JP2004119180A - Charger - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a charger capable of recharging a secondary battery with expired service life or preventing misuse of the secondary battery with expired service life in an apparatus without being troubled by disposition of a secondary battery with expired service life. <P>SOLUTION: In the charger charging the secondary battery, when the secondary battery with a printable area is decided to be expired, it is printed that the service life of the battery is expired in the printable area of the secondary battery. <P>COPYRIGHT: (C)2004,JPO

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a charger for charging a secondary battery.
[0002]
[Prior art]
Conventionally, chargeable / dischargeable secondary batteries such as nickel / cadmium batteries, nickel / hydrogen batteries, and lithium ion batteries are known.
[0003]
When these secondary batteries are repeatedly charged and discharged, they deteriorate and the charging performance gradually decreases. If you try to charge and use a secondary battery whose charge performance has dropped considerably, that is, the cycle life has expired, the time required for charging will be extremely short compared to the beginning, and the operating time of the equipment that uses it will be Will become extremely short.
[0004]
However, when using a secondary battery that has reached the end of its life, a sudden drop in power supply can be considered.For example, if this occurs in a digital camera, the usage time is shortened and the camera is damaged. There is a risk of receiving.
[0005]
Therefore, Japanese Patent Application Laid-Open No. 6-260213 or Japanese Patent Application Laid-Open No. 11-329512 determines whether a secondary battery being charged has expired in a charger for charging the secondary battery. When it is determined that the secondary battery has reached the end of its life, for example, an LED is turned on or an alarm is generated to notify the secondary battery.
[0006]
[Problems to be solved by the invention]
However, after removing the secondary battery from the charger, this battery will not be mixed with other rechargeable batteries. There is a possibility that the battery may be charged, or a secondary battery that has reached the end of its life may be misused to cause damage to the device, which is troublesome.
[0007]
In view of the above circumstances, the present invention can prevent recharging of a secondary battery that has expired or misuse of a secondary battery that has expired without being troubled by the treatment of a secondary battery that has expired. The object is to provide a charger.
[0008]
[Means for Solving the Problems]
To achieve the above object, the charger of the present invention is
In chargers that charge secondary batteries,
The secondary battery to be charged is a secondary battery having a printable area,
Based on the voltage change of the secondary battery that is being charged, a battery life expiration determining unit that determines whether the secondary battery has expired and cannot be charged and used;
In response to the determination that the battery is out of service by the battery out-of-life determination unit, a printing unit is provided for printing the out-of-life of the secondary battery in a printable area of the secondary battery mounted for charging. It is characterized by that.
[0009]
In the charger according to the present invention, if it is determined that the secondary battery having a printable area being charged is out of life, this is printed on the secondary battery itself. Therefore, according to the charger of the present invention, it can be determined at a glance whether or not the secondary battery is out of service life. It is possible to prevent the use of a battery that has expired in recharging or a device using a secondary battery.
[0010]
Here, the battery life expiration determination unit of the charger according to the present invention measures the time from the predetermined first voltage to the predetermined second voltage or full charge voltage higher than the first voltage. In addition, it is preferable to determine that the secondary battery being charged is expired when the time is shorter than the predetermined time.
[0011]
This is due to the fact that secondary batteries that have reached the end of their life have characteristics that they reach the full charge voltage in a short time compared to the beginning because the charging performance is considerably reduced compared to the beginning. In this way, it is possible to easily and accurately determine the end of life.
[0012]
Furthermore, it is also a preferable aspect that the predetermined time used in the determination in the battery life expiration determination unit of the charger of the present invention is set according to the type of the secondary battery.
[0013]
In this way, the accuracy of determination can be further increased.
[0014]
DETAILED DESCRIPTION OF THE INVENTION
Hereinafter, embodiments of the present invention will be described.
[0015]
FIG. 1 is an external perspective view of a charger according to an embodiment of the present invention from the right front. Here, in order to avoid the complexity of the figure, the illustration of the terminal on the charger side that contacts the positive terminal and the negative terminal of the secondary battery is omitted.
[0016]
The charger 1 of this embodiment shown in FIG. 1 is for charging an AA secondary battery, and FIG. 1 shows a state in which two lithium ion batteries 10 are connected. Also shown on the right side is an identification switch 40 provided for selecting the type of battery connected. The charger 1 includes an AC / DC adapter (see FIG. 3), and the current obtained from the external power source is converted from AC to DC and used to charge the connected secondary battery. Yes.
[0017]
The lithium ion battery 10 shown in FIG. 1 is provided with a printable area (hereinafter, this printable area is referred to as a print band), and the charger 1 is provided with the lithium ion battery 10. A light irradiation head 20 for printing on the printing band 10a is provided.
[0018]
FIG. 2 is a diagram showing a secondary battery on which characters indicating inability to charge are printed.
[0019]
The lithium ion battery 10 shown in FIG. 2 is printed with a letter “NG” indicating that the battery has expired due to repeated charge and discharge.
[0020]
As described above, in the charger 1 of the present embodiment, it is determined whether or not the connected secondary battery has expired, and if it has expired, a printing band is provided at a predetermined position. The character 'NG' is printed on the provided secondary battery.
[0021]
FIG. 3 is an internal block diagram of the charger according to the present embodiment. FIG. 3 also shows a secondary battery.
[0022]
FIG. 3 shows an AC / DC converter 70 that converts an alternating current from the outside into a direct current, a lithium ion battery 10 provided with the printing band 10a, and charging and discharging of a connected secondary battery. A control unit 80 for determining the life, a charge control unit 60 for controlling the charging current output from the AC / DC converter 70 in response to an instruction from the control unit 80, a temperature sensor 30 for detecting a cell temperature of the secondary battery, When the print head 20 that performs printing on the print band provided in the secondary battery, the identification switch 40 that is operated according to the type of the secondary battery to be connected, and the secondary battery to be connected is a battery that has expired In addition, a notification unit 50 for notifying that by an alarm and a memory 90 in which various parameters are stored are shown.
[0023]
The charging control unit 60 receives a control signal from the control unit 80 and controls the output of the charging current to the connected secondary battery, and the battery voltage of the connected secondary battery exceeds a predetermined voltage. If it is, it has a refresh function for discharging it and dropping it below a predetermined voltage. This function is particularly effective for a nickel cadmium battery having a remarkable memory effect. The battery voltage of the connected secondary battery is monitored by the control unit 80.
[0024]
The identification switch 40 is a switch that is switched according to the type of secondary battery to be connected. Thus, it is possible to accurately determine whether the battery has expired by accurately recognizing the type of secondary battery to be connected.
[0025]
The print head 20 records characters on the print band 10a wound around the connected secondary battery.
[0026]
The temperature sensor 30 is a temperature detection element that is provided at a position close to the connected secondary battery and detects the temperature of the secondary battery. The temperature information output from the temperature sensor 30 is output to the control unit 80. Since the charging voltage curve representing the change in the battery voltage of the connected secondary battery also varies depending on the temperature of the secondary battery, the life of the secondary battery will be described in detail later. The temperature is also taken into account.
[0027]
The control unit 80 determines whether the connected secondary battery has expired based on the battery voltage of the secondary battery, the input signal indicating the type and temperature of the secondary battery, and the parameters stored in the memory 90. In addition, the charging control unit 60 is controlled. When the control unit 80 determines that the secondary battery has expired, the control unit 80 sends a signal for generating an alarm to the notification unit 50 and sends a control signal instructing to stop the charging process to the charge control unit 60. The feed and print head 20 is instructed to print on the print band. The operation for determining the end of life by the control unit 80 will be described later.
[0028]
The memory 90 stores various parameters set according to the type of the secondary battery, and supplies information specified by the control unit 80.
[0029]
Hereinafter, the charging operation of the charger 1 of the present embodiment will be described.
[0030]
FIG. 4 is a flowchart of determination processing for charging and expiration of the battery charger according to the present embodiment. In addition, in the charger of this embodiment, in order to raise the determination accuracy of the end of life, the secondary battery is divided into two types, and the charging method according to each type and each of these two types of charging methods are supported. A method for determining the end of life is adopted.
[0031]
When the AA secondary battery is connected to a predetermined position of the charger 1 shown in FIG. 1, first, in step S <b> 1, the control unit 80 identifies information about the type of the connected secondary battery by an identification switch. Receive from 40. In the identification switch 40, either a lithium ion battery (Li) or a nickel-based (nickel cadmium, nickel metal hydride) battery (Ni) can be selected. Then, it progresses to step S2 and it is determined whether the selected battery is a lithium ion battery. When the connected battery is a lithium ion battery, the charger 1 first performs constant current (CC) charging, and then switches to constant voltage (CV) charging when the battery voltage reaches a predetermined voltage. A charging method is employed, and the determination of battery life expiration uses the switching timing from this constant current (CC) charging to constant voltage (CV) charging.
[0032]
If it is determined in step S2 that the lithium ion battery is selected, the process proceeds to step S3, and the subroutine “lithium ion battery processing” is executed.
[0033]
FIG. 5 is a flowchart of the subroutine “lithium ion battery processing”.
[0034]
First, in step S301, it is determined whether or not the lithium ion battery connected to the charger 1 is in a fully charged state. This is to cope with a case where a battery that has been fully charged is accidentally reconnected without being used.
[0035]
If it is determined in step S301 that charging is unnecessary because the battery is already fully charged, this subroutine is terminated, and the process returns to step S5 shown in FIG.
[0036]
If it is determined in step S301 that the battery is not fully charged, the process proceeds to step S302, and it is determined whether or not the battery voltage of the connected lithium ion battery is equal to or higher than the voltage VP1. The voltage VP1 is a reference voltage for determining whether or not the above-described refresh process is performed for the lithium ion battery.
[0037]
If it is determined in step S302 that the battery voltage of the lithium ion battery is not equal to or higher than voltage VP1, the process proceeds to step S305, and charging is started.
[0038]
If it is determined in step S302 that the battery voltage of the lithium ion battery is equal to or higher than the reference voltage VP1, the process proceeds to S303, where a discharge process that is a refresh process is performed. In the next step S304, the battery voltage of the lithium ion battery The discharge process is repeated until it is determined that the battery voltage is less than the reference voltage VP1, and when it is determined that the battery voltage of the lithium ion battery is less than the reference voltage VP1, the process proceeds to step S305.
[0039]
After charging is started in step S305, the process proceeds to step S306, where it is determined whether or not the battery voltage exceeds the reference voltage VP1, and if it is determined that the battery voltage is less than the reference voltage VP1, step S306 is repeated.
[0040]
If it is determined in step S306 that the battery voltage is equal to or higher than the reference voltage VP1, the process proceeds to step S307, and time measurement is started. Thereafter, the process proceeds to step S308, where it is determined whether charging for the lithium ion battery has been switched from constant current (CC) charging to constant voltage (CV) charging. Step S308 is repeated until switching is performed, and the above switching is performed. When this is done, the process exits this subroutine and returns to step S5 shown in FIG.
[0041]
In step S5 of the routine shown in FIG. 4, the timing started in step S307 of the subroutine “lithium ion battery processing” is ended.
[0042]
Here, refer to FIG. 6 for a determination method that uses the switching timing from constant current (CC) charging to constant voltage (CV) charging, which is adopted to accurately determine the end of life of the lithium ion battery. While explaining.
[0043]
FIG. 6 is a diagram showing a general change in the voltage of the lithium ion battery due to charging of the lithium ion battery.
[0044]
In FIG. 6, the alternate long and short dash line and the solid line are shown on a graph in which the vertical axis represents voltage and the horizontal axis represents time, and the time until the target voltage value V1 is reached is different. It is shown that both the chain line and the solid line reach the target voltage value V1 and thereafter stabilize at the target voltage value V1. The dashed-dotted line and the solid line shown in FIG. 6 indicate changes in the battery voltage when charging the same lithium ion batteries that have been charged / discharged differently, and the dashed-dotted line is a solid line. The change of the battery voltage of the lithium ion battery in which the frequency | count of charging / discharging is made more than the lithium ion battery shown is represented.
[0045]
FIG. 6 also shows TL1 and TL2, which are the time required to reach the target voltage V1 from the reference voltage VP1, which is a reference for whether or not the refresh process is performed, in each of the alternate long and short dash line. TL1 is shorter in time than TL2, and this is indicated by a one-dot chain line, that is, the battery voltage of a lithium ion battery in which the number of times of charge / discharge is increased is indicated by a solid line. It shows that the rising speed is faster than the battery voltage of a lithium ion battery with a small number of charge / discharge cycles. That is, in the determination using the switching timing from the constant current (CC) charge to the constant voltage (CV) charge, the constant voltage (CC) charge is constant from the timing when the battery voltage of the lithium ion battery reaches the reference voltage VP1. The determination target time, which is the time until the target voltage V1 is reached, which is the switching timing for switching to voltage (CV) charging, is measured. Therefore, the determination target time of a secondary battery whose lifetime has expired is considerably shorter than that at the beginning of use.
[0046]
Here, the description is continued by returning to the place where the process proceeds to step S6 shown in FIG.
[0047]
In step S6, based on the temperature information from the temperature sensor 30 shown in FIG. 3, the determination target time is corrected using a correction value obtained from the parameter stored in the memory 90 shown in FIG. Then, it progresses to step S7.
[0048]
In step S7, the corrected determination target time is set according to the type of the connected secondary battery, and is a reference that is a reference time for determining whether or not the battery has expired It is determined whether it is shorter than the required time.
[0049]
If it is determined in step S7 that this is not short, i.e., that the life has not expired, this routine is terminated.
[0050]
If it is determined in step S7 that it is short, that is, it has expired, the process proceeds to step S8, and charging is instructed. Thereafter, the process proceeds to step S9.
[0051]
In step S9, the fact that the connected secondary battery has expired is transmitted to the notification unit shown in FIG. In response to the notification, the alarm is pronounced. Then, it progresses to step S10.
[0052]
In step S10, a print instruction for the character “NG” shown in FIG. 2 is issued to the print head 20 shown in FIG. Thereafter, this routine is terminated.
[0053]
On the other hand, if it is determined in step S2 that the secondary battery connected this time is not a lithium ion battery, the subroutine “nickel-based battery processing” is executed. When the battery to be connected is a battery other than a lithium ion battery, the charger 1 adopts a charging method that performs only constant current (CC) charging. The timing at which the battery voltage reaches the full charge voltage is used.
[0054]
On the other hand, if it is determined in step S2 shown in FIG. 4 that the connected secondary battery is not a lithium ion battery, the process proceeds to step S4, and the subroutine “nickel-based battery process” is executed.
[0055]
FIG. 7 is a flowchart of the subroutine “nickel-based battery processing”.
[0056]
In step S401 of this subroutine, it is determined whether or not the nickel secondary battery connected to the charger 1 is in a fully charged state. This is to cope with a case where a battery that has been fully charged is accidentally reconnected without being used.
[0057]
If it is determined in step S401 that charging is unnecessary because the battery is already fully charged, this subroutine is terminated, and the process returns to step S5 shown in FIG.
[0058]
If it is determined in step S401 that the battery is not fully charged, the process proceeds to step S402, and it is determined whether or not the battery voltage of the connected nickel-based secondary battery is equal to or higher than the voltage VP2. The voltage VP2 is a reference voltage for determining whether or not the above-described refresh process is performed for the nickel-based battery.
[0059]
If it is determined in step S402 that the battery voltage of the nickel-based battery is not equal to or higher than the reference voltage VP2, the process proceeds to step 405, and charging is started.
[0060]
If it is determined in step S402 that the battery voltage of the nickel-based battery is equal to or higher than the reference voltage VP2, the process proceeds to step S403, and a discharge process that is a refresh process is performed. In the next step S404, the battery of the nickel-based battery is used. The discharge process is repeated until it is determined that the voltage is less than the reference voltage VP2, and when it is determined that the battery voltage of the nickel-based battery is less than the reference voltage VP2, the process proceeds to step S405.
[0061]
After charging is started in step S405, the process proceeds to step S406, where it is determined whether or not the reference voltage VP2 has been exceeded. If it is determined that the reference voltage VP2 has been exceeded, step S406 is repeated.
[0062]
If it is determined in step S406 that the voltage is equal to or higher than the reference voltage VP2, the process proceeds to step S407 and time measurement is started. Thereafter, the process proceeds to step S408, and in charging the nickel-based battery, it is determined whether or not the battery voltage has reached the full charge voltage V2, and step S408 is repeated until arrival is confirmed. Thereafter, when it is confirmed that the full charge voltage V2 has been reached, the process exits this subroutine and returns to step S5 shown in FIG.
[0063]
In step S5 shown in FIG. 4, the timing started in step S405 shown in FIG. 7 is terminated.
[0064]
Here, with reference to FIG. 8, a determination method using the arrival timing to the full charge voltage in constant current (CC) charging, which is adopted to accurately detect the end of life of the nickel-based secondary battery, will be described. explain.
[0065]
FIG. 8 is a diagram showing a general change in battery voltage due to charging of the nickel-based secondary battery.
[0066]
In FIG. 8, the dotted line and the solid line shown ascending right are shown on a graph in which the vertical axis represents voltage and the horizontal axis represents time, and the time required to reach the full charge voltage V2 for each dotted line and solid line. Although it is different, after reaching the full charge voltage V2, it is shown that the full charge voltage V2 starts to decrease. The dotted line and the solid line shown in FIG. 8 indicate changes in the battery voltage when charging the same nickel-based battery that has already been charged and discharged a different number of times, and the dotted line is represented by a solid line. This represents a change in battery voltage of a nickel-based battery in which the number of times of charge / discharge is larger than that of a nickel-based battery.
[0067]
Further, FIG. 8 shows TN1 and TN2 which are the time from the time when the voltage VP2, which is the reference voltage for whether or not the refresh process is performed, to the timing when the full charge voltage V2 is reached, for each of the dotted line and the solid line. It is shown. TN1 is shorter in time than TN2, and this is a charge / discharge represented by a solid line when the battery voltage of a nickel-based battery indicated by a dotted line is increased in the number of times of charge / discharge. This indicates that the rising speed is faster than the battery voltage of a nickel-based battery with a small number of times. That is, in the determination using the timing at which the battery voltage reaches the full charge voltage in constant current (CC) charging, the battery voltage of the nickel-based battery is a voltage value VP2 that is a reference voltage value indicating whether or not the refresh process is performed. The time from when the battery voltage reaches the time when the battery voltage reaches the full charge voltage is measured, this measurement time is corrected by the temperature information, and the corrected measurement time corresponds to this nickel-based secondary battery. Whether or not the nickel-based battery has expired is determined depending on whether or not it is shorter than the set reference required time. In addition, since subsequent description is already demonstrated, it abbreviate | omits.
[0068]
In the charger 1 of the present embodiment described above, secondary batteries are classified into two types, and charging methods corresponding to each type are adopted, and the end of life is determined by a method corresponding to each charging method. When it is determined that the target secondary battery has expired, printing indicating that is performed on the secondary battery itself. Therefore, according to the charger 1 of this embodiment, since it can be seen at a glance whether the secondary battery is a battery that has reached the end of its life, the life of the secondary battery has expired without being bothered by the treatment of the secondary battery that has expired. It is possible to prevent recharging of the secondary battery and misuse of the battery that has expired in the device.
[0069]
In the present embodiment, the secondary battery is divided into two types, and the determination target time obtained by the charging method according to the type is shorter than the reference required time set according to the type of the secondary battery. It is determined whether or not the battery has expired. However, the determination of the expiration of the secondary battery is not limited to two types, but only one type or three or more types of secondary batteries have expired. Furthermore, as long as the end of life is determined based on the voltage change of the secondary battery being charged, the end of life is determined by other charging methods and other determination methods. In addition, the reference required time is set according to the type of the secondary battery, but only one may be set in common.
[0070]
【The invention's effect】
As described above, according to the charger of the present invention, the recharge of the expired secondary battery or the misuse of the expired secondary battery in the device without being bothered by the treatment of the expired secondary battery. Can be prevented.
[Brief description of the drawings]
FIG. 1 is an external perspective view from the right front of an embodiment of the present invention.
FIG. 2 is a diagram showing a secondary battery on which characters indicating inability to charge are printed.
FIG. 3 is an internal block diagram of the charger according to the present embodiment.
FIG. 4 is a flowchart of charging and life determination operation of the charger according to the present embodiment.
FIG. 5 is a flowchart of a subroutine “lithium ion battery processing”.
FIG. 6 is a diagram showing a general change in the voltage of a lithium ion battery due to charging of the lithium ion battery.
FIG. 7 is a flowchart of a subroutine “nickel-based battery processing”.
FIG. 8 is a diagram showing a general change in the voltage of the nickel cadmium battery by charging the nickel cadmium battery.
[Explanation of symbols]
DESCRIPTION OF SYMBOLS 1 Charger 10 Lithium ion battery 10a Printing band 20 Light irradiation head 30 Temperature sensor 40 Identification switch 50 Notification part 60 Charging control part 70 AC / DC converter 80 Control part 90 Memory

Claims (3)

In the charger that charges the secondary battery,
The secondary battery to be charged is a secondary battery having a printable area,
Based on the voltage change of the secondary battery that is being charged, a battery life expiration determining unit that determines whether the secondary battery has expired and cannot be charged and used;
In response to the determination that the battery is out of service by the battery out-of-life determination unit, a printing unit that prints out the out-of-life of the secondary battery in a printable area of the secondary battery mounted for charging A charger characterized by that. The battery end-of-life determination unit measures a time from a predetermined first voltage until a predetermined second voltage or full charge voltage higher than the first voltage is charged, and the time is longer than a predetermined time. 2. The battery charger according to claim 1, wherein a short-life time of the secondary battery being charged is determined based on a short time. 3. The charger according to claim 2, wherein the predetermined time is set according to a type of the secondary battery.

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