JP3989979B2 - Secondary battery tester - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a tester for a secondary battery, and more particularly to a tester for a secondary battery that can automatically determine the deterioration of a nickel-cadmium battery used in an electric vehicle.
[0002]
[Prior art]
Conventionally, the determination of the degree of deterioration of a nickel-cadmium battery has been performed in the following steps. First, the battery is connected to a discharger and deeply discharged. This deep discharge is performed to eliminate the memory effect and improve the charging efficiency based on temperature. Here, the memory effect refers to a phenomenon in which, in a nickel-cadmium storage battery, the capacity is apparently reduced when a charge / discharge cycle of shallow discharge is repeated. The charging efficiency is also referred to as ampere hour efficiency and refers to the ratio of the amount of discharged power to the amount of charged power. Nickel-cadmium batteries generate heat by discharging and absorb heat by charging. Therefore, the temperature of the nickel-cadmium storage battery after discharging with a large current is rising. In addition, when the amount of discharge is small, if the battery is charged as it is, the battery temperature during charging is not sufficiently lowered by the endothermic reaction due to charging, and the charging efficiency is deteriorated. Therefore, it is necessary to perform deep discharge in order to eliminate the remaining capacity of the battery before charging.
[0003]
After such deep discharge, the battery is connected to a charger and fully charged. Next, the battery is reconnected from the charger to the discharger. Next, the battery is discharged at a constant current, and the discharge time until the capacity of the fully charged battery is exhausted, that is, until the discharge voltage is lowered to the discharge end voltage, is measured with a stopwatch. The degree of deterioration is determined based on this measurement time.
[0004]
[Problems to be solved by the invention]
However, in the work for determining the degree of battery deterioration in the above-described prior art, each of the above-described charging / discharging steps is performed manually by an operator. For this reason, the work is cumbersome and the operator is restrained, and there is a possibility that wrong work or setting may be performed in the change work or the start / stop work of charge / discharge.
[0005]
The present invention has been made in view of the above-described drawbacks of the prior art, and an object of the present invention is to provide a secondary battery tester capable of automatically and accurately determining the deterioration degree of a secondary battery.
[0006]
[Means for Solving the Problems]
In order to achieve the above object, the present invention comprises a charger for charging a secondary battery, an adapter for detachably mounting the secondary battery, and a tester body to which the charger and the adapter are connected. The tester body includes a discharge unit for discharging the secondary battery, a timer for measuring a discharge time of the secondary battery, a first display and a second display for displaying the measurement time by the timer , A control unit for controlling the discharge unit, the charger, the timer, and the first and second displays, a voltage detector for detecting the discharge voltage of the secondary battery, and detecting a charging state by the charger of the secondary battery A charge state detector, wherein the control unit determines a discharge state of the secondary battery based on a signal input from the voltage detector, and uses the signal input from the charge state detector to determine the secondary battery. Fulfillment of A determination unit for determining a state, and an operation control unit for controlling the discharge unit, the charger, the timer, and the first and second indicators based on a determination signal from the determination unit; From the start of discharge measured by the timer until the observation voltage is reached when the voltage of the secondary battery reaches a predetermined observation voltage before reaching the final discharge end voltage during the discharge by the discharge unit. The discharge time is displayed on the first display, and when the voltage of the secondary battery reaches the discharge end voltage, the discharge time from the start of discharge measured by the timer until the discharge end voltage is reached. There is provided a tester for a secondary battery, characterized in that the secondary display displays the second display .
[0007]
In a preferred embodiment, a temperature detection unit for the secondary battery is provided, and the temperature detection unit is connected to the control unit.
[0009]
In another preferred embodiment, the operation control unit inputs a first discharge end signal from the determination unit to stop the first discharge of the secondary battery, and to initiate the first charge, by entering the first full-charge signal from the determination unit, to stop the said first charge, to start the second discharge of the secondary battery, further wherein the timer Starting the measurement by, when the voltage of the secondary battery reaches the observed voltage, to display the discharge time from the start of discharge measured by the timer until reaching the observed voltage on the first display, When the voltage of the secondary battery reaches the discharge end voltage and a second discharge end signal is input from the determination unit, the second discharge of the secondary battery is stopped and the secondary battery Second time Charging is started, to further display the discharge time from said been discharge start measured by the timer to reach the final discharge voltage to the second display unit, enter the second full-charge signal from the determination unit The second charging of the secondary battery is stopped.
[0010]
According to the above configuration, when the secondary battery is attached to the adapter, the control unit of the tester main body automatically performs deep discharge to temporarily eliminate the remaining capacity of the secondary battery through the discharge unit. The deeply discharged secondary battery is fully charged by the charger whose operation is controlled by the controller. The fully charged secondary battery is discharged to a predetermined end-of-discharge voltage by the discharge unit whose operation is controlled by the control unit. The time until the second deep discharge is measured by a timer and displayed on a display. From this display, the deterioration degree of the secondary battery can be determined. After the end of the second deep discharge for determining such deterioration, the control unit can recharge and recharge the secondary battery with the charger.
[0011]
In addition, if the temperature of the secondary battery is detected by the temperature detector after the first deep discharge is completed and the battery is charged after waiting for the temperature to drop, the secondary battery can be charged at an appropriate temperature, which increases the battery life. Charging can be performed with high charging efficiency without adverse effects.
[0012]
DETAILED DESCRIPTION OF THE INVENTION
FIG. 1 is an explanatory diagram showing a basic configuration of a tester for a secondary battery according to the present invention.
[0013]
The tester 1 includes a tester main body 2, a charger 3 and an adapter 4 connected to the tester main body 2 via a connector. A battery box 6 containing a secondary battery for judging the degree of deterioration is detachably attached to the adapter 4. As the secondary battery, a nickel-cadmium storage battery is generally used. As the charger 3, a dedicated or normally used electric vehicle charger can be used for charging the secondary battery. FIG. 2 is a circuit explanatory diagram of the basic configuration of FIG. The tester body 2 discharges the secondary battery 5, the timer 8 that measures the discharge time of the secondary battery 5, the display 9 that displays the measurement time by the timer 8, and controls them. A control unit 10 and a power switch 17 are included.
[0014]
The indicator 9 is composed of a three-digit 7-segment LED (see FIG. 4), and displays the discharge time in minutes as will be described later.
[0015]
The control unit 10 includes a determination unit 18 that is activated when the power switch 17 is turned on, and an operation control unit 19 connected thereto.
[0016]
The discharge unit 7 includes a resistor 11 for constant current discharge, and the discharge voltage is detected by the voltage detector 12 and input to the determination unit 18 of the control unit 10. The discharge unit 7 is connected to the battery box 6 in the adapter 4 via a discharge switch 20.
[0017]
The charger 3 is connected to the determination unit 18 of the control unit 10 through a charging switch 21 and a charging state detector that detects a charging state in the form of current or voltage.
[0018]
The temperature of the secondary battery 5 is detected by the temperature detector 16 via the thermosensor 15 and input to the determination unit 18 of the control unit 10.
[0019]
The timer 8 is connected to the operation control unit 19 of the control unit 10. The operation control unit 19 is further connected to the charge switch 21 and the discharge switch 20.
[0020]
The determination unit 18 receives a signal from the voltage detector 12 and determines whether or not the voltage of the secondary battery 5 is equal to or lower than a discharge end voltage (a voltage that is a measure of the end of discharge). The determination unit 18 receives a signal from the charge state detector 14 and determines whether or not the secondary battery 5 is fully charged. Further, the determination unit 18 inputs a signal from the temperature detector 16 and determines whether or not the secondary battery 5 is in a low temperature refresh state.
[0021]
The operation control unit 19 includes a discharge switch 20 interposed between the connection portion of the resistor 11 of the discharge unit 7 and the secondary battery 5 of the battery box 6, as will be described later, the discharge end voltage from the determination unit 18. On / off control is performed based on the signal.
[0022]
The control unit 19 closes the charging switch 21 when a discharge end voltage signal is input from the determination unit 18 and starts charging. When the full charge signal is input from the determination unit 18, the control unit 19 closes the charging switch 21. Control is performed so that charging is stopped by opening the charging switch 21. In this case, the operation control unit 19 may control to close the charging switch 21 when a refresh signal that has been lowered to a predetermined temperature is input from the determination unit 18. The tester body 2 and the charger 3 are connected to an AC 100V power source via plugs 22 and 23, respectively.
[0023]
Next, the operation of the tester of the secondary battery having the above configuration will be described.
[0024]
FIG. 3 is a flowchart showing the operation of the first embodiment of the present invention, and FIG. 4 is an explanatory diagram showing the display process of the display unit 9 in this flow in order. First, the charger 3 and the adapter 4 are connected to the tester main body 2 by a connector. Further, the tester body 2 and the charger 3 are connected to an AC 100V power source by plugs 22 and 23 (step S0).
[0025]
After the battery box 6 containing the secondary battery 5 to be judged for deterioration is set in the adapter 4, first, in step S1, the power switch 17 is turned on to start the operation of the tester. The part 18 is put into an operating state. In step S <b> 2, the determination unit 18 checks the remaining capacity of the secondary battery 5 in the set battery box 6. This check is performed based on whether or not the signal from the voltage detector 12 is equal to or lower than a predetermined discharge end voltage. When the voltage is equal to or lower than the discharge end voltage, that is, when there is no remaining capacity in the battery, the process proceeds to step S5 described later, and charging is immediately started.
[0026]
If the discharge end voltage is higher than the discharge end voltage in step S2, that is, if the capacity remains in the battery, the process proceeds to step S3, where the operation control unit 19 of the control unit 10 turns on the switch discharge 20 and turns on the secondary battery 5. The first constant current is discharged through the resistor 11. This discharge is performed in order to force the secondary battery 5 to deeply discharge.
[0027]
As described above, the deep discharge is performed to eliminate the memory effect and improve the charging efficiency. In the present embodiment, during this first discharge, the display 9 does not indicate a numerical value, and the lamp 24 at the right bottom period position blinks to notify that it is the first discharge as shown in FIG. .
[0028]
Next, in step S4, it is determined whether or not the secondary battery 5 has been deeply discharged. In this case, the determination unit 18 determines the end of the deep discharge based on whether or not the signal from the voltage detector 12 is equal to or lower than the discharge end voltage. When the discharge end voltage is exceeded, the discharge is further continued.
[0029]
When the voltage becomes equal to or lower than the discharge end voltage, in step S5, the operation control unit 19 turns off the discharge switch 20 and stops the first discharge of the secondary battery 5 by the discharge end voltage signal from the determination unit 18. Subsequently, the operation control unit 19 turns on the charging switch 21 to start the first charging of the secondary battery 5.
[0030]
In the display 9, the lower one digit of the display 9 indicates 0 as shown in FIG. The zero display is continued during charging.
[0031]
After the start of charging, in step S6, the determination unit 18 determines whether or not the secondary battery 5 is fully charged based on a signal from the charging state detector 14. If the battery is not fully charged, charging is further continued.
[0032]
When the fully charged state is reached, the process proceeds to step S7, and the operation control unit 19 turns off the charging switch 21 and stops the first charging of the secondary battery 5 by the full charge signal from the determination unit 18. Next, the discharge switch 20 is turned on to start the second discharge of the secondary battery 5. This second discharge is performed to determine the deterioration of the secondary battery 5, and the operation control unit 19 starts the measurement of the timer 8. When the second discharge starts, the lamp 24 at the lower right corner of the display 9 blinks as shown in FIG. 4C, the discharge measurement time by the timer is displayed, and the discharge time is known by a three-digit number that increases every moment. Is done.
[0033]
In step S <b> 8 after the start of discharge, the determination unit 18 determines whether or not the discharge end voltage is equal to or lower than the signal from the voltage detector 12. When the discharge end voltage is exceeded, the discharge is further continued.
[0034]
When the voltage is equal to or lower than the discharge end voltage, the operation control unit 19 turns off the discharge switch 20 and stops the second discharge of the secondary battery 5 by the discharge end voltage signal from the determination unit 18 in step S9. Subsequently, the charging switch 21 is turned on to start the second charging of the secondary battery 5.
[0035]
When the discharge is stopped, the discharge time from the start to the stop measured by the timer is displayed. The measurement time of the timer 8 due to the discharge stop is continuously displayed by blinking the lower two digits of the display 9 as shown in FIG. 4D during the second charge. During the second charge, the number blinks and the lower right lamp 24 is lit.
[0036]
The second discharge measurement time described above displays the deterioration degree of the secondary battery 5 by the discharge time, and indicates that the deterioration is progressing as the time is shorter.
[0037]
FIG. 5 shows the relationship between the second discharge time and the battery capacity. In FIG. 5, the horizontal axis represents the discharge time, and the vertical axis represents the capacity (percentage of deterioration with respect to the rated capacity). In this example, the value 36 of the display 9 indicates that the discharge time is 36 minutes as shown in FIG. In this case, it can be seen from the graph of FIG. 5 that the capacity of this battery is approximately 70% of the rated capacity. In the graph of FIG. 5, the relationship between the discharge time (min) and the capacity (%) has a width as shown by diagonal lines, depending on the type of the secondary battery 5 and the like. This is because there is a slight difference and the degree of deterioration changes depending on the discharge time.
[0038]
Subsequently, in step S <b> 10, the determination unit 18 determines whether the secondary battery 5 is fully charged and regenerated based on a signal from the charge state detector 14. If the battery is not fully charged, the operation control unit 19 further continues charging. When the full charge signal is input from the determination unit 18, the operation control unit 19 turns off the charge switch 21 and stops the second charging of the secondary battery 5. When the charging is stopped, the display unit 9 turns on the number blinking during charging as shown in FIG. 4E to notify the end of charging.
[0039]
According to the secondary battery tester having the above-described configuration and operation, the secondary battery 5 is automatically deeply discharged, fully charged, and deteriorated automatically by simply setting the battery box 6 to the adapter 4 and turning on the power switch 17. The battery is sequentially discharged and recharged, and the state of the battery is displayed on the display 9. Therefore, a person can lie on the side to determine the deterioration of the secondary battery, There is no need to make settings, and there is no need to perform wrong operations or settings, and it is possible to make accurate judgments without human intervention.
[0040]
FIG. 6 is a flowchart showing another example of the tester for the secondary battery according to the present invention. In this example, it is determined whether or not the temperature of the secondary battery 5 has dropped to a predetermined temperature A ° C. or less between the end of the first discharge in the example of FIG. A function for starting the first charging of the secondary battery 5 when it is lowered is added. Other configurations, functions, and effects are the same as those in the example of FIG.
[0041]
Hereinafter, the characteristic part of this example will be described based on the flowchart of FIG. 6 and the circuit diagram of FIG. 2 described above. That is, in this example, steps S11 to S13 for temperature determination are added between step S4 and step S5 in the flowchart of FIG.
[0042]
The determination unit 18 receives the end-of-discharge voltage from the voltage detector 12 and transmits it to the operation control unit 19. The operation control unit 19 turns off the discharge switch 20 to stop deep discharge of the secondary battery 5. . In this state, the temperature signal of the secondary battery 5 from the temperature detector 16 is input, and it is determined whether or not the secondary battery 5 has become A ° C. or less (step S11). In the case of AC or higher, the temperature is waited until the temperature of the secondary battery 5 becomes AC or lower (Step S12).
[0043]
In this temperature waiting state, the determination unit 18 determines a temperature detection signal (step S13). When the temperature is A ° C. or less, the operation control unit 19 turns on the charging switch 21 by the A ° C. or less signal from the determination unit 18. Then, charging of the secondary battery 5 is started (step S5).
[0044]
As for the lamp display state, during the first discharge, the right end lamp 24 is blinked as shown in FIG. 4A, and when the discharge is completed and the temperature is waited, the lamp 24 is turned on and the temperature is It is informed that the battery is in a state of waiting for the battery to drop to a predetermined temperature. When the temperature waiting is completed and the first charging is started, the rightmost period position lamp is turned off and the numeral 0 is turned on and fixedly displayed as shown in FIG. The subsequent lamp display is as described in FIGS. 4C to 4E.
[0045]
If the temperature is A ° C. or lower in step S11 when the discharge is completed, the process immediately proceeds to step S5 without waiting for the temperature, and the first charge is started.
[0046]
FIG. 7 is a graph showing the relationship between the charge / discharge time of the secondary battery and the temperature. (A) shows a case where the temperature is waited, and (B) shows a case where the temperature is not waited.
[0047]
As can be seen from the figure, when waiting for the temperature, the first charging (charging 1) is performed at a low temperature, so the charging efficiency is high. On the other hand, when the temperature is not waited, as shown in (B), the temperature is high at the start of charging. A state cannot be obtained.
[0048]
That is, if charging is started immediately after the first discharge of the secondary battery without waiting for the temperature, the temperature of the secondary battery 5 becomes higher than B ° C. during the second discharge as shown by the curve in FIG. 7B. As described above, the charging efficiency is deteriorated in the second charging.
[0049]
Therefore, in this example, charging / discharging of the secondary battery 5 is repeated as shown in FIG. 5A while waiting for the temperature after the first discharge so as not to exceed B ° C.
[0050]
In the above two embodiments, the discharge end voltage at the time of the first discharge and the second time are set to the same, but can be set differently, and the number of series cells of the secondary battery The set value can be changed according to the difference.
[0051]
In addition, by changing the discharge end voltage, the optimum deep discharge time can be set according to the battery to be inspected, and the reliability of deterioration determination can be enhanced. Furthermore, two or more indicators can be provided corresponding to the discharge end voltage, temperature state, etc., and detection accuracy can be improved.
[0052]
FIG. 8 is a flowchart of still another embodiment of the present invention, and FIGS. 9A to 9F are explanatory diagrams sequentially showing the display states of the display device in this embodiment.
[0053]
In this embodiment, a first display 91 and a second display 92 are provided side by side on a tester. Thereby, the discharge voltage is measured in two stages. That is, in this embodiment, in the second discharge measurement step S7 in the flowchart of FIG. 6 described above, when a predetermined observation voltage before reaching the final discharge end voltage is reached, this is displayed in steps S14 and 15 Is added. The other flow is substantially the same as the flowchart of FIG. Here, the observed voltage is, for example, a value corresponding to a voltage value that issues a warning when the remaining battery level becomes a predetermined amount or less. That is, in a normal electric vehicle, when the capacity of the battery decreases, a warning is given by blinking the display lamp, and when the capacity is completely exhausted, the display lamp is turned on or off to finish the operation. . In this embodiment, after the battery is fully charged and before reaching the final voltage due to discharge, the time until the observed voltage corresponding to such a battery shortage state is measured and displayed. It is.
[0054]
The first discharge is performed from the start of processing by the tester (steps S0 to S4), the battery temperature is waited (steps S11 to 13), the first charging is performed (steps S5 and S6), and the second time after the charging is completed. The operation is the same as that in the flowchart of FIG. 6 described above until step S7 at which discharge is started. In this case, the first and second indicators 91 and 92 are both displayed in the same state as shown in FIGS. When the measurement of the discharge time is started in step S7, it is first determined whether or not it is equal to or lower than a predetermined observation voltage (step S14). If the observed voltage is not reached, the discharge is continued and the time is continuously measured. At this time, as shown in FIG. 9D, in the first and second indicators 91 and 92, the LED at the rightmost period position blinks, the measurement time is displayed, and the number increases. When the observation voltage is reached, the first display 91 is lit and displayed at a fixed measurement time (step S15). In this example, the observation voltage is reached in 42 minutes. Even after reaching this observation voltage, the discharge is continued until the discharge end voltage is reached (step S8). In this case, the display time of the second display 92 changes while the first display 91 is fixedly displayed in 42 minutes.
[0055]
When the discharge reaches the end voltage, the measurement time at the time of the discharge is fixedly displayed on the second display 92. In this example, it is assumed that the discharge end voltage is reached in 45 minutes. Subsequently, the second charging of the battery is started (step S9). During this charging, as shown in FIG. 9 (E), the first display unit 91 continues the fixed display state of the observed voltage arrival time (42 minutes), and the second display unit 92 maintains the discharge end voltage arrival time ( (45 minutes) flashing is displayed, and it is informed that charging is in progress by flashing. When the charging is completed, as shown in FIG. 9 (F), the second display 92 is changed from the blinking display to the lighting display to inform the end of the charging. The final display time of the first and second indicators 91 and 92 confirms the arrival time to the observation voltage and the arrival time to the discharge end voltage. Thus, by displaying the discharge voltage measurement time in two stages, for example, time to reach the warning voltage shortage battery remaining amount is Ru divided.
[0056]
【The invention's effect】
As described above, according to the present invention, it is possible to automatically determine the deterioration degree of the secondary battery simply by setting the secondary battery in the adapter, and the deterioration of the secondary battery as in the prior art. In order to judge the condition, there is no need to manually change the rechargeable battery from charge to discharge or to measure the discharge time. By measuring the discharge time with high accuracy, it is possible to easily and accurately determine the deterioration degree (remaining capacity) of the secondary battery. If this is utilized, for example, in a service station, the lifetime of the secondary battery of the electric vehicle is easily clarified and the replacement time of the secondary battery is clarified.
[Brief description of the drawings]
FIG. 1 is an explanatory diagram showing a basic configuration of a tester for a secondary battery according to the present invention.
FIG. 2 is an explanatory diagram of an example showing the basic configuration of FIG. 1 in a circuit form;
FIG. 3 is a flowchart for explaining the operation of the tester of FIG. 1;
FIGS. 4A and 4B are explanatory diagrams sequentially showing display processes of the display of the tester of FIG.
FIG. 5 is a graph showing the relationship between discharge time and capacity of a secondary battery.
FIG. 6 is a flowchart showing another example of a tester for a secondary battery according to the present invention.
7 is a diagram showing the relationship between the temperature of the secondary battery and the charge / discharge states in the tester of FIG. 6. FIG.
FIG. 8 is a flowchart showing the operation of another embodiment of the present invention.
FIG. 9 is an explanatory view showing the display states of the display unit in the embodiment of FIG. 8 in order.
[Explanation of symbols]
1: Tester, 2: Tester body, 3: Charger, 4: Adapter, 5: Secondary battery, 6: Battery box, 7: Discharge unit, 8: Timer, 9: Display, 10: Control unit, 11: Resistance: 12: Voltage detector, 13: Charging unit, 14: Charge state detector, 15: Thermo sensor, 16: Temperature detector, 17: Power switch, 18: Judgment unit, 19: Operation control unit, 20: Discharge Switch, 21: Charge switch, 22, 23: Plug.

Claims (3)

A charger for charging a secondary battery, an adapter for detachably mounting the secondary battery, and a tester body to which the charger and the adapter are connected,
The tester body includes a discharge unit for discharging the secondary battery, a timer for measuring a discharge time of the secondary battery, a first display and a second display for displaying the measurement time by the timer , and the discharge Unit, a charger, a timer and a control unit for controlling the first and second indicators, a voltage detector for detecting a discharge voltage of the secondary battery, and a charge for detecting a charging state by the charger of the secondary battery A state detector,
The control unit determines a discharge state of the secondary battery based on a signal input from the voltage detector, and determines a charge state of the secondary battery based on a signal input from the charge state detector. And an operation control unit that controls the discharge unit, the charger, the timer, and the first and second displays based on a determination signal from the determination unit,
The operation control unit is configured to start from the discharge start measured by the timer when the voltage of the secondary battery reaches a predetermined observation voltage before reaching the final discharge end voltage during the discharge by the discharge unit. The discharge time until reaching the observation voltage is displayed on the first display, and when the voltage of the secondary battery reaches the discharge end voltage, the discharge end voltage is reached from the start of discharge measured by the timer. The secondary battery tester is characterized in that the discharge time until is displayed on the second display .   The secondary battery tester according to claim 1, further comprising a temperature detection unit of the secondary battery, and the temperature detection unit is connected to the control unit. The operation control unit inputs a first discharge end signal from the determination unit to stop the first discharge of the secondary battery, and starts the first charge of the secondary battery, and the determination The first full charge signal from the unit is input, the first charge is stopped, the second discharge of the secondary battery is started, and the measurement by the timer is started, and the secondary battery is started. When the voltage of the secondary battery reaches the observed voltage, a discharge time from the start of discharge measured by the timer until the observed voltage is reached is displayed on the first display, and the voltage of the secondary battery is When the voltage reaches the voltage and a second discharge end signal is input from the determination unit, the second discharge of the secondary battery is stopped and the second charge of the secondary battery is started. By timer The discharge time measured from the start of discharge until reaching the end-of-discharge voltage is displayed on the second display, the second full charge signal from the determination unit is input, and the second time of the secondary battery The secondary battery tester according to claim 1, wherein charging of the battery is stopped .

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