JPH1179063A - Charge/discharge life judgement and control device for secondary battery - Google Patents

Abstract

PROBLEM TO BE SOLVED: To conveniently detect and alarm the life limit of a secondary battery in charge/discharge. SOLUTION: The terminal voltage of a battery unit 20 is detected by a voltmeter 23 to detect charge/discharge, store the frequency of charge/discharge in a charge/discharge frequency detection and storage part 31 and display the frequency of charge/discharge on an alarm display part 40. In a charge/discharge frequency comparison and control circuit 32, the detected frequency of charge/ discharge is compared with the preset life frequency of charge/discharge and alarm is issued from an alarm display part 40 when a difference therebetween is zero. and a main battery circuit breaker switch 24 is opened by a main battery circuit breaker operation circuit 34 to break a discharge passage for a battery unit 20.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a charge / discharge life determination / control device for a secondary battery, and for example, a life limit of a secondary battery mounted on an electrically assisted bicycle that can be driven by both human power and an electric motor. Can be easily detected, and a warning can be given to the user that the service life is approaching the limit.

[0002]

2. Description of the Related Art An electrically assisted bicycle is a bicycle that can be driven by both human power and an electric motor.
The next battery is installed. Various means for monitoring the actual state of charging / discharging of a secondary battery used in such an electrically assisted bicycle, extending the use time of the battery, determining the charging time, and preventing deep discharge have been proposed. Have been.

It is known that when a secondary battery is discharged to a certain limit or more, the secondary battery deteriorates early and its life is shortened. For this reason, in a control device such as an electrically assisted bicycle, the power supply to the motor is stopped when the voltage of the electric assist secondary battery drops to a predetermined value.

As described above, various means for monitoring the state of charge / discharge of the secondary battery itself have been conventionally proposed. However, a secondary battery that has been repeatedly used is deteriorated, and its charging capacity and battery capacity are exhausted. No convenient means of signaling that the limit was approached was proposed.

[0005]

SUMMARY OF THE INVENTION Secondary batteries (Ni-Cd
When a battery or the like repeats charge and discharge, the number of charge and discharge cycles (the number of times of charge and discharge) has a practical limit life (the number of times of charge and discharge life) depending on the type of the battery. When the number of charge / discharge times of the secondary battery approaches the limit life (number of charge / discharge life times), the battery capacity cannot be returned to a sufficient capacity even if the charge holding time is lengthened, and the discharge time is shortened. For this reason, when the life (the number of times of charge and discharge) of the secondary battery mounted on the electrically assisted bicycle is approaching the limit, the life of the secondary battery is increased during driving of the electrically assisted bicycle. The vehicle may run out of power suddenly, and may not be able to perform the electric assist drive during driving, which may cause inconvenience.

Conventionally, the user senses that the discharge time of the battery has been shortened and replaces the battery. However, the battery capacity gradually decreases, and when the battery capacity is exhausted, the battery capacity rapidly decreases. Therefore, it is difficult to determine the life of the battery, and it often happens that the replacement battery cannot be prepared.

[0007] Even if the voltage of the secondary battery decreases due to discharge, the voltage recovers to some extent if left unattended.
It is possible to restart the assist drive. But,
When such restart is performed several times, the secondary voltage is deeply discharged, and the secondary battery deteriorates earlier than the expected number of charge / discharge life times.

In view of the above prior art, the present invention can easily judge the life of a secondary battery and issue a warning so that deterioration of the secondary battery can be predicted in advance and the battery can be prepared for replacement. It is an object to provide a charge / discharge life determination / control device for a secondary battery.

[0009]

SUMMARY OF THE INVENTION In order to solve the above-mentioned problems, the present invention has a voltage detecting means for detecting a terminal voltage of a secondary battery, and a detecting means for detecting the terminal voltage of the secondary battery based on the voltage detected by the voltage detecting means. A charge / discharge count detecting / storing means for detecting charge / discharge and storing the charge / discharge count; a warning means for issuing a warning; a discharge cutoff means for cutting off a discharge path from the secondary battery to the load;
The number of times of charge / discharge life determined by the type of the next battery is set, and when the number of times of charge / discharge stored in the charge / discharge number detection storage circuit reaches the number of times of charge / discharge life, the discharge path is set by the discharge interrupting means. And a control means for controlling the warning means to generate a warning.

Further, according to the structure of the present invention, when the secondary battery is charged, the charging capacity is calculated by the product of a specified charging current value and a time during which the current flows, and when the charging capacity does not reach the specified charging capacity, It is characterized by further comprising a life judging means for controlling a discharge path to be cut off by the discharge cutoff means and a warning to be generated by the warning means.

Further, according to the structure of the present invention, when the secondary battery is discharged, the discharge capacity is calculated by the product of the discharge current value and the time during which the current flows, and when the discharge capacity does not reach the specified discharge capacity, the discharge interruption is performed. The apparatus further comprises a life determining means for controlling so as to interrupt the discharge path by means and to generate a warning by the warning means.

[0012]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS A charging / discharging life determination / control device for a secondary battery according to an embodiment of the present invention will be described below in detail with reference to the drawings. FIG. 1 shows a second embodiment according to the present invention.
FIG. 2 is a side view showing an electric assist drive bicycle provided with a secondary battery charge / discharge life determination / control device, FIG. 2 is a block diagram showing a control circuit of a secondary battery charge / discharge life determination / control device,
FIG. 3 is a flowchart showing an example of a control program of the secondary battery charge / discharge life determination / control device.

In the electric assist drive bicycle 1 shown in FIG. 1, when the pedal crank 2 is turned by human power, the chain sprocket 3 is turned, and the driven chain sprocket 5 is turned via the chain 4, and the rear wheel 6 is driven to rotate. When the driving torque by the pedal crank 2 becomes equal to or more than a certain value, the motor of the driving unit 10 rotates and transmits the decelerated power to the chain sprocket 3 to assist human power.
The drive unit 10 is mounted on the bicycle frame 7 and driven by the amount of power stored in the battery unit 20.

Further, the electric assist drive bicycle 1 is equipped with an arithmetic storage device 30, an alarm display section 40 and the like. The alarm display unit 40 displays the number of charge / discharge cycles (number of charge / discharge) of the secondary battery, and issues an alarm when the life approaches the limit, that is, when the number of charge / discharge approaches the number of charge / discharge life. , To turn on the warning light.

The battery-assisted driving bicycle 1 includes a battery unit 20, an operation storage unit 30, an alarm display unit (warning means) 40, and other measuring members. The control device 100 is attached, and details thereof will be described with reference to FIG.

Charge / discharge life determination / control device 10 for secondary battery
The configuration of 0 will be described with reference to the block diagram of FIG. As shown in the figure, the battery unit 20 is configured by connecting a plurality of secondary batteries (batteries) 20a in series. The ammeter 21 detects a charging current value when the battery unit 20 is being charged via the charging terminal TC.
Detects the discharge current value when discharging from the battery unit 20 to the load (drive unit 10) via the discharge terminal TD. The terminal voltage of the battery unit 20 is
It is detected by the voltmeter 23. Further, a battery main circuit cutoff switch (discharge cutoff means) 24 is interposed on the discharge path from the battery unit 20 to the load, and the discharge path is cut off when the battery main circuit cutoff switch 24 is opened. .

The charge / discharge count detection storage unit 31 of the arithmetic storage unit 30 stores the detected voltage detected by the voltmeter 23 and the ammeter 2
The charge / discharge of the battery unit 20 is detected based on the detection currents detected by 1 and 22. Specifically, for example, Ni-C
In the d battery, since the battery voltage drops at the end of charging, this drop is detected to recognize the completion of charging, and in discharging,
The end of discharge of the battery (about 90% of the nominal voltage) is detected to recognize the completion of discharge. Then, the charge / discharge count detection storage unit 31 counts and stores the detected charge / discharge count.

The number of times of charge / discharge counted and stored in the number-of-charges / discharges detection storage unit 31 is displayed on the alarm display unit 40.
The charge / discharge count counted and stored in the charge / discharge count detection storage unit 31 is reset to zero when the battery unit (secondary battery) 20 is replaced.

The charge / discharge count comparison control circuit 32 includes a charge count designation unit 33, which controls the battery unit 20 (secondary battery 20).
The number of times of charge / discharge life determined by the type of a) is set. The charge / discharge count comparison control circuit 32 reads the charge / discharge count detection storage unit 31 from the set charge / discharge life count.
When the difference becomes a specific number (specified value), a warning signal is sent to the warning display unit 40 to turn on and display a warning lamp for battery replacement. Further, when the difference becomes zero, a life signal is sent to the alarm display section 40 to turn on and display a battery life warning lamp and generate a warning.

When the difference between the set charge / discharge life count and the charge / discharge count stored in the charge / discharge count detection storage unit 31 becomes zero, the charge / discharge count comparison control circuit 3
2 sends a life signal to the battery main circuit cutoff operation circuit 34.
When the battery main circuit cutoff operation circuit 34 receives the life signal,
The battery main circuit cutoff switch 24 is opened to cut off the discharge path of the battery main circuit.

The discharge capacity calculation storage unit 35 stores the secondary battery 20
, The product of the discharge current value and the time during which the discharge current flows is calculated to calculate and store the discharge capacity. Note that the discharge capacity calculated and stored in the discharge capacity calculation storage unit 35 is reset each time switching between charging and discharging is performed.

In the discharge capacity comparison control circuit 36, the battery unit 20 (secondary battery 20
The lower limit discharge capacity determined by the type of a) is set. Then, when the discharge capacity stored in the discharge capacity calculation storage unit 35 becomes smaller than the set lower limit discharge capacity, the discharge capacity comparison control circuit 36 sends a life signal to the battery main circuit cutoff operation circuit 34. When receiving the life signal, the battery main circuit cutoff operation circuit 34 opens the battery main circuit cutoff switch 24 to cut off the discharge path of the battery main circuit. At this time, the alarm display unit 40 receives the life signal from the discharge capacity comparison control circuit 36, issues an alarm, and simultaneously turns on a battery life warning lamp. The discharge capacity lower limit specified by the discharge capacity specifying unit 37 is a level before the capacity of the secondary battery rapidly decreases.

The control circuit and alarm of the operation storage unit 30
The power source of the warning light uses a secondary battery and is maintained at a constant voltage by a constant voltage device (not shown). Charge / discharge frequency designation unit 3
3 and the setting data stored in the discharge capacity designation unit 37 are:
It is kept intact by non-volatile memory or backup battery built into the circuit.

Next, referring to the block diagram of FIG. 2 and the control program of FIG. 3, the operation status of the secondary battery charge / discharge life determination / control device according to the embodiment of the present invention will be described.

The main power of the electric assist drive bicycle 1 is a human foot pedal, and the electric assist drive is used supplementarily when the power load is increased to some extent.
Since the loadable weight of the bicycle is small, the battery unit 20
Since the (secondary battery 20a) cannot be stacked in a large amount, the capacity thereof cannot be said to be sufficient, and the frequency of charging must be considerably increased.

This program starts with charging. First,
At the time of charging, the terminal voltage of the battery unit 20 (secondary battery 20a) is detected by the voltmeter 23. When the charging is saturated and the voltage becomes equal to the supply power supply voltage, the charging is completed and the charge / discharge count detection storage unit 31 Records +1 as the number of times of charging (the number of times of charging and discharging) (counts up by one), and adds 1 to the display of the alarm display unit 40 (steps 1 to 3).

When the number of times of charging (the number of times of charging / discharging) exceeds the designated value, the battery replacement warning lamp of the alarm display section 40 is turned on (steps 4 and 5). When the number of times of charging (the number of times of charging / discharging) exceeds the number of times of charging / discharging life (step 6), the alarm of the alarm display section 40 is sounded, the battery life warning light is turned on, and at the same time, the battery main circuit shutoff switch 24 Is interrupted (steps 7 and 8).

If the number of times of charging (the number of times of charging / discharging) does not exceed the number of times of charging / discharging life, discharging is possible, and after charging is completed, switching to discharging is performed, and the bicycle is driven by electric assist driving (steps 9 and 10).

When the voltage detected by the voltmeter 23 during the discharge becomes equal to or lower than the practical minimum value, the electric assist drive (discharge) is stopped because the overdischarge beyond that has an adverse effect on the life of the secondary battery 20a. (Steps 11 and 12).

If the discharge capacity of the battery unit 20 (discharge current value × discharge time) falls below the specified lower limit discharge capacity at the end of discharging, an alarm is sounded on the alarm display section 40 and a warning lamp for battery life is turned on. Lights, and at the same time, operates the battery main circuit cutoff switch 24 to cut off the battery main circuit (step 1).
3, steps 7, 8). In this state, the battery unit 20 (secondary battery 20a) must be replaced (step 14).

In the above embodiment, the discharge capacity is calculated by the product of the discharge current value and the time during which the discharge current flows when the battery unit 20 (secondary battery 20a) is discharged, and the discharge capacity reaches the specified discharge capacity. When the battery unit 20 (rechargeable battery 20a) is charged, the discharge path is controlled by the battery main circuit cutoff switch 24 and a warning is generated by the alarm display unit 40 when the battery unit 20 (rechargeable battery 20a) is charged. (For example, a current value of 0.5 CmA or more, which is the original charging mode) and the time during which the charging current flows, the charging capacity is calculated, and when the charging capacity does not reach the specified charging capacity, the battery main circuit cutoff switch 24 May be controlled so that the discharge path is cut off and the alarm display unit 40 generates a warning.

[0032]

As described above in detail with the embodiments, in the present invention, the voltage detecting means for detecting the terminal voltage of the secondary battery, and the secondary detecting means based on the detected voltage detected by the voltage detecting means. Charge / discharge count detection storage means for detecting the charge / discharge of the battery and storing the charge / discharge count; warning means for issuing a warning; discharge cutoff means for cutting off a discharge path from the secondary battery to the load; The number of times of charge / discharge life determined by the type is set, and when the number of times of charge / discharge stored in the number of charge / discharge detection storage circuit reaches the number of times of charge / discharge, the discharge path is cut off by the discharge cutoff means. And control means for controlling the warning means to generate a warning.

According to the present invention, when the secondary battery is charged, the charging capacity is calculated by the product of a specified charging current value and a time during which the current flows, and when the charging capacity does not reach the specified charging capacity, the discharge interruption is performed. Means for interrupting the discharge path by means and controlling to generate a warning by the warning means are further provided.

In the present invention, when the secondary battery is discharged, the discharge capacity is calculated by the product of the discharge current value and the time during which the current flows, and when the discharge capacity does not reach the specified discharge capacity, the discharge interrupting means is used. It is configured to further include a life determining unit that controls the discharge path to be cut off and a warning to be generated by the warning unit.

Since the weight that can be loaded on a bicycle is small, 2
Since the secondary batteries cannot be stacked in a large amount and their capacity is not sufficient, the charging frequency has to be considerably increased depending on the use conditions. However, in many cases, the life of the secondary battery is suddenly exhausted one day. In such a case, the assist drive is suddenly lost and the inconvenience is forced. A battery replacement warning can be issued by the control device.

The charge / discharge life determination / control device for the secondary battery calculates the product of the charge current and the charge time or the product of the discharge current and the discharge time for each charge / discharge to determine the capacity of the battery. When the battery usage falls below the lower limit, a battery replacement warning is issued.

In the above situation, the discharge electric circuit is finally cut off to make it unusable. In addition, it is possible to promptly prepare the battery and realize effective use of the battery and reliable replacement and collection of the battery.

[Brief description of the drawings]

FIG. 1 is a side view showing an electrically assisted bicycle including a secondary battery charge / discharge life determination / control device according to an embodiment of the present invention.

FIG. 2 is a block diagram showing a secondary battery charge / discharge life determination / control device according to the embodiment of the present invention.

FIG. 3 is a flowchart showing a control program of a secondary battery charge / discharge life determination / control device according to the embodiment of the present invention.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Electric assist drive bicycle 10 Drive unit 20 Battery unit 20a Secondary battery 21,22 Ammeter 23 Voltmeter 24 Battery main circuit cutoff switch 30 Operation storage part 31 Charge / discharge frequency detection storage part 32 Charge / discharge frequency comparison control circuit 33 Charge / discharge Number specifying section 34 Battery main circuit cutoff operation circuit 35 Discharge capacity calculation storage section 36 Discharge capacity comparison control circuit 37 Discharge capacity specifying section 40 Alarm display section 100 Charge / discharge life judgment / control device for secondary battery

Claims (3)

[Claims] 1. A voltage detecting means for detecting a terminal voltage of a secondary battery, and a charging / discharging number for detecting charging / discharging of the secondary battery based on a voltage detected by the voltage detecting means and storing the number of charging / discharging. Detection storage means, warning means for issuing a warning, 2
Discharge interruption means for interrupting the discharge path from the secondary battery to the load,
When the number of times of charge / discharge life determined by the type of the secondary battery is set, and the number of times of charge / discharge stored in the charge / discharge number detection storage circuit reaches the number of times of charge / discharge life, the discharge interrupting means discharges. And control means for interrupting the road and controlling the warning means to generate a warning.
Control device. 2. A charging capacity is calculated by a product of a specified charging current value and a time during which the current flows when charging the secondary battery,
2. The apparatus according to claim 1, further comprising a life judging means for controlling a discharge path to be cut off by said discharge cut-off means and a warning to be issued by said warning means when the charge capacity does not reach a prescribed charge capacity. A secondary battery charge / discharge life determination / control device. 3. A discharge capacity is calculated by a product of a discharge current value and a time during which the secondary battery discharges, and when the discharge capacity does not reach a specified discharge capacity, a discharge path is established by the discharge interrupting means. 2. The secondary battery charge / discharge lifetime determination / control device according to claim 1, further comprising a lifetime determination unit that controls to shut off and generate a warning by the warning unit.