Charge / discharge adapter

Abstract

To enable a charge / discharge adapter to switch between power supply and power reception according to the state of a battery pack.SOLUTION: A charge / discharge adapter comprises an external equipment connection part, a battery pack connection part, a power path, a power conversion part, a battery state detection part, and a control part, and the power conversion part is provided in the power path, and configured to switch to convert received electric power from external equipment into charging power to the battery pack, or convert discharge electric power from the battery pack into electric power supplied to the electric power, and the control part is configured to control the switching between power supply to and power reception from the external equipment by the power conversion part according to the state of the battery pack detected by the battery state detection part.SELECTED DRAWING: Figure 2

Description

[Technical field]

[0001] The present disclosure relates to a charge / discharge adapter capable of supplying power from a battery pack to an external device and charging the battery pack from the external device. [Background technology]

[0002] Patent Document 1 describes a charge / discharge adapter equipped with a USB Type-C port (registered trademark, hereinafter referred to as USB-C terminal) as a connection terminal for an external device. A device (Dual Role Power Device) that can be both a source and a sink can be connected to the USB-C terminal as an external device. Therefore, with this charge / discharge adapter, charging and discharging to a battery pack can be performed by switching the function (DRP: Dual Role Power) of the external device.

[0003] In addition, the DRP can change the role of source / sink in both the charge / discharge adapter and the external device through communication after connecting the external device to the USB-C terminal. Therefore, the charge / discharge adapter can operate as a source that supplies power to the external device with the discharged power from the battery pack, and can also operate as a sink that receives power from the external device and charges the battery pack. [Prior art documents] [Patent documents]

[0004] [Patent Document 1] US20210336396A1 Summary of the Invention [Problem to be solved by the invention]

[0005] In the above-mentioned charge / discharge adapter, the source / sink switching is performed, for example, in response to a command from a user or a switching request from an external device, but the switching is performed without taking into consideration the state of the battery pack.

[0006] For this reason, for example, when the power stored in the battery pack is reduced due to discharging and power cannot be supplied to an external device, the role of the charge / discharge adapter may be switched to a source that supplies power to the external device.Also, for example, when the temperature of the battery pack is high and charging to the battery pack cannot be performed normally, the role of the charge / discharge adapter may be switched to a sink that receives power from the external device.

[0007] One aspect of the present disclosure aims to provide a charge / discharge adapter capable of switching between supplying power from a battery pack to an external device and receiving power from an external device, whereby switching between supplying and receiving power can be performed according to the state of the battery pack. [Means for solving the problem]

[0008] A charge / discharge adaptor according to one aspect of the present disclosure includes an external device connection unit, a battery pack connection unit, a power path, a power conversion unit, a battery state detection unit, and a control unit. The external device connection unit includes a power terminal for supplying or receiving power to or from the external device, and the battery pack connection unit includes a battery terminal for connecting a chargeable or dischargeable battery pack and for charging or discharging the battery pack.

[0009] The power path connects a power terminal of the external device connection unit and a battery terminal of the battery pack connection unit. The power conversion unit is provided on the power path and is configured to be able to switch between converting power received from the external device into charging power for the battery pack and converting power discharged from the battery pack into power supplied to the external device.

[0010] The battery state detector detects the state of the battery pack, and the controller controls switching between power supply and power reception from the power converter to the external device in accordance with the state of the battery pack detected by the battery state detector.

[0011] Therefore, according to the charge / discharge adapter of the present disclosure, it is possible to appropriately switch between power supply and power reception for an external device according to the state of the battery pack. That is, for example, when the power stored in the battery pack is low and power cannot be supplied to an external device, it is possible to prevent the charge / discharge adapter from being switched to a source (power supply). Also, for example, when the state of the battery pack is such that normal charging is not possible, it is possible to prevent the charge / discharge adapter from being switched to a sink (power reception). [Brief description of the drawings]

[0012] [Figure 1] 2 is a perspective view showing the appearance of a battery pack and a charge / discharge adapter; FIG. [Diagram 2] FIG. 2 is a block diagram showing an electrical configuration of the charge / discharge adaptor. [Diagram 3] 10 is an explanatory diagram illustrating the relationship between the operation mode of the charge / discharge adapter and a swap operation in response to a swap request. [Figure 4] FIG. 4A is an explanatory diagram showing a swap operation in response to a swap request made by pressing a button, and FIG. 4B is an explanatory diagram showing a swap operation in response to a swap request from an external device. [Diagram 5] 5 is a flowchart showing a control process executed by the MCU and the battery pack when the charge / discharge adapter is in a charge mode. [Figure 6] 10 is a flowchart showing a control process executed by the DRP-IC and an external device when the charge / discharge adapter is in a charge mode. [Figure 7] 5 is a flowchart showing a control process executed by the MCU and the battery pack when the charge / discharge adapter is in a discharge mode. [Figure 8] 10 is a flowchart showing a control process executed by the DRP-IC and an external device when the charge / discharge adaptor is in a discharge mode. [Figure 9] FIG. 11 is a block diagram showing an electrical configuration of a charge / discharge adaptor of a first modified example. [Figure 10] 13 is a flowchart showing a swap possibility determination process according to a fourth modified example. [Figure 11] FIG. 13 is an explanatory diagram showing the operation of the swap permission / prohibition determination in the fourth modified example. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0013] 1. Overview of the embodiment An embodiment may provide a charging / discharging adaptor having at least one of the following features 1 to 6. Feature 1: An external device connection section equipped with a power terminal for supplying or receiving power to or from an external device. Feature 2: A battery pack connection section having a battery terminal to which a rechargeable battery pack is connected and which charges or discharges the battery pack. Feature 3: A power path connecting the power terminal of the external device connection portion and the battery terminal of the battery pack connection portion. Feature 4: A power conversion unit that is provided in the power path and is configured to be capable of switching between converting power received from the external device into charging power for the battery pack, and converting power discharged from the battery pack into power supplied to the external device. Feature 5: A battery status detection unit that detects the status of the battery pack. Feature 6: A control unit configured to control switching of power supply / reception to the external device by the power conversion unit in accordance with the state of the battery pack detected by the battery state detection unit.

[0014] According to the charge / discharge adapter having at least the features 1 to 6, the control unit controls switching between power supply and power reception for the external device according to the state of the battery pack. Therefore, for example, when the power stored in the battery pack is low and power cannot be supplied to the external device, the charge / discharge adapter can be prevented from being switched to a source (power supply). Also, for example, when the battery pack is in a state where it cannot be charged, the charge / discharge adapter can be prevented from being switched to a sink (power reception).

[0015] An embodiment may provide a charging / discharging adapter having the following feature 7 and / or the following feature 8. Feature 7: When the control unit is in a charging mode in which the power conversion unit converts the received power into the charging power, the control unit is configured to determine, based on a state of the battery pack, whether or not it is possible to switch to a discharging mode in which the power conversion unit converts the discharging power into the feeding power, and to permit or prohibit switching to the discharging mode depending on a result of the determination. Feature 8: When in the discharging mode, the control unit is configured to determine whether or not switching to the charging mode is possible based on a state of the battery pack, and to prohibit or permit switching to the charging mode depending on the determination result.

[0016] According to the charge / discharge adapter having at least features 1 to 7, the control unit, when in the charge mode, determines whether or not the mode can be switched to the discharge mode based on the state of the battery pack, and permits or prohibits the mode from being switched to the discharge mode depending on the result of the determination. Therefore, when the battery pack cannot supply power to the external device, the charge / discharge adapter can be prevented from being switched to the source (power supply).

[0017] Furthermore, in a charging / discharging adapter having at least features 1 to 8, the control unit, when in the discharging mode, determines whether or not switching to the charging mode is possible based on the state of the battery pack, and prohibits or permits switching to the charging mode depending on the result of the determination. This makes it possible to prevent the charging / discharging adapter from being switched to the sink (power receiving) mode when the battery pack is in a state where it cannot be charged.

[0018] Next, an embodiment may provide a charging / discharging adaptor having at least one of the following features 9 to 11. Feature 9: The external device connection unit includes an input / output terminal configured to input / output an adjustment signal required for switching between the power supply and the power reception between the external device and the external device. Feature 10: The control unit includes a power supply / power reception switching unit configured to switch to a state in which the power supply to the external device or the power reception from the external device can be performed by inputting or outputting the adjustment signal between the control unit and the external device via the input / output terminal. Feature 11: The control unit includes a main control unit configured to control the switching of the power supply / reception by the power supply / reception switching unit in accordance with the state of the battery pack detected by the battery state detection unit.

[0019] According to the charging / discharging adapter having at least Features 1 to 6 and Features 9 to 11, the power supply / receiving switching unit inputs / outputs an adjustment signal between the external device and the charging / discharging adapter via the input / output terminal, thereby switching to a state in which power can be supplied to the external device or power can be received from the external device. Therefore, the power supply / receiving switching unit can set the operation mode of the charging / discharging adapter to either the discharging mode or the charging mode.

[0020] Furthermore, the main control unit controls the power supply / receiving switching unit to switch between power supply and power reception according to the state of the battery pack detected by the battery state detection unit. Therefore, if the state of the battery pack is such that the operation mode cannot be switched from charging to discharging or from discharging to charging, the main control unit can prohibit the power supply / receiving switching unit from switching the operation mode. Therefore, this charging / discharging adapter can smoothly switch between power supply and power reception with an external device.

[0021] Also, an embodiment may provide a charging / discharging adapter having the following feature 12 and / or the following feature 13. Feature 12: The power supply / receiving switch may be operated externally via an operation unit configured to input a command to switch between power supply and power receiving. Feature 13: When the operation unit is operated, the main control unit is configured to instruct the power supply / receiving switching unit to switch between the power supply and the power receiving in accordance with a state of the battery pack.

[0022] According to the charge / discharge adapter having at least Features 1 to 6 and Features 9 to 13, when the operation unit is operated, the main control unit instructs the power supply / receiving switching unit to switch between power supply and power reception according to the state of the battery pack.

[0023] Therefore, the user can operate the operation unit to cause the power supply / receiving switching unit to switch between power supply and power reception. In addition, the switching is performed only when switching from discharging to charging or from charging to discharging is possible depending on the state of the battery pack, so that the power supply / receiving switching can be performed more smoothly.

[0024] Next, an embodiment may provide a charging / discharging adapter having the following features 14: Feature 14: The main control unit is configured to determine whether or not the power supply / receiving switching is possible depending on a state of the battery pack, and to output a switching possibility signal indicating whether or not the power supply / receiving switching is possible to the power supply / receiving switching unit depending on the determination result.

[0025] According to a charging / discharging adapter having at least Features 1 to 6, Features 9 to 11, and Features 14, a main control unit outputs a switching possibility signal indicating whether or not the state of the battery pack is capable of switching between power supply / reception to a power supply / reception switching unit.

[0026] Therefore, when the power supply / receiving switching unit receives a power supply / receiving switching request from an external device, the power supply / receiving switching unit determines whether or not switching is possible based on the switching possibility signal from the main control unit, and can perform the power supply / receiving switching if switching is possible. This makes it possible to more appropriately perform the power supply / receiving switching.

[0027] Also, an embodiment may provide a charging / discharging adapter having the following features 15: Feature 15: The battery state detection unit is configured to detect a voltage of the battery pack.

[0028] In a charging / discharging adapter having at least Features 1 to 6 and 15, the battery state detection unit detects the voltage of the battery pack. Therefore, the control unit can control switching between power supply and power reception for an external device in accordance with the voltage of the battery pack.

[0029] Therefore, for example, when the voltage of the battery pack is low and power cannot be normally supplied from the battery pack to an external device, the charge / discharge adapter can be prevented from being switched to a source (power supply).

[0030] Also, an embodiment may provide a charging / discharging adapter having the following feature 16 and / or the following feature 17. Feature 16: The battery pack connection portion includes a communication terminal for communicating with the battery pack. Feature 17: The battery state detection unit is configured to acquire the state of the battery pack by communicating with the battery pack via the communication terminal.

[0031] According to a charging / discharging adapter having at least features 1 to 6 and features 16 and 17, the control unit can control switching between power supply and power reception to an external device depending on the state of the battery pack acquired by the battery state detection unit through communication with the battery pack.

[0032] Additionally, an embodiment may provide a charging / discharging adapter having the following features 18: Feature 18: When switching from a charge mode in which the power conversion unit converts the received power into the charging power to a discharge mode in which the power conversion unit converts the discharge power into the power supplying power, the control unit is configured to open a communication terminal of the battery pack connection unit for a predetermined time before switching, thereby returning the battery pack to an initial state.

[0033] According to a charging / discharging adapter having at least features 1 to 6 and feature 18, when the battery pack is connected to the communication terminal of the battery pack connection section, the battery pack can be switched from an initial state in which the battery power is discharged to a chargeable state in which charging is possible, and when the battery pack is in the chargeable state and the connection with the communication terminal is released, the battery pack is configured to return to the initial state, whereby the control unit can appropriately control switching between supplying and receiving power to an external device.

[0034] Next, an embodiment may provide a charging / discharging adapter having the following feature 19 and / or the following feature 20. Feature 19: The device includes an alarm unit that notifies the surrounding area of ​​the control state of the control unit. Feature 20: The control unit is configured to notify, via the notification unit, when the switching between power supply and power reception for the external device cannot be performed.

[0035] According to the charging / discharging adapter having at least Features 1 to 6 and Features 19 and 20, when the control unit cannot switch between power supply and power reception for the external device, the control unit notifies the user through the notification unit. This allows the user to detect that the charging / discharging adapter cannot switch between power supply and power reception for the external device through the notification unit, thereby improving the usability of the charging / discharging adapter.

[0036] Also, an embodiment may provide a charging / discharging adapter having the following features 21. Feature 21: The battery pack connection portion is provided in an attachment portion to which the battery pack is detachably attached, and the battery terminal is electrically connected to the battery pack when the battery pack is attached to the attachment portion.

[0037] According to a charging / discharging adapter having at least Features 1 to 6 and 21, a battery pack can be attached to the attachment portion of the charging / discharging adapter. By attaching the battery pack to the attachment portion, the charging / discharging terminals of the battery pack can be connected to the battery terminals, so that the connection to the battery terminals can be performed extremely easily, improving the usability of the charging / discharging adapter.

[0038] Furthermore, in some embodiments, any combination of the above-mentioned features 1 to 21 may be used. In some embodiments, any of the above-mentioned features 1 to 21 may be excluded.

[0039] For example, the charging / discharging adapter of one embodiment includes: an external device connection unit including a power terminal for supplying or receiving power to or from an external device, and an input / output terminal configured to input / output an adjustment signal required for switching between the power supply / reception to / from the external device; a battery pack connection section including a battery terminal to which a rechargeable / dischargeable battery pack is connected and which charges or discharges the battery pack; a power path connecting the power terminal of the external device connection portion and the battery terminal of the battery pack connection portion; a power conversion unit that is provided in the power path and is configured to be able to switch between converting received power from the external device into charging power for the battery pack and converting discharged power from the battery pack into power to be supplied to the external device; An operation unit configured to input a power supply / receive switching command by an external operation; a power supply / reception switching unit configured to switch to a state in which the power supply to the external device or the power reception from the external device can be performed by inputting / outputting the adjustment signal between the external device and the power supply / reception switching unit via the input / output terminal; a main control unit configured to control switching of the power supply or the power reception by the power supply / power reception switching unit in response to the switching command input from the operation unit; The device may include:

[0040] 2. Specific Exemplary Embodiments Exemplary embodiments of the present disclosure will now be described with reference to the drawings. [Embodiment] As shown in FIG. 1, the charging / discharging adapter 4 of this embodiment comprises an adapter body 8 having an attachment section 6 to which a battery pack 2 is detachably attached, and a hook 9 for attaching the adapter body 8 to a user's belt or an external device 50 (see FIG. 4), etc.

[0041] 2, the attachment section 6 is provided with a battery pack connection section 20 having battery terminals 20A that are connected to the positive and negative electrodes of a battery housed in the battery pack 2 and are used to charge or discharge the battery pack 2. The battery pack connection section 20 also has a communication terminal 20B for communicating with a charge / discharge circuit housed in the battery pack 2.

[0042] The adapter body 8 is also provided with an external device connection section 10, a button 12 as an operation section operated by the user, and an LED 14 included in a notification section 18 shown in Fig. 2. The notification section 18 is also provided with a speaker or buzzer that generates a notification sound (not shown), and the adapter body 8 is also provided with a slit 16 for outputting the notification sound to the outside.

[0043] The button 12 is a normally open push button switch that closes the contacts when pressed by the user. However, since the button 12 is an operation unit of the present disclosure that only needs to be able to detect an operation by the user, a changeover switch that changes the open / closed state of the contacts by an operation by the user may be provided instead of the button 12.

[0044] The external device connection unit 10 is composed of the above-mentioned USB-C terminal, and by connecting the external device 50 to the external device connection unit 10 via a specified cable, it is possible to input and output signals between the external device 50, and to supply power to and receive power from the external device 50.

[0045] For this reason, as shown in FIG. 2, the external device connection unit 10 is provided with a power terminal 10A for supplying or receiving power to or from the external device 50, and an input / output terminal 10B for inputting or outputting various signals to or from the external device 50.

[0046] The external device 50 is an electronic device that has a USB-C terminal similar to the external device connection unit 10, and can switch between supplying and receiving power with the charging / discharging adapter 4 by connecting this USB-C terminal to the external device connection unit 10 via a specified cable.

[0047] Examples of external device 50 include portable information terminal devices with built-in batteries, such as laptop computers, tablet terminals, and smartphones, mobile batteries with USB-C terminals, and other charging and discharging adapters.

[0048] 2, the power terminal 10A of the external device connection unit 10 and the battery terminal 20A of the battery pack connection unit 20 are connected by a power path 21. A bidirectional DC / DC conversion circuit 30 is provided in the power path 21 as a power conversion unit of the present disclosure.

[0049] The bidirectional DC / DC conversion circuit 30 is a step-up / step-down circuit that can switch between converting received power from the external device 50 into charging power for the battery pack 2, or converting discharged power from the battery pack 2 into power supplied to the external device 50.

[0050] Load switches 22, 24 for connecting and disconnecting the power path 21 are provided between the bidirectional DC / DC conversion circuit 30 and the power terminal 10A, and between the bidirectional DC / DC conversion circuit 30 and the battery terminal 20A, respectively.

[0051] 2, the power path 21 is shown as a single path, but in reality, it is composed of two paths that respectively connect the positive and negative electrodes of the battery stored in the battery pack 2 to the positive and negative power lines of the external device 50. Therefore, the power terminal 10A of the external device connection unit 10 and the battery terminal 20A of the battery pack connection unit 20 each include a pair of two terminals, a positive and a negative terminal.

[0052] However, the negative terminals of the power terminal 10A and the battery terminal 20A are connected to the ground which is the reference potential of the charge / discharge adapter 4, and the power path 21 may be provided to connect the positive terminals of the power terminal 10A and the battery terminal 20A to each other. Also, a plurality of input / output terminals 10B of the external device connection unit 10 and a plurality of communication terminals 20B of the battery pack connection unit 20 are provided according to the types of signals to be transmitted.

[0053] The switching of power supply / reception to the external device 50 by the bidirectional DC / DC conversion circuit 30 is controlled by a control unit 42 including a DRP-IC 32 as a power supply / reception switching unit and an MCU 40 as a main control unit.

[0054] The DRP-IC 32 is intended to input and output adjustment signals between the external device 50 via the input / output terminal 10B of the external device connection unit 10, thereby causing the power terminal 10A to function as a power supply terminal to the external device 50 or a power receiving terminal from the external device 50.

[0055] That is, the DRP-IC 32 is an integrated circuit that switches power supply / reception to the external device 50 in accordance with USBPD (USB Power Delivery), which is a power supply standard compatible with a USB-C terminal, between the DRP-IC 32 and the external device 50 connected to the external device connection unit 10. Note that this switching is called a "Power Role Swap," and therefore in the following description, the switching of power supply / reception is also referred to as a "swap."

[0056] The MCU 40 is a microcontroller unit including a CPU, a ROM, a RAM, etc., and controls switching between power supply and power reception by the DRP-IC 32 according to the state of the battery pack 2 (hereinafter referred to as the battery state).

[0057] For this reason, the charging / discharging adapter 4 of this embodiment is provided with a voltage detection circuit 36 ​​that detects the voltage of the battery pack 2 (hereinafter, referred to as pack voltage) as a battery state detection unit that detects the battery state. Then, the MCU 40 obtains the pack voltage detected by the voltage detection circuit 36 ​​and determines whether the battery pack 2 is in a state in which it can switch between power supply and power reception.

[0058] The charge / discharge adapter 4 of this embodiment also includes a battery interface (hereinafter, battery I / F) 34 connected to the communication terminal 20B of the battery pack connection unit 20. Therefore, by communicating with the battery pack 2 via the battery I / F 34, the MCU 40 can obtain battery states other than the pack voltage, such as the temperature of the battery pack 2, the voltage of the battery cell, SOC (State Of Charge), and the time elapsed since the completion of full charging, and can also determine whether the battery pack 2 is in a state in which it can switch between power supply and power reception.

[0059] The MCU 40 detects that the battery pack 2 is connected to the battery pack connection unit 20 from the pack voltage detected by the voltage detection circuit 36, and turns on the load switch 24 and operates the battery I / F 34. The DRP-IC 32 also detects that the external device 50 is connected to the external device connection unit 10 from an input from the power terminal 10A or the input / output terminal 10B of the external device connection unit 10, and turns on the load switch 22.

[0060] The charge / discharge adaptor 4 also includes a control power supply circuit 38 that generates a power supply voltage to be supplied to the DRP-IC 32 and the MCU 40. The control power supply circuit 38 receives DC voltage from the power path 21 between the load switch 22 on the external device connection unit 10 side and the bidirectional DC / DC conversion circuit 30, and from the battery terminal 20A of the battery pack connection unit 20, and generates a constant power supply voltage from this DC voltage. Therefore, the DRP-IC 32 and the MCU 40 can operate stably with the power supply voltage supplied from the control power supply circuit 38.

[0061] Note that the control power supply circuit 38 cuts off the input of DC voltage from the battery terminal 20A when charging the battery pack 2. This is to suppress fluctuations in the charging current caused by the operation of the control power supply circuit 38 when charging the battery pack 2.

[0062] A load switch 26 is connected to the output path of the power supply voltage from the control power supply circuit 38 to the DRP-IC 32 and the MCU 40. This load switch 26 is provided to suppress a delay in the start of power supply to the external device 50 caused by a delay in the switching operation of the bidirectional DC / DC conversion circuit 30 when the DRP-IC 32 switches the power terminal 10A from receiving to supplying power to start supplying power to the external device 50.

[0063] That is, when the DRP-IC 32 starts supplying power to the external device 50, the load switch 26 is switched to the on state and supplies the power supply voltage generated by the control power supply circuit 38 to the power path 21 between the load switch 22 and the bidirectional DC / DC conversion circuit 30. As a result, when the power terminal 10A is switched from receiving to supplying power, power can be supplied to the external device 50 with the power supply voltage generated by the control power supply circuit 38 until the bidirectional DC / DC conversion circuit 30 is able to supply power to the external device 50.

[0064] The charging / discharging adapter 4 of this embodiment configured as described above can switch the operation mode between the discharging mode and the charging mode shown in FIG. 3 by the power supply / receiving switching operation (hereinafter also referred to as the swap operation) by the DRP-IC 32.

[0065] Here, the charging mode is an operation mode in which the bidirectional DC / DC conversion circuit 30 converts the received power from the external device 50 into charging power for the battery pack 2. In this operation mode, the role of the charging / discharging adapter 4 is a "sink" for the external device 50, and the role of the external device 50 is a "source" for the charging / discharging adapter 4.

[0066] The discharge mode is an operation mode in which the bidirectional DC / DC conversion circuit 30 converts the discharge power from the battery pack 2 into power to be supplied to the external device 50. In this operation mode, the role of the charge / discharge adapter 4 is the “source” and the role of the external device 50 is the “sink”.

[0067] 3, when the charging / discharging adapter 4 is in the charging mode, if the button 12 is operated (pressed) to input a switching request (hereinafter also referred to as a swap request), a swap operation A for changing the role is performed. Also, when the charging / discharging adapter 4 is in the charging mode, if a swap request is input from the external device 50, a swap operation B for changing the role is performed.

[0068] Furthermore, when the charging / discharging adapter 4 is in the discharging mode, if the button 12 is pressed and a swap request is input, a swap operation C for role change is performed. Furthermore, when the charging / discharging adapter 4 is in the discharging mode, if a swap request is input from the external device 50, a swap operation D for role change is performed.

[0069] Of the above four swap operations A to D, swap operations A and C are operations for changing the role when button 12 is pressed, and therefore, power supply / reception with external device 50 is switched due to the operation of MCU 40.

[0070] Specifically, as shown in FIG. 4A, (step 1) a user presses button 12 to input a swap request, and (step 2) MCU 40 determines whether or not switching (swapping) between power supply and power reception is possible based on the battery state.

[0071] Then, when the MCU 40 determines that swapping is possible, it stops the charging current to the battery pack 2 (step 3), and instructs the DRP-IC 32 to swap (step 4). Note that the stopping of the charging current in (step 3) is performed when the operating mode is the charging mode and charging current is being supplied to the battery pack 2. Also, when the MCU 40 determines in (step 2) that swapping is not possible, it stops operations from (step 3) onwards.

[0072] When the DRP-IC 32 receives a swap instruction from the MCU 40, it (step 5) outputs a swap request to the external device 50, and (step 6) executes a power supply / power reception switch (swap) by inputting / outputting an adjustment signal between the DRP-IC 32 and the external device 50.

[0073] Then, when the swap with the external device 50 is successful, (step 7) the DRP-IC 32 outputs a swap completion interrupt to the MCU 40 to notify the MCU 40 of the success of the swap.

[0074] On the other hand, the swap operations B and D are operations performed when a swap request is input from the external device 50, and therefore, the power supply / reception with the external device 50 is switched due to the operation of the DRP-IC 32.

[0075] Specifically, as shown in FIG. 4B, (step 1) when a swap request is input from an external device 50 to the DRP-IC 32, (step 2) the DRP-IC 32 determines whether or not a swap is possible based on the swap possibility signal input from the MCU 40.

[0076] Then, when the DRP-IC 32 determines that swapping is possible, it stops the charging current to the battery pack 2 (step 3), and executes the swap by inputting and outputting an adjustment signal between the DRP-IC 32 and the external device 50 (step 4).

[0077] Furthermore, when the swap with the external device 50 is successful, the DRP-IC 32 outputs a swap completion interrupt to the MCU 40 (step 5) to notify the MCU 40 of the success of the swap. Note that the stopping of the charging current in step 3 is performed when the operating mode is the charging mode and the charging current is being supplied to the battery pack 2, similar to the swap operation shown in FIG. 4A.

[0078] Next, the control processes executed by the MCU 40 and the DRP-IC 32 to perform the above four swap operations A to D will be described with reference to the flowcharts shown in FIGS.

[0079] 5 and 6 are flowcharts showing swap operations A and B when the charge / discharge adapter 4 is in the charge mode (role: sink). Specifically, Fig. 5 shows the control process executed by the MCU 40 together with the control process on the battery pack 2 side, and Fig. 6 shows the control process executed by the DRP-IC 32 together with the control process on the external device 50 side.

[0080] 5, when the charge / discharge adapter 4 is in the charge mode, in S110, the MCU 40 performs periodic communication during charging with the battery pack 2. Note that in this periodic communication, the state of the battery pack 2 (for example, the battery temperature, the voltage of the battery cell, the SOC, the time elapsed since the completion of full charge, etc.) is monitored.

[0081] Next, in S120, the pack voltage is obtained from the voltage detection circuit 36, and in S130, a swap permission determination is made by determining whether the pack voltage is sufficient to supply power to the external device 50. Then, in S140, a swap permission signal is output to the DRP-IC 32 in accordance with the result of the determination in S130, and the process proceeds to S150.

[0082] In S150, it is determined whether or not button 12 has been pressed. If button 12 has been pressed, it is determined that a swap request has been input by the user, and the process proceeds to S160, where it is determined whether or not battery pack 2 is in a swappable state in which it is capable of supplying power to external device 50.

[0083] For this determination, the determination result in S130 can be used. In addition to the determination result in S130, the battery temperature, the battery cell voltage, the SOC, the elapsed time from the completion of full charge, and the like obtained in the periodic communication during charging in S110 can also be used.

[0084] If it is determined in S160 that swapping is possible, the process proceeds to S180, where the charging current output from the bidirectional DC / DC conversion circuit 30 to the battery pack 2 is stopped, and the process proceeds to S190. If it is determined in S160 that swapping is not possible (i.e., not possible), the process proceeds to S170, where a notification that swapping is not possible is issued, for example, by blinking the LED 14 of the notification unit 18 a predetermined number of times, and the process proceeds to S110.

[0085] The notification in S170 may be made by sounding a buzzer provided in the notification unit 18 or by outputting audio from a speaker, instead of by blinking the LED 14, or may be made by a combination of these.

[0086] Next, in S190, a swap instruction is output to the DRP-IC 32, thereby starting swap processing by the DRP-IC 32. Then, in the following S200, the process waits for input of a swap completion interrupt from the DRP-IC 32, which is output when the swap processing is completed.

[0087] If it is determined in S200 that a swap completion interrupt has been input, the process proceeds to S210, where status confirmation communication is performed with the DRP-IC 32. Then, in S220, it is determined whether or not it has been confirmed in the status confirmation communication in S210 that the swap was successful, and if the swap failed, the process proceeds to S230, and if the swap was successful, the process proceeds to S240.

[0088] In S230, since the swap has failed, for example, the LED 14 of the notification unit 18 is caused to flash a predetermined number of times to notify the user of the failure of the swap, and the process proceeds to S110. Note that the notification in S230 may be performed by sounding a buzzer provided in the notification unit 18 or by outputting audio from a speaker, instead of flashing the LED 14, as in the notification in S170 described above, or may be performed by a combination of these.

[0089] In S240, since the swap is successful, the operation mode of the charge / discharge adapter 4 is switched to the discharge mode. Note that this switching is performed by reversing the direction of conversion of the DC voltage by the bidirectional DC / DC conversion circuit 30.

[0090] Then, in S250, the DT terminal, which is one of the communication terminals 20B of the battery pack connection unit 20, is disconnected and opened for a predetermined time, thereby switching the operation mode of the battery pack 2 from the charge mode to the discharge mode.

[0091] That is, the battery pack 2 is configured to be switchable from an initial state (discharge mode) in which the battery power is discharged to a charge mode when a DT terminal provided as one of the communication terminals 20B is connected to the battery pack connection section 20. In addition, the battery pack 2 is configured to cut off the connection to the DT terminal for a certain period of time in order to switch from the charge mode to the discharge mode, which is the initial state.

[0092] Therefore, in S250, the DT terminal of the battery pack connection unit 20 is opened for a predetermined time to cut off the connection with the battery pack 2, and the operation mode of the battery pack 2 is switched from the charge mode to the discharge mode.

[0093] Therefore, in the control process executed in the charging / discharging circuit of the battery pack 2 when the battery pack 2 is in the charging mode, after performing periodic communication with the MCU 40 during charging in S62, it is determined in S64 whether or not the DT terminal is connected.

[0094] If it is connected to the DT terminal, the process proceeds to S62 and regular communication during charging is performed, and if it is not connected to the DT terminal (i.e., if the DT terminal of the battery pack connection unit 20 has been open for a certain period of time or more), the process proceeds to S66 and switches to the discharge mode.

[0095] Next, in the control process executed by the MCU 40, if it is determined in S150 that the button 12 is not pressed, the process proceeds to S260, where it is determined whether or not a swap completion interrupt has been input from the DRP-IC 32.

[0096] That is, a swap request may be input from the external device 50 to the DRP-IC 32, and swap processing may be performed between the DRP-IC 32 and the external device 50. For this reason, in S260, by determining whether a swap completion interrupt has been input from the DRP-IC 32, it is determined whether the swap processing based on the swap request input from the external device 50 has been completed.

[0097] Then, if it is determined in S260 that the swap completion interrupt has not been input, the process proceeds to S110, and if it is determined in S260 that the swap completion interrupt has been input, the process proceeds to S210.

[0098] Therefore, even when a swap request is input from the external device 50 to the DRP-IC 32 and the swap process is executed, it is possible to determine whether the swap is successful or not, and if the swap is successful, to switch the charge / discharge adapter 4 from the charge mode to the discharge mode.

[0099] Next, as shown in FIG. 6, in the control process executed by the DRP-IC 32 when the charge / discharge adapter 4 is in the charge mode, first, in S310, it is determined whether or not swapping is possible based on the swap possibility signal transmitted from the MCU 40.

[0100] If it is determined in S310 that swapping is not possible, the determination process of S310 is executed again, and if it is determined in S310 that swapping is possible, the process proceeds to S320, where it is determined whether a swap request has been input from the external device 50.

[0101] The swap request determined in S320 is a swap request output from the external device 50 to the DRP-IC 32 when a swap command is input from the outside on the external device 50 side. That is, in the control process executed by the external device 50, it is determined in S500 whether or not a swap command has been input from the outside by a user's operation, etc. Then, if it is determined in S500 that a swap command has been input, a swap request is output to the DRP-IC 32 in S510, and the process proceeds to S550.

[0102] For this reason, in S320, it is determined whether or not a swap request has been input from the external device 50, and if it is determined that a swap request has been input from the external device 50, the process proceeds to S330, where a "response" indicating that the swap request has been received is transmitted to the external device 50. Then, once the "response" has been transmitted in S330, the process proceeds to S360.

[0103] The "answer" from the DRP-IC 32 includes information "accept" indicating that the swap request has been accepted, or "reject" indicating that the swap request has been rejected. Therefore, the external device 50 can determine whether the DRP-IC 32 is capable of swapping by determining whether the information included in the "answer" from the DRP-IC 32 is "accept".

[0104] However, in the DRP-IC 32, when it is determined in S310 that swapping is possible, the process of S320 is executed, so that the information contained in the "answer" from the DRP-IC 32 is usually "accept".

[0105] Next, in the control process executed by the DRP-IC 32, if it is determined in S320 that a swap request has not been input from an external device, the process proceeds to S340 to determine whether or not a swap instruction has been input from the MCU 40. Then, if it is determined in S340 that a swap instruction has not been input from the MCU 40, the process proceeds to S310.

[0106] On the other hand, if the DRP-IC 32 determines in S340 that a swap instruction has been input from the MCU 40, the process proceeds to S350, where a swap request is output to the external device 50, and the process proceeds to S360.

[0107] On the other hand, when it is determined in S500 that a swap command has not been inputted, the external device 50 proceeds to S520 and determines whether or not a swap request has been inputted from the DRP-IC 32.

[0108] If it is determined in S520 that a swap request has not been input from the DRP-IC 32, the process proceeds to S500, and if it is determined in S520 that a swap request has been input from the DRP-IC 32, the process proceeds to S530.

[0109] In S530, a swap acceptance determination process is executed to determine whether or not the role of the external device 50 can be changed from "source" to "sink" by accepting the swap request from the DRP-IC 32 based on the state of the external device 50.

[0110] Then, in the next S540, based on the result of the determination in S530, information indicating whether or not the role can be changed is output to the DRP-IC32 as a "response" to the swap request from the DRP-IC32.

[0111] In addition, this "answer" includes information indicating the result of the determination, such as "accept", which indicates that the role can be changed and the swap request has been accepted, or "reject", which indicates that the role cannot be changed and the swap request has been rejected.

[0112] Therefore, the DRP-IC 32 can determine whether the external device 50 is swappable by determining whether the information included in the "answer" from the external device 50 is "accept."

[0113] Next, in the control processing executed by the DRP-IC 32, in S360, the "answer" sent to the external device 50 in S330 or the "answer" sent from the external device 50 in response to the swap request sent in S350 is acquired.

[0114] In addition, in S360, it is determined whether the information included in the acquired "answer" is "accept" to thereby determine whether both the DRP-IC 32 and the external device 50 are swappable.

[0115] If it is determined in S360 that swapping is not possible, the process proceeds to S430, where a swap completion interrupt is output to the MCU 40. Then, in the following S440, status confirmation communication is executed with the MCU 40 to notify that swapping is not possible, in other words, that swapping has failed.

[0116] On the other hand, if it is determined in S360 that both the DRP-IC 32 and the external device 50 are swappable, in S370 to S420, a swap process is executed to change the roles between the DRP-IC 32 and the external device 50 and switch the direction of power supply / receive, and then the process proceeds to S430.

[0117] Then, in S430, a swap completion interrupt is output to the MCU 40, and in the following S440, status confirmation communication is executed with the MCU 40 to notify that the swap has been successful.

[0118] Next, in the control process executed by the external device 50, in S550, the "answer" sent to the DRP-IC 32 in S540 or the "answer" sent from the DRP-IC 32 in response to the swap request sent in S510 is obtained.

[0119] In addition, in S550, it is determined whether the information included in the acquired "answer" is "accept" to thereby determine whether both the DRP-IC 32 and the external device 50 are swappable.

[0120] If it is determined in S550 that both the DRP-IC 32 and the external device 50 are swappable, swap processing is executed in S560 to S580 and S420 to change the roles between the DRP-IC 32 and the external device 50 and switch the power supply / receive direction. If it is determined in S550 that swapping is not possible, the swap processing is not executed and the process returns to S500.

[0121] The swap process executed by the DRP-IC 32 and the external device 50, including the processes of S330, S360, and S540, is defined by power supply standards such as USBPD. Therefore, in this embodiment, the swap process will be briefly described.

[0122] That is, in the DRP-IC 32, in S370, the charging current output from the bidirectional DC / DC conversion circuit 30 to the battery pack 2 is stopped. The process of S370 is executed when there is a swap request from the external device 50. This is because when there is a swap instruction from the MCU 40, the charging current has already been stopped in S180 of the control process executed on the MCU 40 side. Then, in the following S380, power consumption on the DRP-IC 32 side is turned off.

[0123] Meanwhile, in the external device 50, in S560, the VBUS, which is the power line supplying power to the DRP-IC 32 side, is turned off, and in the following S570, the role of the external device 50 is changed to "sink." Then, in the following S580, a power OK communication is performed to notify the DRP-IC 32 that the VBUS has been turned off.

[0124] When the DRP-IC 32 turns off power consumption in S380, it confirms the role change on the external device 50 side by a power OK communication from the external device 50, and proceeds to S390. Then, in S390, it turns on the load switch 26 and sets VBUS to the on state of the specified voltage of 5V from the battery pack 2 via the control power supply 38, thereby enabling power supply to the external device 50, and in S400, it changes the role of the DRP-IC 32 to "source".

[0125] In this embodiment, the load switch 26 is provided and turned on when starting power supply to the external device 50 to suppress a delay in starting power supply to the external device 50, but it is not essential to provide the load switch 26. In other words, when starting power supply to the external device 50, VBUS may be set to the specified voltage of 5 V only by the operation of the bidirectional DC / DC conversion circuit 30.

[0126] In the next step S410, a power OK communication is performed to notify the external device 50 that VBUS has been turned on. Finally, in step S420, power negotiation is performed with the external device 50 to adjust the power supply, etc. In the above swap process, the signal (information) transmitted and received between the DRP-IC 32 and the external device 50 corresponds to the adjustment signal of the present disclosure.

[0127] Next, swap operations C and D when the charge / discharge adapter 4 is in the discharge mode (role: source) will be described with reference to the flowcharts shown in Fig. 7 and Fig. 8. Fig. 7 shows the control process executed by the MCU 40 together with the control process on the battery pack 2 side, and Fig. 8 shows the control process executed by the DRP-IC 32 together with the control process on the external device 50 side.

[0128] 7, when the charge / discharge adapter 4 is in the discharge mode, in S115, the MCU 40 performs periodic communication during discharging with the battery pack 2. Note that in this periodic communication, the state of the battery pack 2 (e.g., battery temperature) is monitored, similarly to S110 in FIG.

[0129] After the periodic communication in S115, the processes of S120 to S170 and S260 are executed in the same manner as the control process shown in Fig. 5. If it is determined in S160 that swapping is possible, the process proceeds to S190, where a swap instruction is output to the DRP-IC 32, thereby starting swap processing by the DRP-IC 32.

[0130] After the process of S190 is executed, the processes of S200 to S230 are executed in the same manner as the control process shown in FIG. 5, and if it is determined in S220 that the swap has been successful, the process proceeds to S280.

[0131] In S280, since the swap is successful, the operation mode of the charge / discharge adapter 4 is switched to the charge mode. This switching is performed by reversing the direction of DC voltage conversion by the bidirectional DC / DC conversion circuit 30. Then, in the following S290, initial charge communication is performed with the battery pack 2 to notify that the operation mode of the charge / discharge adapter 4 has been switched from the discharge mode to the charge mode.

[0132] In contrast, in the control processing executed in the charge / discharge circuit of the battery pack 2 when the battery pack 2 is in the discharge mode, in S72, regular communication during discharging is performed with the MCU 40, and then in S74, it is determined whether or not there has been an initial charging communication from the MCU 40.

[0133] Then, if it is determined in S74 that there has been no initial charging communication, the process proceeds to S72 where regular communication during discharging is carried out, and if it is determined in S74 that there has been initial charging communication, the process proceeds to S76 where the operating mode of the battery pack 2 is switched to the charging mode.

[0134] Next, as shown in Fig. 8, when the charging / discharging adapter 4 is in the discharging mode, the control process executed by the DRP-IC 32 executes the processes of S310 to S360 in the same procedure as the control process shown in Fig. 6. Also, in response to the processes of S310 to S360 executed by the DRP-IC 32, the external device 50 executes the processes of S500 to S550 in the same procedure as the control process shown in Fig. 6.

[0135] In the control process executed by the DRP-IC 32, when it is determined in S360 that both the DRP-IC 32 and the external device 50 are swappable, the process proceeds to S460, where the VBUS, which is the power line supplying power to the external device 50, is turned off. Then, in the following S470, the role of the DRP-IC 32 is changed to "sink", and further, in the following S480, a power OK communication is performed to notify the external device 50 that the VBUS has been turned off.

[0136] On the other hand, in the control process executed by the external device 50, if it is determined in S550 that both the DRP-IC 32 and the external device 50 are swappable, the power consumption on the external device 50 side is turned off in S610. After that, it is confirmed that the role has been changed on the DRP-IC 32 side by a power OK communication from the DRP-IC 32, and the process proceeds to S620.

[0137] In S620, VBUS is turned on at the specified voltage of 5V, thereby enabling power supply to the DRP-IC 32, and in S630, the role of the external device 50 is changed to "source." In addition, in the following S640, a power OK communication is performed to notify the DRP-IC 32 that VBUS has been turned on.

[0138] Finally, in the same manner as in the swap process shown in FIG. 6, power negotiation is performed with the DRP-IC 32 in S420 to adjust the power supply and the like, and the swap process is terminated.

[0139] After the swap process is completed, the control process executed by the DRP-IC 32 outputs a swap completion interrupt to the MCU 40 in S430, as in the control process shown in FIG.

[0140] As a result, the MCU 40 is notified that the swap on the DRP-IC 32 side has been successful or has failed, and if the swap is successful, the operating mode of the charge / discharge adapter 4 on the MCU 40 side is changed to the charge mode.

[0141] As described above, in the charging / discharging adapter 4 of this embodiment, when the user presses the button 12 on the adapter body 8 to input a swap command, or when a swap request is input from the external device 50, a swap process is performed to change the role together with the external device 50.

[0142] Furthermore, whether or not this swap process can be performed is determined based on the state of the battery pack 2 (pack voltage, battery temperature, etc.), and the swap process is performed only if it is possible. Therefore, for example, when the power stored in the battery pack 2 decreases due to discharging and the pack voltage becomes low, the operation mode of the charge / discharge adapter 4 can be prevented from being switched from the charge mode to the discharge mode.

[0143] Also, for example, even if the temperature of the battery pack 2 is high and normal charging is not possible, it is possible to prevent the operation mode of the charge / discharge adapter 4 from being switched from the discharge mode to the charge mode.

[0144] Therefore, according to the charge / discharge adapter 4 of the present embodiment, the role change between the charge / discharge adapter 4 and the external device 50 can be appropriately performed according to the state of the battery pack 2.

[0145] Furthermore, in this embodiment, the determination as to whether or not swapping is possible is made taking into consideration not only the state of the battery pack 2 but also the state of the external device 50, so that role change can be more appropriately performed.

[0146] Although one embodiment of the present disclosure has been described above, the present disclosure is not limited to the above-described embodiment and can be implemented in various modified forms. [First Modification] For example, in the above embodiment, the power path 21 connecting the power terminal 10A and the battery terminal 20A is described as being provided with the bidirectional DC / DC conversion circuit 30 as a power conversion unit. However, the power conversion unit of the present disclosure may be configured with a plurality of power conversion units including a charging DC / DC conversion circuit 30A and a discharging DC / DC conversion circuit 30B as shown in Fig. 9.

[0147] 9, the power path 21 connecting the power terminal 10A and the battery terminal 20A is divided into a power path 21A for charging from the external device 50 to the battery pack 2, and a power path 21B for discharging from the battery pack 2 to the external device 50. The charging DC / DC conversion circuit 30A is provided in the charging power path 21A, and the discharging DC / DC conversion circuit 30B is provided in the discharging power path 21B.

[0148] The charging DC / DC conversion circuit 30A is a step-up / step-down circuit that steps up or steps down the received power of +5V to +20V from the external device 50 to convert it into charging power for the battery pack 2. The discharging DC / DC conversion circuit 30B is a step-up / step-down circuit that steps up or steps down the discharge power from the battery pack 2 to supply power of +5V to +20V to convert it into supply power for the external device 50.

[0149] In the charging power path 21A, load switches 22, 24 are provided between the power terminal 10A and the charging DC / DC conversion circuit 30A, and between the charging DC / DC conversion circuit 30A and the battery terminal 20A, respectively. In the discharging power path 21B, a load switch 28 is provided between the power terminal 10A and the discharging DC / DC conversion circuit 30B.

[0150] When the external device 50 is connected to the external device connection unit 10, the battery pack 2 is connected to the battery pack connection unit 20, and the operation mode is the charging mode, the DRP-IC 32 and the MCU 40 turn on the load switches 22 and 24. In addition, in the charging mode, the DRP-IC 32 and the MCU 40 turn off the load switch 28 and operate the charging DC / DC conversion circuit 30A.

[0151] As a result, when the operation mode of the charge / discharge adapter 4 is the charge mode, the charging DC / DC conversion circuit 30A converts the power received from the external device 50 into charging power for the battery pack 2, and charges the battery pack 2.

[0152] Furthermore, when the external device 50 is connected to the external device connection unit 10, the battery pack 2 is connected to the battery pack connection unit 20, and the operation mode is the discharge mode, the DRP-IC 32 and the MCU 40 turn on the load switch 28. Furthermore, in the discharge mode, the DRP-IC 32 and the MCU 40 turn off the load switches 22 and 24 and operate the discharging DC / DC conversion circuit 30B.

[0153] As a result, when the operation mode of the charge / discharge adapter 4 is the discharge mode, the discharge DC / DC conversion circuit 30B converts the discharge power from the battery pack 2 into power to be fed to the external device 50, and supplies the power to the external device 50.

[0154] 9 can also switch between power supply and power reception with the external device 50, as in the above embodiment. In addition, the DRP-IC 32 and the MCU 40 can perform the same control process as in the above embodiment, thereby providing the same effect as in the above embodiment.

[0155] 9, the control power supply circuit 38 receives power from a power path 21A between the load switch 22 and the charging DC / DC conversion circuit 30A, and a power path 21B between the discharging DC / DC conversion circuit 30B and the battery terminal 20A, and generates a power supply voltage. Similarly to the above embodiment, the control power supply circuit 38 cuts off the input of DC voltage from the battery terminal 20A when charging the battery pack 2.

[0156] [Second modified example] In the above embodiment and the first modified example, the bidirectional DC / DC conversion circuit 30, the charging DC / DC conversion circuit 30A, and the discharging DC / DC conversion circuit 30B have been described as step-up and step-down circuits. However, each of these circuits may step-up or step-down depending on the voltage of the battery pack 2 (e.g., rated 10.8V, 14.4V, 18V, 36V, 64V, etc.) and the voltage output to the external device 50 (e.g., 5V, 9V, 15V, 20V, 48V, etc.). Therefore, the bidirectional DC / DC conversion circuit 30, the charging DC / DC conversion circuit 30A, and the discharging DC / DC conversion circuit 30B may be a so-called step-up and step-down converter, a step-up converter, or a step-down converter.

[0157] [Third Modification] In the above embodiment, the pack voltage acquired from the voltage detection circuit 36 ​​is used to determine whether or not swapping is possible in S130. However, the determination of whether or not swapping is possible may also be performed depending on a state of the battery pack 2 other than the pack voltage.

[0158] For example, when the battery temperature is below a predetermined temperature (eg, 0° C.), switching from the discharge mode to the charge mode is prohibited, thereby suppressing deterioration of the battery cells caused by charging the battery pack in a low temperature state.

[0159] Furthermore, when the battery temperature is equal to or higher than a predetermined temperature (for example, 60° C.), switching from the discharge mode to the charge mode is prohibited, thereby making it possible to suppress deterioration of the battery cells caused by charging the battery pack in a high-temperature state.

[0160] In addition, the determination of whether or not swapping is possible may be performed based on the battery cell voltage, SOC, the elapsed time since the battery was fully charged, etc., making it possible to appropriately switch from charge mode to discharge mode and from discharge mode to charge mode.

[0161] [Fourth Variation] For example, in S130 of the above embodiment, as illustrated in FIG. 10, when it is determined in S810 that the pack voltage is equal to or greater than the lower limit voltage, and when it is determined in S820 that the pack voltage is equal to or less than the upper limit voltage, the determination as to whether swapping is possible may be permitted.

[0162] In other words, as shown in FIG. 11, when the pack voltage is within a voltage range from a lower limit voltage Vth2 (e.g., 20 V) to an upper limit voltage Vth1 (e.g., 38 V), the swap feasibility determination is permitted, but outside this voltage range, the swap feasibility determination is prohibited in S860.

[0163] In this way, when the pack voltage (lower limit voltage Vth2 or lower) causes the battery pack 2 to be over-discharged, switching from the charge mode to the discharge mode is prohibited, thereby preventing breakdown of the battery pack. Also, when the pack voltage (upper limit voltage Vth1 or higher) causes the battery pack 2 to be nearly fully charged, switching from the discharge mode to the charge mode is prohibited, thereby preventing the battery pack from being accidentally charged.

[0164] Then, when the affirmative determination is made in S810 and S820 and the swap possibility determination is permitted, the swap possibility determination is performed according to the battery temperature, the battery cell voltage, and the SOC, as in the third modified example.

[0165] In FIG. 10, when positive judgments are made in S810 and S820, it is determined in S830 that the battery temperature is equal to or lower than the upper limit temperature, and when it is determined in S840 that the battery temperature is equal to or higher than the lower limit temperature, the swap feasibility determination is permitted.

[0166] Therefore, in the swap feasibility determination process of FIG. 10, when the pack voltage is within a predetermined voltage range and the battery temperature is within a predetermined temperature range, a swap feasibility determination is performed in S850 based on the battery cell voltage, SOC, etc. [Other embodiments] Next, in the above embodiment, the control unit 42 has been described as including the DRP-IC 32 as a power supply / receive switching unit and the MCU 40 as a main control unit. However, the control unit 42 may be configured as one control circuit configured by a microcomputer including a CPU, a ROM, a RAM, etc. Also, the control unit 42 may be configured as three or more control circuits that further separate the functions of the above-mentioned DRP-IC 32 and the MCU 40.

[0167] In addition, multiple functions possessed by one component in the above embodiments may be realized by multiple components, or one function possessed by one component may be realized by multiple components. Also, multiple functions possessed by multiple components may be realized by one component, or one function realized by multiple components may be realized by one component. Also, part of the configuration of the above embodiments may be omitted. Also, at least part of the configuration of the above embodiments may be added to or substituted for the configuration of another of the above embodiments.

[0168] In addition to the charge / discharge adapter, the present disclosure can also be realized in various forms, such as a system that includes a charge / discharge adapter as a component, a program for causing a computer to function as a charge / discharge adapter, a non-transient physical recording medium such as a semiconductor memory on which this program is recorded, and a method for switching the operating mode of a charge / discharge adapter. [Explanation of symbols]

[0169] 2...battery pack, 4...charging / discharging adapter, 10...external device connection section, 10A...power terminal, 20...battery pack connection section, 20A...battery terminal, 21...power path, 30...bidirectional DC / DC conversion circuit, 36...voltage detection circuit, 42...control section, 50...external device.

Claims

1. an external device connection unit including a power terminal for supplying and receiving power to and from an external device; a battery pack connection section including a battery terminal to which a rechargeable / dischargeable battery pack is connected and which charges or discharges the battery pack; a power path connecting the power terminal of the external device connection portion and the battery terminal of the battery pack connection portion; a power conversion unit that is provided in the power path and is configured to be able to switch between converting received power from the external device into charging power for the battery pack and converting discharged power from the battery pack into power to be supplied to the external device; a battery state detection unit that detects a state of the battery pack; a control unit configured to control switching of power supply / reception to the external device by the power conversion unit in accordance with a state of the battery pack detected by the battery state detection unit; Equipped with a charge / discharge adapter.

2. 2. The charge / discharge adaptor according to claim 1, wherein the control unit is configured to determine, when in a charging mode in which the power conversion unit converts the received power into the charging power, whether or not it is possible to switch to a discharging mode in which the power conversion unit converts the discharging power into the feeding power, based on a state of the battery pack, and to permit or prohibit switching to the discharging mode depending on a result of the determination.

3. 3. The charge / discharge adaptor according to claim 2, wherein the control unit is configured to determine, when in the discharge mode, whether or not switching to the charge mode is possible based on a state of the battery pack, and to prohibit or permit switching to the charge mode depending on a result of the determination.

4. the external device connection unit includes an input / output terminal configured to input / output an adjustment signal required for switching between the power supply and the power reception between the external device and the external device; The control unit is a power supply / reception switching unit configured to switch to a state in which the power supply to the external device or the power reception from the external device can be performed by inputting / outputting the adjustment signal between the external device and the power supply / reception switching unit via the input / output terminal; a main control unit configured to control switching of the power supply / reception by the power supply / reception switching unit in accordance with the state of the battery pack detected by the battery state detection unit; The charge / discharge adaptor according to any one of claims 1 to 3, further comprising:

5. An operation unit configured to input a power supply / receive switching command by an external operation, 5. The charge / discharge adaptor according to claim 4, wherein the main control unit is configured to instruct the power supply / receiving switching unit to switch between the power supply and the power receiving mode in accordance with a state of the battery pack when the operation unit is operated.

6. 5. The charging / discharging adaptor according to claim 4, wherein the main control unit is configured to determine whether or not the switching between power supply and power reception is possible depending on a state of the battery pack, and to output a switching possibility signal indicating whether or not the switching between power supply and power reception is possible to the power supply / power reception switching unit depending on the determination result.

7. 4. The charge / discharge adaptor according to claim 1, wherein the battery state detector is configured to detect a voltage of the battery pack.

8. the battery pack connection unit includes a communication terminal for communicating with the battery pack, The charge / discharge adapter according to any one of claims 1 to 3, wherein the battery state detection unit is configured to acquire a state of the battery pack by communicating with the battery pack via the communication terminal.

9. the battery pack is configured to be switchable from an initial state in which battery power is discharged to a chargeable state in which battery power can be charged when the battery pack is connected to a communication terminal of the battery pack connection section, and to return to the initial state when the battery pack is disconnected from the communication terminal while in the chargeable state; The charge / discharge adaptor according to any one of claims 1 to 3, wherein when switching from a charge mode in which the power conversion unit converts the received power into the charging power to a discharge mode in which the power conversion unit converts the discharge power into the supply power, the control unit is configured to open the communication terminal of the battery pack connection unit for a predetermined time before switching, thereby returning the battery pack to the initial state.

10. A notification unit that notifies the surroundings of a control state by the control unit, The charge / discharge adaptor according to any one of claims 1 to 3, wherein the control unit is configured to notify via the notification unit when the switching of the power supply / reception to the external device cannot be performed.

11. the battery pack connection portion is provided in an attachment portion to which the battery pack is detachably attached, and the battery terminal is electrically connected to the battery pack when the battery pack is attached to the attachment portion. The charge / discharge adaptor according to any one of claims 1 to 3.

Images