Secondary battery charging device, charging method, and program

Abstract

To provide a secondary battery charging device, a charging method, and a program that can properly charge an inactive nickel-metal hydride secondary battery without erroneous detection.SOLUTION: A charging device charges an attached secondary battery and includes a detection threshold setting unit that sets a detection threshold for detecting the type of battery in accordance with the ambient temperature of the attached battery, and a battery type determination unit that determines whether the attached battery is a secondary battery on the basis of the battery voltage and the detection threshold, and when the charging time from the start of charging of the battery is within a predetermined time, the detection threshold setting unit sets a value obtained by increasing the detection threshold corresponding to a predetermined temperature environment including the ambient temperature of the attached battery by a predetermined value as a new detection threshold.SELECTED DRAWING: Figure 2

Description

[Technical field]

[0001] The present disclosure relates to a charging device, a charging method, and a program for a secondary battery. [Background technology]

[0002] Conventionally, chargeable and dischargeable secondary batteries such as nickel-metal hydride secondary batteries have been widely used as power sources for operating various devices, etc. Generally, chargers for charging secondary batteries are equipped with a battery detection function so that when a different type of battery such as a primary battery is attached, it is not charged by mistake (for example, see Patent Document 1).

[0003] For example, chargers for charging nickel-metal hydride secondary batteries are equipped with an alkaline battery detection function that detects alkaline batteries, which are primary batteries. If a user mistakenly inserts an alkaline battery into a charger for nickel-metal hydride secondary batteries, the alkaline battery detection function detects this as an error and prevents charging.

[0004] The alkaline battery detection function detects the type of battery based on, for example, the battery voltage. Since the battery voltage of an alkaline battery is usually higher than that of a nickel-metal hydride secondary battery, an alkaline battery can be detected by setting the detection threshold for the battery voltage for detecting the type of battery higher than the battery voltage of a nickel-metal hydride secondary battery. If the charger detects that the installed battery is an alkaline battery, it stops charging and displays an error message indicating that an alkaline battery has been installed. [Prior art documents] [Patent documents]

[0005] [Patent Document 1] Special Publication No. 2015-532584 Summary of the Invention [Problem to be solved by the invention]

[0006] When nickel-metal hydride secondary batteries are left unused for long periods of time, they can enter an inactive state in which their internal chemical reactivity decreases. Nickel-metal hydride secondary batteries in an inactive state have the property that the impedance becomes high immediately after charging begins, causing the battery voltage to increase during charging, but when charging is continued for a certain period of time, the impedance returns to its original value, and the battery voltage during charging returns to its original state.

[0007] When such an inactive nickel-metal hydride secondary battery is charged, the battery voltage increases due to an increase in impedance during the initial charging period, exceeding a detection threshold preset in the charger, causing the battery to be erroneously detected as an alkaline battery.

[0008] One possible method to solve this problem is to raise the detection threshold so that it is higher than the battery voltage of the nickel-metal hydride secondary battery at the beginning of charging. However, if the detection threshold is made too high, the alkaline battery may be erroneously detected as a nickel-metal hydride secondary battery and may leak if it is charged for a long period of time.

[0009] The present disclosure has been made in consideration of the problems in the above-mentioned conventional technology, and aims to provide a secondary battery charging device, charging method, and program that can properly charge a nickel-metal hydride secondary battery in an inactive state without erroneous detection. [Means for solving the problem]

[0010] A charging device for a secondary battery according to the present disclosure includes: A charging device that charges an attached secondary battery, a detection threshold setting unit that sets a detection threshold for detecting the type of the attached battery in accordance with the environmental temperature of the battery; a battery type determination unit that determines whether the attached battery is a secondary battery based on the battery voltage and the detection threshold; having The detection threshold setting unit is If the charging time from the start of charging the battery is within a predetermined time, a detection threshold corresponding to a predetermined temperature environment including the environmental temperature of the installed battery is increased by a predetermined value and set as a new detection threshold.

[0011] In addition, the charging method according to the present disclosure includes: A charging method for charging an attached secondary battery, comprising the steps of: When setting a detection threshold for detecting the type of the attached battery according to the environmental temperature of the attached battery, if the charging time from the start of charging of the battery is within a predetermined time, a detection threshold corresponding to a predetermined temperature environment including the environmental temperature of the attached battery is increased by a predetermined value and set as a new detection threshold; It is determined whether the attached battery is a secondary battery based on the battery voltage and the detection threshold.

[0012] Furthermore, the program according to the present disclosure includes: The above charging method is executed by a computer. Effect of the Invention

[0013] According to the present disclosure, a nickel-metal hydride secondary battery in an inactive state can be appropriately charged without erroneous detection. [Brief description of the drawings]

[0014] [Figure 1] FIG. 1 is a block diagram showing an example of the configuration of a charging device according to this embodiment. [Diagram 2] FIG. 2 is a functional block diagram illustrating an example of the configuration of the control unit in FIG. [Diagram 3] FIG. 3 is a schematic diagram for explaining the relationship between the detection threshold of the charging device according to the present embodiment and the charging characteristics of a nickel-metal hydride secondary battery in an inactive state. [Figure 4] FIG. 4 is a graph showing an example of the charging characteristics of an inactive nickel-hydrogen secondary battery. [Diagram 5]FIG. 5 is a flowchart showing an example of the flow of the detection threshold change process and the charging process performed by the charging device according to this embodiment. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0015] Hereinafter, embodiments of the present disclosure will be described with reference to the drawings. The present disclosure is not limited to the following embodiments, and various modifications are possible without departing from the spirit of the present disclosure. In addition, in each drawing, the same reference numerals are used to denote the same or equivalent parts, and this is common throughout the entire specification.

[0016] Hereinafter, a first embodiment of the present disclosure will be described. A charging device for a secondary battery according to the first embodiment is for charging, for example, a nickel-metal hydride secondary battery, and is equipped with an alkaline battery detection function.

[0017] [Configuration of charging device 100] Fig. 1 is a block diagram showing an example of the configuration of a charging device 100 according to the present embodiment. As shown in Fig. 1, the charging device 100 includes an AC / DC conversion unit 10, a CV / CC conversion unit 20, a DC / DC conversion unit 30, a charging circuit 40, a control unit 50, a detection unit 60, and a notification unit 70. The charging device 100 is connected to an external commercial power source (not shown). The commercial power source is, for example, a 100V AC power source.

[0018] The AC / DC conversion unit 10 converts an AC voltage supplied from an external commercial power source into a predetermined DC voltage and outputs it. The CV / CC conversion unit 20 is a circuit that converts the DC voltage, which is a constant voltage converted by the AC / DC conversion unit 10, into a charging current, which is a constant current required by the charging circuit 40. The DC / DC conversion unit 30 converts the DC voltage converted by the AC / DC conversion unit 10 into a predetermined DC voltage required for the control unit 50 to operate and outputs it.

[0019] When a battery is attached, the charging circuit 40 charges the battery. The charging circuit 40 is provided with a switch (not shown). In the charging circuit 40, a control signal from the control unit 50 is sent to the switch, which is disposed on a path connected to the attached battery, to turn on the switch, thereby charging the battery. In the charging circuit 40, a control signal from the control unit 50 is sent to turn off the switch, thereby stopping charging of the battery attached to the charging circuit 40. Note that in the following description, attaching a battery to the charging circuit 40 may be described as "attaching a battery to the charging device 100."

[0020] The detection unit 60 is, for example, a sensor group made up of various sensors. In this embodiment, the detection unit 60 has a temperature detection means for detecting an environmental temperature Ta, which is the temperature around the battery attached to the charging device 100.

[0021] The detection unit 60 also has a voltage detection means for detecting the inter-electrode voltage applied between the two electrodes arranged at the battery mounting position. When a battery is mounted in the charging device 100, the inter-electrode voltage is the battery voltage of the battery. When no battery is mounted in the charging device 100, the inter-electrode voltage is the voltage output from the CV / CC conversion unit 20 connected to the charging circuit 40.

[0022] The notification unit 70 notifies of abnormalities that occur during various processes performed by the control unit 50. In this embodiment, the notification unit 70 notifies of an abnormality in the battery type when a battery of a type different from the battery to be charged is installed. Specifically, for example, when an alkaline battery is installed instead of a nickel-metal hydride secondary battery, the notification unit 70 notifies that an alkaline battery has been installed.

[0023] The notification unit 70 is, for example, a display means such as an LED (Light Emitting Diode) and displays an abnormality that has occurred by lighting or blinking, etc. Note that the notification unit 70 is not limited to this and may be, for example, an audio output means such as a speaker that outputs audio.

[0024] The control unit 50 controls the entire charging device 100. The control unit 50 includes an MPU (Micro Processing Unit), a ROM (Read Only Memory), a RAM (Random Access Memory), and the like (none of which are shown). The CPU reads out a program corresponding to the processing contents from the ROM, loads it into the RAM, and centrally controls the operation of the charging device 100 in cooperation with the loaded program.

[0025] For example, control unit 50 controls charging circuit 40 based on information related to the battery detected by detection unit 60. In the present embodiment, control unit 50 sets a detection threshold, which is a threshold for the battery voltage for detecting the type of battery attached to charging device 100, based on the various information detected by detection unit 60, and performs detection threshold change processing and charging processing, which will be described later.

[0026] Fig. 2 is a functional block diagram showing an example of the configuration of the control unit 50 in Fig. 1. As shown in Fig. 2, the control unit 50 has an information acquisition unit 51, a battery type determination unit 52, a charging state determination unit 53, a detection threshold setting unit 54, a charging control unit 55, a timer 56, and a storage unit 57. Note that Fig. 2 shows only the processing units for functions related to charging processing and detection threshold change processing among the configuration of the control unit 50.

[0027] The information acquiring unit 51 acquires various pieces of information detected by the detecting unit 60. For example, in the present embodiment, the information acquiring unit 51 acquires the inter-electrode voltage and the environmental temperature Ta in the charging circuit 40 detected by the detecting unit 60. The acquired inter-electrode voltage and the environmental temperature Ta are supplied to the battery type determining unit 52.

[0028] During the detection threshold change process and charging process, battery type determination unit 52 determines the battery state, such as whether a battery is attached to charging device 100 and the type of the attached battery. For example, battery type determination unit 52 compares the battery voltage of the battery attached to charging device 100 with the detection threshold stored in memory unit 57, and determines the type of the attached battery according to the comparison result.

[0029] In this embodiment, the battery type determination unit 52 determines whether the battery type is a nickel-metal hydride secondary battery or an alkaline battery. Specifically, when the battery voltage is equal to or greater than the detection threshold, the battery type determination unit 52 determines that the installed battery is an alkaline battery. Also, when the battery voltage is less than the detection threshold, the battery type determination unit 52 determines that the installed battery is a nickel-metal hydride secondary battery.

[0030] During detection threshold change processing and charging processing, charging state determination unit 53 determines the charging state of the battery attached to charging device 100. For example, in the present embodiment, charging state determination unit 53 determines, based on the count value of timer 56, whether or not the elapsed time since charging started is within a predetermined time.

[0031] The detection threshold setting unit 54 sets the detection threshold according to the environmental temperature Ta and the battery size of the battery attached to the charging device 100. In the present embodiment, when the temperature environment is "Ta>10", the detection threshold setting unit 54 changes and sets the detection threshold corresponding to the battery size to a value increased by a predetermined value from the initial value.

[0032] The charging control unit 55 controls charging of the battery attached to the charging device 100. For example, in the present embodiment, the charging control unit 55 controls the charging circuit 40 to start and stop charging of the attached battery according to the determination result of the type of the battery attached to the charging device 100.

[0033] The timer 56 starts counting when charging begins for a battery attached to the charging device 100. In other words, the timer 56 counts the charging time for the attached battery.

[0034] The storage unit 57 stores various types of information used by the control unit 50. In the present embodiment, the storage unit 57 pre-stores, as initial values ​​for each temperature environment of the battery, detection threshold values ​​for the battery voltage used by the battery type determination unit 52 to detect the type of the battery.

[0035] [Detection threshold change] Next, a description will be given of the change in the detection threshold in the charging device 100 according to this embodiment. As explained in the Background section, in an inactive nickel-metal hydride secondary battery, the impedance becomes high immediately after the start of charging, causing the battery voltage to become high during charging. On the other hand, after a certain time has passed since the start of charging, the impedance returns to its original value, and the battery voltage during charging returns to its original state.

[0036] When such an inactive nickel-metal hydride secondary battery is charged with a normal charging device, the battery voltage caused by the rise in impedance immediately after charging starts may exceed the detection threshold for battery voltage used to detect the battery type. For example, when a nickel-metal hydride secondary battery is attached to a charging device, it may be erroneously detected as an alkaline battery and become unable to be charged.

[0037] Therefore, the charging device 100 of this embodiment performs a detection threshold change process that changes the detection threshold so that even if the attached battery is an inactive nickel-metal hydride secondary battery, it can be properly charged without being erroneously detected as an alkaline battery.

[0038] (Detection threshold and charging characteristics of inactive nickel-metal hydride secondary batteries) Fig. 3 is a schematic diagram for explaining the relationship between the detection threshold of the charging device 100 according to this embodiment and the charging characteristics of an inactive nickel-hydrogen secondary battery. Fig. 3 shows the detection threshold when the battery state is classified by "temperature environment" and "battery size", and the charging characteristics of an inactive nickel-hydrogen secondary battery (hereinafter appropriately referred to as an "inactive nickel-hydrogen secondary battery") attached to the charging device 100.

[0039] The "temperature environment" is a rough classification of the environmental temperature Ta, which is the temperature around the battery attached to the charging device 100. In this example, the temperature environment is classified into "Ta≦10" and "Ta>10". Here, as an example of the temperature environment of "Ta≦10", a case where the environmental temperature Ta is "-5°C" is shown. Also, as an example of the temperature environment of "Ta>10", cases where the environmental temperature Ta is "6°C" and "40°C" are shown.

[0040] In this example, the case is shown where the measurement error of the temperature detection means in the detection unit 60 is a maximum of about 5° C. Taking this into consideration, an environmental temperature Ta of 6° C. can be considered to be equivalent to an environmental temperature Ta of 11° C. Therefore, here, the example where the environmental temperature Ta is 6° C. is included in the temperature environment of Ta>10° C.

[0041] "Battery size" indicates the size of the battery that is attached to the charging device 100. In this example, the battery sizes are classified into "AA" and "AAA."

[0042] In addition, in FIG. 3, the detection threshold is set to a different value depending on the temperature environment and the battery size. This is because the peak value of the battery voltage of an inactive nickel-metal hydride secondary battery during charging differs depending on the temperature environment and the battery size. In this example, the detection thresholds when the temperature environment is Ta≦10 and the battery sizes are AA and AAA are "2.10V" and "2.50V", respectively. Furthermore, the detection thresholds when the temperature environment is Ta>10 and the battery sizes are AA and AAA are "2.00V" and "2.20V", respectively.

[0043] Furthermore, in this example, a "peak value" and a "margin" are shown as the charging characteristics of the inactive nickel-hydrogen secondary battery. The "peak value" is the maximum value of the battery voltage in the inactive nickel-hydrogen secondary battery during charging. The "margin" is the difference between the detection threshold value and the peak value.

[0044] (Margin changes and possible impacts) Incidentally, the peak value of the battery voltage during charging of an inactive nickel-metal hydride secondary battery varies depending on the environmental temperature Ta and the battery size, as shown in Fig. 3. Therefore, the margin, which is the difference between the detection threshold and the peak value of the battery voltage, also varies depending on the environmental temperature Ta and the battery size.

[0045] For example, in this example, when the environmental temperature Ta is 6° C. and the battery size is AAA, the margin is 20 mV, which is smaller than the margin under other conditions. Therefore, when determining the type of battery using the detection threshold shown in Fig. 3, there is a possibility that the battery voltage of an inactive nickel-hydrogen secondary battery during charging may exceed the detection threshold due to individual differences in the inactive nickel-hydrogen secondary battery and measurement errors in the battery voltage.

[0046] Fig. 4 is a graph showing an example of the charging characteristics of an inactive nickel-hydrogen secondary battery. In Fig. 4, the horizontal axis indicates charging time [min] and the vertical axis indicates battery voltage [V]. This example also shows the battery voltage from the start of charging an inactive nickel-hydrogen secondary battery with an environmental temperature Ta of 6°C and a battery size of AAA.

[0047] As shown in Figure 4, the battery voltage of an inactive nickel-metal hydride secondary battery rises to about 2.16 V immediately after the start of charging, then drops, and after 1 minute (60 seconds) it reaches about 2.06 V. Thus, with an inactive nickel-metal hydride secondary battery, a peak value of the battery voltage appears immediately after the start of charging, and at this time the margin, which is the difference between the detection threshold and the peak value of the battery voltage, reaches a minimum value.

[0048] As described above, if the margin is small, the battery voltage of the inactive nickel-metal hydride secondary battery may exceed the detection threshold, resulting in erroneous detection of the battery type. Therefore, one method of preventing erroneous detection is to increase the detection threshold to increase the margin.

[0049] If the detection threshold is changed uniformly regardless of the battery size and the ambient temperature Ta, there is a possibility that an alkaline battery mounted in the charging device 100 may be erroneously detected as a nickel-metal hydride secondary battery. Therefore, in this embodiment, the detection threshold under conditions with a small margin is raised by a predetermined value. Specifically, in this embodiment, the detection threshold when the ambient temperature Ta exceeds 10° C. (Ta>10) is raised by a predetermined value.

[0050] Also, the battery voltage of an inactive nickel-metal hydride secondary battery rises immediately after the start of charging, but returns to a normal state after a certain time has passed since the start of charging. Therefore, in this embodiment, the detection threshold is raised only until a certain time has passed since the start of charging, and then returned to the initial value.

[0051] For the above reasons, in this embodiment, when the margin is small and the environmental temperature Ta exceeds 10°C, the detection threshold is increased by a predetermined value until a predetermined time has elapsed since the start of charging, and after the predetermined time has elapsed, a detection threshold change process is performed in which the detection threshold is returned to the initial value.

[0052] According to the results shown in Fig. 4, the battery voltage drops one minute after the start of charging. Furthermore, if the increase in the detection threshold is too large, the detection threshold will exceed the battery voltage of the alkaline battery, making it impossible to properly detect the alkaline battery. Therefore, in the detection threshold change process, it is preferable to increase the detection threshold by, for example, about 0.1 V until one minute (60 seconds) has elapsed since the start of charging.

[0053] (Detection threshold change process) Fig. 5 is a flowchart showing an example of the flow of the detection threshold change process and the charging process by the charging device 100 according to this embodiment. Fig. 5 shows the processes performed by the control unit 50 during the detection threshold change process and the charging process.

[0054] In step S1, battery type determination unit 52 of control unit 50 determines whether or not a battery is attached to charging device 100. Specifically, for example, information acquisition unit 51 acquires an inter-electrode voltage applied between two electrodes placed at the battery attachment position in charging circuit 40, detected by detection unit 60, and supplies it to battery type determination unit 52. Then, battery type determination unit 52 determines whether or not a battery is attached based on the inter-electrode voltage received from information acquisition unit 51.

[0055] When no battery is attached to the charging circuit 40, the inter-electrode voltage is a predetermined voltage output from the connected CV / CC conversion unit 20. On the other hand, when a battery is attached to the charging circuit 40, the inter-electrode voltage is the battery voltage of that battery. In this case, the battery voltage is a voltage lower than the predetermined voltage output from the CV / CC conversion unit 20.

[0056] For example, when the voltage output from CV / CC conversion unit 20 is 4 V, the inter-electrode voltage will be 4 V when no battery is attached to the charging device 100. Therefore, battery type determination unit 52 determines that a battery is attached to the charging device 100 when the inter-electrode voltage is lower than 4 V. Also, battery type determination unit 52 determines that no battery is attached to the charging device 100 when the inter-electrode voltage is 4 V or higher.

[0057] If it is determined that a battery is attached to the charging device 100 (step S1: Yes), the process proceeds to step S2. On the other hand, if it is determined that a battery is not attached to the charging device 100 (step S1: No), the process ends.

[0058] In step S2, charging state determination unit 53 determines whether or not the elapsed time from the start of charging is within 60 seconds, based on the count value of timer 56. If the result of the determination by charging state determination unit 53 is that the elapsed time is within 60 seconds from the start of charging (step S2: Yes), detection threshold setting unit 54 changes the setting value of the detection threshold, based on the result of the determination by charging state determination unit 53, in step S3.

[0059] In this case, in the present embodiment, the detection threshold setting unit 54 sets the detection thresholds corresponding to the AA and AAA sizes to values ​​increased by 0.1 V when the environmental temperature Ta is higher than 10° C. That is, in the example of Fig. 3, the detection threshold setting unit 54 sets the detection thresholds corresponding to the AA and AAA sizes to "2.10 V" and "2.30 V", which are increased by 0.1 V, when the environmental temperature Ta is higher than 10° C.

[0060] On the other hand, if 60 seconds have passed since the start of charging (step S2: No), in step S4, the detection threshold setting unit 54 resets the detection threshold setting value to the initial value based on the determination result of the charging state determination unit 53. In the example of Fig. 3, the detection threshold setting unit 54 sets the detection thresholds corresponding to AA and AAA to their initial values ​​of "2.00V" and "2.20V", respectively, when the environmental temperature Ta is higher than 10°C. Note that if the detection thresholds have not been changed, the current settings are maintained.

[0061] Next, in step S5, control unit 50 determines the type of the attached battery. Specifically, for example, information acquisition unit 51 acquires the battery voltage of the battery attached to charging device 100 detected by detection unit 60, and supplies it to battery type determination unit 52. Battery type determination unit 52 compares the battery voltage received from information acquisition unit 51 with a detection threshold set in step S3 or step S4 according to the state of the attached battery (temperature environment including the measured environmental temperature Ta and battery size), and determines whether the attached battery is a nickel-metal hydride secondary battery or an alkaline battery.

[0062] If the comparison shows that the battery voltage is equal to or higher than the detection threshold (step S5: Yes), battery type determination unit 52 determines that the installed battery is an alkaline battery. Then, in step S6, battery type determination unit 52 notifies, using notification unit 70, that the battery installed in charging device 100 is an alkaline battery. Then, in step S7, charging control unit 55 supplies a control signal to the switch of charging circuit 40 to stop charging the installed battery.

[0063] Next, in step S8, battery type determination unit 52 determines whether or not the battery attached to charging device 100 has been replaced. If the battery has been replaced (step S8: Yes), the process proceeds to step S9. If the battery has not been replaced, the process returns to step S8, and the process of step S8 is repeated until the battery is replaced.

[0064] On the other hand, if the battery voltage is less than the detection threshold in step S5 (step S5: No), battery type determination unit 52 determines that the attached battery is a nickel-metal hydride secondary battery, and the process proceeds to step S9.

[0065] In step S9, charging state determination unit 53 determines whether or not the battery attached to charging device 100 is being charged. If the battery is being charged (step S9: Yes), the process proceeds to step S12. On the other hand, if the battery is not being charged (step S9: No), the process proceeds to step S10.

[0066] In step S10, the charging control unit 55 supplies a control signal to a switch (not shown) of the charging circuit 40, and starts charging the battery attached to the charging device 100. In step S11, the charging control unit 55 starts counting the elapsed time from the start of charging using the timer 56.

[0067] In step S12, the charging state determination unit 53 determines whether charging of the battery attached to the charging device 100 is complete. Whether charging is complete is determined using a well-known charging control method such as the -ΔV method or the dT / dt method. If charging is complete (step S12: Yes), in step S13, the charging control unit 55 supplies a control signal to the switch of the charging circuit 40 to stop charging the attached battery. The process proceeds to step S13.

[0068] On the other hand, if charging is not complete (step S12: No), the process returns to step S2, whereby charging of the attached battery continues.

[0069] As described above, in charging device 100 according to this embodiment, when the charging time from the start of charging of a battery attached to charging device 100 is within a predetermined time, a detection threshold corresponding to a predetermined temperature environment including the environmental temperature of the attached battery is increased by a predetermined value and set as a new detection threshold. As a result, even if an inactive nickel-hydrogen secondary battery with a high battery voltage at the beginning of charging is attached to charging device 100, the battery voltage will not exceed the detection threshold. Therefore, the nickel-hydrogen secondary battery can be properly charged without being erroneously detected as an alkaline battery by the inactive nickel-hydrogen secondary battery.

[0070] Furthermore, the detection threshold is temporarily changed in the early stage of charging, which makes it possible to prevent an alkaline battery from being erroneously detected as a nickel-metal hydride secondary battery and being erroneously charged. [Explanation of symbols]

[0071] 10 AC / DC conversion section 20 CV / CC conversion section 30 DC / DC conversion section 40 Charging circuit 50 Control section 51 Information Acquisition Department 52 Battery type determination section 53 Charging state determination unit 54 Detection threshold setting unit 55 Charging control unit 56 Timer 57 Memory section 60 Detection unit 70 Notification Department 100 Charging device

Claims

1. A charging device that charges an attached secondary battery, a detection threshold setting unit that sets a detection threshold for detecting the type of the attached battery in accordance with the environmental temperature of the battery; a battery type determination unit that determines whether the attached battery is a secondary battery based on the battery voltage and the detection threshold; having The detection threshold setting unit is When the charging time from the start of charging the battery is within a predetermined time, a detection threshold corresponding to a predetermined temperature environment including the environmental temperature of the attached battery is increased by a predetermined value, and a new detection threshold is set. Charging device.

2. The detection threshold setting unit is When the charging time is within 60 seconds, a value obtained by increasing the detection threshold corresponding to a temperature environment including the environmental temperature exceeding 10° C. by 0.1 V is set as the new detection threshold. The charging device according to claim 1 .

3. The detection threshold setting unit is The detection threshold is set according to the environmental temperature and the battery size of the installed battery. The charging device according to claim 1 .

4. The battery type determination unit is If the battery voltage is less than the detection threshold, it is determined that the attached battery is a nickel-metal hydride secondary battery. The charging device according to claim 1 .

5. The battery type determination unit is If the battery voltage is equal to or greater than the detection threshold, the installed battery is determined to be an alkaline battery. The charging device according to claim 1 .

6. The battery may further include a notification unit that notifies the user that an abnormality has occurred when the installed battery is determined to be an alkaline battery. The charging device according to claim 1 .

7. A charging method for charging an attached secondary battery, comprising the steps of: When setting a detection threshold for detecting the type of the attached battery according to the environmental temperature of the attached battery, if the charging time from the start of charging of the battery is within a predetermined time, a detection threshold corresponding to a predetermined temperature environment including the environmental temperature of the attached battery is increased by a predetermined value and set as a new detection threshold; Based on the battery voltage and the detection threshold, it is determined whether the attached battery is a secondary battery. Charging method.

8. A program for causing a computer to execute the charging method according to claim 7.

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