JP2001128371A - Power supply system for motor-driven vehicle - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a power supply system, for a motor-driven vehicle, by which a user will not be given misunderstanding of failure or the like, even when a charging operation is stopped such as when a charging stop temperature is reached or the like before a rechargeable battery is fully charged. SOLUTION: This power supply system for a motor-driven vehicle is provided with a rechargeable battery 102. The system is provided with a charging device 112, which charges the rechargeable battery 102. The system is provided with a battery control device 105, which functions as a charging control means used to control a charging state by the charging device 112 and which functions as a display control means, in such a way that a display in a charging operation by a display means 119 used to display a battery state, including the charging capacity of the rechargeable battery corresponds to the charging capacity. By the display control means, when the charging control means stops the charging operation before the rechargeable battery is fully charged, a temporary fully charged display by which a charging capacity in a stop before the rechargeable battery is fully charged, is displayed as 100 by the display means 119. By the charging control means, the charging device 112 performs additional charging operation, after the stop before the rechargeable battery is fully charged.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a power supply system for an electric vehicle provided with a rechargeable battery such as Ni-Cd or Ni-MH used as an energy source in, for example, electric bicycles, electric wheelchairs, electric scooters and the like. In particular, the present invention relates to an improvement in a method of displaying a charged capacity when charging is stopped before the battery is fully charged.

[0002]

2. Description of the Related Art The rechargeable battery, if exposed to too high a temperature during charging, shortens the battery life. To prevent this, a charge stop temperature Tco is provided, and when the battery temperature reaches this charge stop temperature. Stops charging. However, when charging is stopped by detecting the charging stop temperature, a sufficient charging capacity may not be secured. When a charging capacity indicator comprising a plurality of LED indicators and configured so that the number of indicators increases with an increase in charging capacity is provided, if the charging capacity is not sufficient, only a small number of indicators are turned on. It will be. Therefore, for the purpose of securing the charge amount, the above-described charging is regarded as the main charging and the additional charging is performed.

[0003]

However, since the additional charging is performed with a lower charging current value than the main charging, a considerable time is required for charging, and therefore the number of lights of the display does not increase easily. However, there is a case where a user who sees this may misunderstand that the charger has failed or the battery has reached the end of its life, and an improvement in this respect is required.

SUMMARY OF THE INVENTION The present invention has been made in view of the above-mentioned problems, and provides a power supply system for an electric vehicle which does not give a user a misunderstanding such as a failure even when charging is stopped before full charge such as reaching a charging stop temperature. The challenge is to provide

[0005]

According to the first aspect of the present invention, there is provided a rechargeable battery, charging means for charging the rechargeable battery, charge control means for controlling a state of charge by the charging means, and a rechargeable battery. Display means for displaying a battery state including a charge capacity;
A display control means for controlling a display at the time of charging by the display means to correspond to a charge capacity, wherein the display control means is such that the charge control means is fully charged. When the charging is stopped before, the display means displays a temporary full charge display in which the charge capacity at the time of the stop before the full charge is set to 100, and the charging control means causes the charging means to perform the full charging. It is characterized in that additional charging is performed after the previous stop.

According to a second aspect of the present invention, in the first aspect, the display control means causes the display means to display the temporary full charge display only when the charge capacity at the time of the stop before full charge is equal to or greater than a lower threshold. It is characterized by:

According to a third aspect of the present invention, in the first or second aspect, the display control means causes the display means to perform full charge of the temporary full charge display when the charge capacity reaches an upper limit threshold by the additional charge. It is characterized by switching to display.

[0008]

According to the first aspect of the present invention, when charging is stopped before the battery is fully charged, a temporary full charge display is displayed in which the charge capacity at the time of the stop before the full charge is set to 100. Therefore, it is possible to prevent a problem that the user has unnecessary misunderstanding and anxiety due to a small number of lightings by the display means. In this case, additional charging is performed automatically, so that the charging capacity increases to the normal full charging capacity, and there is almost no problem that the mileage becomes shorter.

According to the second aspect of the present invention, the provisional full charge display is performed only when the charge capacity at the time of the stop before full charge is equal to or more than the lower limit threshold, so that the actual charge capacity is displayed. It is possible to prevent an excessive difference from being generated between the charging capacity and the charging capacity, and it is possible to prevent the traveling distance from being shortened when the vehicle starts traveling in the provisionally full charged state.

According to the third aspect of the present invention, the provisional full charge display is switched to the full charge display when the charge capacity reaches the upper limit threshold due to the additional charge, so that the provisional full charge display is performed. In most cases, when the vehicle actually travels, a normal full charge display is displayed, and there is almost no difference between the actual charge capacity and the display capacity.

[0011]

Embodiments of the present invention will be described below with reference to the accompanying drawings. 1 to 4 are views for explaining a power supply system for an electric assisted bicycle according to an embodiment of the present invention. FIG. 1 is a side view of the electric assisted bicycle as the electric vehicle, and FIG. FIG. 3 is a schematic diagram of a display, and FIG. 4 is a battery temperature and battery voltage characteristic diagram for explaining the operation.

In the figure, reference numeral 1 denotes an electric assisted bicycle as an electric vehicle provided with a detachable battery case in which a charging device is not mounted on the vehicle in the power supply system of the present embodiment. A down tube 4 extending obliquely downward from the head pipe 3 to the rear of the vehicle body, a seat tube 5 extending substantially upright from a rear end of the down tube 4, and extending substantially horizontally rearward from a rear end of the down tube 4. A pair of left and right chain stays 6, a pair of left and right seat stays 7 connecting the rear ends of both chain stays 6 and the upper end of the seat tube 5, the head pipe 3 and the seat tube 5, And a top tube 11 for connecting the

A front fork 8 is pivotally supported on the head pipe 3 so as to be rotatable left and right. A front wheel 9 is pivotally supported at the lower end of the front fork 8, and a steering handle 10 is fixed at the upper end. A saddle 12 is attached to the upper end of the seat tube 5. Further, a rear wheel (wheel) 13 is supported at the rear end of the chain stay 6.

Although not shown, an instrument panel (not shown) provided with a speed meter and the like is provided at the center of the steering handle 10, and it is determined that a refresh discharge is necessary in this panel portion. A display device may be provided for displaying the fact when the display is completed.

At the lower end of the body frame 2, a pedaling force (manpower) input to a pedal 16 b via a crank arm 16 a attached to a projecting portion at both ends of the crankshaft 16, and a force from a built-in electric motor 17. A power unit 15 for outputting a resultant force with auxiliary power proportional to the magnitude of human power is mounted. That is, the magnitude of the pedal effort becomes the motor drive command 28. The output from the power unit 15 is transmitted to the rear wheel 13 via a chain 30.

A battery case 100 serving as a power source for the electric motor 17 and the like is detachably attached to the vehicle body along the rear surface of the seat tube 5 and between the left and right seat stays 7,7. It is arranged. The battery case 100 houses a battery (rechargeable battery) 102 formed by connecting a number of unit cells 101 in series. The battery case 100 also includes a temperature sensor 103 for detecting the temperature of the battery 102, and a current of the battery 102. And an ammeter 104 for measuring a value. Further, the battery case 100 includes a battery management device 105 for managing the battery 102 and the like, and an EEPROM 106 for storing predetermined data. This EE
The PROM 106 stores the remaining capacity, temperature, and the like of the rechargeable battery during charging as the predetermined data.

When the battery case 100 is mounted on a vehicle, the motor drive circuit 22 is connected by the connectors 107 and 108.
And a communication I / F 1 with a travel control unit 109 for controlling the travel of the electric assist bicycle 1 by the connectors 110 and 111.
They are connected via 20a and 120b.

On the other hand, the battery case 100 is connected to the output side of a non-vehicle completely independent charging device 112 by the connectors 113 and 114 in a state where the battery case 100 is detached from the vehicle body during charging or in a vehicle-mounted state. Then, the connectors 115 and 116 are connected via the communication I / Fs 127 and 120c of the charging device 112.

In FIG. 1, reference numeral 100a denotes a charging port provided in the battery case 100.
The battery case side terminals of the connectors 113, 114, 115, and 116 are arranged in the battery case. Reference numeral 121 denotes the charging device 11
2 is a charging plug, in which the connectors 113 to 113 are connected.
116 charging device side terminals are arranged, and can be freely inserted into the charging port 100a. The battery case 100 and the charging device 112 constitute the power supply system 21 in the present embodiment.

The battery management device 105 receives the battery temperature data T from the temperature sensor 103, the current value data I from the ammeter 104, and the voltage data V of the battery 102, and A battery management / control unit 117 for controlling refresh discharge and the like and the EEPROM 106 for storing predetermined data are provided. Also, the battery management device 105 displays various information such as the remaining battery capacity and refresh notification information by pressing a display button 118 when a display is required based on a signal from the battery management / control unit 117. And a communication I / F 120c for performing communication with the charging device 112.

As shown in FIG. 3, a display panel of the display device 119 has a battery status display section 119a including seven LEDs 140a to 140g and one LED 140h.
And a push button switch 138 are provided. Battery status display section 119
a is the remaining rate (% of the remaining capacity with respect to the initial capacity) of the battery 102 based on the pressing pattern of the push button switch 138 and the display pattern of the LEDs 140a to 140g;
Any one of the number of charge / discharge cycles, the charge rate (% of the charge capacity to the initial capacity), etc. is displayed, and the notification display section 119b indicates that the battery needs to be replaced or refreshed by blinking or continuous lighting of the LED 140h. Indicates that discharge is required. The initial capacity means the maximum capacity when the unused battery is fully charged.

Then, the battery management / control unit 117
In addition to functioning as charge control means for controlling the state of charge of the battery 102 by the charging device 112, that is, charge start conditions, charge stop conditions, charge end conditions, and the like, the battery 10
2 functions as display control means for causing the display device 119 to display the charge capacity.

The charge start condition is, for example, that charging starts when the battery temperature is equal to or higher than the lower limit temperature of the charge start and equal to or lower than the upper limit temperature. As a charge stop condition, for example, when the battery temperature reaches the charge stop temperature Tco, the charge is temporarily stopped regardless of the charge capacity. In this case, the function as the charge control means of the battery management / control section 117 causes the charging device 112 to perform the additional charge when a predetermined additional charge start condition is satisfied. Further, as the condition for terminating the charging, there is a point that when the battery voltage decreases from the maximum voltage −ΔV or when the battery temperature rise rate dT / dt is equal to or more than a predetermined value, the battery is considered to be fully charged and the charging ends.

The battery management / control section 117 functions as the display control means so that the display device 119 is operated.
To make the following display. For example, when charging is stopped before the battery is fully charged due to the battery temperature reaching the charging stop temperature Tco, and the charging capacity at that time has reached a predetermined lower threshold (for example, a charging rate of 70%). Causes the display device 119 to perform a provisional full charge display in which the charge capacity at the time of stop before full charge is set to 100.

The above-mentioned battery management / control unit 117 determines that the charge capacity is such that the charge capacity is a predetermined upper limit threshold and the charge rate is such that there is no practical problem assuming full charge, for example, 9
The display device 119 causes the display device 119 to display a full charge when the charge reaches 0%.

The charging device 112 is an AC / DC converter (charging means) 124 for converting AC power supplied by connecting the plug 123 to an outlet to DC.
A voltmeter 125 and an ammeter 126 for measuring a voltage value and a current value of the output of the converter 124;
02, a discharger 135 for performing a refresh discharge, measurement values from the voltmeter 125 and the ammeter 126, and the communication I
/ F127 and a charge / discharge control unit 128 to which a predetermined signal or the like is input.

The charging device 112 includes a battery connection detecting unit 129 that outputs a connection signal indicating that the charging device 112 and the battery case 100 are connected to the charging / discharging control unit 128. ing.

Further, when the display device 133 (described later) indicates that refresh discharge is necessary, the user presses the charge device 112 to issue a refresh discharge instruction signal to the charge / discharge control unit 128. Is provided. As shown in FIG. 2, the refresh switch 13 having the same function as the refresh switch 131 is used.
7 may also be provided on the battery case 100 side.

The output of the AC / DC converter 124 is supplied to the charge / discharge control unit 128 via the output control unit 132.
Is controlled by The display device 133 and the discharger 135 are controlled by the charge / discharge control unit 128. The display device 133 displays information such as charging standby, charging, charging completion, charging stop, refresh notification, refreshing, refresh end, and the like.
Of these, the refresh notice may be simultaneously displayed on the display device 119 on the battery case side.

Next, the lighting control of the display device 119 during charging by the battery management / control section 117 will be described. FIG.
As shown in FIG. 5, in the case of a relatively new battery having a short operating time, the battery temperature gradually rises almost over the entire charging range as shown by the curve a, and rises relatively sharply at the end of charging when the battery is fully charged. As shown by a curve b, the battery voltage has a so-called -ΔV characteristic in which the voltage slightly rises abruptly at the end of charging and then slightly decreases from the maximum voltage. Therefore, when it is detected that dT / dt or -ΔV is equal to or greater than a predetermined value, the charging capacity is substantially full. At this time, in the display device 119, as the charging progresses, 14
0f, 140e,..., And at the end of the charging, all the LEDs 140g to 140a are lit.

On the other hand, in the case of a battery in which the internal resistance has increased due to a long use time, the battery temperature rises relatively sharply in the first half of charging and reaches the charging stop temperature Tco early, as shown by the curve c. As shown in FIG. 3A, the charging may be stopped when the charging capacity becomes, for example, near a charging rate of more than 70%. In this case, in this embodiment, as shown in FIG.
Assuming 0, all the LEDs 140g of the battery state display section 119a
A temporary full charge display for lighting 140a is performed.

In fact, the display by the display device 119 is terminated by the stop of the charging, and all the LEDs are illuminated. However, when the charging rate is displayed by pressing the push button switch 138, the above-mentioned temporary state is displayed. By the full charge display, all the LEDs 140g to 140a are turned on.

Further, as described above, when the charging is stopped, the additional charging is started when the additional charging condition is satisfied, and the temporary full charge display is displayed when the charging rate reaches the upper limit threshold that can be regarded as the full charge. The display is canceled and the display is switched to the full charge display in which the charge exceeding the upper limit threshold is regarded as the full charge.

As described above, according to the present embodiment, when the charging is stopped due to the battery temperature reaching the charging stop temperature Tco before the battery is fully charged, the charging capacity at the time of stopping before the full charging (for example, Since the provisional full charge display in which the charge rate is 70%) is displayed as 100, the battery state display unit 11
Since all the LEDs 140g to 140a of 9a are turned on, and the appearance is fully charged, it is possible to prevent the user from having a useless misunderstanding or anxiety due to a low displayed charging rate. In this case, since additional charging is performed automatically, the charging rate rises to a normal full charge, and there is almost no problem that the travelable distance is shortened.

When the vehicle starts running immediately after the provisional full charge display, the assistable travel distance becomes shorter because the absolute capacity of the battery is small because the charge rate of 70% is displayed as 100%. However, it is not often that the vehicle starts running immediately after the above display, and after a considerable amount of time,
For example, since traveling often starts on the next day, the above-described additional charging is performed during that time, and the problem that the assistable travel distance is shortened hardly occurs.

Also, the provisional full charge display is performed only when the charge capacity at the time of the stop before the full charge is equal to or more than the lower limit threshold, for example, the charge rate is 70%, so that the actual charge capacity and the displayed charge capacity are displayed. This can prevent an excessive difference from occurring, and can suppress a reduction in the assistable travel distance when the vehicle starts traveling in the provisionally full charged state.

Further, when the charge capacity reaches the upper limit threshold value by additional charge, for example, a charge rate (about 90%) that does not cause a problem assuming full charge, a full charge display indicating that the battery is fully charged is displayed. Therefore, while performing the provisional full charge display, most of the time when actually driving is a normal full charge display, and there is no difference between the actual charge capacity and the display capacity. rare.

[Brief description of the drawings]

FIG. 1 is a side view of an electric assist bicycle according to an embodiment of the present invention.

FIG. 2 is a block diagram of a power supply system according to the embodiment.

FIG. 3 is a schematic diagram of a display device of the power supply system.

FIG. 4 is a battery temperature and battery voltage characteristic diagram for explaining the operation of the device of the embodiment.

[Explanation of symbols]

21 Power supply system 102 Rechargeable battery 112 Charging device (charging means) 117 Battery management / control unit (charging control means, display control means) 119 Display device (display means)

Claims (3)

[Claims] 1. A rechargeable battery, charging means for charging the rechargeable battery, charge control means for controlling a state of charge by the charging means, and display means for displaying a battery state including a charge capacity of the rechargeable battery. And a display control means for controlling a display at the time of charging by the display means to be in accordance with the charge capacity, wherein the display control means comprises: If the charging is stopped before reaching the condition, the display means performs a provisional full charge display in which the charging capacity at the time of the stop before the full charge is displayed as 100, and the charging control means causes the charging means to A power supply system for an electric vehicle, wherein additional charge is performed after a stop before full charge. 2. The display control device according to claim 1, wherein the display control means causes the display means to display the temporary full charge display only when the charge capacity at the time of the stop before full charge is equal to or more than a lower threshold. Power supply system for electric vehicles. 3. The display control means according to claim 1, wherein the display control means causes the display means to switch the temporary full charge display to a full charge display when the charge capacity reaches an upper limit threshold due to the additional charge. Characteristic power supply system for electric vehicles.