JPH10257688A - Battery charging device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a battery charging device which can accurately detect a state of full charge and also enables avoidance of a state with the generation of energizing stoppage in the course of charging and shortage of charging. SOLUTION: In this device, an energizing circuit 32 is provided and made to function as a refreshing means for making a battery discharge to a prescribed voltage or below and also to function as a means for energizing this battery. A charge amount detecting sensor 35 is provided, so as to detect the amount of charge of the battery. Moreover, a controller (CPU) 33 is provided and made to function as an energizing control means, which stops the energizing of the battery at the time when the amount of charge of the battery becomes a prescribed value or above in the charging, after the refresh processing has been executed.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a rechargeable battery (battery) charging apparatus such as a nickel-cadmium battery or a nickel-metal hydride battery.

[0002]

2. Description of the Related Art Conventionally, a battery employed in an electrically assisted vehicle or the like is charged by a charging device as the discharge proceeds.
In the conventional battery charger, when any one of a temporary decrease (−ΔV) of the battery voltage that occurs at the time of full charge, which is equal to or more than a predetermined value, an increase of the battery temperature, which is equal to or more than a predetermined value, and a lapse of a predetermined energizing time is detected. The power supply is stopped assuming that the battery is fully charged.

[0003]

However, in the above-mentioned conventional charging device, the above-mentioned temporary drop (-.DELTA.V) of the battery voltage, which is a condition for detecting that the battery has reached full charge, is as follows.
If the battery temperature at the start of charging is a high value (for example, 30 ° C. or higher), it is unlikely to occur. On the other hand, there is a case where the voltage temporarily abnormally changes due to noise or the battery state regardless of the battery temperature or the charge amount. Therefore, in the case of the method of stopping the power supply on condition that the temporary decrease (−ΔV) of the battery voltage is detected, it is possible to accurately determine whether or not the battery is fully charged depending on the battery temperature at the start of the power supply. If the voltage is temporarily changed abnormally due to noise or battery status during charging, it is erroneously recognized as -ΔV and the power supply is stopped before reaching full charge, and sufficient charging cannot be performed. There is a problem that there is.

The present invention has been made in view of the above problems, and provides a battery charger capable of accurately detecting a full charge state and avoiding a problem that power supply is stopped during charging and insufficient charging occurs. It is intended to be.

[0005]

According to the first aspect of the present invention, there is provided a refresh processing means for discharging a battery until the voltage becomes equal to or lower than a predetermined voltage, an energizing means for energizing the battery, and a charge amount for detecting a charge amount of the battery. It is characterized by comprising a detection unit and an energization control unit that stops energization of the battery when the charge amount of the battery becomes equal to or more than a predetermined value in charging after the refresh processing.

According to a second aspect of the present invention, there is provided an energizing means for energizing the battery, a temperature detecting means for detecting the temperature of the battery, a voltage detecting means for detecting the voltage of the battery, and a temperature at the start of charging of the battery. Is less than or equal to a predetermined value,
And a power supply control means for stopping power supply to the battery when a decrease of the battery voltage by a predetermined value or more is detected.

According to a third aspect of the present invention, there is provided an energizing means for energizing the battery, a temperature detecting means for detecting a temperature of the battery, a temperature at the time of starting charging of the battery being equal to or higher than a predetermined value, and And a power supply control means for stopping power supply to the battery when the elapsed time is equal to or more than a predetermined value or when the battery temperature becomes equal to or more than a predetermined value.

According to a fourth aspect of the present invention, there is provided an energizing means for energizing the battery, an ambient temperature detecting means for detecting a temperature around the charging device, and a charging current value when the ambient temperature is low when the ambient temperature is high. And a power supply control means for controlling the power supply means so as to be higher than a charging current value.

According to a fifth aspect of the present invention, there is provided an energizing means for energizing the battery, a battery temperature detecting means for detecting the temperature of the battery, and energizing the energizing means when the battery temperature is equal to or higher than a predetermined charging start temperature. And a power supply control means for stopping power supply to the power supply means when the temperature is equal to or lower than a charge stop instruction temperature set to a temperature lower than the charge start temperature.

[0010]

Embodiments of the present invention will be described below with reference to the accompanying drawings. FIGS. 1 to 4 are views for explaining a battery charging device for a battery-assisted bicycle according to a first embodiment of the present invention. FIG. 1 is a side view of the battery-assisted bicycle, and FIG. FIG. 3 is a flowchart illustrating the operation of the charging device, and FIG. 4 is a characteristic diagram illustrating the relationship between time, voltage, and temperature during charging and discharging of the charging device. .

In FIG. 1, reference numeral 1 denotes an electric assisted bicycle. A body frame 2 has a head pipe 3, a down tube 4 extending obliquely rearward and downward from the head pipe 3, and a rear end of the down tube 4. A seat tube 5 extending substantially upright, a pair of left and right chain stays 6 extending substantially horizontally rearward from a rear end of the down tube 4, a rear end portion of both the chain stays 6 and the seat tube 5 And a pair of left and right seat stays 7 that are coupled to the upper end of the seat stay.

The down tube 4 and the seat tube 5
A mounting bracket 2a is welded to the joint portion between the left and right chain stays 6 to the mounting bracket 2a.

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 seat post 11 is inserted into the seat tube 5 so as to be adjustable in height, and a saddle 12 is mounted on an upper end of the seat post 11. Further, a rear wheel 13 is pivotally supported at the rear end of the chain stay 6, and the rear wheel 13 is locked by a key type wheel lock 14 attached to the seat stay 7. The key can be removed only in the locked state of the wheel lock 4.

An auxiliary drive device 15 is mounted on the vehicle body frame 2.
Is installed. The auxiliary drive device 15 includes a power unit 20 that outputs a combined force of a pedal depression force input to a crankshaft 16 and an auxiliary force from an electric motor 17, a battery 21 that supplies power to the electric motor 17, And a controller 22 for variably controlling the auxiliary force from the controller 17.

The battery 21 is disposed along the rear surface of the seat tube 5 and in a space surrounded by the seat tube 5, the left and right seat stays 7, and the rear fender 13a. A handle 2 is provided on the upper wall of the battery 21.
1a is formed, and can be taken in and out upward by the handle 21a. When the battery 21 is taken in and out, the saddle 12 is tilted forward. The battery 21 is provided with a charging plug so that the battery 21 can be charged in either a state where the battery 21 is mounted on the vehicle body or a state where the battery 21 is removed.

A support box 25 for supporting the battery 21 is bolted to the upper wall of the mounting bracket 2a. A motor-side terminal that is automatically connected to the power supply when the battery 21 is inserted is provided in the support box 25.

In FIG. 2, reference numeral 31 denotes a charging device for charging the battery 21. The charging device 31 includes an energizing circuit 32 as energizing means for changing a current value to the battery 21, and a controller (CPU) 33 for controlling the operation of the energizing circuit 32. An energization time detection sensor 34 for detecting the energization time to the battery 21, a charge amount of the battery 21, specifically, a charge amount detection sensor 35 for detecting the battery voltage, and a temperature for detecting the battery temperature and the ambient temperature of the charging device 31. Each detection value from the detection sensor 36 is input, and based on the input value, functions as an energization control unit that controls a charging current value to the battery 21 and starts and stops energization.

A main switch 37 is connected to the controller 33, and an "ON, OFF, REF" signal indicating the position of the switch is input. When the main switch 37 is turned to the refresh position “RFE” when the connection terminal 38 of the charging device 31 is connected to the charging terminal of the battery 21, the controller 33 operates the energization circuit 32. The battery 21
Is performed so that the voltage is reduced to a predetermined voltage or less, and the energization is started after the refresh processing. Reference numeral 39 denotes an outlet for a 100V external power supply 40.

Next, the charging operation of the charging device 31 of the present embodiment will be described mainly with reference to FIGS. here,
The characteristic line A in FIG. 4 shows the change in the voltage between the terminals of the battery 21 with the lapse of the charging time, the curve B shows the change in the voltage between the terminals of the battery 21 with the lapse of the discharging time, and C, D indicates a change in the temperature of the cell surface of the battery 21 and a change in the temperature of the case surface of the battery 21 with the elapse of the charging time.

The charging device 31 is connected to the battery 21 and the main switch 37 is set to the refresh position "RF
When it is turned to "E", the above-described discharge processing is performed (steps S1 and S2).

After the discharging process, the temperature of the battery 21 becomes 3
If the temperature is equal to or higher than 0 ° C., the energization is started, and when the energizing time has passed 4.5 hours, when the temperature of the battery 21 has risen to 45 ° C. or higher, the charge amount of the battery 21, specifically, the battery voltage The power supply to the battery 21 is stopped with any satisfaction when the value has exceeded the predetermined value (step S).
3-S8). In addition, as a method of detecting the charge amount, a method based on an integrated value of the charging current value × time can be adopted.

In step S1, the execution of the refresh process is not instructed and the main switch 37 is set to "O".
When rotated to the "N" position, the charging process is performed without going through the refresh process (step S9). After the refresh processing, if the battery temperature is lower than 30 ° C. in the above-mentioned step S3, the process proceeds to step 9 to perform charging. Then, similarly to the above steps S5 to S6, when the energization time has passed 4.5 hours or when the battery temperature is 4
When the temperature reaches 5 ° C. or higher, the charging is completed, the energization is stopped, and the temporary decrease in the battery voltage is reduced to a predetermined value (−Δ
V) The energization is also stopped when it is detected that the voltage is equal to or more than V) (step S12).

As the charging time elapses, the voltage of the battery 21 rises as shown by a characteristic line A in FIG.
At the time of full charge, the voltage temporarily decreases as indicated by -ΔV.
Further, as shown by the characteristic lines C and D, the temperature of the battery 21 gradually increases after the start of charging due to the endothermic reaction of the battery.
After once decreasing by t ° C., it increases when approaching full charge. A predetermined condition is satisfied in steps S5 to S7 and steps S10 to S12, and a broken line E
When the energization is stopped at the point of, the battery voltage drops stepwise from the voltage at the time of full charge by a predetermined value. Further, the voltage of the battery 21 decreases as shown by a characteristic line B during discharging.

As shown by the characteristic lines C and D, the temperature of the battery 21 once decreases by Δt ° C. after energization, and in order to prevent the charging operation from being stopped by the temperature decrease of Δt ° C. It is desirable to provide a so-called hysteresis of Δt ° C. or more between the two temperatures so that the charging stop instruction temperature is, for example, −5 ° C. or less, while the temperature is 0 ° C. or more, for example.

As described above, in the present embodiment, it is determined that the charging is completed when the battery charge amount reaches the predetermined value on the condition that the refresh processing is performed. Drop (-ΔV)
Battery temperature at the start of charging is 30 ° C
Under the above circumstances where -ΔV is unlikely to occur originally, -ΔV
Since V is not used as a charge completion condition, even if a temporary abnormal change in voltage occurs due to noise or a battery state, this is not erroneously recognized as -ΔV, and power is supplied before reaching full charge. Stopping can be prevented and full charging can be ensured.

In the case where charging is started without performing the refresh process at the start of charging, or when the battery temperature at the start of charging is lower than 30 ° C., the occurrence of −ΔV is used as the charging end condition. In this case, when the battery is fully charged, -ΔV is reliably generated, so that the fully charged state can be reliably detected.

Next, the operation of the battery charger according to the second embodiment of the present invention will be described with reference to FIG. Note that the configuration of the battery charger is the same as that of FIG.

As shown in FIG. 5, in the battery charging device 31 of the second embodiment, the power-off condition is set based on the battery temperature at the start of charging regardless of the presence or absence of the refresh processing.

Specifically, when the charging device 31 is connected to the battery 21 and the main switch 37 is turned to the refresh position "RFE", the above-described discharging process is performed (steps S21 and S22). When the main switch 37 is turned to the ON position "ON", the process immediately proceeds to step S23.

After the discharging process, charging by the charging device 31 is started. If the temperature of the battery 21 is 30 ° C. or more, when the energizing time has passed 4.5 hours or the battery 21 The power supply to the battery 21 is stopped with any satisfaction when the temperature of the battery 21 rises to 45 ° C. or higher (steps S23 to S27). That is, when the battery temperature at the start of energization is higher than 30 ° C., a temporary decrease in battery voltage −ΔV is not set as the charge completion condition.

On the other hand, if the battery temperature is lower than 30 ° C. in the above step S23, the above steps S25 and S2
6, the energization is stopped either when the energization time has passed 4.5 hours or when the battery temperature has risen to 45 ° C. or higher, and the battery voltage temporarily drops (−Δ
The current supply is also stopped when V) is detected (steps S29 to S31).

As described above, regardless of the presence or absence of the refresh processing, when the battery temperature at the start of charging is lower than 30 ° C., a temporary drop (−ΔV) of the battery voltage that occurs reliably at the time of full charging is detected. With this configuration, similarly to the charging device of the first embodiment, a fully charged state can be reliably detected.

On the other hand, in a situation where -ΔV is originally unlikely to occur, such as when the temperature at the start of charging is 30 ° C. or higher, -ΔV is not used as a charge completion condition. Even if a change occurs, this is not erroneously recognized as -ΔV, and the power supply does not stop before full charge.

Next, the charging operation of the charging device according to the third embodiment of the present invention will be described with reference to FIG.
Note that the configuration of the battery charger is the same as that of FIG.

When the charging device 31 is connected to the battery 21 and the main switch 37 is turned ON, the ambient temperature of the charging device 31 and the battery temperature are detected (step S40), and the battery temperature is reduced to 0 ° C. If the temperature is lower than 40 ° C., the power supply to the battery 21 is started (steps S41 to S42). In this case, the charging current value is controlled to be larger as the ambient temperature is lower. For example, as shown in Table 1,
When the ambient temperature is 0 ° C., 20 ° C., and 40 ° C., the charging current is set to 5.0 A, 2.5 A, and 1.0 A, respectively.
Then, when the battery temperature during charging falls to -5 ° C or lower, the power supply is terminated as an abnormality (steps S43 to S43).
44).

[0036]

[Table 1]

On the other hand, when the battery temperature is in the normal range higher than -5.degree. C., when the energizing time exceeds 4.5 hours, when the temperature of the battery 21 rises to 45.degree. The power supply to the battery 21 is stopped at any time when the temporary decrease (−ΔV) occurs (steps S45 to S48).

As described above, in the present embodiment, the charging device 31
Since the charging current value is set to be larger as the ambient temperature is lower, the time required for charging can be shortened accordingly. For example,
As shown in Table 1, when the charging current value is 1.0 A, it takes 6 hours to fully charge, whereas 2.5 A, 5.0 A
In the case of A, the battery was fully charged in 2 hours and 1 hour.

Here, the larger the charging current is set, the higher the temperature of the charging device 31 is, the shorter the life of the charging device 31 is, and the more care must be taken in handling. However, when the ambient temperature is low, Even if the charging current is increased, the surface temperature of the charging device 31 is about 50 ° C., and there is not much problem.

In the present embodiment, when the battery temperature is abnormally lowered, when the power supply is terminated during the charging, the temperature at which charging can be started is 0 ° C. or higher, whereas the charging stop instruction temperature is-. Since the temperature is set to 5 ° C or less, if charging is started in a cold environment where the ambient temperature is 0 to 2 ° C, even if the battery temperature drops slightly due to an endothermic reaction that occurs even during normal charging, this temperature drop is abnormal until -5 ° C. Can be prevented from being recognized, and the stop of energization before reaching full charge can be prevented.

[0041]

As described above, according to the battery charger of the first aspect of the present invention, the power supply to the battery is stopped when the charge amount of the battery becomes equal to or more than a predetermined value on condition that the charge after the refresh processing is performed. In other words, the condition is that the battery is charged from a so-called "empty" state, so that the full charge state of the battery can be reliably detected, and a temporary voltage drop (-.DELTA.V) is not a charge completion condition. Therefore, it is possible to prevent a temporary abnormal change in the battery voltage caused by noise or the battery state from being erroneously recognized as -ΔV, and to prevent the power supply from being stopped before reaching the full charge. Has the effect of being fully charged.

According to the second aspect of the present invention, the condition that the temperature at the start of charging of the battery is equal to or lower than a predetermined value, that is, a temporary decrease (−Δ
Since the energization is stopped when the temporary decrease is detected on condition that V) occurs reliably, the full charge state can be reliably detected. If the temperature at the time is equal to or higher than a predetermined value, -ΔV
Is not set as the charge completion condition, the temporary abnormal voltage change caused by noise or the battery is not erroneously recognized as -ΔV, and there is an effect that the full charge can be reliably performed.

According to the fourth aspect of the present invention, the charging current value when the ambient temperature of the charging device is low is higher than that when the ambient temperature is high. In addition, there is an effect that the time required for charging can be reduced without requiring special handling precautions.

According to the fifth aspect of the present invention, since the charge stop instruction temperature is set lower than the charge start temperature, that is, hysteresis is provided between the two temperatures, the temperature drop in the endothermic reaction that occurs even in normal charging. Even if there is, the temperature does not reach the charge stop instruction temperature, and it is possible to prevent the power supply from being stopped before reaching the full charge.

[Brief description of the drawings]

FIG. 1 is a side view of a battery-assisted bicycle provided with a battery charging device according to a first embodiment of the present invention.

FIG. 2 is a block diagram showing a configuration of the charging device.

FIG. 3 is a flowchart illustrating a control operation of the charging device.

FIG. 4 is a characteristic diagram showing a relationship between charging and discharging times of the charging device, a battery voltage, and a battery temperature.

FIG. 5 is a flowchart for explaining the operation of the charging device according to the second embodiment of the second and third aspects of the present invention.

FIG. 6 is a flowchart for explaining the operation of the charging device according to a third embodiment of the present invention.

[Explanation of symbols]

DESCRIPTION OF SYMBOLS 21 Battery 31 Battery charger 32 Current supply circuit (refresh processing means, current supply means) 33 Controller (current supply control means) 35 Charge amount detection sensor (charge amount detection means, battery voltage detection means) 36 Temperature detection sensor (temperature detection means, surroundings) Temperature detection means)

Claims (5)

[Claims] 1. A refresh processing means for discharging a battery until a voltage becomes equal to or lower than a predetermined voltage, an energizing means for energizing the battery, a charge amount detecting means for detecting a charge amount of the battery, and a charge after the refresh processing. A battery charging device comprising: a power supply control unit configured to stop power supply to the battery when a charge amount of the battery becomes equal to or more than a predetermined value. 2. An electricity supply means for supplying electricity to a battery, a temperature detection means for detecting a temperature of the battery, a voltage detection means for detecting a voltage of the battery, and a temperature at the start of charging of the battery being lower than a predetermined value. And a power supply control means for stopping power supply to the battery when a decrease of the battery voltage by a predetermined value or more is detected. A power supply means for supplying power to the battery; a temperature detection means for detecting a temperature of the battery; a temperature at the time of starting charging of the battery being equal to or higher than a predetermined value, and an elapsed time after starting charging is predetermined. And a power supply control means for stopping power supply to the battery when the battery temperature becomes equal to or higher than a predetermined value or the battery temperature becomes equal to or higher than a predetermined value. 4. An energizing means for energizing a battery, an ambient temperature detecting means for detecting a temperature around a charging device, and a charging current value when the ambient temperature is low is higher than a charging current value when the ambient temperature is high. And a power supply control means for controlling the power supply means to be higher. 5. An energizing means for energizing the battery, a battery temperature detecting means for detecting a temperature of the battery, and energizing the energizing means when the battery temperature is equal to or higher than a predetermined charging start temperature, and starting the charging. A battery charger comprising: a power supply control means for stopping power supply to the power supply means when the temperature is equal to or lower than a charge stop instruction temperature set to a temperature lower than the temperature.