Charger and charging system

Abstract

To provide a charger and a charging system capable of limiting the number of chargers for charging a battery pack when a plurality of chargers is connected to a power supply path from an external power supply and suppressing current flowing through the power supply path.SOLUTION: A charger includes a housing to which a battery pack can be attached, a charging circuit, a control unit, a communication unit, and a determination unit. The determination unit determines whether or not the communication unit receives second charging information indicating a charging operation state from a second charger when the battery pack is attached to the housing and charging of the battery pack from the charging circuit is enabled, causes the control unit to wait for execution of the charging control when the communication unit is receiving the second charging information, and permits the control unit to execute the charging control when the communication unit is not receiving the second charging information.SELECTED DRAWING: Figure 3

Description

[Technical Field]

[0001] The present disclosure relates to a charger and a charging system for charging a battery pack. [Background technology]

[0002] Patent Document 1 discloses a charger that can charge a high-capacity battery pack with a nominal capacity of 5 Ah or more at a charging current rate of 2 C to 3 C. With this type of charger, for example, a high-capacity battery pack with a rated capacity of 8 Ah can be charged at a charging rate of 3 C, thereby reducing the charging time to 20 minutes or less. In other words, the time required to charge a high-capacity battery pack can be shortened. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Patent No. 6699078 Summary of the Invention [Problem to be solved by the invention]

[0004] Incidentally, when charging a battery pack with a rated capacity of 8Ah at a charge rate of 3C as mentioned above, if the rated voltage of the battery pack is 36V and the charging voltage is 40V, the charging current will be 24A, so the output from the charger will be 40V x 24A = 960W. Therefore, if the power conversion efficiency of the charger is 90% and the power factor is 1, the AC power consumption will be approximately 1100W, and when considering the AC 100V commercial power supply used in Japan, a maximum of 11A will flow per charger.

[0005] In contrast, the rated current of a typical household outlet in Japan is 15A, and the maximum current that can be supplied from one breaker to the outlet is 20A. Therefore, if multiple chargers like the one above are connected to an outlet that receives power from a single breaker and two or more of the chargers are used to charge a battery pack, the breaker will trip. This will cut off the power supply to each charger, and none of the chargers will be able to charge the battery pack.

[0006] One aspect of the present disclosure aims to provide a charger and charging system that, when multiple chargers are connected to a power supply path from an external power source, can limit the number of chargers that charge a battery pack, thereby suppressing the current flowing in the power supply path. [Means for solving the problem]

[0007] A charger according to one aspect of the present disclosure includes a housing capable of receiving a battery pack, a charging circuit, a control unit, a communication unit, and a determination unit. The charging circuit is configured to receive power from an external power source and generate charging power for the battery pack, and the control unit is configured to execute charging control for controlling the supply of charging power from the charging circuit to the battery pack. At least the charging circuit and the control unit are disposed within the housing.

[0008] The communication unit is configured to be able to communicate with an external second charger, and the determination unit determines whether or not to permit the control unit to execute charging control according to the communication result between the communication unit and the second charger.

[0009] Specifically, when the battery pack is attached to the housing and charging from the charging circuit to the battery pack becomes possible, the determination unit determines whether the communication unit has received second charging information representing the charging operation status from the second charger. When the communication unit has received the second charging information, the determination unit causes the control unit to wait for execution of charging control, and when the communication unit has not received the second charging information, the determination unit allows the control unit to execute charging control.

[0010] Therefore, according to the charger of the present disclosure, when the battery pack is attached to the housing, if the second charger is in a charging operation state, it will automatically wait for the start of charging the battery pack, and the current flowing from the external power source to the charger itself can be limited to the standby current.

[0011] Therefore, for example, when a second charger is connected to the power supply path through which the charger of the present disclosure receives power from an external power source and the second charger is in a charging operation state, the control unit can be prevented from starting charging control.

[0012] Therefore, according to the charger disclosed herein, when two chargers receiving power from the same power supply path perform charging operations simultaneously, it is possible to prevent the current flowing through the power supply path from exceeding the allowable current and causing the power supply path to be cut off by a safety device such as a breaker. [Brief explanation of the drawings]

[0013] [Figure 1] 1 is a block diagram showing the overall configuration of a charging system according to an embodiment; [Figure 2] FIG. 2 is a perspective view showing the appearance of a charger and a battery pack that constitute the charging system. [Figure 3] FIG. 2 is a block diagram showing the circuit configuration of a charger. [Figure 4] 4 is a flowchart showing a charging permission determination process executed by a control circuit. [Figure 5] 5 is a flowchart showing information output processing executed in S300 of FIG. 4. [Figure 6] 5 is a flowchart showing a conflict avoidance process executed in S400 of FIG. 4. DETAILED DESCRIPTION OF THE INVENTION

[0014] [Summary of the embodiment] In some embodiments, the charger may include a housing into which the battery pack can be attached. Additionally or alternatively, the charger may include a charging circuit configured to receive power from an external power source and generate charging power for the battery pack.

[0015] Additionally or alternatively, the charger may include a controller configured to perform charging control that controls the supply of charging power from the charging circuit to the battery pack. Additionally / alternatively, the charger may include a communication unit configured to be able to communicate with an external second charger.

[0016] Additionally / alternatively, the charger may include a determination unit configured to determine whether or not to permit the control unit to execute charging control, based on the result of communication with the second charger by the communication unit. Additionally / alternatively, at least the charging circuitry and the control unit may be disposed within the housing.

[0017] Additionally / alternatively, the determination unit may be configured to determine whether or not the communication unit has received second charging information representing the charging operation status from the second charger when the battery pack is attached to the housing and charging from the charging circuit becomes possible, and to cause the control unit to wait for execution of charging control when the communication unit has received the second charging information, and to allow the control unit to execute charging control when the communication unit has not received the second charging information.

[0018] In one embodiment, if a charger includes the above-mentioned housing, charging circuit, control unit, communication unit, and determination unit, when a battery pack is attached to the housing, if the second charger is in a charging operation state, the charger will wait for the start of charging the battery pack.

[0019] With this type of charger, by waiting for charging to start, the current flowing into the charger itself from the external power source is limited to a standby current, and the charging operations of the two chargers, the charger itself and the second charger, can be prevented from causing a large current to flow in the power supply path. This prevents the current flowing in the power supply path from exceeding the allowable current and causing a safety device such as a breaker to cut off the power supply path.

[0020] Additionally / alternatively, the communication unit may be configured to be able to communicate with an external third charger in addition to the second charger. Additionally / alternatively, the determination unit may be configured to determine whether the communication unit has received second charging information or third charging information representing the charging operation status from the second charger or third charger when the battery pack is attached to the housing and charging from the charging circuit becomes possible, and to cause the control unit to wait for execution of charging control when the communication unit has received the second charging information or the third charging information, and to allow the control unit to execute charging control when the communication unit has not received the second charging information or the third charging information.

[0021] According to a charger having the communication unit and judgment unit configured as described above, when the battery pack is attached to the housing, if the second charger or the third charger is in a charging operation state, the charger will wait for the start of charging the battery pack.

[0022] Therefore, with this charger, even when three chargers, the charger itself (hereinafter also referred to as the first charger), the second charger, and the third charger, are connected to the power supply path from the external power source, it is possible to prevent a large current from flowing through the power supply path due to the charging operation of the first charger. This makes it possible to prevent the current flowing through the power supply path from exceeding the allowable current and causing the power supply path to be cut off.

[0023] Additionally / alternatively, the determination unit may be configured to cause the communication unit to transmit first charging information representing a charging operation status to the third charger when the communication unit receives second charging information from the second charger.

[0024] According to the charger having the determination unit configured in this way, when the second charger is in a charging state, the first charging information can be transmitted to the third charger. Therefore, if the third charger is configured similarly to the first charger, when the second charger is in a charging state, the third charger can be made to wait for charging, thereby more effectively preventing the second charger and another charger among the three chargers from simultaneously performing charging operations.

[0025] Additionally / alternatively, when it becomes possible to charge the battery pack from the charging circuit, the determination unit may be configured to, if it determines that the communication unit has not received the second charging information and the third charging information, cause the communication unit to transmit the first charging information to the second charger and the third charger, and cause the control unit to continue waiting to execute charging control, and then, within a predetermined time, determine whether the communication unit has received the second charging information, and, if the communication unit receives the second charging information within the predetermined time, cause the communication unit to transmit charging stop information to the second charger indicating that the charger is in a charging stop state.

[0026] A charger having a determination unit configured in this manner makes it possible to charge the battery pack, and if the communication unit has not received the second charging information and the third charging information, it will send the first charging information to the second charger and the third charger, but will wait without charging the battery pack.

[0027] Therefore, the second or third charger can be prevented from transmitting the second or third charging information at approximately the same time as the first charger transmits the first charging information, thereby preventing the first charger and the second or third charger from starting charging operations.

[0028] Furthermore, if the communication unit of the first charger receives the second charging information within a predetermined time period after transmitting the first charging information to the second and third chargers, the first charger transmits charging stop information to the second charger. Therefore, if the second charger has the same configuration as the first charger, the first charger can notify the second charger that it has stopped its charging operation, allowing the second charger to prioritize the charging operation.

[0029] Additionally / alternatively, the determination unit may be configured to permit the control unit to execute charging control when it determines that the communication unit has not received the second charging information and the third charging information during the lapse of the predetermined time.

[0030] In a charger with such a determination unit, if the second charger and the third charger do not receive the second charge information and the third charge information within a predetermined time, the second charger and the third charger will start charging the battery pack because both are in a charging stopped state. Therefore, of the three chargers, only the first charger will charge the battery pack, thereby suppressing the current flowing through the power supply path from the external power source.

[0031] Additionally / alternatively, the determination unit may be configured to notify the controller that the charger is in a charging standby state when the determination unit causes the controller to wait for execution of charging control. With a charger having such a configuration, when the user attaches the battery pack to the charger housing but the charger does not start charging, the charger notifies the user that the charger is in a charging standby state, thereby notifying the user that the charger is operating normally.

[0032] Additionally / alternatively, the determination unit may be configured to permit the control unit to execute the charging control when the communication unit no longer receives the second charging information while the control unit is waiting to execute the charging control.

[0033] With a charger having such a determination unit, when the second charger is in a charging operation state and the control unit is waiting to execute charging control, the control unit can be made to immediately start charging control when the second charger finishes charging. Therefore, when the charger is in a charging standby state, the user can automatically start charging the battery pack without performing any special operation, improving the usability of the charger.

[0034] In one embodiment, the charger described above may be included as at least one of a plurality of chargers in a charging system including a plurality of chargers. In this case, if the plurality of chargers in the charging system are connected to a single power supply path to which power is supplied from an external power source, the total number of chargers that start charging operations will be reduced, thereby preventing the current flowing through the power supply path from exceeding the allowable current and causing the power supply path to be cut off.

[0035] Specific Exemplary Embodiments A specific exemplary embodiment will be described below. This specific exemplary embodiment is merely an example, and the present disclosure is not limited to this embodiment and can be implemented in any form.

[0036] [Embodiment] [composition] As shown in FIG. 1, the charging system 10 of this embodiment includes eight chargers 20 that receive power via two table taps 8 from outlets 6 provided in a power supply path that supplies AC power from a commercial power source, which is an external power source 2, via a breaker 4.

[0037] The chargers 20 are connected in order from the first charger 20-1 to the eighth charger 20-8 via a communication line 40. Therefore, the first charger 20-1 can communicate with the second charger 20-2, the second charger 20-2 to the seventh charger 20-7 can communicate with the two chargers 20 before and after it, and the eighth charger 20-8 can communicate with the seventh charger 20-7.

[0038] Each charger 20 is for charging a battery pack 30 for an electric work machine as shown in FIG. 2, and includes a housing 21 into which the battery pack 30 to be charged can be attached. The battery pack 30 is attached to an electric work machine such as a rechargeable power tool, a rechargeable vacuum cleaner, or a rechargeable lawn mower to supply DC power. The battery pack 30 has a built-in rechargeable battery, and is provided on the outside of its housing with an attachment section 34 for detachably attaching the battery to the electric work machine or the charger 20. The attachment section 34 is also provided with terminal sections 36 for electrically connecting the battery pack to the electric work machine or the charger 20.

[0039] On the other hand, the housing 21 of the charger 20 is formed with an attachment section 24 that corresponds to the attachment section 34 of the battery pack 30. The attachment section 24 is also provided with a terminal section 26 that is electrically connected to the terminal section 36 of the battery pack 30 when the battery pack 30 is attached to the attachment section 24.

[0040] The housing 21 of the charger 20 contains a charging circuit (see Figure 3) that takes in AC power supplied from the outlet 6 or the power strip 8 via the power cord 22 and generates DC power for charging the battery pack 30.

[0041] The housing 21 is also provided with a display unit 28 for displaying the operating state of the charger 20. The display unit 28 includes two indicator lamps 28A and 28B, which are configured, for example, by LEDs.

[0042] 1, when both indicator lamps 28A, 28B are lit, they indicate that the battery pack 30 is being charged, and when only one is lit, they indicate that the battery pack 30 is waiting to be charged. When both indicator lamps 28A, 28B are off, they indicate that the charger 20 has stopped charging. Therefore, when no battery pack 30 is attached to the attachment portion 24, both indicator lamps 28A, 28B are off. The display contents in the upper right column of FIG. 1 are shown schematically, and the method of displaying various states such as charging and standby can be changed as appropriate. For example, various states may be displayed by changing the display pattern of a single indicator lamp, such as lighting or blinking. Also, various states may be displayed by changing the display color in a single display area. Also, various states may be notified by displaying characters or figures representing the various states on a predetermined display panel.

[0043] The terminal section 36 of the battery pack 30 is provided with power supply terminals connected to the positive and negative electrodes of the battery and a voltage output terminal connected to the connection points of the cells that make up the battery, as terminals that are electrically connected when the battery pack 30 is attached to an external device such as the charger 20 or an electric work machine. The terminal section 36 of the battery pack 30 also has a signal output terminal that outputs a signal that indicates the state of the battery pack 30, such as the temperature of the cells that make up the battery or the active / inactive status of a control circuit in the battery pack 30.

[0044] For this reason, as shown in FIG. 3, the terminal section 26 of the charger 20 is provided with a positive terminal 51, a negative terminal 52, voltage input terminals 53 and 54, and a signal input terminal 55 corresponding to the terminal section 36 of the battery pack 30.

[0045] Therefore, when the battery pack 30 is attached to the charger 20, the positive terminal 51 and the negative terminal 52 are connected to the positive and negative electrodes of the battery, and the voltage input terminals 53 and 54 are connected to the connection points between the cells that make up the battery. Also, signals that indicate the state of the battery pack 30, such as the cell temperature and whether the control circuit is active or inactive, are input to the signal input terminal 55.

[0046] As shown in FIG. 3, the housing 21 of the battery pack 30 is provided with two communication terminals 41 and 43 for connecting the communication line 40 in addition to the terminal portion 26. Of these, the communication terminal 41 is used as a communication terminal for connecting a charger 20 having a higher charging priority than the charger 20 provided with the communication terminal 41. The communication terminal 43 is used as a communication terminal for connecting a charger 20 having a lower charging priority than the charger 20 provided with the communication terminal 43.

[0047] Therefore, as shown in FIG. 1, the charging priority of the eight chargers 20 is determined by connecting the communication terminal 43 of the higher-ranking charger 20 to the communication terminal 41 of the lower-ranking charger 20 via the communication line 40 in the order in which the chargers 20 are arranged, with the first charger 20-1 being the highest.

[0048] In the following explanation, when describing the operation of each charger 20, the charger 20 whose operation is being explained will be referred to as the first charger 20A, and the charger 20 connected to the communication terminal 41 of the first charger 20A and having a higher charging priority than the first charger 20A will be referred to as the second charger 20B. Furthermore, the charger 20 connected to the communication terminal 43 of the first charger 20A and having a lower charging priority than the first charger 20A will be referred to as the third charger 20C.

[0049] [Charging circuit configuration] Next, as shown in FIG. 3, the charging circuit provided within the housing 21 includes a first communication circuit 42, a second communication circuit 44, a voltage detection circuit 56, a signal input circuit 58, a control circuit 60, a rectifier circuit 62, a charging switching power supply circuit 64, a power supply circuit 66, and a display unit 28.

[0050] The first communication circuit 42 is a communication circuit that communicates with the second charger 20B connected to the communication terminal 41 via the communication line 40, and the second communication circuit 44 is a communication circuit that communicates with the third charger 20C connected to the communication terminal 43 via the communication line 40. The first communication circuit 42 and the second communication circuit 44 correspond to the communication unit of the present disclosure.

[0051] The communication method used by the first communication circuit 42 and the second communication circuit 44 may be, for example, a communication method that simply transmits and receives information using Hi-Lo signals, or a communication method that uses Universal Asynchronous Communication (UART). In other words, this communication method only needs to be able to transmit and receive charging information indicating that the charger 20 is in a charging operation and charging stop information indicating that charging is stopped between the first charger 20A and the second charger 20B or the third charger 20C.

[0052] The voltage detection circuit 56 detects the battery voltage and the battery cell voltage based on the voltage signal input from the battery pack 30 via the positive terminal 51 and the voltage input terminals 53 and 54, and inputs the detected voltage to the control circuit 60. The signal input circuit 58 is a circuit that takes in an input signal from the battery pack 30 and inputs it to the control circuit 60, and includes, for example, a filter for noise removal.

[0053] Meanwhile, rectifier circuit 62 rectifies and converts into direct current the AC voltage (e.g., 100 V AC) input from power supply terminals 22A and 22B connected to power cord 22. Charging switching power supply circuit 64 has a switching regulator that steps down the voltage rectified by rectifier circuit 62 to generate a charging voltage for charging battery pack 30. The charging voltage generated by charging switching power supply circuit 64 is then output from positive terminal 51 to battery pack 30.

[0054] Furthermore, the power supply circuit 66 steps down the voltage rectified by the rectifier circuit 62 to generate a power supply voltage (constant DC voltage) Vdd within the charger 20. The generated power supply voltage Vdd is then supplied to internal circuits of the charger 20, such as the control circuit 60 and the first and second communication circuits 42, 44.

[0055] The control circuit 60 includes a microcomputer including a CPU, ROM, RAM, etc. The control circuit 60 may also include a flash memory for storing various data. The control circuit 60 detects that the battery pack 30 is connected to the charger 20 based on an input signal from the signal input circuit 58, and controls the charging switching power supply circuit 64. Therefore, the control circuit 60 functions as the control unit 70 of the present disclosure, as shown in FIG. 3. The rectifier circuit 62 and the charging switching power supply circuit 64 function as the charging circuit of the present disclosure.

[0056] The control circuit 60 also controls the charging power supplied to the battery pack 30 by controlling the charging switching power supply circuit 64, and when carrying out this charging control, the control circuit 60 checks the charging operation status of the second and third chargers 20B and 20C via the first and second communication circuits 42 and 44.

[0057] When the battery pack 30 is attached to the charger 20 and charging control is to start, if the second charger 20B or the third charger 20C is in charging operation, the control circuit 60 waits to execute charging control for the battery pack 30. In other words, when the second charger 20B and the third charger 20C are not in charging operation, the control circuit 60 permits execution of charging control and starts charging the battery pack 30 from the charger 20.

[0058] Next, a description will be given of the charging permission determination process executed by the control circuit 60 before starting charging of the charger 20. By executing this charging permission determination process, the control circuit 60 also functions as the determination unit 80 of the present disclosure, as shown in FIG.

[0059] [Charging permission determination process] 4, in the charging permission determination process, first, in S110 (S represents step), it is determined whether or not the battery pack 30 is attached to the attachment portion 24 of the housing 21 and the internal circuitry of the battery pack 30, including the battery, is connected to the terminal portion 26. Note that an input signal from the signal input circuit 58 is used for this determination.

[0060] If it is determined in S110 that the battery of the battery pack 30 is connected, the process proceeds to S120, where it is determined whether the output flag for the charging state has been cleared. The output flag is initialized to a cleared state when the battery is connected, and is then set when charging information is transmitted to the second and third chargers 20B and 20C via the first and second communication circuits 42 and 44 in the process described below.

[0061] In the following description, the charging information transmitted from the first charger 20A to the second and third chargers 20B and 20C is referred to as first charging information. Also, the charging information received by the first communication circuit 42 from the second charger 20B (in other words, the charger 20 with the higher charging priority) is referred to as second charging information. Also, the charging information received by the second communication circuit 44 from the third charger 20C (in other words, the charger 20 with the lower charging priority) is referred to as third charging information.

[0062] If it is determined in S120 that the output flag is cleared, the process proceeds to S130, where it is determined whether the second charger 20B and the third charger 20C are in a charging stopped state (in other words, not charging).

[0063] If it is determined in S130 that the second and third chargers 20B, 20C are not charging, the process proceeds to S140, where first charger 20A notifies the second and third chargers 20B, 20C that it is in a charging state by transmitting first charging information to them. Then, in the following S150, a timer counter that measures a determination time for determining whether or not to start charging the battery pack 30 is initialized, and the process proceeds to S160.

[0064] Next, if it is determined in S130 that the second and third chargers 20B and 20C are not in a non-charging state, the process proceeds to S300, where information output processing is executed to the second and third chargers. The information output processing of S300 is executed even when it is determined in S110 that the battery of the battery pack 30 is not connected, and is executed according to the procedure shown in FIG.

[0065] That is, in the information output process of S300, in S310, it is determined whether the second charger 20B is in a charging operation state (in other words, charging) based on the second charging information transmitted from the second charger 20B.

[0066] If the second charger 20B is currently charging, the process proceeds to S320, where the first charging information is sent to the third charger 20C to notify it that a charger (including the first charger 20A) with a higher charging priority than the third charger 20C is currently charging, and the process proceeds to S340.

[0067] Furthermore, if it is determined in S310 that the second charger 20B is not charging, the process proceeds to S330, where charging stop information is sent to the third charger 20C, thereby notifying the charger with a higher charging priority than the third charger 20C that it is not charging, and the process proceeds to S340.

[0068] In S340, it is determined whether the third charger 20C is in a charging operation state (in other words, charging) based on the third charging information transmitted from the third charger 20C. If the third charger 20C is charging, the process proceeds to S350, where the third charger 20C transmits the first charging information to the second charger 20B to notify it that a charger with a lower charging priority than the second charger 20B is charging.

[0069] Furthermore, if it is determined in S340 that the third charger 20C is not charging, the process proceeds to S360, where charging stop information is sent to the second charger 20B, thereby notifying the second charger 20B that the charger with a higher charging priority than the second charger 20B is not charging. Then, in S350 or S360, the first charging information or charging stop information is sent to the second charger 20B, and the information output process ends.

[0070] Therefore, in the charging system 10 of this embodiment, when any one of the eight chargers 20 receiving power from the external power source 2 enters a charging operation state, that charger 20 transmits charging information to both the chargers 20 with higher and lower charging priorities. Therefore, the chargers 20 other than the charger 20 that transmitted the charging information detect that the other chargers 20 in the charging system 10 are in a charging operation state, and wait for their own chargers 20 to start their own charging operation.

[0071] Then, when it is determined in S110 that the battery of the battery pack 30 is not connected and the information output process of S300 is executed, the process proceeds to S110, and the processes of S110 and S300 are repeatedly executed.

[0072] Furthermore, when it is determined in S130 that the second and third chargers 20B, 20C are not non-charging and the information output process of S300 is executed, the process proceeds to S170. In S170, the operation mode of the control circuit 60 is set to a charging standby mode, and the control unit 70 function is made to wait before executing charging control of the battery pack 30 attached to the housing 21.

[0073] Then, in the next step S180, since one of the second and third chargers 20B and 20C is already charging, and there is no need for the first charger 20A to perform its own charge start determination in the conflict avoidance process described below, the charge start determination execution flag is set. Note that, like the charge status output flag described above, the charge start determination execution flag is initialized to a cleared state when the battery is connected.

[0074] In the following S190, one indicator lamp 28B of the display unit 28 is turned on to notify that the charger 20 is in a charging standby state, and the process proceeds to S160. In S160, since the first charging information was transmitted in S140 or S300, the output flag for the charging state described above is set, and the process proceeds to S200.

[0075] In S200, it is determined whether the execution flag for the above-mentioned charge start determination is cleared. If the execution flag is not cleared, that is, if the execution flag is set, there is no need to execute the conflict avoidance process of S400, so the charge permission determination process is temporarily terminated and the process proceeds to S110.

[0076] On the other hand, if it is determined in S200 that the execution flag for determining whether to start charging is cleared, the conflict avoidance process of S400 is executed, and the process proceeds to S110. The conflict avoidance process of S400 is a process for preventing charging conflicts from occurring when batteries are connected or powered on at approximately the same time in the charger 20 serving as the first charger 20A and other chargers 20 including the second and third chargers 20B and 20C, and is executed according to the procedure shown in FIG.

[0077] As shown in FIG. 6, in the conflict avoidance process, first, in S410, a timer counter is counted up, and the time elapsed since the battery was connected while other chargers in the charging system 10 were not charging is counted as the charging start determination time.

[0078] Next, in S420, it is determined whether the charging start determination time has exceeded a first preset time set for abnormality determination. If the charging start determination time has exceeded the first preset time, it is determined that an abnormality has occurred in the subsequent processing, and the conflict avoidance processing is terminated in S430. Note that the abnormality determination processing in S430 may, for example, display an error by flashing the indicator lamps 28A and 28B of the display unit 28, or may execute the conflict avoidance processing again.

[0079] Next, if it is determined in S420 that the charging start determination time has not reached the first set time, the process proceeds to S440, where it is determined whether or not third charging information has been input from the second communication circuit 44. If the third charging information has been input, the third charger 20C that transmitted the third charging information has a lower charging priority than the charger 20 itself, which is the first charger 20A, and therefore the conflict avoidance process is terminated.

[0080] In addition, the third charger 20C, which has a lower charging priority than the charger 20 itself, performs conflict avoidance processing in the same manner as the charger 20, and therefore transmits charging stop information to the charger 20 itself, which becomes the first charger 20A, through the processing described below.

[0081] Therefore, in the charger 20 (i.e., the first charger 20A) that receives the charging stop information from the third charger 20C, it is determined in S440 that the third charging information has not been input, and the process of S450 is executed.

[0082] Next, in S450, it is determined whether or not second charging information has been input from the first communication circuit 42. If the second charging information has been input, the process proceeds to S460, where charging stop information is transmitted from the first communication circuit 42 to the second charger 20B, thereby notifying the first charger 20A that it is in a charging stop state.

[0083] Next, in S470, the operation mode of the control circuit 60 is set to a charge standby mode, thereby putting the control unit 70 on standby to control charging of the battery pack 30, and in S480, the execution flag for determining whether to start charging is set. Then, in the next S490, one of the indicator lamps 28B of the display unit 28 is turned on to indicate that the charger 20 is in a charge standby state, and the conflict avoidance process ends.

[0084] Furthermore, if it is determined in S450 that the second charging information has not been input, the process proceeds to S500, where it is determined whether the charging start determination time measured by the processing of S410 has elapsed a second set time that is preset for determining whether to start charging.

[0085] If the charging start determination time has not elapsed the second set time, the conflict avoidance process is terminated, and if the charging start determination time has elapsed the second set time, the process proceeds to S510, where a charging start determination implementation flag is set, and the process proceeds to S520.

[0086] In S520, even though the charging start determination time has passed the second set time, the other chargers including the second and third chargers 20B and 20C are in a charging stopped state, so the operation mode of the control circuit 60 is set to the charging execution mode, thereby permitting the start of charging control by the control unit 70. As a result, charging of the battery pack 30 attached to the charger 20, which is the first charger 20A, is started from the charger 20.

[0087] Furthermore, when the start of charging control is permitted in S520, the two indicator lamps 28A and 28B of the display unit 28 are turned on in S530 to notify that charging is in progress, and the conflict avoidance process is terminated.

[0088] [effect] In the charging system 10 of this embodiment, eight chargers 20 are connected to a single power supply path to which AC power from an external power source 2 is supplied via a breaker 4. Each charger 20 has the same configuration, and a control circuit 60 housed in a housing 21 of each charger 20 executes the above-described charging permission determination process as a determination unit of the present disclosure.

[0089] In this charging permission determination process, when the battery pack 30 is attached to the housing 21 and becomes capable of being charged, the first and second communication circuits 42, 44 determine whether charging information has been received from another charger 20. If charging information has been received from another charger 20, the control unit 70 is put on hold before it can control charging of the battery pack 30, and if charging information has not been received from another charger 20, the control unit 70 is permitted to control charging.

[0090] Therefore, in the charging system 10, the number of chargers 20 that charge the battery packs 30 is limited to one out of eight, thereby suppressing the current flowing through the power supply path. This prevents the current flowing through the power supply path from exceeding the allowable current, turning off the breaker 4, and interrupting the power supply path.

[0091] Furthermore, a charging priority is assigned to each charger 20 in the order of connection via the communication line 40. If two or more chargers 20 are ready for charging at approximately the same time and each charger 20 attempts to start charging, a conflict avoidance process allows only the charger 20 with the highest charging priority to execute charging control, while the other chargers 20 enter a charging standby state.

[0092] Therefore, according to the charging system 10 of this embodiment, the number of chargers 20 that charge the battery pack 30 can be more appropriately limited to one, and the breaker 4 can be prevented from being turned off and all chargers 20 being unable to charge.

[0093] Furthermore, the charger 20 that has been put on standby for charging due to contention with another charger 20 notifies the user of the standby state via the display unit 28, allowing the user to confirm that the charger is in the standby state and wait for charging to begin for the battery pack 30. Therefore, the charger 20 of this embodiment not only prevents the breaker 4 from being turned off, but also prevents a decrease in usability for the user by displaying the standby state for charging.

[0094] [Other embodiments] Although the embodiments of the present disclosure have been described above, the present disclosure is not limited to the above-described embodiments and can be implemented in various modified forms.

[0095] For example, in the above embodiment, it was described that the multiple chargers 20 are connected via the communication line 40 in order of charging priority, and each charger 20 identifies the priority of the connected charger 20 based on the position of the communication circuit 42, 44 to which the communication line 40 is connected.

[0096] However, in order to be able to identify the priority of other chargers that can communicate with the charger 20 that is the first charger 20A, for example, information that allows the priority to be identified may be added to the transmission signal from each charger 20.

[0097] In other words, in this case, the charger 20 that receives a transmission signal from another charger 20 can detect that it has received information from the second charger 20B or the third charger 20C based on the identification information attached to the received signal.

[0098] In this way, there is no need to connect multiple chargers 20 in order of charging priority via communication lines 40; each charger 20 can be bus-connected to a common communication line 40, or each charger 20 can be connected via a wireless communication path.

[0099] In addition, in the present embodiment, the eight chargers 20 that receive power from the external power source 2 via the breaker 4 are all described as being connected via the communication lines 40. However, for example, four chargers 20 that are respectively connected to table taps 8 on a power supply path that is separated into two systems from an outlet 6 on the power supply path may be connected via the communication lines 40.

[0100] In this way, it becomes possible to suppress the current flowing through each of the two separate power supply paths from the outlet 6. Furthermore, in the above embodiment, the external power source 2 has been described as being a commercial power source, but the external power source 2 may also be a generator or a large-capacity battery.

[0101] Furthermore, in the above embodiment, the function of the determination unit 80 has been described as being realized by the charging permission determination process executed by the control circuit 60 having the function of the control unit 70, but the determination unit 80 may be configured as an electronic circuit configured separately from the control unit 70. In this case, the electronic circuit functioning as the determination unit 80 may be configured as a communication unit using a microcomputer or the like having a communication function as a communication unit, and may be externally attached to the housing 21 of the charger 20.

[0102] The functions of the control unit 70 and the determination unit 80 may be realized by a dedicated computer configured with a processor and memory programmed to execute one or more functions embodied in a computer program. Alternatively, the functions of the control unit 70 and the determination unit 80 may be realized by a dedicated computer configured with a processor comprising one or more dedicated hardware logic circuits. Alternatively, the functions of the control unit 70 and the determination unit 80 may be realized by one or more dedicated computers configured by combining a processor and memory programmed to execute one or more functions with a processor configured with one or more hardware logic circuits. Furthermore, the computer program may be stored as instructions executed by a computer on a computer-readable non-transitory tangible recording medium. Furthermore, the method for realizing the functions of the control unit 70 and the determination unit 80 does not necessarily need to include software; all of the functions may be realized using one or more hardware components.

[0103] Furthermore, 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. Furthermore, 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. Furthermore, part of the configuration of the above embodiments may be omitted. Furthermore, 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.

[0104] In addition to the charger or charging system described above, the technology of the present disclosure can also be realized in various forms, such as a program for causing a computer to function as a charger or charging system, a non-transient physical recording medium such as a semiconductor memory on which this program is recorded, and a charging method. [Explanation of symbols]

[0105] 2...external power supply, 4...breaker, 6...outlet, 8...table tap, 10...charging system, 20...charger, 21...casing, 22...power cord, 28...display unit, 30...battery pack, 42...first communication circuit, 44...second communication circuit, 60...control circuit, 62...rectifier circuit, 64...charging switching power supply circuit, 70...control unit, 80...determination unit.

Claims

1. A housing into which a battery pack can be attached; a charging circuit configured to receive power from an external power source and generate charging power for the battery pack; a control unit configured to execute charging control for controlling supply of the charging power from the charging circuit to the battery pack; a communication unit configured to be able to communicate with an external second charger; a determination unit configured to determine whether to permit the control unit to execute the charging control according to a communication result between the communication unit and the second charger; Equipped with At least the charging circuit and the control unit are disposed within the housing, the determination unit is configured to, when the battery pack is attached to the housing and the charging circuit is able to charge the battery pack, determine whether the communication unit has received second charging information representing a charging operation status from the second charger, and, when the communication unit has received the second charging information, make the control unit wait to execute the charging control, and, when the communication unit has not received the second charging information, allow the control unit to execute the charging control.

2. 2. The charger according to claim 1, the communication unit is configured to be able to communicate with an external third charger in addition to the second charger, the determination unit is configured to, when the battery pack is attached to the housing and charging of the battery pack from the charging circuit becomes possible, determine whether the communication unit has received the second charging information or the third charging information representing a charging operation status from the second charger or the third charger, and, when the communication unit has received the second charging information or the third charging information, make the control unit wait to execute the charging control, and, when the communication unit has not received the second charging information or the third charging information, allow the control unit to execute the charging control.

3. 3. The charger according to claim 2, The charger, wherein the determination unit is configured to, when the communication unit receives the second charging information from the second charger, cause the communication unit to transmit first charging information representing a charging operation status to the third charger.

4. The charger according to claim 2 or 3, The charger is configured such that, when the determination unit permits the control unit to execute the charging control, the determination unit causes the communication unit to transmit first charging information representing a charging operation status to the second charger and the third charger.

5. 5. The charger according to claim 4, The determination unit When it becomes possible to charge the battery pack from the charging circuit, if it is determined that the communication unit has not received the second charging information and the third charging information, the communication unit transmits the first charging information to the second charger and the third charger, and the control unit continues to wait for execution of the charging control; Thereafter, it is determined whether or not the communication unit has received the second charging information during the lapse of a predetermined time, and when the communication unit has received the second charging information during the lapse of the predetermined time, the communication unit transmits charging stop information indicating that the charger is in a charging stop state to the second charger. The charger is configured as follows:

6. 6. The charger according to claim 5, The charger is configured such that, when the determination unit determines that the communication unit has not received the second charging information and the third charging information within the predetermined time period, the determination unit allows the control unit to execute the charging control.

7. The charger according to any one of claims 1 to 6, The charger, wherein the determination unit is configured to notify the control unit that the charger is in a charging standby state when the determination unit causes the control unit to wait for execution of the charging control.

8. The charger according to any one of claims 1 to 7, the determination unit is configured to permit the control unit to execute the charging control when the second charging information is no longer received by the communication unit while the control unit is waiting to execute the charging control.

9. A charging system including a plurality of chargers connected to a single power supply path that receives power from an external power source and capable of charging battery packs attached to the housings of the chargers themselves, the plurality of chargers being communicatively connected via a communication path, A charging system, wherein at least one of the plurality of chargers is the charger according to any one of claims 1 to 8.

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