed of an EEPROM (Electrically Erasable Programmable ROM) or a flash memory. In addition to the program, the ROM 52 stores a battery capacity learning value, the number of charge / discharge cycles, a set voltage, a set current, and various set data.

  The CPU 51 executes processing such as calculation and input / output according to a control program stored in advance in the ROM 52. For example, the CPU 51 takes in the voltage values of the battery blocks 11, 12, and 13 and the detection value of the charging / discharging current of the secondary battery 1 at a cycle of 250 ms, and based on the taken-in voltage value and detection value, The remaining capacity is accumulated and stored in the RAM 53. The CPU 51 also generates remaining capacity data and writes the generated data to a register (not shown) of the communication unit 9 to output the remaining capacity data from the communication unit 9. The CPU 51 further specifies the highest voltage (hereinafter referred to as the maximum cell voltage) among the taken voltage values of the battery blocks 11, 12, 13 and stores it in the RAM 53. The fetch period of the voltage value and the detected value of the charge / discharge current is not limited to 250 ms.

  The breaker 7 is electrically connected between the drain electrode and the source electrode of each of the MOSFETs 71 and 72 when an ON signal of L (low) level is given from the I / O port 55 to the gate electrodes of the MOSFETs 71 and 72 during normal charge / discharge. To do. When the charging current of the secondary battery 1 is cut off, an H (high) level off signal is applied from the I / O port 55 to the gate electrode of the MOSFET 71 for charging, whereby conduction between the drain electrode and the source electrode of the MOSFET 71 is achieved. Is cut off. Similarly, when the discharge current of the secondary battery 1 is cut off, an H (high) level off signal is given from the I / O port 55 to the gate electrode of the MOSFET 72 for discharge, whereby the drain electrode and the source electrode of the MOSFET 72 are connected. Is interrupted. When the secondary battery 1 is in a properly charged state, the MOSFETs 71 and 72 of the circuit breaker 7 are both turned on, and the secondary battery 1 is in a state where it can be discharged and charged.

  The electric device 20 includes a terminal unit 22 connected to a control / power supply unit 21. When the battery pack 10 is attached to the electric device 20, the terminals 23, 24, and 25 are connected to the positive (+) terminal 83, the negative (−) terminal 84, and the B / I terminal 85, respectively. The The terminals 24 and 25 are connected inside the electric device 20. The control / power supply unit 21 is supplied with electric power from a commercial power source (not shown) to drive the terminal unit 22, and the secondary battery 1 is connected via the plus (+) terminal 83 and the minus (−) terminal 84 of the battery pack 10. A charging current is supplied to the charging / discharging path.

  The control / power supply unit 21 also drives the terminal unit 22 by the discharge current supplied from the charge / discharge path of the secondary battery 1 when the supply of power from the commercial power supply is cut off. When the secondary battery 1 charged by the control / power supply unit 21 is a lithium ion battery, for example, a constant current (MAX current of about 0.5 to 1 C) and a constant voltage (MAX 4.2 to 4.4 V / battery cell) Charging is performed. When the battery voltage of the secondary battery 1 is equal to or higher than the full charge detection start voltage and the charging current is equal to or lower than a predetermined value, the secondary battery 1 is set to a fully charged state.

  Communication between the control / power supply unit 21 and the communication unit 9 is performed by a communication method such as an SMBus (System Management Bus) method using the control / power supply unit 21 as a master and the control unit 5 including the communication unit 9 as a slave. In the case of the SMBus system, the serial clock (SCL) is supplied from the control / power supply unit 21, and the serial data (SDA) is transferred between the control / power supply unit 21 and the communication unit 9 in both directions. In the present embodiment, the control / power supply unit 21 polls the communication unit 9 at a cycle of 2 seconds and reads the contents of the register of the communication unit 9. The polling cycle of 2 seconds depends on the setting on the control / power supply unit 21 side. By this polling, for example, the remaining capacity data of the secondary battery 1 is transferred to the control / power supply section 21 via the communication section 9 in a cycle of 2 seconds, and the remaining capacity data is displayed on a display (not shown) of the electric device 20. Displayed as a value (%).

  In the configuration described above, when the battery pack 10 is not attached to the electric device 20, an ON signal of H (high) level is given to the gate electrode of the MOSFET 61 pulled up by the resistor 62. For this reason, the drain electrode and the source electrode of the MOSFET 61 become conductive, and an L (low) level signal is given to the I / O port 55.

  Next, when the battery pack 10 is attached to the electric device 20, the B / I terminal 85 is connected to the minus (−) terminal 84 via the terminals 25 and 24. As a result, the gate electrode of the MOSFET 61 has the same potential as the source electrode, and conduction between the drain electrode and the source electrode is interrupted. On the other hand, since the input terminal of the I / O port 55 connected to the drain electrode of the MOSFET 61 is internally pulled up, an H (high) level signal is given to the I / O port 55. When a signal whose level changes due to the attachment / detachment of the battery pack 10 is taken into the CPU 51 from the I / O port 55 as described above, the CPU 51 can determine whether the battery pack 10 is attached to / detached from the electric device 20.

  Now, when shipping with the battery pack 10 attached to the electric device 20, the secondary battery 1 of the battery pack 10 is overdischarged due to leakage current inside the electric device 20 during transportation and storage. In order to prevent this, the charge / discharge MOSFETs 71 and 72 are turned off and set to the shipping mode. Further, in order to cut off the leakage current in the electric device 20, the discharging MOSFET 72 may be turned off and the charging MOSFET 71 may be turned on. When power is supplied by connecting an AC adapter (which converts AC power from a commercial power source to DC power) to the electric device 20 with respect to the battery pack 10 that is mounted on the electric device 20 and set to the shipping mode. When the release of the shipping mode is instructed by a predetermined communication command received via the communication unit 9, or when the application of the charging voltage from the electric device 20 is detected by the voltage detection unit (not shown), the shipping mode Is released and MOSFETs 71 and 72 are turned on. As described above, since the function of canceling the shipping mode by connecting the AC adapter can be installed as before, the convenience for the user is expanded.

  In addition to being able to cancel the shipping mode as described above, when the user starts using the electric device 20, in this embodiment, the battery pack 10 set to the shipping mode receives AC power from a commercial power source. Even when the battery device 10 is attached to the electrical device 20 that is not supplied, when the user once removes the battery pack 10 from the electric device 20 and attaches the battery pack 10 to the electric device 20 again, the battery pack 10 The charging and discharging MOSFETs 71 and 72 are turned on for a predetermined time (for example, about 1 hour) from when the mounting is detected by the level change of the signal applied from the B / I terminal 85 to the gate electrode of the MOSFET 61. Thereby, for example, the MOSFETs 71 and 72 for charging / discharging the battery pack 10 once set to the shipping mode before shipment are temporarily turned on, so that the AC adapter is connected to the electric device 20 to which the battery pack 10 is to be mounted. Thus, there is no need to start up the electric device 20. When the user operates the electric device 20 while the MOSFETs 71 and 72 are temporarily turned on, the shipping mode is canceled when a specific communication or discharge current is detected.

  Further, when there is no operation on the electric device 20 while the MOSFETs 71 and 72 are temporarily turned on, the MOSFETs 71 and 72 of the battery pack 10 are turned on until the predetermined time described above elapses. When the time has elapsed, the MOSFETs 71 and 72 are automatically turned off. Thereby, the MOSFETs 71 and 72 that are temporarily turned on are turned off again even if the battery pack 10 is mounted on the electric device 20 inadvertently or as necessary, for example, in the process before shipment. Therefore, it is not necessary to attach the battery pack 10 to the electric device 20 and transmit a communication command from the electric device 20.

Below, operation | movement of the control part 5 of the pack battery 10 mentioned above is demonstrated using the flowchart which shows it. The following processing is executed by the CPU 51 according to a control program stored in advance in the ROM 52.
FIG. 2 is a flowchart showing a processing procedure of the CPU 51 for temporarily discharging the secondary battery 1 in the battery pack 10 according to the present invention. Each of FIGS. 3 and 4 is for shipping mode determination and electrical equipment mounting determination. It is a flowchart which shows the process sequence of CPU51 which concerns on a subroutine. The processing in FIG. 2 is started at a cycle of 32 ms (0.032 seconds) from when the battery pack 10 is set to the shipping mode and the charge / discharge MOSFETs 71 and 72 are turned off, for example. The period to be activated is not limited to 32 ms.

  The shipping mode flag used in the processing of FIGS. 2 and 3 is set to 1 when, for example, the battery pack 10 attached to the electrical device 20 is set to the shipping mode by a communication command from the electrical device 20. . The mounting flag and the mounting notification flag used in the processing of FIGS. 2 and 4 are cleared to 0 at least when the battery pack 10 is removed from the electric device 20. These flags are all stored in the RAM 53.

  When the process of FIG. 2 is activated, the CPU 51 calls and executes a subroutine relating to the shipping mode determination (S11). Turning to FIG. 3, when the subroutine relating to the shipping mode determination is called from the main routine of FIG. 2, the CPU 51 determines whether or not the shipping mode flag is set to 1 (S31) and is set to 1. If yes (S31: YES), the satisfaction of the shipping mode cancellation condition is checked (S32). The shipment mode release condition here is, for example, a case where a predetermined communication command is transmitted from the control / power supply unit 21 after the battery pack 10 is attached to the electric device 20, and the release of the shipment mode is instructed. When the charging / discharging current of the secondary battery 1 is detected, the charging voltage applied from the control / power supply unit 21 between the plus (+) terminal 83 and the minus (−) terminal 84 is detected by a voltage detection unit (not shown). And so on.

  Next, the CPU 51 determines whether or not the above-described shipping mode cancellation condition is satisfied (S33), and when no condition is satisfied (S33: NO), the CPU 51 returns to the main routine. On the other hand, when at least one condition is satisfied (S33: YES), the CPU 51 clears the shipping mode flag to 0 (S34) and returns to the main routine.

  When the shipping mode flag is not set to 1 in step S31 (S31: NO), that is, when the shipping mode is canceled, the CPU 51 checks whether the shipping mode setting condition is satisfied (S35). The shipment mode setting conditions here are, for example, a case where a communication command is transmitted from the control / power supply unit 21 and the shipment mode setting is instructed as described above after the battery pack 10 is attached to the electric device 20. And the case where the charge / discharge current of the secondary battery 1 is not detected for a certain period of time.

  Next, the CPU 51 determines whether or not the above-described shipping mode setting conditions are satisfied (S36), and when no conditions are satisfied (S36: NO), the CPU 51 returns to the main routine. On the other hand, if at least one condition is satisfied (S36: YES), the CPU 51 sets the shipping mode flag to 1 (S37) and returns to the main routine.

  Returning to FIG. 2, when the process returns from the subroutine related to the shipping mode determination, the CPU 51 calls and executes the subroutine related to the electrical equipment mounting determination (S12). Next, moving to FIG. 4, when the subroutine related to the electrical device mounting determination is called from the main routine of FIG. 2, the CPU 51 determines whether or not the mounting flag is cleared to 0 (S <b> 41). If cleared to 0 (S41: YES), that is, if the fact that the battery pack 10 is not attached to the electrical device 20 is registered in the RAM 53, the CPU 51 determines whether the MOSFET 61 fetched from the I / O port 55 Based on the level of the drain electrode, it is determined whether or not the battery pack 10 is attached to the electric device 20 (S42). If not (S42: NO), the process returns to the main routine.

  When the battery pack 10 is mounted on the electric device 20 (S42: YES), the CPU 51 sets the mounting flag to 1 (S43) and registers it in the RAM 53, and sets the mounting notification flag to 1 ( S44) Return to the main routine. By setting the mounting notification flag to 1, the main routine is notified that the battery pack 10 that has not been mounted on the electrical device 20 until that time has been mounted on the electrical device 20 (change point).

  If the mounting flag is not cleared to 0 in step S41 (S41: NO), that is, if it is registered that the battery pack 10 is mounted on the electrical device 20, the CPU 51 determines whether the I / O port Based on the level of the drain electrode of the MOSFET 61 taken in from 55, it is determined whether or not the battery pack 10 is attached to the electric device 20 (S45). If it is attached (S45: YES), the process returns to the main routine. When the battery pack 10 is not attached to the electric device 20 (S45: NO, the CPU 51 clears the attachment flag to 0 (S46) and registers it in the RAM 53, and clears the attachment notification flag to 0 (S47). ) Return to the main routine.

  Returning to FIG. 2, when returning from the subroutine related to the electrical device attachment determination, the CPU 51 determines whether or not the attachment flag is set to 1, that is, the battery pack 10 is attached to the electrical device 20. It is determined whether or not it is registered in the RAM 53 (S13). If it is not set to 1 (S13: NO), the process proceeds to step S21 to be described later in order to turn off the charge / discharge MOSFETs 71 and 72.

  If it is set to 1 (S13: YES), the CPU 51 determines whether or not the shipping mode flag is set to 1 (S14). If it is not set to 1 (S14: NO), the shipping mode is set. In order to turn on the charge / discharge MOSFETs 71 and 72 in response to the fact that is canceled, the process proceeds to step S18 described later. On the other hand, when the shipping mode flag is set to 1 (S14: YES), the CPU 51 determines whether or not the mounting notification flag is set to 1, that is, the battery pack 10 is mounted on the electric device 20. It is determined whether or not notification is made (S15).

  When the mounting flag is set to 1 (S15: YES), the CPU 51 counts the number of loops corresponding to the ON time of the charge / discharge MOSFETs 71 and 72 after clearing the mounting notification flag to 0 (S16). In order to do this, the on-time counter is cleared to 0 (S17), and then the CPU 51 turns on the charge / discharge MOSFETs 71 and 72 (S18) and ends the processing of FIG.

  When the mounting flag is not set to 1 in step S15 (S15: NO), the CPU 51 adds 1 to the on-time counter (S19), and whether the on-time counter with 1 added has reached a predetermined number. For example, when counting the number of loops corresponding to 10 seconds, the predetermined number is 313 (= 10 seconds / 0.032 seconds). When the on-time counter has not reached the predetermined number (S20: NO), the CPU 51 once ends the process of FIG. On the other hand, when the on-time counter has reached the predetermined number (S20: YES), the CPU 51 turns off the MOSFETs 71 and 72 for charging / discharging (S21) and ends the processing of FIG.

As described above, according to the present embodiment, when the charge / discharge MOSFET is turned off at the time of setting the shipping mode and it is detected that the MOSFET is mounted on an electric device to be supplied with power, the charge / discharge MOSFET is Is turned on and turned off after a predetermined time.
Thereby, even if it is a case where it is a case where it is mounted | worn with the electric equipment which is not connected also to an AC adapter and the power supply is not turned on, charging / discharging MOSFET is temporarily turned on only for predetermined time.
Therefore, even when power is not supplied to the electric device to which the battery pack is attached, the secondary battery whose discharge has been stopped can be discharged.

Also, after turning on the charge / discharge MOSFET after detecting that it was installed in an electrical device, it was turned on when a predetermined communication command was sent from the control / power supply unit of the electrical device to instruct to cancel the shipping mode. Regardless of the elapsed time, the shipping mode flag is cleared to 0, and the charge / discharge MOSFET is kept on in step S18.
In other words, the charge / discharge MOSFET is always turned on from the time when the shipping mode is instructed to be released, and even if a predetermined time has elapsed since the charge / discharge MOSFET was first turned on, the charge / discharge MOSFET Therefore, the charge / discharge MOSFET can be prevented from being turned off.

Further, when the charging / discharging current of the secondary battery is detected after detecting that it is mounted on the electric device and turning on the charging / discharging MOSFET, the shipping mode flag is set to 0 regardless of the elapsed time after the turning on. In step S18, the charge / discharge MOSFET is kept on.
In other words, the charge / discharge MOSFET is always turned on from the time when the charge / discharge current of the secondary battery is detected, and the charge / discharge is performed even when a predetermined time has elapsed since the charge / discharge MOSFET was turned on first. Since the on-state MOSFET is kept on, it is possible to prevent the charge / discharge MOSFET from being turned off thereafter.

  In the present embodiment, when the battery pack 10 is set to the shipping mode, the charge / discharge MOSFETs 71 and 72 are temporarily turned on when it is detected that the battery pack 10 is attached to the electric device 20. Although it is turned off, the process for detecting such attachment is not limited to the case where the battery pack 10 is set to the shipping mode. For example, even when a name is not particularly given to the state of the battery pack 10, the above-described processing at the time of mounting detection may be performed when the MOSFETs 71 and 72 for charging / discharging are turned off.

  Further, in the present embodiment, the condition for canceling the shipping mode is satisfied after a predetermined time elapses after the MOSFETs 71 and 72 for charging are temporarily turned on by detecting that they are attached to the electric device 20. Even in this case, the charging and discharging MOSFETs 71 and 72 are turned on, but the present invention is not limited to this. For example, the shipping mode may be canceled and the charge / discharge MOSFETs 71 and 72 may be turned on only when the shipping mode cancellation condition is satisfied before the predetermined time has elapsed.

  The embodiment disclosed this time is to be considered as illustrative in all points and not restrictive. The scope of the present invention is defined by the terms of the claims, rather than the meanings described above, and is intended to include any modifications within the scope and meaning equivalent to the terms of the claims.

1 Secondary battery 10 Pack battery 2 Current detector (current detector)
4 A / D converter 5 Control unit 51 CPU
52 ROM
53 RAM
54 Timer (Timekeeping means)
61 MOSFET (mounting detector)
72 MOSFET (switching element)
9 Communication Department 20 Electrical Equipment 21 Control / Power Supply

Claims (6)

In the method for discharging a secondary battery in a battery pack comprising a secondary battery and a switching element that cuts off a discharge current of the secondary battery, and the switching element is turned off.
Detect whether it is attached to the electrical equipment to be powered
When mounting is detected, the switching element is turned on,
Time elapsed since turning on,
The secondary battery discharging method, wherein the switching element is turned off when a predetermined time is counted. Prepare a communication unit capable of communicating with the electrical equipment,
2. The discharge of the secondary battery according to claim 1, wherein when the communication unit communicates predetermined data with the electrical device, the switching element is turned on regardless of the elapsed time. Method. Prepare a current detector for detecting the charge / discharge current of the secondary battery,
3. The method of discharging a secondary battery according to claim 1, wherein when the current detection unit detects a charging / discharging current, the switching element is turned on regardless of the elapsed time measured. In a battery pack comprising a secondary battery and a switching element that cuts off a discharge current of the secondary battery, and the switching element is turned off,
A mounting detection unit for detecting whether or not the power supply is mounted on an electrical device;
Means for turning on the switching element when the mounting detection unit detects mounting;
Time measuring means for measuring the elapsed time since the means was turned on;
A battery pack comprising: means for turning off the switching element when the means measures the predetermined time. A communication unit capable of communicating with the electrical device;
5. The means for turning on the switching element regardless of the elapsed time measured by the time measuring means when the communication unit communicates predetermined data with the electrical device. The battery pack described in 1. A current detector for detecting a charge / discharge current of the secondary battery;
6. The battery pack according to claim 4, further comprising: a unit that turns on the switching element regardless of an elapsed time measured by the time measuring unit when the current detection unit detects a charging / discharging current. .

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