Electrically assisted vehicle, battery pack, and method for displaying remaining battery capacity

Abstract

To suppress the user's discomfort in display of the remaining battery capacity of a battery that can set the charging mode in which the charging is completed when the battery is charged to a predetermined remaining battery capacity lower than the full charge.SOLUTION: A power-assisted vehicle includes a display device that displays the remaining battery capacity, a battery pack that can set either a first charge mode in which a battery cell is charged until the battery is fully charged, or a second charge mode in which charging is completed when the battery cell is charged to a predetermined remaining battery capacity lower than the full charge, and a control device that cause the display device to display the remaining battery capacity on the basis of the current remaining battery capacity notified from the battery pack when the charging mode notified from the battery pack is the first charging mode, and adjusts the current remaining battery capacity notified from the battery pack when the charge mode notified from the battery pack is a second charge mode, and causes the display device to display the battery remaining capacity on the basis of the adjusted remaining battery capacity.SELECTED DRAWING: Figure 4

Description

[Technical Field]

[0001] The present invention relates to a technology for displaying the remaining battery capacity of a battery used in an electrically assisted vehicle such as an electrically assisted bicycle. [Background technology]

[0002] BACKGROUND ART Electrically assisted bicycles are known that have a regenerative function that uses a battery to supply power to generate driving force for a motor to assist human power, and that generates electricity using the back electromotive force of the motor to charge the battery.

[0003] However, when the battery is fully charged and cannot accept any more charge, such as immediately after charging is complete, the battery cannot accept any more charge through regeneration, and so regenerative charging is not possible at this time. In this case, the braking force differs between when regenerative charging is not possible and when regenerative charging is possible, so the user must intentionally increase the amount of brake lever operation to obtain the same braking force, which can be disconcerting for the user. Conversely, if the amount of brake lever operation is the same, the braking distance will increase.

[0004] To effectively utilize such a regenerative function, there is a technology described in Patent Document 1. That is, a charge control device accepts designation of a charge mode that allows charging to full charge and a charge mode that stops charging while leaving room for charging, and charges the power storage device in the designated charge mode. By designating the latter charge mode, it is possible to prevent the occurrence of an event in which regenerative charging is not possible.

[0005] On the other hand, typical electric assist bicycles are equipped with a function that detects and displays the remaining battery capacity even while riding. This function allows the user to know the remaining battery capacity while riding, so they can estimate how far they can ride and when they need to charge the bicycle based on the distance traveled so far and the rate at which the remaining battery capacity is decreasing.

[0006] However, Patent Document 1 does not disclose any special measures for displaying the remaining battery capacity, and for example, even if charging is completed in the latter charging mode with the remaining battery capacity at 80%, the remaining battery capacity display will likely remain at 80%. As a result, even immediately after charging is completed, the remaining battery capacity display will not be 100% or an equivalent, which may cause the user to feel uncomfortable with this display.

[0007] Patent Document 2 discloses a technology that prohibits charging of a secondary battery in a charge-prohibited capacity range between the full charge capacity and the recharge capacity, and outputs a capacity greater than the detected or calculated capacity in the charge-prohibited capacity range. This technology is said to reduce the likelihood of determining that the battery, the electrical device containing the battery, or the charger is faulty, due to the user being unable to charge in the charge-prohibited capacity range. However, this technology assumes the existence of a charge-prohibited capacity range, and its technical direction differs from that of the technology disclosed in Patent Document 1, which does not provide a charge-prohibited capacity range and instead provides a charging mode that leaves room for charging. [Prior art documents] [Patent documents]

[0008] [Patent Document 1] Japanese Patent Application Laid-Open No. 2017-103871 [Patent Document 2] Japanese Patent Application Laid-Open No. 2005-351870 Summary of the Invention [Problem to be solved by the invention]

[0009] Therefore, an object of the present invention is to provide a technology for adjusting the display of the remaining battery capacity of a battery pack that can be set to a charging mode that completes charging when the battery is charged to a predetermined remaining battery capacity that is lower than full charge, in a manner that reduces discomfort to the user. [Means for solving the problem]

[0010] The electrically assisted vehicle of the present invention comprises a display device that displays the remaining battery capacity, a battery pack that can be set to either a first charging mode in which the battery cells are charged until fully charged, or a second charging mode in which charging is completed when the battery cells are charged to a predetermined remaining battery capacity that is lower than fully charged, and a control device that, if the charging mode notified from the battery pack is the first charging mode, causes the display device to display the remaining battery capacity based on the current remaining battery capacity notified from the battery pack, and, if the charging mode notified from the battery pack is the second charging mode, adjusts the current remaining battery capacity notified from the battery pack and causes the display device to display the remaining battery capacity based on the adjusted remaining battery capacity.

[0011] The battery pack of the present invention includes a battery cell and a management unit that can be set to either a first charging mode in which the battery cell is charged until fully charged, or a second charging mode in which charging is completed when the battery cell is charged to a predetermined remaining battery capacity that is lower than fully charged, and that adjusts the current remaining battery capacity value when the charging mode is the second charging mode.

[0012] In addition, the motor drive control device of the present invention has a means for displaying the remaining battery capacity on a display device of the electrically assisted vehicle based on the current remaining battery capacity notified from the battery pack when the charging mode notified from the battery pack, which can be set to either a first charging mode in which the battery cells are charged until they are fully charged, or a second charging mode in which charging is completed when the battery cells are charged to a predetermined remaining battery capacity that is lower than full charge, is the first charging mode, and a means for adjusting the current remaining battery capacity notified from the battery pack and displaying the remaining battery capacity on a display device based on the adjusted remaining battery capacity when the charging mode notified from the battery pack is the second charging mode. [Effects of the Invention]

[0013] Even if charging is completed in a charging mode in which charging is completed when the battery reaches a predetermined remaining capacity that is lower than full charge, it is possible to suppress the user's discomfort. [Brief explanation of the drawings]

[0014] [Figure 1] FIG. 1 is a diagram showing the appearance of an electrically assisted bicycle. [Figure 2] FIG. 2 is a diagram illustrating an example of the configuration of a battery pack. [Figure 3] FIG. 3 is a diagram illustrating an example of the configuration of a charger. [Figure 4] FIG. 4 is a diagram illustrating an example of the configuration of a motor drive control device. [Figure 5] FIG. 5 is a diagram illustrating an example of the configuration of the operation panel. [Figure 6] FIG. 6 is a diagram showing an operation flow of the battery pack according to the first embodiment. [Figure 7] FIG. 7 is a diagram showing an operation flow of the battery pack according to the first embodiment. [Figure 8] 8(a) and (b) are diagrams showing LED lighting patterns according to the charging mode. [Figure 9] FIG. 9 is a diagram showing an operation flow of the motor drive control device according to the first embodiment. [Figure 10] FIG. 10 is a diagram illustrating an example of adjustment of the remaining battery charge according to the first embodiment. [Figure 11] FIG. 11 is a diagram showing one mode of displaying the remaining battery capacity on the operation panel. [Figure 12] FIG. 12 is a diagram showing an operation flow of the motor drive control device according to the second embodiment. [Figure 13] FIG. 13 is a diagram for explaining the correction coefficient. [Figure 14] FIG. 14 is a diagram showing an operation flow of the motor drive control device according to the second embodiment. [Figure 15] FIG. 15 is a diagram illustrating an example of adjustment of the remaining battery charge according to the second embodiment. [Figure 16] 16(a) to 16(c) are diagrams showing an example of the transition of the remaining battery capacity. [Figure 17] FIG. 17 is a diagram showing an operation flow of the battery pack according to the third embodiment. [Figure 18] FIG. 18 is a diagram showing an operation flow of the motor drive control device according to the third embodiment. [Figure 19] FIG. 19 is a diagram illustrating an example of adjustment of the remaining battery charge according to the third embodiment. [Figure 20] FIG. 20 is a diagram illustrating an example of adjustment of the remaining battery charge according to the third embodiment. [Figure 21] FIG. 21 is a diagram for explaining a problem in the third embodiment. [Figure 22] FIG. 22 is a diagram illustrating an example of adjustment of the remaining battery charge according to the fourth embodiment. [Figure 23] FIG. 23 is a diagram showing an operation flow of the battery pack according to the fourth embodiment. [Figure 24] FIG. 24 is a diagram showing an operation flow of the motor drive control device according to the fourth embodiment. DETAILED DESCRIPTION OF THE INVENTION

[0015] Hereinafter, an embodiment of the present invention will be described using an example of an electrically assisted bicycle, which is an example of an electrically assisted vehicle. However, the application of the embodiment of the present invention is not limited to electrically assisted bicycles, but can also be applied to electrically assisted vehicles such as carts and wheelchairs. Furthermore, if it is only a battery pack, the application is not limited to electrically assisted vehicles.

[0016] [Embodiment 1] 1 is an external view showing an electrically assisted bicycle, which is an example of an electrically assisted vehicle according to this embodiment. This electrically assisted bicycle 1 is equipped with a motor drive device. The motor drive device has a battery pack 101, a motor drive control device 102, a torque sensor 103, a pedal rotation sensor 104, a motor 105, an operation panel 106, and a brake sensor 107.

[0017] The power-assisted bicycle 1 also has a front wheel, a rear wheel, a headlight, a transmission, and the like.

[0018] The battery pack 101 is, for example, a lithium ion secondary battery, but may be other types of batteries, such as a lithium ion polymer secondary battery or a nickel-metal hydride battery. The battery pack 101 supplies power to the motor 105 via the motor drive control device 102, and during regeneration, is also charged by the regenerated power from the motor 105 via the motor drive control device 102. The battery pack 101 has, for example, five LEDs (Light Emitting Diodes) for indicating the charge level corresponding to the remaining battery capacity (SOC: State Of Charge), and an indicator button for issuing an instruction to light up the LEDs.

[0019] The torque sensor 103 is provided near the crankshaft, detects the pedal force applied by the user, and outputs the detection result to the motor drive control device 102. Similarly to the torque sensor 103, the pedal rotation sensor 104 is provided near the crankshaft, and outputs a signal corresponding to the pedal rotation to the motor drive control device 102.

[0020] Brake sensor 107 detects the brake operation by the driver and outputs a signal related to the brake operation (for example, a signal indicating whether the brake is applied or not) to motor drive control device 102. Specifically, it is a sensor using a magnet and a reed switch.

[0021] Motor 105 is, for example, a well-known three-phase DC brushless motor, and is attached to, for example, the front wheel of power-assisted bicycle 1. Motor 105 assists the rotation of the front wheel. Furthermore, motor 105 is equipped with a rotation sensor such as a Hall element, and outputs rotation information (i.e., a Hall signal) of a rotor provided inside motor 105 to motor drive control device 102.

[0022] The motor drive control device 102 performs predetermined calculations based on signals from the rotation sensor of the motor 105, the torque sensor 103, the pedal rotation sensor 104, the brake sensor 107, etc., to control the drive of the motor 105 and also control regeneration by the motor 105.

[0023] The operation panel 106 receives instructions from the user, such as turning a power switch on and off, and outputs the instructions to the motor drive control device 102. The operation panel 106 may also have a display unit such as an LED (Light Emitting Diode), which displays to the user, for example, the remaining battery capacity of the battery pack 101, the on / off state, the assist mode corresponding to the desired assist ratio, and so on.

[0024] 2 shows an example configuration of the battery pack 101. The battery pack 101 has a connector unit 1011 for connecting to the motor drive control device 102 or a charger, a battery management system (BMS) 1012, and battery cells 1013. The battery cells 1013 are, for example, a plurality of battery cells, each of which is a unit storage battery, connected in series, and the entire battery cell 1013 is also called a battery. The connector unit 1011 has a charging / discharging terminal 1011a, a communication terminal 1011b, an ID (IDentification) terminal 1011c for notifying the charger of the type of battery pack, and a ground terminal 1011d.

[0025] The battery management system 1012 has a battery management unit 10121, a resistor 10127 that functions as a battery current detection unit, a battery cell monitoring unit 10124 that monitors the state of the battery cell 1013, a charging FET (Field Effect Transistor) 10125, a discharging FET 10126, an LED 10122, and a switch 10123 corresponding to the indicator button.

[0026] The battery management unit 10121 communicates with the motor drive control device 102 via a communication circuit and terminal 1011b (not shown) regarding the remaining battery capacity and the charging mode (described below). Since the voltage of the battery cell 1013 corresponds to the remaining battery capacity, the following description will be given assuming that the voltage of the battery cell 1013 is substantially the same as the remaining battery capacity. The battery management unit 10121 also works in conjunction with the battery cell monitoring unit 10124 to measure the battery current using a resistor 10127, detect the state of the battery cell 1013, detect the temperatures of the battery cell 1013, the discharge FET 10126, and the charge FET 10125 using a temperature sensor (not shown), and control charging and discharging using the charge FET 10125 and the discharge FET 10126. The battery management unit 10121 also notifies the charger of the type of the battery pack 101, for example, in terms of voltage, via an ID terminal circuit and ID terminal 1011c (not shown).

[0027] Furthermore, when the indicator button is pressed by the user, switch 10123 is turned on, and accordingly, battery management unit 10121 displays the charge level according to the remaining battery capacity using LED 10122. Also, if the indicator button is pressed and held by the user for, for example, 10 seconds while connected to a charger, switch 10123 is turned on during that time, and accordingly, battery management unit 10121 switches the charge mode. If currently in normal charge mode, it switches to limit charge mode, and if currently in limit charge mode, it switches to normal charge mode.

[0028] In this embodiment, the normal charging mode is a mode in which charging is performed until the battery cell 1013 is fully charged when charging using a charger. The limited charging mode is a mode in which charging is completed when the battery reaches a predetermined remaining capacity (for example, 80%, or when the cell voltage of the battery cell 1013 reaches 3.95V), leaving room for regenerative power when charging using a charger. Full charging refers to a state in which the remaining battery capacity is 100%. Completion of charging refers to a state in which the predetermined remaining battery capacity is reached and charging is complete.

[0029] At least some of the functions of the battery management unit 10121 are realized by, for example, the processor 1012a executing a predetermined program stored in the memory 1012b. The battery management unit 10121 not only controls the entire battery pack 101, but also manages and controls its state.

[0030] 3 shows an example of the configuration of a charger. Charger 200 includes terminal group 201 (terminal 201a for charging, terminal 201b connected to ID terminal 1011c, and ground terminal 201c), AC / DC conversion unit 210, switch 220, resistor 230 for detecting charging current, and attachment plug 240 for connecting to a commercial power source such as a household power source. AC / DC conversion unit 210 includes charging control unit 211. When charging control unit 211 detects connection between ID terminal 1011c and terminal 201b and identifies the type of battery pack, it turns on switch 220 and controls the AC / DC conversion performed by AC / DC conversion unit 210 so that it is appropriate for the type of battery pack 101. In addition, charging control unit 211 detects the charging current from the potential difference across resistor 230, and when it detects that charging on the battery pack 101 side has been completed and the charging current has stopped flowing, it turns off switch 220.

[0031] 4 shows an example configuration of the motor drive control device 102. The motor drive control device 102 has a bridge circuit including FETs S11 to S16, an FET S17, a motor drive control unit 1022, an operation control unit 1021 that controls the entire motor drive control device 102, and a connector unit 1023 for connecting to the battery pack 101.

[0032] The motor drive control unit 1022 controls the switching of FETs S11 to S17 in response to instructions from the operation control unit 1021. For example, when the motor 105 is to be powered or regeneratively driven, the motor drive control unit 1022 turns on FET_S17 and turns on or off FETs S11 to S16 in a predetermined pattern.

[0033] The connector portion 1023 has a terminal 1023a for connection to the charging / discharging terminal 1011a of the battery pack 101, a terminal 1023b for connection to the communication terminal 1011b, and a ground terminal 1023c for connection to the ground terminal 1011d.

[0034] The operation control unit 1021 controls the entire motor drive control device 102, and is connected to various sensors such as the torque sensor 103, the pedal rotation sensor 104, and the Hall sensor included in the motor 105, as well as the brake sensor 107, and is also connected to the operation panel 106. The operation control unit 1021 is also connected to a battery management unit 10121 of the battery pack 101 via a terminal 1023b. The operation control unit 1021 controls the motor drive control unit 1022 and displays information on the display unit of the operation panel 106 based on signals from the operation panel 106, various sensors, the brake sensor 107, etc. At least some of the functions of the operation control unit 1021 are realized, for example, by the processor 1021a executing a predetermined program stored in the memory 1021b.

[0035] 5 shows an example of the configuration of the operation panel 106. The operation panel 106 has a light switch 1061, a power switch 1062 that also serves as an assist mode selection button, an LED 1063 for indicating the power on / off state, two 7-segment LEDs 1064, and an LED 1065 for indicating the assist mode.

[0036] The operation control unit 1021 is activated in response to pressing of the power switch 1062, and causes the LED 1063 to light up. The operation control unit 1021 also causes the 7-segment LED 1064 to display the remaining battery capacity based on the remaining battery capacity notified by the battery pack 101. The 7-segment LED 1064 may display information indicating an error mode or other setting mode in addition to the remaining battery capacity. The operation control unit 1021 also causes the LED 1065 to display the current assist mode. For example, if the mode is the weakest assist mode, only one of the LEDs 1065 is lit; if the mode is the next strongest assist mode, two of the LEDs 1065 are lit; and if the mode is the strongest assist mode, all three of the LEDs 1065 are lit. If the power switch 1062 is pressed briefly after the operation control unit 1021 has been activated, the operation control unit 1021 is set to shift the assist mode, for example, from the weak assist mode to the next strongest assist mode, and the operation control unit 1021 changes the illumination pattern of the LED 1065. When the power switch 1062 is pressed during operation, the operation control unit 1021 assumes that a power-off command has been issued and stops the operation.

[0037] In this embodiment, even when the limited charging mode is set for the battery pack 101, the display of the remaining battery capacity by the 7-segment LED 1064 after charging of the battery pack 101 is completed is not made to give the user the feeling of discomfort as if charging is not taking place.

[0038] Specifically, the operations shown in FIGS. 6 to 11 are executed by the battery management unit 10121 of the battery pack 101 and by the operation control unit 1021 of the motor drive control device 102.

[0039] First, the operation of the battery management unit 10121 of the battery pack 101 will be described with reference to FIGS.

[0040] First, the battery management unit 10121 determines whether or not it is connected to the charger 200 via the ID terminal 1011c or the like (step S1). For convenience of explanation, it is assumed here that it determines whether or not it is connected to the charger 200. If it is not connected to anything, the battery management unit 10121 determines whether or not the indicator button has been pressed (step S3). As described above, it determines whether or not the switch 10123 has been turned on. If the indicator button has not been pressed, the process returns to step S1.

[0041] On the other hand, if it is determined that the indicator button has been pressed, this is an instruction to display the charge level corresponding to the remaining battery capacity using the LED 10122, so the battery management unit 10121 acquires the battery cell voltage from the battery cell monitoring unit 10124 and determines the remaining battery capacity from the battery cell voltage (step S5). The correspondence between the battery cell voltage and the remaining battery capacity is known, and the remaining battery capacity is determined from the current battery cell voltage based on this correspondence.

[0042] Then, the battery management unit 10121 determines whether the current charging mode stored in the memory 1012b is the limited charging mode (step S7). If the current charging mode is the normal charging mode, the process proceeds to step S11.

[0043] On the other hand, if the current charging mode is the limit charging mode, the battery management unit 10121 adjusts the identified value SOC of the remaining battery capacity in accordance with a predetermined rule (step S9). In this embodiment, when charging in the limit charging mode, charging is completed at a predetermined remaining battery capacity that is lower than the remaining battery capacity in the fully charged state. However, by displaying the completed charging as if the battery is fully charged, the user's sense of discomfort is reduced. For this purpose, the value SOC of the actual remaining battery capacity is adjusted, for example, as follows. However, adjustment is made only when the actual remaining battery capacity exceeds 20%, and is not made when it is below 20%. Adjusted remaining battery capacity = (actual remaining battery capacity - B) / (AB) x (100 - B) + B For example, A=80% and B=20%. The upper limit of the remaining battery capacity after adjustment is 100.

[0044] The specific meaning of such adjustment will be explained in more detail later when explaining the display on the operation panel 106 (specifically, see the explanation of step S61 in FIG. 9). However, the above formula is adjusted so that in the limit charge mode in which charging is completed at 80%, when the actual remaining battery capacity is 80%, the adjusted remaining battery capacity is 100%, and the remaining battery capacity decreases linearly until the actual remaining battery capacity reaches 20%.

[0045] Then, the battery management unit 10121 lights up the LED 10122 according to the remaining battery capacity (the adjusted remaining battery capacity if adjustment is performed in the limit charge mode, or the actual remaining battery capacity if the normal charge mode) (step S11). When five LEDs are used, for example, if the remaining battery capacity is 100%, five LEDs are turned on; if the remaining battery capacity is less than 100% but 80% or more, the four LEDs from the bottom are turned on; if the remaining battery capacity is less than 80% but 60% or more, the three LEDs from the bottom are turned on; if the remaining battery capacity is less than 60% but 40% or more, the two LEDs from the bottom are turned on; if the remaining battery capacity is less than 40% but 20% or more, the one LED from the bottom is turned on; and if it is less than 20%, no LEDs are turned on. Such LED lighting rules are arbitrary.

[0046] The battery management unit 10121 stops lighting the LED 1063 after a certain period of time (step S13), and the process returns to step S1.

[0047] On the other hand, if it is determined that the battery pack 101 is connected to the charger 200, the battery management unit 10121 identifies the current charging mode and the current remaining battery capacity (step S15). The battery management unit 10121 determines whether the current remaining battery capacity is in a charging-completed state according to the charging mode (step S17). In the limited charging mode, charging is completed at, for example, 80%, and in the normal charging mode, charging is completed at 100%. If the charging is completed according to the current charging mode, no further charging will be performed, and the process proceeds to step S27.

[0048] On the other hand, if the charging is not completed according to the current charging mode, the battery management unit 10121 turns on the charging FET 10125 to start charging (step S19). Then, it determines whether the current charging mode is the limit charging mode (step S21), and if it is the limit charging mode, it adjusts the value SOC of the remaining battery capacity (step S23). This is the same as step S9. On the other hand, if the current charging mode is the normal charging mode, the process proceeds to step S25.

[0049] Thereafter, the battery management unit 10121 lights up the LEDs 10122 according to the remaining battery capacity (the adjusted remaining battery capacity if adjustment is performed in the limit charge mode, or the actual remaining battery capacity if the normal charge mode) (step S25). In this step, for example, if the remaining battery capacity is less than 20%, the first LED from the bottom blinks; if the remaining battery capacity is 20% or more but less than 40%, the first LED from the bottom blinks and the second LED blinks; if the remaining battery capacity is 40% or more but less than 60%, the two LEDs from the bottom blink and the third LED blinks; if the remaining battery capacity is 60% or more but less than 80%, the three LEDs from the bottom blink and the fourth LED blinks; and if the remaining battery capacity is 80% or more but less than 100%, the four LEDs from the bottom blink and the fifth LED blinks. Such LED lighting rules are arbitrary.

[0050] Then, the battery management unit 10121 determines whether or not the indicator button has been pressed (step S27). In this embodiment, if the indicator button is pressed and the switch 10123 is turned on while the battery is connected to the charger 200, this indicates that a charge mode switch has been instructed. If the indicator button has not been pressed, the process proceeds to the process of FIG. 7 via terminal B. On the other hand, if the indicator button has been pressed, the process proceeds to the process of FIG. 7 via terminal A.

[0051] 7 via terminal A. When the indicator button is pressed, the battery management unit 10121 switches the charging mode (step S29). If the current charging mode is the normal charging mode, it switches to the limit charging mode. If the current charging mode is the limit charging mode, it switches to the normal charging mode. The current charging mode is recorded in a predetermined area of ​​the memory 1012b, for example. The battery management unit 10121 then lights up the LEDs corresponding to the current charging mode (step S31). For example, if the charging mode after the switch is the normal charging mode, the first and fifth LEDs from the bottom are turned on, as shown in FIG. 8(a). On the other hand, if the charging mode after the switch is the limit charging mode, the second to fourth LEDs from the bottom are turned on, as shown in FIG. 8(b). This allows the user to visually recognize the charging mode after the switch. Note that such LED lighting rules are arbitrary.

[0052] Thereafter, the battery management unit 10121 determines whether or not the charging has reached a completion state according to the current charging mode (step S33). As described above, charging is completed at, for example, 80% in the limited charging mode, and at 100% in the normal charging mode, so it determines whether or not these conditions are met.

[0053] If charging is complete according to the current charging mode, the battery management unit 10121 turns off the charging FET 10125 to stop charging (step S35), and the process then ends.

[0054] On the other hand, if the charging is not completed according to the current charging mode, the battery management unit 10121 continues charging if charging is in progress, or turns on the charging FET 10125 to start charging if charging is not in progress (step S37). Then, the process returns to step S27 in FIG. 6 via terminal C.

[0055] By executing the above-described processing, it becomes possible to switch the charging mode and to display the charging level according to the charging mode using an LED.

[0056] In this embodiment, when the battery management unit 10121 is connected to the motor drive control device 102 and becomes capable of communication, it notifies the motor drive control device 102 of the current charge mode and the current remaining battery capacity (before adjustment) numerical value SOC. In the example described above, the battery management unit 10121 adjusts the remaining battery capacity numerical value SOC if the battery is in the limited charge mode, but since the LED 10122 has only five LEDs, it is also possible not to make the adjustment.

[0057] Next, the operation of the motor drive control device 102 will be described with reference to FIGS.

[0058] The operation control unit 1021 acquires the current charging mode from the battery management unit 10121 of the battery pack 101 (step S51). The operation control unit 1021 also acquires the current remaining battery capacity SOC from the battery management unit 10121 of the battery pack 101 (step S53). These are notified from the battery management unit 10121 of the battery pack 101 by communication via the terminals 1023b and 1011b.

[0059] Then, the operation control unit 1021 determines whether the current charging mode is the limit charging mode (step S55). If the current charging mode is the normal charging mode and not the limit charging mode, the operation control unit 1021 sets the current remaining battery capacity SOC as the display remaining battery capacity dSOC, which is the basis for the remaining battery capacity to be displayed on the display unit (step S57). Then, the process proceeds to step S63.

[0060] On the other hand, if the current charging mode is the limited charging mode, the operation control unit 1021 determines whether the current battery remaining capacity SOC exceeds the adjustment lower limit B (step S59). In this embodiment, for example, B is set to 20%. If the condition of step S59 is not met, for example, if the current battery remaining capacity SOC is 20% or less, the process proceeds to step S57, and dSOC becomes SOC without adjustment.

[0061] On the other hand, if SOC>adjustment lower limit B, the operation control unit 1021 adjusts the current remaining battery capacity SOC to determine the remaining battery capacity dSOC for display (step S61).

[0062] For example, if the relationship between the display remaining battery capacity dSOC and the current remaining battery capacity SOC is defined as a linear relationship, the current remaining battery capacity SOC is adjusted as follows. Display remaining battery capacity dSOC = (SOC-B) / (AB) x (100-B)+B A is the remaining battery capacity when charging is completed in the limited charging mode, and is, for example, 80%. The adjustment lower limit B is, for example, 20%. The upper limit of the display remaining battery capacity dSOC is 100%.

[0063] This adjustment is shown in Figure 10. In Figure 10, the horizontal axis represents the current remaining battery capacity SOC, and the vertical axis represents the display remaining battery capacity dSOC. The solid line a represents the relationship between the current remaining battery capacity SOC and the display remaining battery capacity dSOC in normal charging mode, where no adjustment is performed. On the other hand, the dashed-dotted line b represents the relationship between the current remaining battery capacity SOC and the display remaining battery capacity dSOC in the limited charging mode, as expressed by the above formula. That is, if the current remaining battery capacity SOC is 80% or more, the display remaining battery capacity dSOC remains at 100%, but if the current remaining battery capacity SOC is less than 80% but exceeds 20%, it is increased in accordance with the linear relationship represented by the dashed-dotted line b. If it is 20% or less, it becomes the same as in normal charging mode.

[0064] Instead of adjusting the current remaining battery capacity in this linear relationship, the current remaining battery capacity SOC may be adjusted to the display remaining battery capacity dSOC in accordance with a nonlinear relationship as shown by the two-dot chain line c. This adjustment results in a value that is closer to the actual remaining battery capacity than the adjustment as shown by the one-dot chain line b.

[0065] A function for such adjustment may be prepared in advance and adjustment may be performed based on the function, or a conversion table based on the function may be prepared and adjustment may be performed based on the conversion table.

[0066] By adjusting the display remaining battery capacity dSOC in this way, even if the actual remaining battery capacity SOC is 80% immediately after charging is completed in the limited charge mode, the display remaining battery capacity dSOC will be 100%. In other words, this prevents a typical user from mistaking charging for completion even immediately after charging is complete. Furthermore, even if charging is not completed immediately, the display remaining battery capacity dSOC gradually approaches the actual remaining battery capacity, making it less likely that the user will feel uncomfortable.

[0067] Then, the operation control unit 1021 converts the remaining battery capacity dSOC for display into the display content of the operation panel 106 (step S63). For example, the remaining battery capacity dSOC for display may be displayed as is on the display panel 106, but if it exceeds 20%, the remaining battery capacity may be displayed in 5% increments. For example, as shown in FIG. 11, if the remaining battery capacity dSOC for display is 96% or more, "FL" is displayed; if it is 91% to 95%, "95" is displayed; and if it is 86% to 90%, "90" is displayed. Note that such LED lighting rules are arbitrary. The dSOC may be displayed as is.

[0068] Thereafter, the operation control unit 1021 outputs the above-mentioned display contents to the operation panel 106, and causes the two 7-segment LEDs 1064, which are the display unit, to display them (step S65).

[0069] Then, the operation control unit 1021 determines whether the processing has ended, for example, by pressing the power switch 1062 to instruct power off (step S67). If the processing has not ended, the processing returns to step S51. On the other hand, if the processing has ended, the processing ends here. The processing of steps S51 to S65 is performed, for example, at predetermined time intervals.

[0070] As described above, in the limited charging mode, the display value of the charge level indicator of the battery pack 101 and the display value of the remaining battery capacity on the operation panel 106 are changed from the charging completion state to the display content expected by the user, and then gradually approach the actual remaining battery capacity, thereby reducing the sense of discomfort felt by the user. This also makes it possible to prevent the user from mistakenly thinking that charging is not yet complete and connecting the battery pack 101 to the charger 200 again.

[0071] In the limited charge mode, charging is completed at a predetermined remaining battery capacity (e.g., 80%) that is lower than full charge for regenerative charging, so in this embodiment, regenerative charging continues until the battery is truly fully charged even if the display remaining battery capacity dSOC is 100%. In other words, when the actual remaining battery capacity is in the range of, for example, 80% or more but less than 100%, the remaining battery capacity display remains "FL," but regenerative charging continues when the vehicle is running in a state where regeneration is possible.

[0072] Furthermore, the method for adjusting the remaining battery capacity in the battery management unit 10121 of the battery pack 101 and the method for adjusting the remaining battery capacity in the operation control unit 1021 of the motor drive control device 102 may be different.

[0073] [Embodiment 2] In the first embodiment, an example was shown in which the actual remaining battery capacity SOC was simply adjusted to the display remaining battery capacity dSOC. However, a large difference between the actual remaining battery capacity SOC and the display remaining battery capacity dSOC is undesirable in estimating the remaining driving distance. In other words, it is preferable that the actual remaining battery capacity SOC and the display remaining battery capacity dSOC coincide at an earlier stage. However, if the adjustment causes the display remaining battery capacity dSOC to change too rapidly, the user will feel uncomfortable.

[0074] In this embodiment, to address this problem, the operation control section 1021 of the motor drive control device 102 performs the operations shown in Figures 12 to 15 instead of the operations shown in Figure 9. Note that the same reference numerals are used to designate the same processing steps as in Figure 9.

[0075] First, the operation control unit 1021 acquires the current charging mode from the battery management unit 10121 of the battery pack 101 (step S51). Also, the operation control unit 1021 acquires the current remaining battery capacity SOC from the battery management unit 10121 of the battery pack 101 (step S53).

[0076] Then, the operation control unit 1021 determines whether the current charging mode is the limit charging mode (step S55). If the current charging mode is the normal charging mode and not the limit charging mode, the operation control unit 1021 sets the current remaining battery capacity SOC to the display remaining battery capacity dSOC (step S57). Then, the process proceeds to the process of FIG. 14 via terminal E.

[0077] On the other hand, if the current charging mode is the limit charging mode, the operation control unit 1021 determines whether the current battery remaining capacity SOC is equal to or greater than the charging completion level (e.g., 80%) (step S71). If the current battery remaining capacity SOC is equal to or greater than the charging completion level, the operation control unit 1021 resets the accumulated mileage to 0 (step S73). Then, the process proceeds to step S59. On the other hand, if the current battery remaining capacity SOC is less than the charging completion level, the process proceeds to step S59. In this embodiment, the degree of adjustment of the battery remaining capacity is changed based on the accumulated mileage since charging completion by the charger 200, so the accumulated mileage is reset each time charging completion by the charger 200. For this reason, charging completion is determined based on the condition in step S71, but data indicating whether charging has been completed in the limit charging mode may be obtained from the battery pack 101.

[0078] Then, the operation control unit 1021 determines whether the current remaining battery capacity SOC exceeds the adjustment lower limit B (step S59). For example, B is set to 20%. If the condition of step S59 is not met, for example, if the current remaining battery capacity SOC is 20% or less, the process proceeds to step S57, and dSOC=SOC without adjustment.

[0079] On the other hand, if the current remaining battery charge SOC exceeds the adjustment lower limit B, the operation control unit 1021 calculates a correction coefficient D for adjustment according to, for example, the following formula (step S75). D = cumulative distance traveled x coefficient Note that D≦100−A (A is, for example, 80). The cumulative travel distance can be obtained, for example, by adding the cumulative travel distance from the previous calculation to the travel distance from the previous calculation to the current calculation. The travel distance may be calculated, for example, by multiplying the number of tire rotations during that period (for example, the number of rotations of the motor 105 provided on the front wheel) by the tire circumference. It may also be calculated by multiplying the number of pedal rotations during that period by the gear ratio by the tire circumference. If the vehicle speed of the electrically assisted bicycle 1 can be obtained, the vehicle speed may be stored at regular intervals (for example, every second), and the travel distance may be calculated from the cumulative value of the vehicle speed during that period. The coefficient is a predetermined value, for example, 0.01.

[0080] An example of the relationship between the cumulative mileage and the correction coefficient D is shown in FIG. 13. In this example, the value is multiplied by a coefficient of 0.01 up to a cumulative mileage of 20 km, and is therefore represented by a straight line d. Note that the correction coefficient D is maintained at 20 for cumulative mileages of 20 km or more. The straight line d is just an example, and the correction coefficient D may also be calculated from the cumulative mileage using a non-linear relationship such as that represented by the dotted curve e. The correction coefficient D may also be calculated using a function represented by the straight line d or the dotted curve e shown in FIG. 13, or a conversion table may be prepared and used for calculation.

[0081] 14 via terminal D, the operation control unit 1021 determines whether the correction coefficient D is equal to or less than the correction limit value (for example, 100-A, more specifically, for example, 20) (step S77). If the correction coefficient D exceeds the correction limit value, the operation control unit 1021 sets the correction coefficient D to be equal to the correction limit value (step S79). Then, the process proceeds to step S81. On the other hand, if the correction coefficient D is equal to or less than the correction limit value, the process proceeds to step S81 without performing any action.

[0082] Then, the operation control unit 1021 adjusts the current remaining battery capacity using the correction coefficient D to determine the remaining battery capacity dSOC for display (step S81).

[0083] For example, the current battery state of charge SOC is adjusted as follows: Display remaining battery capacity dSOC = (SOC-B) / {(A+D)-B}×(100-B)+B The difference from the formula shown in the first embodiment is that in the denominator, (AB) is replaced by {(A+D)-B}, where B is, for example, 20 and A is, for example, 80.

[0084] The meaning of this formula will be explained using Figure 15. The basic part of this figure is the same as Figure 11, but as the correction coefficient D increases, the slope of line b decreases and becomes line X. When the correction coefficient D reaches its correction limit value, the slope of line b becomes the same as line a in the normal charging mode. In other words, the actual remaining battery capacity SOC and the displayed remaining battery capacity dSOC become the same.

[0085] In this way, immediately after charging is complete, the display battery remaining capacity is 100%, allowing the user to recognize that charging is complete. As the cumulative mileage increases, the strength of the adjustment to the battery remaining capacity SOC gradually weakens, and when the correction coefficient D reaches the correction limit value, the adjustment ceases. In other words, as the vehicle continues to travel, the difference between the battery remaining capacity and the display battery remaining capacity gradually decreases, allowing the user to accurately estimate how far the vehicle can travel from the display battery remaining capacity. In the first embodiment, if the vehicle is traveling in an assist mode with low power consumption and the actual battery remaining capacity does not decrease easily, it will take some time for the battery remaining capacity and the display battery remaining capacity to match. By taking the cumulative mileage into account in this way, the battery remaining capacity and the display battery remaining capacity can be made to match once the cumulative mileage reaches a certain distance.

[0086] Then, the operation control unit 1021 converts the remaining battery capacity dSOC for display into the display content of the operation panel 106 (step S63). For example, as shown in Fig. 11, if the remaining battery capacity dSOC for display is 96% or more, "FL" is displayed, if it is 91% to 95%, "95" is displayed, and if it is 86% to 90%, "90" is displayed.

[0087] Thereafter, the operation control unit 1021 outputs the above-mentioned display contents to the operation panel 106, and causes the two 7-segment LEDs 1064, which are the display unit, to display them (step S65).

[0088] Then, the operation control unit 1021 determines whether the processing has ended, for example, by pressing the power switch 1062 to instruct power-off (step S67). If the processing has not ended, the processing returns to step S51 in FIG. 12 via terminal F.

[0089] On the other hand, if the processing is to be completed, the operation control unit 1021 stores the current cumulative travel distance in the memory 1021b (step S83) to prepare for the next travel. Then, the processing is terminated. Note that the processing of steps S51 to S65 in Figs. 12 and 14 is also performed, for example, at predetermined time intervals.

[0090] In this way, by weakening the degree of adjustment to the remaining battery capacity according to the distance traveled, the decrease in the remaining battery capacity appears large compared to the distance traveled immediately after charging is complete, but as the distance traveled increases, the excessive decrease in the remaining battery capacity gradually decreases, and after a certain distance has been traveled, the actual remaining battery capacity and the displayed remaining battery capacity match. This allows the user to accurately estimate how far they can travel from the remaining battery capacity display on the operation panel 106. For example, if the remaining battery capacity does not seem sufficient for the distance to be traveled, they can switch to an assist mode with a weaker assist power to suppress the decrease in the remaining battery capacity, making it easier to manage the battery so that it does not run out of power while riding.

[0091] The method of calculating the correction coefficient D can be modified in various ways. For example, the rate of increase of the correction coefficient D may be changed depending on the assist mode. For example, the rate of increase of the correction coefficient D may be increased in an assist mode with high power consumption, and may be decreased in an assist mode with low power consumption. The higher the power consumption, the faster the battery approaches the normal charging mode, thereby displaying a more accurate remaining battery capacity.

[0092] It is also possible to consider a mode in which the time elapsed since the completion of charging is added to the correction parameter based on the cumulative mileage. Also, although the straight line b is assumed above, it may be a curved line.

[0093] [Embodiment 3] In the first embodiment, as shown in Fig. 16(a), when the limit charge mode is set and charging is completed, dSOC will be 100% even if SOC is 80%. If the battery pack 101 is then connected to the motor drive control device 102 and the motor 105 is driven to a certain extent, as shown in Fig. 16(b), for example, SOC will decrease to 65%, but dSOC will be 80%. Now, assume that the battery pack 101 is charged again.

[0094] Here, no particular problem occurs if charging is performed without changing the limit charging mode, but problems may arise if the limit charging mode is switched to the normal charging mode. For example, if charging is stopped when the SOC is 70% after switching to the normal charging mode, as shown in FIG. 16(c), if the SOC is 70%, dSOC will also be 70% because no adjustment has been made. In FIG. 16(b), dSOC is 80%, so 80% is displayed on the operation panel 106. However, in FIG. 16(c), even though charging has actually been performed, the display shows 70%, leading the user to mistakenly believe that charging has not been performed. This embodiment solves this problem.

[0095] For this reason, the battery management unit 10121 of the battery pack 101 executes the processes of Figures 6 and 17 instead of the processes of Figures 6 and 7. The part of Figure 6 is the same, so its explanation will be omitted, and the part of Figure 17 that differs from Figure 7 will be explained.

[0096] In the first embodiment, the set charging mode (normal charging mode or limited charging mode) is notified directly from the battery management unit 10121 of the battery pack 101 to the operation control unit 1021 of the motor drive control device 102, but in this embodiment, the set charging mode is used for its own charging control, but the charging mode to be notified to the motor drive control device 102 is managed separately.

[0097] Therefore, when it is determined in step S33 that charging is complete according to the current charging mode and charging is stopped in step S35, the battery management unit 10121 updates the charging mode at the time of charging completion, for example, in memory 1012b (step S91). That is, if charging is not complete, the charging mode at the time of charging completion is not updated, and the charging mode at the time of the previous charging completion is maintained as is. Thereafter, the charging mode at the time of charging completion is notified to the motor drive control device 102. In addition, the battery management unit 10121 updates the remaining battery capacity at the time of charging completion, for example, in memory 1012b (step S93). This remaining battery capacity at the time of charging completion is notified to the motor drive control device 102.

[0098] Next, the operation of the operation control unit 1021 in the motor drive control device 102 will be described with reference to FIG.

[0099] First, the operation control unit 1021 acquires the charging mode at the time of completion of charging (which may differ from the current charging mode) from the battery management unit 10121 of the battery pack 101 (step S101). The operation control unit 1021 also acquires the remaining battery capacity at the time of completion of charging from the battery management unit 10121 of the battery pack 101 (step S103). The operation control unit 1021 also acquires the current remaining battery capacity SOC from the battery management unit 10121 of the battery pack 101 (step S53). These are notified from the battery management unit 10121 of the battery pack 101 by communication via the terminals 1023b and 1011b.

[0100] Then, the operation control unit 1021 determines whether the acquired charging mode is the limit charging mode (step S55). If the acquired charging mode is the normal charging mode and not the limit charging mode, the operation control unit 1021 sets the current remaining battery capacity SOC to the display remaining battery capacity dSOC (step S57). Then, the process proceeds to step S63.

[0101] On the other hand, if the acquired charging mode is the limited charging mode, the operation control unit 1021 determines whether the current battery remaining capacity SOC exceeds the adjustment lower limit B (step S59). In this embodiment, for example, B is set to 20%. If the condition of step S59 is not met, for example, if the current battery remaining capacity SOC is 20% or less, the process proceeds to step S57, and dSOC becomes SOC without adjustment.

[0102] On the other hand, if the current battery remaining capacity SOC exceeds the adjustment lower limit B, the operation control unit 1021 adjusts the current battery remaining capacity SOC using the battery remaining capacity at the time of completion of charging to determine the display battery remaining capacity dSOC (step S105).

[0103] For example, if the relationship between the display remaining battery capacity dSOC and the current remaining battery capacity SOC is defined as a linear relationship, the current remaining battery capacity SOC is adjusted as follows. Display remaining battery capacity dSOC = (SOC-B) / (remaining battery capacity at full charge - B) x (100-B) + B In the first embodiment, A was fixed at 80%, but in this embodiment, the remaining battery capacity at the time of completion of charging is used instead of A. The adjustment lower limit B is, for example, 20. Also, the upper limit of the display remaining battery capacity dSOC is 100. If the remaining battery capacity at the time of completion of charging is 80, the same formula as in the first embodiment is used.

[0104] 16(c), if the charging mode is switched from the limit charging mode to the normal charging mode and charging is stopped when the SOC is 70%, and the SOC is 70%, the dSOC will also be 70% because there is no adjustment in the normal charging mode. However, in this embodiment, if charging is not completed in the normal charging mode even after switching to the normal charging mode, steps S91 and S93 are not executed, so the charging mode at the completion of charging is the limit charging mode, and the remaining battery capacity at the completion of charging is the remaining battery capacity when charging is completed in the limit charging mode.

[0105] Therefore, step S105 is executed, and as shown in Figure 19, even if the SOC is 70%, the display battery remaining capacity dSOC is calculated using the formula shown above and determined to be 87% by processing in the limited charge mode.

[0106] If charging is completed in the limited charging mode, the SOC will be 80% and the dSOC will be 100%, as shown in Figure 16(a). On the other hand, if charging is completed without stopping the charging by switching to the normal charging mode, the SOC will be 100% and the dSOC will also be 100%, as shown in Figure 20.

[0107] Then, the operation control unit 1021 converts the remaining battery capacity dSOC for display into the display content of the operation panel 106 (step S63). For example, as shown in Fig. 11, if the remaining battery capacity dSOC for display is 96% or more, "FL" is displayed, if it is 91% to 95%, "95" is displayed, and if it is 86% to 90%, "90" is displayed.

[0108] Thereafter, the operation control unit 1021 outputs the above-mentioned display contents to the operation panel 106, and causes the two 7-segment LEDs 1064, which are the display unit, to display them (step S65).

[0109] Then, the operation control unit 1021 determines whether the processing has ended, for example, by pressing the power switch 1062 to instruct power off (step S67). If the processing has not ended, the processing returns to step S101. On the other hand, if the processing has ended, the processing ends here. The processing of steps S101 to S65 is performed, for example, at predetermined time intervals.

[0110] In this way, the user will not feel uncomfortable even in the situation described in FIG.

[0111] The above description deals with the case where the remaining battery capacity at the time of completion of charging is notified from the battery pack 101. This is effective in a situation where the remaining battery capacity at the time of completion of charging in the limit charge mode differs depending on the battery pack 101, but if the remaining battery capacity at which charging is completed in the limit charge mode is the same, it is also possible not to receive the notification from the battery pack 101. In other words, steps S103 and S93 may be omitted.

[0112] In the third embodiment, the correction coefficient D, which is a function of the cumulative mileage, was not mentioned, but the correction coefficient D may be introduced as in the second embodiment. Furthermore, the modified example of the correction coefficient D described in the second embodiment may be introduced in the third embodiment. Furthermore, in step S105, an example has been shown in which dSOC varies linearly with SOC except for the portion where dSOC is 100%, but dSOC may also vary nonlinearly with SOC.

[0113] [Embodiment 4] In the third embodiment, if the battery pack 101 is fully charged in the limited charge mode, consumes a certain amount of power, and then switches to the normal charge mode and charges until the current battery remaining capacity SOC reaches, for example, 95%, the display remaining battery capacity dSOC shown by the bold dotted line f in FIG. 21 is obtained. That is, when the SOC is between 95% and 80%, even if the battery pack 101 is attached to the power-assisted bicycle 1 and driven with assist, dSOC remains 100%, and the operation panel 106 displays "FL" indicating full charge. After that, as the SOC decreases, dSOC also decreases, and when the SOC falls below 20%, dSOC = SOC. Note that the solid line a always represents the normal charge mode, where dSOC = SOC.

[0114] A change in dSOC such as the bold dotted line f gives the user a sense of incongruity. For example, if it is assumed that the vehicle can travel 100 km when the SOC is 100%, then charging until the SOC reaches 95% will allow the vehicle to travel 95 km. According to the third embodiment, the display on the operation panel 106 remains fully charged until the SOC reaches 80%, i.e., until the vehicle has traveled 15 km. In addition, if the SOC decreases as the vehicle continues to travel, the remaining battery capacity displayed on the operation panel 106 rapidly decreases, which also gives the user a sense of incongruity. This makes it difficult for the user to understand the relationship between the remaining battery capacity displayed on the operation panel 106 and the travel distance.

[0115] The above describes the case where the SOC is charged to 95%, but the closer the charging is to 100%, the longer the SOC interval W displayed on the operation panel 106 as fully charged, and the greater the sense of discomfort caused by the adjustment of the remaining battery capacity according to the third embodiment.

[0116] Therefore, in this embodiment, once the battery pack 101 has been fully charged in the limit charge mode, a certain amount of power is consumed, and then the battery is switched to the normal charge mode and charged until the current battery remaining capacity SOC reaches, for example, 95%, dSOC is immediately reduced in accordance with the reduction in SOC, as shown by the fine thick dotted line g in Figure 22. In this way, if charging is stopped when the SOC is between 80% and 100%, which is the SOC at which charging is completed in the limit charge mode, the display battery remaining capacity dSOC is set to 100% based on the battery remaining capacity at the time charging was stopped, and dSCO is reduced as the SOC decreases. Note that when the SOC falls below 20%, dSOC = SOC.

[0117] The operation for calculating such dSOC will be described with reference to FIGS.

[0118] The processing flow in FIG. 23 is a modification of the processing flow in FIG. 17, and the differences will be mainly described below. Steps S29 to S33 are the same as in FIG. 17, and if it is determined that charging has reached a completion state according to the charging mode (step S33: Yes route), the battery management unit 10121 stops charging (step S35) and updates the charging mode at the time of completion of charging, for example, in memory 1012b (step S91). In other words, if charging is not completed, the charging mode at the time of completion of charging is not updated, and the charging mode at the time of the previous completion of charging is maintained as is. Thereafter, the charging mode at the time of completion of charging is notified to the motor drive control device 102. Up to this point, the processing is the same as in FIG. 17.

[0119] Furthermore, the battery management unit 10121 updates the remaining battery capacity at the time of charging stop in, for example, the memory 1012b (step S99). This remaining battery capacity at the time of charging stop is notified to the motor drive control device 102. Since charging is complete, 100% is recorded as the remaining battery capacity at the time of charging stop in the normal charging mode, and 80% is recorded in the limit charging mode.

[0120] If the remaining battery capacity at which charging is completed in the limited charging mode is other than 80%, the remaining battery capacity at the time of charging completion is recorded in, for example, memory 1012b, separately from the remaining battery capacity at the time charging is stopped.

[0121] On the other hand, if charging has not reached the charging completion state according to the charging mode, the battery management unit 10121 determines whether charging has been stopped because the user removed the battery pack 101 or unplugged the attachment plug 240 of the charger 200 from the commercial power source (step S95). If charging has not been stopped, the battery management unit 10121 continues charging if charging is in progress, or turns on the charging FET 10125 to start charging if charging is not in progress (step S37). Then, the process returns to step S27 in FIG. 6 via terminal C.

[0122] On the other hand, if charging is stopped, the battery management unit 10121 updates the remaining battery capacity at the time of charging stop in, for example, the memory 1012b (step S97). This process is the same as step S99. Then, the process ends.

[0123] Thereafter, the remaining battery capacity at the time charging is stopped, which is recorded in, for example, memory 1012b, is notified to the motor drive control device 102.

[0124] Next, the operation of the operation control unit 1021 in the motor drive control device 102 will be described with reference to FIG.

[0125] First, the operation control unit 1021 acquires the charging mode at the time of charging completion (which may differ from the current charging mode) from the battery management unit 10121 of the battery pack 101 (step S101). The operation control unit 1021 also acquires the remaining battery capacity C at the time charging stopped from the battery management unit 10121 of the battery pack 101 (step S111). The operation control unit 1021 also acquires the current remaining battery capacity SOC from the battery management unit 10121 of the battery pack 101 (step S53). These are notified from the battery management unit 10121 of the battery pack 101 by communication via the terminals 1023b and 1011b.

[0126] Then, the operation control unit 1021 determines whether the charge mode acquired in step S101 is the limit charge mode (step S55). If it is the normal charge mode rather than the limit charge mode, the operation control unit 1021 sets the current remaining battery capacity SOC to the display remaining battery capacity dSOC (step S57). Then, the process proceeds to step S63.

[0127] On the other hand, if the charging mode acquired in step S101 is the limit charging mode, the operation control unit 1021 determines whether the current remaining battery capacity SOC exceeds the adjustment lower limit B and whether the remaining battery capacity C at the time when charging stopped is equal to or greater than the remaining battery capacity A at which charging is completed in the limit charging mode (step S113). In this embodiment, for example, B is set to 20%, and A is set to 80%. A may be variable, and in that case, is notified by the battery management unit 10121 of the battery pack 101. If the condition of step S113 is not met, for example, if the current remaining battery capacity SOC is 20% or less, or if the remaining battery capacity C at the time when charging stopped is less than the remaining battery capacity A at which charging is completed in the limit charging mode, the process proceeds to step S57, and dSOC=SOC is set without adjustment.

[0128] On the other hand, if the condition of step S113 is met, the operation control section 1021 adjusts the current remaining battery capacity SOC using the remaining battery capacity when charging was stopped, and determines the remaining battery capacity dSOC for display (step S115).

[0129] For example, if the relationship between the display remaining battery capacity dSOC and the current remaining battery capacity SOC is defined as a linear relationship, the current remaining battery capacity SOC is adjusted as follows. Display remaining battery capacity dSOC = (SOC-B) / (remaining battery capacity when charging stops CB) x (100-B) + B The upper limit of the remaining battery capacity dSOC for display is 100. The difference from the third embodiment is that the remaining battery capacity C when charging is stopped is used instead of the remaining battery capacity when charging is completed.

[0130] The following processing is the same as that in FIG. 18 and that in FIG. 9, and therefore will not be described. In this way, unless the remaining battery capacity C exceeds 90%, for example, if the remaining battery capacity C when charging is stopped is 90% and the current remaining battery capacity SOC increases to 95% due to regeneration or the like, the display remaining battery capacity dSOC will not be maintained at 100%. However, if the current remaining battery capacity SOC falls below 90% due to power consumption, the display remaining battery capacity dSOC will become lower than 100%.

[0131] Therefore, the user is less likely to experience the sense of discomfort described with reference to FIG.

[0132] In the fourth embodiment, the correction coefficient D, which is a function of the cumulative mileage, was not mentioned, but the correction coefficient D may be introduced as in the second embodiment. Furthermore, the modified example of the correction coefficient D described in the second embodiment may be introduced in the fourth embodiment. Furthermore, in step S115, an example has been shown in which dSOC varies linearly with SOC except for the portion where dSOC is 100%, but dSOC may also vary nonlinearly with SOC.

[0133] Although the embodiments of the present invention have been described above, the present invention is not limited to these. For example, depending on the purpose, any technical feature in each of the above-described embodiments may be deleted, or any technical feature described in another embodiment may be added.

[0134] Furthermore, the above-described representation of the component group is merely an example, and one component may be divided into multiple components, or multiple components may be integrated into one component. Regarding the operational flow, the order of steps may be changed or multiple steps may be executed in parallel, as long as the content of the operation remains the same.

[0135] Furthermore, although memory 1012b and memory 1021b are shown as single components, they may include a ROM (Read Only Memory) portion and a RAM (Random Access Memory) portion. Processor 1012a and 1021a may also be a combination of multiple microprocessors, rather than just one.

[0136] The above-described embodiment can be summarized as follows.

[0137] The electrically power-assisted vehicle of this embodiment includes: (A) a display device (e.g., a display unit of the operation panel 106) that displays the remaining battery capacity; (B) a battery pack that can be set to either a first charging mode (e.g., a normal charging mode) that charges the battery cells (e.g., the battery cells 1013 in the battery 101) until they are fully charged, or a second charging mode (e.g., a limited charging mode) that completes charging when the battery cells are charged to a predetermined remaining battery capacity (e.g., 80% in this embodiment) that is lower than full charge; and (C) a control device (e.g., the motor drive control device 102) that, when the charging mode notified from the battery pack is the first charging mode, causes the display device to display the remaining battery capacity based on the current remaining battery capacity notified from the battery pack, and, when the charging mode notified from the battery pack is the second charging mode, adjusts the current remaining battery capacity notified from the battery pack and causes the display device to display the remaining battery capacity based on the adjusted remaining battery capacity.

[0138] In the second charging mode, charging is completed when the battery cells are charged to a predetermined remaining battery capacity that is lower than full charge, so if the actual remaining battery capacity is displayed as is, the user may mistakenly believe that the battery is not fully charged. In this embodiment, in the second charging mode, the current remaining battery capacity is adjusted to prevent the user from misunderstanding or feeling uncomfortable.

[0139] The above-mentioned adjustment may be a process in which, when the current remaining battery capacity is equal to or greater than a predetermined first value (for example, 20% in the embodiment, which is the lower limit of the adjustment) but less than the predetermined remaining battery capacity, the current remaining battery capacity is increased based on a predetermined linear or non-linear relationship with the adjusted remaining battery capacity, and the current remaining battery capacity is fully charged when it is equal to or greater than the predetermined remaining battery capacity. With such adjustment, the second charging mode is notified, and if the current remaining battery capacity is equal to or greater than the predetermined remaining battery capacity, the remaining battery capacity is displayed as fully charged, thereby preventing the user from feeling uncomfortable.

[0140] The control device described above may also be configured to weaken the intensity of the adjustment as the driving distance of the electrically assisted vehicle increases. In other words, the remaining battery charge is brought closer to the current remaining battery charge as the driving distance of the electrically assisted vehicle increases. By weakening the intensity of the adjustment in accordance with the user's perception of the remaining battery charge decreasing as a result of driving, the user's sense of discomfort is reduced.

[0141] Furthermore, the above-described battery pack may store the first charging mode when the battery cells are fully charged in the first charging mode, and may store the second charging mode when the battery cells are fully charged in the second charging mode, and may notify the above-described control device of the last stored charging mode, in order to solve the display problem that occurs when the charging mode is switched before charging is complete and the battery is removed from the charger.

[0142] Furthermore, the control device described above may weaken the strength of the adjustment in accordance with an increase in an index value (e.g., correction coefficient D) based on the cumulative traveling distance of the electrically assisted vehicle, and may vary the degree of increase in the index value based on the cumulative traveling distance of the electrically assisted vehicle in accordance with the assist mode of the electrically assisted vehicle. For example, if the electrically assisted vehicle is traveling in an assist mode with high power consumption, increasing the index value further weakens the strength of the adjustment in accordance with the user's perception that the remaining battery capacity is decreasing rapidly, and the remaining battery capacity display can quickly approach the current remaining battery capacity.

[0143] Furthermore, the above-described battery pack may store the first charging mode when the battery cells are fully charged in the first charging mode, and may store the second charging mode when the battery cells are fully charged in the second charging mode, store the second remaining battery capacity at the time when charging was stopped, and notify the above-described control device of the last stored charging mode and the last stored second remaining battery capacity. In this case, the adjustment may be a process of increasing the current remaining battery capacity based on a predetermined linear or nonlinear relationship with the adjusted remaining battery capacity when the current remaining battery capacity is equal to or greater than a predetermined first value (e.g., 20% in the embodiment) and less than the second remaining battery capacity, and the second remaining battery capacity is equal to or greater than the predetermined remaining battery capacity, and full charging when the current remaining battery capacity is equal to or greater than the second remaining battery capacity.

[0144] In this way, it is possible to reduce the range of remaining battery capacity in which the adjusted remaining battery capacity is set to full charge, thereby reducing the sense of discomfort felt by the user.

[0145] Even when the second battery remaining capacity is used, the control device described above may weaken the strength of the adjustment in accordance with an increase in the distance traveled by the electric assist vehicle, or may weaken the strength of the adjustment in accordance with an increase in the index value based on the cumulative distance traveled by the electric assist vehicle, and may change the degree of increase in the index value based on the cumulative distance traveled by the electric assist vehicle in accordance with the assist mode of the electric assist vehicle.

[0146] The battery pack according to this embodiment can be set to either (D) a battery cell, (E) a first charging mode (e.g., a normal charging mode) in which the battery cell is charged until it is fully charged, or a second charging mode (e.g., a limit charging mode) in which charging is completed when the battery is charged to a predetermined remaining battery capacity that is lower than the full charge, and has a management unit (e.g., a battery management unit 10121) that adjusts the current remaining battery capacity value when the charging mode is the second charging mode. In this way, the remaining battery capacity may be adjusted on the battery pack side.

[0147] The battery pack may further include (F) a display unit (e.g., LED 10122) that displays the charge level. The management unit may cause the display unit to display the charge level based on the current remaining battery capacity when the charge mode is the first charge mode, and may cause the display unit to display the charge level based on the adjusted remaining battery capacity when the charge mode is the second charge mode. The charging status according to the charge mode can be checked even if the battery pack is not connected to the electrically power assisted vehicle.

[0148] Furthermore, the management unit may store the first charging mode when the battery cells are fully charged in the first charging mode, and store the second charging mode when the battery cells are fully charged in the second charging mode, and notify the control device of the electrically power assisted vehicle of the last stored charging mode. This solves the display problem that occurs when the charging mode is switched before charging is complete and the vehicle is removed from the charger.

[0149] Furthermore, the management unit may store the first charging mode when the battery cells are fully charged in the first charging mode, store the second charging mode when the battery cells are fully charged in the second charging mode, store the second remaining battery capacity at the time charging was stopped, and notify the control device of the electrically power assisted vehicle of the last stored charging mode and the last stored second remaining battery capacity. This is to solve, by another method, the display problem that occurs when the charging mode is switched before charging is complete and the battery is removed from the charger.

[0150] The display method according to this embodiment includes the steps of: (G) displaying the remaining battery capacity on a display device of the electrically power-assisted vehicle based on the current remaining battery capacity notified from the battery pack when the charging mode notified from the battery pack is set to either a first charging mode in which the battery cells are charged until fully charged or a second charging mode in which charging is completed when the battery cells are charged to a predetermined remaining battery capacity lower than fully charged; and (H) adjusting the current remaining battery capacity notified from the battery pack and displaying the remaining battery capacity on the display device based on the adjusted remaining battery capacity when the charging mode notified from the battery pack is the second charging mode. In the second charging mode, adjusting the current remaining battery capacity reduces user misunderstanding and discomfort. Note that this display method may be executed by a motor drive control device, in which case the motor drive control device has components for executing each step as hardware, software, or a combination thereof.

[0151] Such a configuration is not limited to the matters described in the embodiment, and may be implemented in other configurations that provide substantially the same effects. [Explanation of symbols]

[0152] 101 Battery pack 102 Motor drive control device 1012 Battery Management System 10121 Battery management unit 1013 Battery Cells 106 Operation Panel 1021 Motion control unit

Claims

1. a display device that displays the remaining battery capacity; a battery pack that can be set to either a first charging mode in which the battery cells are charged until they are fully charged, or a second charging mode in which charging is completed when the battery cells are charged to a predetermined remaining battery capacity that is lower than the full charge; a control device that, when the charging mode notified from the battery pack is the first charging mode, causes the display device to display the remaining battery capacity based on the current remaining battery capacity notified from the battery pack, and, when the charging mode notified from the battery pack is the second charging mode, adjusts the current remaining battery capacity notified from the battery pack and causes the display device to display the remaining battery capacity based on the adjusted remaining battery capacity; and The adjustment is When the current remaining battery capacity is equal to or greater than a predetermined first value and less than the predetermined remaining battery capacity, the current remaining battery capacity is increased based on a predetermined linear or non-linear relationship with the adjusted remaining battery capacity, and when the current remaining battery capacity is equal to or greater than the predetermined remaining battery capacity, the battery is fully charged. Electrically assisted vehicle.

2. The control device The strength of the adjustment is weakened as the travel distance of the electrically assisted vehicle increases. The electrically assisted vehicle according to claim 1.

3. The battery pack If the battery cell is in the first charging mode, the first charging mode is stored when the battery cell is fully charged; In the second charging mode, when the battery cell is charged up to the predetermined remaining battery capacity, the second charging mode is stored; Informing the control device of the last stored charging mode 3. The electrically assisted vehicle according to claim 1 or 2.

4. The control device weakening the strength of the adjustment in accordance with an increase in an index value based on a cumulative traveling distance of the electrically assisted vehicle; The degree of increase in the index value based on the cumulative traveling distance of the electrically assisted vehicle is changed according to the assist mode of the electrically assisted vehicle. The electrically assisted vehicle according to claim 1 or 3.

5. a display device that displays the remaining battery capacity; a battery pack that can be set to either a first charging mode in which the battery cells are charged until they are fully charged, or a second charging mode in which charging is completed when the battery cells are charged to a predetermined remaining battery capacity that is lower than the full charge; a control device that, when the charging mode notified from the battery pack is the first charging mode, causes the display device to display the remaining battery capacity based on the current remaining battery capacity notified from the battery pack, and, when the charging mode notified from the battery pack is the second charging mode, adjusts the current remaining battery capacity notified from the battery pack and causes the display device to display the remaining battery capacity based on the adjusted remaining battery capacity; and The battery pack If the battery cell is in the first charging mode, the first charging mode is stored when the battery cell is fully charged; In the second charging mode, when the battery cell is charged up to the predetermined remaining battery capacity, the second charging mode is stored; storing the second remaining battery capacity at the time when charging was stopped; notifying the control device of the last stored charging mode and the last stored remaining capacity of the second battery; The adjustment is When the current remaining battery capacity is equal to or greater than a predetermined first value and less than the second remaining battery capacity, and when the second remaining battery capacity is equal to or greater than the predetermined remaining battery capacity, the current remaining battery capacity is increased based on a predetermined linear or non-linear relationship with the adjusted remaining battery capacity, and when the current remaining battery capacity is equal to or greater than the second remaining battery capacity, the battery is fully charged. Electrically assisted vehicle.

6. The control device The strength of the adjustment is weakened as the travel distance of the electrically assisted vehicle increases. The electrically assisted vehicle according to claim 5.

7. The control device weakening the strength of the adjustment in accordance with an increase in an index value based on a cumulative traveling distance of the electrically assisted vehicle; The degree of increase in the index value based on the cumulative traveling distance of the electrically assisted vehicle is changed according to the assist mode of the electrically assisted vehicle. The electrically assisted vehicle according to claim 5.

8. A battery cell; a management unit that can set either a first charging mode in which the battery cells are charged until they are fully charged, or a second charging mode in which charging is completed when the battery cells are charged to a predetermined remaining battery capacity that is lower than the full charge, and that adjusts the current remaining battery capacity value when the charging mode is the second charging mode; and The adjustment is When the current remaining battery capacity is equal to or greater than a predetermined first value and less than the predetermined remaining battery capacity, the current remaining battery capacity is increased based on a predetermined linear or non-linear relationship with the adjusted remaining battery capacity, and when the current remaining battery capacity is equal to or greater than the predetermined remaining battery capacity, the battery is fully charged. Battery pack.

9. Charge level display and The management unit When the charging mode is the first charging mode, the display unit displays a charging level based on a current remaining battery capacity; When the charging mode is the second charging mode, the display unit is caused to display a charge level based on the adjusted remaining battery capacity.

9. The battery pack according to claim 8.

10. The management unit If the battery cell is in the first charging mode, the first charging mode is stored when the battery cell is fully charged; In the second charging mode, when the battery cell is charged up to the predetermined remaining battery capacity, the second charging mode is stored; Notify the control device of the electrically assisted vehicle of the last stored charging mode 10. The battery pack according to claim 8 or 9.

11. The management unit If the battery cell is in the first charging mode, the first charging mode is stored when the battery cell is fully charged; In the second charging mode, when the battery cell is charged up to the predetermined remaining battery capacity, the second charging mode is stored; storing the second remaining battery capacity at the time when charging was stopped; notifying a control device of the electrically assisted vehicle of the last stored charging mode and the last stored remaining capacity of the second battery; 10. The battery pack according to claim 8 or 9.

12. a step of displaying a remaining battery capacity on a display device of the electrically power assisted vehicle based on the current remaining battery capacity notified from a battery pack that can be set to either a first charging mode in which the battery cells are charged until they are fully charged or a second charging mode in which charging is completed when the battery cells are charged to a predetermined remaining battery capacity that is lower than the full charge; when the charging mode notified from the battery pack is the first charging mode, adjusting a current remaining battery capacity notified by the battery pack when the charging mode notified by the battery pack is the second charging mode, and displaying the remaining battery capacity on the display device based on the adjusted remaining battery capacity; Including, The adjustment is a process of increasing the current remaining battery capacity based on a predetermined linear or non-linear relationship with the adjusted remaining battery capacity when the current remaining battery capacity is equal to or greater than a predetermined first value and less than the predetermined remaining battery capacity, and fully charging the battery when the current remaining battery capacity is equal to or greater than the predetermined remaining battery capacity; How to display remaining battery capacity.

13. a means for displaying a remaining battery capacity on a display device of the electrically power assisted vehicle based on the current remaining battery capacity notified from the battery pack when the charging mode notified from the battery pack is the first charging mode, the battery pack being capable of being set to either a first charging mode in which the battery cells are charged until they are fully charged or a second charging mode in which charging is completed when the battery cells are charged to a predetermined remaining battery capacity that is lower than the full charge; means for adjusting a current remaining battery capacity notified from the battery pack when the charging mode notified from the battery pack is the second charging mode, and displaying the remaining battery capacity on the display device based on the adjusted remaining battery capacity; and The adjustment is When the current remaining battery capacity is equal to or greater than a predetermined first value and less than the predetermined remaining battery capacity, the current remaining battery capacity is increased based on a predetermined linear or non-linear relationship with the adjusted remaining battery capacity, and when the current remaining battery capacity is equal to or greater than the predetermined remaining battery capacity, the battery is fully charged. Motor drive control device.

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