JP2000023374A - Device and method for identifying secondary cell - Google Patents

Abstract

PROBLEM TO BE SOLVED: To precisely identify the type of a secondary cell. SOLUTION: When a secondary cell 14 connected to a connection terminal 12 is charged by a constant-current constant-voltage charging system, a control roller 24 detects the change in the charge voltage, measures a constant-current charge period, corrects measured time by voltage, when starting charging and temperature being detected by a temperature sensor 38, recognizes the type of the cell corresponding to the corrected constant-current charge time period by the stored data in a memory 40, and sets pre-end and end voltages corresponding to the type of the cell. When the output of the secondary cell, where the type is identified is to be supplied to a load circuit 20 at discharging, the controller 24 monitors a discharge voltage, compares the set pre-end and end voltages with the discharge voltage, outputs an alarm when the discharge voltage reaches the set voltages, and outputs control signals 112 and 116 for prohibiting the discharge of the secondary cell.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an apparatus and a method for identifying a secondary battery that can be charged and discharged, and for example, an identification of a secondary battery that identifies the type of a lithium ion secondary battery. Apparatus and method.

[0002]

2. Description of the Related Art For example, nickel-cadmium (Ni-Cd) batteries, nickel-metal hydride (Ni-MH) batteries, and lithium (Li) ion batteries are mounted on portable electronic devices and generate electric power for driving the devices. Such secondary batteries that can be charged and discharged are known. In such a secondary battery, the battery characteristics are further improved by each manufacturer, and the battery characteristics are different depending on the type of the battery according to the manufacturer and design specifications. Is different.

For example, when a discharge voltage curve of each type of a lithium ion secondary battery of a different type is measured depending on a manufacturer, a manufacturing method, and the like, particularly, a pre-end voltage or a discharge end voltage (judgement) for judging that the capacity of the battery has become small. End voltage). For this reason, if the voltage at which the device stops operating in response to a decrease in the battery voltage is fixedly set on the side of the electronic device that uses the battery, the battery capacity cannot be used up sufficiently or the discharge ends. There is a possibility that the operation of the device is continued in the state where the voltage is lower than the voltage, the battery voltage is rapidly reduced, and the device malfunctions. Therefore, it is necessary to accurately identify the type of the battery and use the battery in an appropriate method according to the type of the battery.

Therefore, for example, as described in Japanese Patent Application Laid-Open No. 5-184076, an identification portion such as a protrusion, a dent, and a contact for identifying the capacity of a battery is provided on the secondary battery side, and It has been proposed to recognize the low or high capacitance according to the on / off state of the capacitance detection switch (SW).

In Japanese Patent Application Laid-Open No. Hei 9-130983, a battery identification terminal for outputting a cell voltage is provided separately from a terminal for outputting a battery voltage, and the type of the battery is identified. It has been proposed to set

[0006]

However, if a terminal serving as a contact for identification is provided on the battery, or a terminal for detection is provided on the electronic device side for housing the battery, the space for arranging them and the space for operation are provided. However, there is a problem that each part becomes large. Portable electronic devices such as mobile phones and digital cameras are required to be smaller and lighter, and increasing the number of components for battery identification is disadvantageous for miniaturization and weight reduction. Was.

When a mechanical switch for identifying a battery is provided, the structure of the device for accommodating the battery is complicated by a switch member and the like, and an engaging portion between the identification portion and the mechanical switch is provided on the battery pack side. This complicates the structure. In this case, it is necessary to further prepare a battery usable for each type on the electronic device side, and it has been difficult to share and use a general-purpose battery. Further, the performance of secondary batteries has been improving rapidly, and their capacities and types have also been diversified. Even when a battery pack containing such a secondary battery is configured, the structure of the battery pack has to be improved. It has been difficult to provide a structure that can identify the type of battery with a simple configuration while ensuring excellent compatibility with various battery packs.

The present invention solves the above-mentioned drawbacks of the prior art, and a battery identification device capable of accurately identifying various types of batteries with a simple configuration without changing the shape of the battery or the device. And a method.

[0009]

SUMMARY OF THE INVENTION In order to solve the above-mentioned problems, the present invention connects a secondary battery of any one of a plurality of types of secondary batteries to identify a secondary battery. In the battery identification device, the device stores charging means for charging a connected secondary battery at a constant current, and a reference time at which the secondary battery is charged at a constant current for each type of the secondary battery. Storage means, and identification means for identifying the type of secondary battery based on a change in battery voltage during constant current charging, and the identification means includes timing means for timing the constant current charging time for the secondary battery. The type of the secondary battery is identified based on the constant current charging time measured by the timer and the contents stored in the storage.

Further, in order to solve the above-mentioned problems, the present invention connects a secondary battery of any one of a plurality of types of secondary batteries and identifies the secondary battery. In this device, charging means for charging the connected secondary battery at a constant current, measuring means for measuring a rise in battery voltage during the constant current charging of the secondary battery, and a battery during the constant current charging Storage means for storing the rise value of the voltage for each type of battery; and identification means for identifying the type of the secondary battery based on the rise value measured by the measurement means and the contents stored in the storage means. It is characterized by having.

According to another aspect of the present invention, there is provided a method for identifying a secondary battery by connecting any one of a plurality of types of secondary batteries to identify the secondary battery. In this method, a first set value corresponding to a change in battery voltage when the secondary battery is charged at a constant current is stored for each type of the secondary battery, and the secondary battery is charged at a constant current. In this case, a value corresponding to a change in the charging voltage at that time is detected, and the type of the secondary battery is identified based on the detection result and the first set value.

[0012]

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a block diagram showing an embodiment of an apparatus and a method for identifying a battery according to the present invention;

Referring to FIG. 3, a battery A and a battery B, which are chargeable / dischargeable lithium (Li) ion secondary batteries of different types,
And charging voltage curves 2a and 2b when charging is performed by the constant current and constant voltage charging method, respectively. As shown in the figure, even in the same lithium ion battery, for example, in different batteries of different manufacturers and the like, the change in charging voltage at the time of constant current charging is different, and the constant current charging (CC) of each battery is different. It turns out that time is a different characteristic. In this example, the battery A has been charged for about 15 minutes from the start of constant current charging (time Δt1).
4.1V or 4.2V constant voltage charging (CV)
The battery B shifts to constant voltage charging approximately 50 minutes (time Δt2) from the start of constant current charging. As shown by the time Δt1 and the time Δt2, the constant current charging time differs depending on the type of the battery. In these lithium ion secondary batteries, after the charging is performed after the transition to the constant voltage charging, the full charge state of the battery is determined and the charging ends.

As described above, if the type of the battery is different, the constant current charging time is different, so that the type of the battery can be accurately identified based on the difference. Furthermore, based on the identification result, it is possible to determine the full charge state according to the battery type, and to control the discharge of the battery according to the battery type when using the charged battery as it is. Become. Therefore, in the following embodiment, a charging / discharging device for identifying the type of battery based on the constant current charging time (referred to as CC time) will be described. In the following description, parts not directly related to the present invention are not shown and described, and reference numerals of signals are represented by reference numerals of connection lines in which the signals appear.

The charging / discharging device 10 shown in FIG.
This is a charge / discharge device having a function of identifying the type of battery when charging the battery 14 detachably connected to the battery, and performing discharge control according to the identified type of battery. The charge / discharge device 10 is provided in an information processing device such as a digital camera or a portable personal computer that captures an image of an object scene, compresses and encodes the image information, and records the image information on a recording medium. The battery 14 is charged by the supplied DC power and the battery 14 or AC adapter
The DC output from 16 is supplied to a DC-DC converter 18 to be converted into various voltages for driving each unit, and is supplied to each unit of the charge / discharge device 10 and a load circuit 20 constituting an information processing device. Further, the charge / discharge device 10 identifies the type of the accommodated battery, sets a parameter corresponding to the battery, and recognizes the discharge state of the battery 14 based on the parameter. In particular, the charge / discharge device 10 of the present embodiment accurately recognizes the pre-end voltage or the end voltage according to the type of the battery, and stops discharging from the battery 14 according to the remaining capacity recognized based on the discharge voltage of the battery. Let me
It has a discharge control function of outputting a voltage warning indicating a battery near end or the like.

FIG. 2 shows the discharge voltage characteristics of the battery 14. When the batteries A and B from different manufacturers are respectively discharged by a predetermined load, the battery A has a pre-end voltage as the remaining battery power decreases. When the discharge proceeds as it is, it becomes the end cutoff voltage V11. In battery B,
As the discharge proceeds, the voltage reaches the pre-end voltage V20, and finally reaches the end voltage V21. The end voltage in the present embodiment is a voltage corresponding to the discharge end voltage of the battery 14,
The pre-end voltage is, for example, several tens of millivolts to several hundred millivolts higher than the end voltage, and the output voltage of the battery is about several minutes to several hours using a device at a current value flowing through the load circuit 20 or the like. Is set as a voltage that can be an end voltage. In the present embodiment, when it is detected that the battery voltage has reached the end voltage, the discharge is stopped to prevent an adverse effect on the battery life due to overdischarge of the battery, and that a sudden voltage drop occurs and the device malfunctions. prevent. After the detection of the pre-end voltage, a warning display indicating a low battery level is output to prompt the user to replace or charge the battery.

Each part of the charging / discharging device 10 will be described in detail.
A commercial AC power supply is connected to the inputs 100a and 100b of the AC adapter 16 that generates the DC power, and the DC output 10 of the AC adapter 16 is connected.
2 is detachably connected to the connection terminal 22 of the charging / discharging device 10. This input terminal 22 is connected to a diode D1 via a connection line 104.
Of the diode D1
The connection line 106 on the cathode side of the DC-DC converter 18
The DC input, the charge control circuit 28, and the cathode of the diode D2 are connected to each other.

On the other hand, a battery 14 as a power source for driving the present device 10 and the load circuit 20 is detachably connected to the connection terminal 12 of the charging / discharging device 10. The battery 14 in this embodiment is a standard-shaped battery in which a lithium-ion secondary battery cell is sealed in a cylindrical case. Although the embodiment will be described using a battery in such a cylindrical case state, the battery 14 may be formed by packaging a battery cell of, for example, a circular, square, or flat type, and a case of a synthetic resin or the like. A battery pack prepared in this way may be used. Such batteries 14
Is housed in the main body of the charging / discharging device 10, or a battery pack is loaded by engaging with the exterior of the device 10, for example. The output of the charge control circuit 28 and the inputs of the discharge control circuit 30 and the controller 24 are connected to the connection terminal 12 via a connection line 108, respectively.

The charging control circuit 28 supplies the power supplied from the AC adapter 16 via the diode D1 to the battery 14 under the control of the controller 24, and charges the battery 14 by a constant current and constant voltage charging method. It is. The charge control circuit 28
Using a semiconductor switch such as an FET as a charging switch, the charging current for the battery 14 is controlled in accordance with a control signal 110 supplied from the controller 24. The charge control circuit 24
When the terminal voltage of the battery 14 is detected, the battery 14 is turned off in response to the control signal 110, and when the charging voltage is detected, the battery 14 is turned on.

Under the control of the controller 24, the discharge control circuit 30 outputs the output 108 of the battery 14 to the DC-DC
This is a circuit that supplies power to the converter 18 and supplies power of the battery 14 to each unit such as the load circuit 20. The discharge control circuit 30 turns on or off the conduction between the connection terminal 12 and the diode D2 according to the discharge control signal 112 supplied from the controller 24.

The controller 24 controls the battery 14 according to the AC adapter 16 and the battery 14 connected to the connection terminals 20 and 12.
Charge and discharge, or a DC-DC converter
The control unit determines whether the power supplied from 18 is output to the load circuit 20, and controls charging and discharging by the AC adapter 16 and the battery 14. The controller 24 in the present embodiment includes:
The battery voltage at the time of charging is converted into a digital value and measured. The battery has a battery identification function for identifying the type of the battery 14 based on the measurement result, and charge / discharge is controlled in accordance with the identified type of the battery.

Specifically, the controller 24 detects the voltage appearing at the input 104, recognizes that the AC adapter 16 has been connected to the connection terminal 22, and monitors the input 108,
The open terminal voltage of the battery 14 is measured. Controller 24
It is determined whether the charging process for the connected battery 14 is necessary based on the terminal voltage, and when it is determined that charging is necessary, the charging can be performed with reference to the terminal voltage and the environmental temperature. Determine whether or not.

The controller 24 generates a control signal 110 for driving the charge control circuit 28 and outputs it to the charge control circuit 28.
A charge current is supplied from the charge control circuit 28 to the battery 14 and the battery
It has a charge control function of controlling the charging process for 14. The charging / discharging device 10 in the present embodiment has a counter for measuring the CC time during the charging process, and identifies the type of the battery based on the count value. Specifically, the controller 24 measures the battery terminal voltage at the start of charging, stores and holds the terminal voltage, and starts charging. The stored value of this terminal voltage changes according to the remaining battery capacity,
Since the CC time differs depending on the battery voltage, the CC time is used when correcting the measured CC time according to the battery voltage at the start of charging. The controller 24 detects that the constant-current charging is completed, for example, by switching to the constant-voltage charging and ends the time measurement, and compares the time measurement result at that time with the set value stored in the memory 40. Recognize the type of battery corresponding to the clock result and the set value.

As described above, the controller according to the present embodiment
24 stores the battery voltage at the start of charging and starts timing, but the present invention is not limited to this.For example, it is detected that the charging voltage has reached a predetermined voltage after the start of charging, and the time since the detection is detected. The controller 24 may be configured to measure and recognize the constant current charging time of the battery. In this case, the timing at which charging is started and time measurement is started is standardized, so that it is possible to omit the process of correcting the CC time according to the charging start voltage.

The controller 24 has a function of recognizing the environmental temperature based on the voltage value applied to the input 114 and recognizing the cell temperature of the battery 14 while the battery 14 is being charged and discharged. ing. The temperature sensor 38 connected to the input 114 of the controller 24 is applied with a temperature detecting element such as a thermistor whose resistance value changes according to the temperature, and is connected to the battery 14 in order to detect the surface temperature of the loaded battery 14. It is arranged to be close to. The controller 24 corrects the measured CC time according to the detected temperature data.

FIG. 4 shows characteristics of charging voltage curves 54 and 56 when a lithium ion secondary battery is charged by a constant current and constant voltage charging method at cell temperatures of 0 ° C., 25 ° C., and 40 ° C., respectively. And 58 are shown. As shown in the figure, among the charging voltage characteristics of the secondary battery, it can be seen that the rising tendency of the battery voltage particularly at the time of constant current charging differs depending on the temperature. In this example, the characteristics when the cell temperature is 0 degrees
The period ta during which the constant current charging is performed in 54 is shorter than the constant current charging period tb in the characteristic 56 at 25 degrees,
Further, the constant current charging period tc in the characteristic 58 when the cell temperature is 40 degrees is longer than the period tb when the cell temperature is 25 degrees. Thus, even in a specific secondary battery, the constant current charging period changes according to the cell temperature at the time of charging, and as a result,
Since the charge capacity also changes, the controller 24 in the present embodiment corrects the separately measured constant current time by addition / subtraction operation based on the detected cell temperature, and determines the type of battery based on the corrected constant current time. Identify.

Specifically, the controller 24 has a memory 40
Reference the time correction coefficient for each type of battery stored in, and correct the clocked CC time with the time correction coefficient corresponding to the voltage at the start of charging, and further correct the corrected time with the time correction coefficient corresponding to the detected temperature. It has a function to correct. This is performed for each set value of the various batteries stored in the memory 40, and the controller 24 calculates the CC time thus corrected in the constant current charging time set value (Δt1, Δt2,・ ・) Controller 24
Based on the comparison result, a battery type substantially matching the set value is identified, and the identified battery type is stored.

Further, when the battery 14 is discharged, the controller 24 controls the battery 14 based on the identified and stored battery type.
Recognize and store the pre-end voltage and the end voltage according to. If the CC time of the battery being charged does not substantially match the constant current charging time set value, the device 10
It recognizes that it is an unexpected non-standard battery used in, stops the charging process and executes an alarm process.

In this embodiment, by preparing a detailed temperature correction coefficient for each type of battery for each type of battery, it is possible to accurately recognize the battery capacity as a result of charging. In addition, by storing the detected temperature at the time of charging, it is possible to correct and recognize the charged capacity when the battery is fully charged, and to accurately predict the discharge time at the time of discharging, in particular. Value can be obtained.

The temperature sensor 38 detects the temperature before the start of charging, and the controller 24 determines whether or not the environmental temperature is a temperature at which charging is possible, and controls the charging process according to the determination result. Further, the controller 24 detects a temperature of the battery 14 during charging and discharging, and has a protection function for urgently stopping the charging process and the discharging process when detecting an abnormal temperature rise due to, for example, overcurrent or overcharging of the battery. Have. If the battery 14 is formed as a battery pack and the battery pack has a built-in temperature sensor, the detected value is taken out and the input 114 of the controller 24 is input.
May be provided.

The controller 24 monitors the battery voltage at the time of discharging, compares the battery voltage with the stored pre-end voltage and the stored end voltage, and performs discharge control according to the battery capacity. Specifically, the controller 24 outputs a control signal 118 for outputting a warning when the battery voltage drops to the pre-end voltage. When the battery voltage reaches the end voltage, a control signal 112 for turning off the conduction of the discharge control circuit 30 is output.

The memory 40 connected to the controller 24
This is a storage circuit for storing various parameters required for charge / discharge control. In this embodiment, an EEPROM is used. Specifically, when the type of the battery is identified by the constant current charging time, for example, as shown in FIG. 5, the memory 40 stores a constant current charging time set value (Δt1, Δt2,・
・), Charging start voltage and corresponding time correction data (Ka11, Ka12 ・ ・, Kb11, Kb12 ・ ・), time correction data corresponding to detected temperature (Ka21, Ka22 ・ ・, Kb21, Kb22 ・ ・) ,
Full charge judgment value, pre-end voltage setting value (Va10, Vb10,
.) And end voltage set values (Va11, Vb11,...) Are stored for each battery type. In this embodiment, the full charge determination value is a set value for determining full charge after shifting to constant voltage charging, and is a specified voltage value of the battery (4.1
Volts, 4.2 volts), the time during which charging is continued for a predetermined period after shifting from constant current charging to constant voltage charging, and the like are stored in the memory 40 as set values. These stored data are
The data is read by the controller 24 and is referred to at the time of charging and discharging. The voltage value at the start of charging stored in the controller 24 may be stored in a storage element such as an SRAM provided in the controller 24 or may be written in the memory 40.

In the present embodiment, a time correction coefficient for correcting the CC time is stored in the memory 40, and the time correction coefficient is stored in the controller 40.
24 is configured to calculate using this coefficient to correct the CC time.However, the present invention is not limited to this.For example, a constant current charging time set value corresponding to each charging start voltage may be set for each battery type. The stored table may be configured in the memory 40, and the controller 24 may be configured to correct the CC time by referring to the set value based on the charging start voltage. Similarly, a table storing the constant current charging time set value corresponding to each detected temperature for each battery type is configured in the memory 40, and the controller 24 corrects the CC time by referring to the set value based on the detected temperature. It may be configured as follows.

By rewriting the various set values stored in the memory 40, even when the type of battery to be used is changed or the charge control or discharge control of the device is changed,
By changing the parameters, it is possible to support batteries having various characteristics. With such a configuration, the memory 40 stores the set values that are used in various types of devices and that are suitable for various types of batteries, such as voltage, capacity, and battery size.
The charging device 10 can be applied to various information processing devices.

The controller 24 generates a control signal 112 for driving the discharge control circuit 30 and outputs a discharge current from the battery 14 to the DC-D
It has a discharge control function of controlling the discharge process for the battery 14 by supplying it to the C converter 18. When a power switch (not shown) is turned on, the controller 24 supplies the power supplied from the AC adapter 16 via the charge control circuit 28 or the power supplied from the battery 14 to the DC- D
Supply to C converter 18. Also, the controller 24
When the end voltage is detected by monitoring the discharge voltage of the battery 14, a discharge control signal for stopping the discharge is output to the discharge control circuit 30.

The DC-DC converter 18 is a voltage conversion circuit that converts a voltage applied to an input into a required voltage by a load circuit 20 and outputs the required voltage.
The reference numeral 18 supplies DC power of various voltages for driving an image sensor, a signal processing circuit, a recording circuit, and the like (not shown) to each unit in response to a control signal supplied from the controller 24.

The controller 24 detects an end voltage or a pre-end voltage at the time of discharging the battery 14 according to the stored value of the pre-end voltage or the end voltage corresponding to the identified battery type, and stops the discharge according to the detection result. It has a discharge control function of outputting a control signal 112, further outputting a control signal 116 to the DC-DC converter 18, and outputting a control signal 118 for outputting an alarm or the like to the alarm output circuit 42.

Upon receiving the warning signal 118 output from the controller 24, the alarm output circuit 42 notifies the user of the fact that the battery voltage has reached the pre-end voltage and the end voltage by visual and audible display. In addition, when the controller 24 detects that an unspecified battery is connected, the alarm output circuit 42 outputs an alarm indicating that the battery cannot be used or that the remaining amount warning cannot be accurately detected.

The operation of the charging / discharging device 10 in the present embodiment having the above-described configuration will be described with reference to FIG. Steps
At 600, when the battery 14 is connected to the connection terminal 12 in a state where the AC adapter 16 is connected to the connection terminal 22 and DC power from the AC adapter 16 is supplied to each part of the device 10, first, The terminal voltage of the battery applied to the input 108 of the controller 24 is measured and stored. Controller 24
Determines whether the connected battery is a battery that needs charging based on the measured voltage value,
Based on the battery voltage and the temperature value detected by the temperature sensor 38, it is determined whether or not the battery can be charged.

When it is determined that the battery needs to be charged and has a voltage and temperature environment in which the charging process can be performed, the charging process for the battery connected to the connection terminal 12 is started. When starting charging the battery, the controller 24 controls the charging control circuit 28 to be in the ON state, supplies the charging current supplied from the AC adapter 16 to the battery, and measures the charging voltage at the start of the charging. Remember.

When constant current charging of the battery is started, in step 602, counting by a counter for counting the constant current charging time is started. In step 604, it is determined whether constant current charging is completed. You. Here, if the current period is the constant current charging period, the time counting process by the counter is continued, and the time counting process is continued until the end of the constant current charging period is detected. When the controller 24 recognizes that the constant-current charging has ended, that is, that the switching to the constant-voltage charging has been performed, the counting of the counter is stopped, and the CC time indicated by the counted value is recognized by the controller 24 (step 606). ).

Then, when the flow advances to step 608, the measured
The CC time is corrected based on the temperature at the time of charging and the voltage at the start of charging. The controller 24 stores the stored time correction coefficient corresponding to the charging start voltage in the memory 40.
Of the memory 40, and a time correction coefficient corresponding to the temperature measured during the constant current charging period is stored in the memory 40.
, And by using these time correction coefficients,
Correct the CC time according to the set battery.

The controller 24 compares the CC time corrected for each battery type with the set value of the constant current charging time of each battery type to determine whether the battery is being charged. First, as shown in step 610, the constant current charging time corrected by the time correction coefficients ka11, ka12,..., Ka21, ka22,. It is determined whether they are equal. Here, the CC time is almost equal to the set value Δt1 (CC time ≒ Δt1)
Is obtained, it is determined that the battery type is the battery A, and the routine proceeds to step 612, where the pre-end voltage Va10 and the end voltage Va11 suitable for the battery A are set.

If it is determined in step 610 that the battery type is not battery A, the flow advances to step 614 to determine whether the constant current charging time is substantially equal to the constant current charging set value Δt2 corresponding to battery B. A comparison operation is performed. Here, when a comparison result that the CC time is substantially equal to the set value Δt2 (CC timetΔtb) is obtained, it is determined that the battery type is the battery B, and the process proceeds to step 616, where the pre-end voltage Vb10 suitable for the battery B is obtained. And the end voltage Vb11. Thereafter, battery C
Is stored in the memory 40, the set value of the constant current charging time corresponding to the battery C is compared with the corrected CC time. Are identified.

If the comparison results in steps 610 and 614 do not satisfy the conditions, the process proceeds to step 618, where the connected battery is not intended to be used in the apparatus 10. Upon being recognized, the charging process for the battery is terminated, and the control signal 118 for outputting an alarm to the alarm output circuit 42 is output.
As a result, an alarm sound is output from the alarm output circuit 42, and a character or lamp indicating the abnormality blinks.

In steps 612 and 616, when the parameters corresponding to the identified battery are set and the constant voltage charging process is continued, it is determined that the charging process at the charging voltage has passed for a predetermined time. It is determined that the battery 14 is fully charged. Then, the charging control circuit 28 is controlled to be in the off state, and the supply of the charging current to the battery 14 is stopped. In this case, a charge completion display may be output.

In this way, when the identification process for the battery 14 is completed and the battery 14 is fully charged, the user of the device removes the AC adapter 16 from the device 10 and disconnects the information processing device including the device 10. The user carries the camera and performs operations such as photographing and recording image reproduction. When the device is used, such as when going out, the charging / discharging device 10 monitors the discharge voltage of the battery 14, and the battery terminal voltage at the time of the discharge corresponds to the pre-end voltage and the end voltage set in advance. Is periodically compared. When it is detected that the discharge voltage matches the pre-end voltage, the control signal 118 is supplied to the alarm output circuit 42 to display an alarm indicating the battery near end and output an alarm sound. As a result, the user of the device recognizes that the battery capacity is low, and is conscious of the need to shorten the power-on time of the device or stop using the device and charge the device.

If the discharge voltage of the battery 14 further decreases while the use of the device is continued, the battery voltage becomes equal to the end voltage. When the controller 24 recognizes this state, it outputs a control signal 116 to the converter 18, outputs a control signal 112 to the discharge control circuit 30, stops power supply to the load circuit 20, and discharges the battery 14. At the same time, the alarm output circuit 42 outputs and displays a warning display indicating that the terminal voltage of the battery 14 becomes the discharge end voltage and the power is turned off. The pre-end voltage and the end voltage are determined based on an appropriate value according to the type of the battery 14, so that each battery can be appropriately discharged, and the battery capacity can be used up according to the battery, Since the use of the device is prohibited before the voltage suddenly drops below the discharge end voltage, malfunction of the device can be prevented.

The identification result and the set pre-end voltage and end voltage are stored in the memory 40 or the storage element in the controller 24 at least until the battery 14 is removed, and the same battery that is continuously mounted is stored.
When recharging the battery 14, the battery identification process can be omitted. In this case, for example, when the charging and discharging characteristics of the same battery are repeatedly used, if the charging voltage characteristic changes, a parameter corresponding to the characteristic change is set in the memory 40, and the parameter is set for each charging process. , The CC time and the voltage rise value appropriately corresponding to the current characteristic may be recognized.

In the above embodiment, the charging / discharging device for identifying the type of battery based on the CC time has been described. In the following, however, the charging / discharging device for identifying the type of battery based on the voltage rise of the battery during a predetermined constant current charging period will be described. The discharge device will be described.

First, FIG. 7 shows how the charging voltage has increased after a certain period of time from the start of constant current charging of the lithium ion secondary battery, as can be seen from the charging voltage curve shown in FIG. The rise value of the charging voltage after a certain period of time differs depending on the type of battery. In this example, battery A has a period Δt from the start of charging to a predetermined time,
The charging voltage of the battery A is increased by about 0.9 volt (voltage ΔV1), and the charging voltage of the battery B is increased by about 0.7 volt (voltage ΔV2).
As described above, the voltage increase value representing the change in the charging voltage during the constant current charging period differs depending on the type of the battery,
It is possible to identify the type of battery based on this difference.

The voltage rise value differs depending on the temperature at the time of charging, for example, as shown in FIG. The figure shows lithium ion secondary batteries at 0 degrees Celsius and 25 degrees Celsius, respectively.
The charging voltage curves 70, 72 and 74 when the battery is charged by constant current charging at a cell temperature of 40 ° C. and 40 ° C. are shown, respectively. From this figure, it can be seen that the rising tendency of the constant current charging voltage characteristic of the secondary battery changes according to the temperature.
In this example, the voltage rise value in the characteristic 70 when the cell temperature is 0 degrees is the highest, and the voltage rise value becomes lower as the cell temperature becomes 25 degrees or 40 degrees. As a result, even in a specific secondary battery, the voltage rise value in a predetermined period changes according to the cell temperature at the time of charging, so the charging / discharging device according to the present embodiment separately operates based on the detected cell temperature. Correct the voltage rise value during the measured constant current charging time,
The type of the battery is identified based on the corrected voltage rise value.

An example of the configuration of a charging / discharging device for identifying the type of a battery based on a voltage rise value will be described with reference to FIGS. The charging / discharging device in the present embodiment is the charging / discharging device 10 shown in FIG.
Since the functional configurations of the controller 24 and the memory 40 are different, and other configurations may be the same as the configurations of the respective units of the charge / discharge device 10,
The 76 and the memory 78 will be described.

The controller 76 in this embodiment compares the set voltage rise value set in the memory 78 with the charge rise value after a certain period of time from the start of charging, and determines the type of the battery 14 based on the comparison result. Is a control circuit having a battery type identification function for identifying Specifically, as shown in FIG.
The memory 40 stores a voltage rise set value (ΔV1, ΔV2,...) Instead of or in addition to the constant current charge time set value and each time correction coefficient in the first embodiment.
And a voltage correction coefficient (ka31, ka3
, Kb31, kb32, ...) and the voltage correction coefficient (ka41, ka42, ..., kb41, kb42 ...) corresponding to the detected temperature
Are stored for each type. Also, memory 78
Stores a value defining a period Δt for monitoring the voltage rise value. These various set values are read by the controller 76 and are referred to at the time of charging and discharging.

The controller 76 has a function of measuring and calculating the rise value of the charging voltage during a predetermined period Δt after starting the constant current charging process for the battery 14.
For example, the controller 76 determines the battery voltage Vs at the start of charging.
In order to recognize the value of the voltage that has risen from (FIG. 7) to a predetermined period Δt, the voltage Vs is stored and held, and the time Δt is counted by a counter. The controller 76 stops the counter when the time Δt has elapsed, and measures the battery voltage at the time of the charging again. Then controller 76
Calculates the difference between the measured value Vup and the charging start voltage Vs, and temporarily stores the absolute value of the calculation result as a voltage rise value. The controller 76 uses the temporarily stored voltage rise value as
Correction is performed using a voltage correction coefficient corresponding to the voltage Vs at the start of charging, and further using a voltage correction coefficient corresponding to the temperature detected by the sensor. The controller 76 compares the voltage rise value corrected for each battery type in this manner with a voltage rise set value set for each battery, and calculates a battery that substantially matches the voltage rise set value. Is identified, and the identification result is stored.

When the identification of the battery type is completed, the controller
76 stores the pre-end voltage and the end voltage corresponding to the identified battery type in the memory in the same manner as in the first embodiment.
Read from 78 and store. When controlling the discharge to the load circuit 20, the controller 76 monitors the discharge voltage of the battery 14, recognizes an appropriate pre-end voltage and end voltage according to the type of the battery, and responds to the discharge voltage of the battery 14. To properly control the discharge.

The operation of the charging / discharging device in this embodiment is shown in FIG.
This will be described with reference to FIG. In step 1000, when the battery 14 is connected to the connection terminal 12 in a state where the AC adapter 16 is connected to the connection terminal 22 and DC power from the AC adapter 16 is supplied to each part of the device 10, First, the controller
The battery terminal voltage applied to the input 108 is measured and stored. The controller 76 determines whether the connected battery is a battery that needs to be charged based on the measured voltage value, and based on the battery voltage and the temperature value detected by the temperature sensor. Then, it is determined whether the charging process for the battery is possible.

If the battery is capable of performing the charging process and the environment in which the charging process can be performed, the charging process for the battery connected to the connection terminal 12 is started. When starting charging the battery, the controller 76 controls the charging control circuit 28 to be in the ON state, supplies the charging current supplied from the AC adapter 16 to the battery, and measures the charging voltage at the start of the charging. Is memorized.

When constant-current charging of the battery is started, in step 1002, a counter for counting the constant-current charging time is counted, and in step 1004, the time t indicated by the counted value is set to the time set value Δt and It is determined whether or not they are equal. Here, if they are equal, that is, if Δt has elapsed since the start of charging, the process proceeds to step 1006, and if the time Δt has not elapsed, the time counting process by the counter is continued, and this time counting process elapses the time Δt Continued until When it is determined that the time Δt has elapsed, step 1006
And the counting of the counter is stopped, and the time Δ
The constant current charging voltage Vup at the time point t is measured (step 1006).

Next, at step 1008, the difference between the voltage Vs at the start of charging and the voltage Vup at the time when the time Δt has elapsed is calculated, and the calculation result is temporarily stored as a voltage rise value. Next, the stored voltage rise value is corrected based on the temperature at the time of charging and the voltage at the start of charging. In detail, the controller 76 reads out the stored voltage correction coefficient corresponding to the charging start voltage from the storage area of the memory, and reads out the time correction coefficient corresponding to the temperature measured during the constant current charging period from the memory 78. Then, the voltage rise values calculated by the above-described measurement and calculation are respectively corrected by the voltage correction coefficients in correspondence with the batteries.

The controller 76 compares the voltage rise value corrected for each battery type with the set voltage rise value of each battery type to compare and determine whether the battery is being charged. First, as shown in step 1010, it is determined whether the voltage rise value corrected by the voltage correction coefficients ka31, ka32,... Ka41, ka42,... Is substantially equal to the voltage rise set value corresponding to the battery A. Is determined. Here, when a comparison result that the voltage rise value is substantially equal to the set value ΔV1 (voltage rise value ΔV1) is obtained, it is determined that the type of the battery is the battery A, and the process proceeds to step 1012 to be compatible with the battery A. The pre-end voltage Va10 and the end voltage Va11 are set.

If it is determined in step 1010 that the battery type is not battery A, the process proceeds to step 1014, where it is determined whether the voltage rise value is substantially equal to the voltage rise set value ΔV2 corresponding to battery B. Is calculated. Here, when a comparison result that the voltage rise value is substantially equal to the set value ΔV2 (voltage rise value ≒ ΔV2) is obtained, it is determined that the battery type is the battery B, and the process proceeds to step 1016. The voltage Vb10 and the end voltage Vb11 are set. Thereafter, when the parameter setting corresponding to the battery C is stored in the memory 40, the voltage rise setting value corresponding to the battery C is compared with the corrected voltage rise value. ,
The type of the battery is identified.

If the comparison results in steps 1010 and 1014 do not satisfy the conditions, the flow advances to step 1018 to determine that the connected battery is not intended for use in the device 10. Upon recognition, the charging process for the battery is terminated, and a control signal 118 for outputting an alarm to the alarm output circuit 42 is output. As a result, an alarm sound is generated from the alarm output circuit 42, and a character or lamp indicating the abnormality blinks.

When the pre-end voltage and the end voltage according to the type of the battery 14 are set in this way, the output of the battery 14 is supplied to the load circuit 20 in the same manner as in the first embodiment. At this time, the charge / discharge device 10 monitors the discharge voltage of the battery 14, and supplies a control signal 118 to the alarm output circuit when the battery terminal voltage at the time of the discharge reaches the pre-end voltage or end voltage set in advance. Then, an alarm corresponding to the voltage is output, and in the case of the end voltage, the power supply is controlled to an off state.

In the second embodiment, in addition to the effect of the above-described first embodiment, there is a merit that the battery type can be identified before shifting to the constant voltage charging, that is, in a relatively short time. is there.

As described in the first and second embodiments, without changing the outer shape of the battery or the like,
The type of battery can be identified based on a change in charging voltage during constant current charging. The battery voltage is monitored at the time of battery discharge, and when the battery voltage drops to the end voltage, the battery discharge is controlled. As a result, system down due to malfunction or the like is prevented from occurring, and safe and reliable operation becomes possible. In addition, the battery capacity can be used up as much as possible, and the battery can be operated efficiently. Also,
Since various types of batteries can be accurately identified, it is advantageous to not only effectively use the batteries but also to easily obtain an alternative battery when the battery is exhausted, for example. When a product is supplied to the market by being attached to an electronic device, the product is not limited to a specific type of battery, so that a better product can be more stably supplied to the market.

It should be noted that the method of identifying the battery by the CC time and the method of identifying the battery by the voltage rise value can be used not only individually but also in combination. In this case, the memory 40 stores both the constant current charging time set value and the voltage rise set value for each type of battery, and further stores a time correction value and a voltage correction value corresponding to the detected temperature. The controller 76 can accurately determine another type of battery based on these set values and the actually detected time and voltage values.

Further, in the above-described embodiment, the charge / discharge device using the lithium ion secondary battery having different characteristics depending on the manufacturer or the design has been described. For example, the present invention is applied to a nickel cadmium secondary battery and a nickel hydride secondary battery. Again, various parameters are prepared, and in the same manner as in the above embodiment, the type of various batteries can be identified, and at the time of discharging, the battery voltage can be monitored to perform discharge control according to the set voltage.

The various setting values stored in the memories 40 and 78 are previously written,
The present invention is not limited to this. For example, when a new secondary battery is actually charged at a constant current and a constant voltage under the reference temperature condition by the charging and discharging device in the above-described embodiment, the constant current charging time and the voltage rise value are measured. The measurement results can be stored in the memories 40 and 78 as set values corresponding to the respective battery types.

[0070]

As described above, according to the present invention, with a simple structure, the type of a secondary battery can be reliably identified based on a change in charging voltage when the secondary battery is charged at a constant current.
When the battery output is supplied to the load circuit and discharged, appropriate discharge control according to the battery can be performed. In this case, the shape such as the outer shape of the battery may be a common shape, and it is not necessary to provide a special shape and an identification member for identification on the battery and the device side. It is possible to identify the battery type. In addition, since a plurality of parameters corresponding to the battery type can be prepared in accordance with the battery, it is possible to appropriately cope with various types of batteries, and by changing the parameters, a high performance secondary battery can be obtained. Even when the next battery is supplied to the market, the parameters corresponding to that battery are stored, so that the type of the latest battery can be identified without changing the circuit configuration for identifying the battery. can do.

[Brief description of the drawings]

FIG. 1 is a block diagram showing a charge / discharge device to which the present invention is applied.

FIG. 2 is a graph showing an example of a pre-end voltage and an end voltage in a discharge voltage curve of a secondary battery.

FIG. 3 is a graph showing charging voltage curves when different types of secondary batteries are charged at a constant current and a constant voltage, showing different constant current charging times.

FIG. 4 is a graph showing different charging voltage curves according to temperature.

FIG. 5 is a diagram showing stored contents of a memory in the first embodiment.

FIG. 6 is a flowchart illustrating an operation of the charge / discharge device according to the first embodiment.

FIG. 7 is a graph showing charging voltage curves when different types of secondary batteries are charged at a constant current and a constant voltage, showing different voltage rise values during a predetermined period.

FIG. 8 is a graph showing different charging voltage curves depending on temperature.

FIG. 9 is a diagram showing storage contents of a memory in the second embodiment.

FIG. 10 is a flowchart illustrating an operation of the charge / discharge device according to the second embodiment.

[Explanation of symbols]

 10 Charge / discharge device 14 Secondary battery 16 AC adapter 18 DC-DC converter 24,76 Controller 28 Charge control circuit 30 Discharge control circuit 40,78 Memory 42 Alarm output circuit

──────────────────────────────────────────────────続 き Continued on the front page (51) Int.Cl. ⁷ Identification symbol FI Theme coat ゛ (Reference) H02J 7/10 H02J 7/10 BK

Claims (20)

[Claims] 1. A secondary battery identification device for identifying any one of a plurality of types of secondary batteries by connecting any of the plurality of types of secondary batteries, the device comprising: Charging means for charging the secondary battery at a constant current; storage means for storing a reference time at which the secondary battery is charged at a constant current in association with each type of the secondary battery; Identification means for identifying the type of the secondary battery based on a change in voltage, wherein the identification means includes timing means for timing a constant current charging time for the secondary battery, and is timed by the timing means. A rechargeable battery identification device that identifies the type of the rechargeable battery based on the constant current charging time and the content stored in the storage unit. 2. The identification device according to claim 1, wherein said identification means includes a correction means for correcting said constant current charging time, and based on said constant current charging time corrected by said correction means. An apparatus for identifying a secondary battery, wherein the type of the secondary battery is identified. 3. The identification device according to claim 2, wherein the correction unit corrects the constant current charging time according to a charging voltage at the start of constant current charging. apparatus. 4. The identification device according to claim 2, wherein the device has a temperature detecting unit for detecting a temperature of the secondary battery, and the correcting unit detects the temperature detected by the temperature detecting unit. An apparatus for identifying a secondary battery, wherein the constant-current charging time is corrected in accordance therewith. 5. The identification device according to claim 1, wherein the device includes a power supply unit that supplies an output of the secondary battery to a load circuit, and discharges the secondary battery according to a type of the secondary battery. Control means for controlling the voltage value for discharge control in accordance with the type of the identified battery. A secondary battery identification device that monitors a voltage and controls a discharge state of the secondary battery based on the monitored voltage and the set voltage. 6. The identification device according to claim 5, wherein the control unit compares the monitor voltage with the set voltage, and when the monitor voltage drops to the set voltage, the control unit outputs a signal from the secondary battery. An identification device for a secondary battery, which performs discharge control for stopping discharge. 7. The identification device according to claim 6, wherein the control unit outputs a warning for stopping discharge from the secondary battery when the monitor voltage drops to the set voltage. Secondary battery identification device. 8. The identification device according to claim 6, wherein the storage means stores an end voltage corresponding to an end-of-discharge voltage and a pre-end voltage as the voltage value according to a battery type. Means for setting a voltage value corresponding to the secondary battery according to the stored voltage value, the control means, when detecting the pre-end voltage of the identified secondary battery, output a warning, An apparatus for identifying a secondary battery, wherein when the end voltage is detected, the discharge of the secondary battery is stopped. 9. A secondary battery identification device for connecting any one of a plurality of types of secondary batteries and identifying the secondary battery, wherein the device comprises: Charging means for charging the secondary battery at a constant current; measuring means for measuring a rise in the battery voltage during the constant current charging of the secondary battery; and a battery type for measuring the rise in the battery voltage during the constant current charging. Storage means for storing each of the battery types, and identification means for identifying the type of the secondary battery based on the rise value measured by the measurement means and the storage content of the storage means. Rechargeable battery identification device. 10. The identification device according to claim 9, wherein
The identification means includes a correction means for correcting the rise value measured by the measurement means, and identifies the type of the secondary battery based on the rise value corrected by the correction means. Secondary battery identification device. 11. The identification device according to claim 10, wherein the correction means corrects the increase value according to a charging voltage at the start of constant current charging. 12. The identification device according to claim 11, wherein the device has a temperature detecting means for detecting a temperature of the secondary battery, and the correcting means detects the temperature detected by the temperature detecting means. An identification device for a secondary battery, wherein the increase value is corrected according to the value. 13. The identification device according to claim 9, wherein
The apparatus includes a power supply unit that supplies an output of the secondary battery to a load circuit, and a control unit that controls discharge of the secondary battery according to a type of the secondary battery. Means for switching and setting a voltage value for control in accordance with the type of the identified battery, and monitoring a battery voltage at the time of discharging the secondary battery, based on the monitored voltage and the set voltage. And controlling the discharge state of the secondary battery. 14. The identification device according to claim 13, wherein the control unit compares the monitor voltage with the set voltage, and when the monitor voltage drops to the set voltage, the control unit outputs a signal from the secondary battery. An identification device for a secondary battery, which performs discharge control for stopping discharge. 15. The identification device according to claim 14, wherein the control unit outputs a warning for stopping discharge from the secondary battery when the monitoring voltage decreases to the set voltage. Secondary battery identification device. 16. The identification device according to claim 14, wherein the storage means stores an end voltage corresponding to a discharge end voltage and a pre-end voltage as the voltage value in accordance with a battery type. Means for setting a voltage value corresponding to the secondary battery according to the stored voltage value, the control means, when detecting the pre-end voltage of the identified secondary battery, output a warning, An apparatus for identifying a secondary battery, wherein when the end voltage is detected, the discharge of the secondary battery is stopped. 17. A method for identifying a secondary battery by connecting any one of a plurality of types of secondary batteries and identifying the secondary battery, the method comprising: A first set value corresponding to a change in the battery voltage when the battery is charged at a constant current is stored for each type of the secondary battery, and the first set value is stored in accordance with a change in the charging voltage when the secondary battery is charged at a constant current. Detecting the value of the secondary battery and identifying the type of the secondary battery based on the detection result and the first set value. 18. The identification method according to claim 17, wherein the value according to the change in the charging voltage is a constant current charging time for the secondary battery, and the value based on the constant current charging time for the secondary battery. A method for identifying a secondary battery, comprising identifying a type of the secondary battery. 19. The identification method according to claim 17, wherein the value corresponding to the change in the charging voltage is a voltage increase value during a constant current charging period for the secondary battery, and the value based on the voltage increase value. A method for identifying a secondary battery, comprising identifying a type of a secondary battery. 20. The identification method according to claim 17, wherein the method sets a second set value for controlling discharge of the secondary battery in accordance with an identification result for the secondary battery. When supplying the output of the secondary battery to the load circuit, the discharge voltage of the secondary battery is monitored, and the discharge of the secondary battery is controlled based on the discharge voltage and the second set value. A method for identifying a secondary battery.