JP5867107B2 - Charging device, connection determination method, and charging method - Google Patents

Description

  The present invention relates to a technique for charging an object including a secondary battery.

  Currently, rechargeable batteries (secondary batteries) are widely used. In recent years, attention has been focused on the use of secondary batteries as an energy source even in vehicles such as automobiles in terms of reducing carbon dioxide emissions and reducing dependence on fossil fuels. As a result, automakers are actively developing electric vehicles (electric vehicles).

  For the spread of electric vehicles, it is essential to improve the charging infrastructure for charging electric vehicles. Accordingly, the spread of charging devices that charge electric vehicles is also important.

  In order for an electric vehicle to be able to drive a motor for a long time, a large-capacity secondary battery is required. For this reason, the charging device must apply a high voltage when charging the electric vehicle. Accordingly, the charging device is required to ensure safety by not applying a high voltage in a state where the electric vehicle is not connected.

  The charging device includes a connector (plug, hereinafter referred to as “charging connector”) for connection to an electric vehicle, and is connected to the electric vehicle via the connector. Thus, safety can be ensured by letting the user instruct the start of charging after connecting the charging connector of the charging device to the electric vehicle. However, since the user must instruct the start of charging in addition to connecting the electric vehicle to the charging connector, the operability is poor. Thereby, it can be said that it is important for the user to realize high operability.

  There is also a demand for such operability and safety, and at present, a standard that can determine whether or not an electric vehicle is connected on the charging device side has been established. The standards include SAE J1772 and IEC61851-21. Hereinafter, the standard is collectively referred to as “normal charging standard” for convenience.

  When both the charging device and the electric vehicle comply with such a normal charging standard, the charging device can determine whether or not the electric vehicle is connected by communication with the electric vehicle at any time. However, when at least one of the charging device and the electric vehicle does not conform to the normal charging standard, the charging device cannot determine whether or not the electric vehicle is connected. For this reason, it is desirable that the charging device be able to recognize the connection while ensuring high operability and safety even when an electric vehicle that does not conform to the normal charging standard is connected. It can be said.

  Among conventional charging devices, a high voltage for charging and an AC voltage as low as about 5 V can be selectively applied to the charging connector, and an AC current is detected when an AC voltage is applied to the charging connector. There is something to check whether or not. Thus, the conventional charging device determines that the electric vehicle is connected when the AC voltage is detected, and determines that the electric vehicle is not connected when the AC voltage is not detected (Patent Document 1). ). Since such a determination can be made and a high voltage for charging can be applied to the electric vehicle, charging of the electric vehicle can be started automatically. In a situation where the electric vehicle is not connected, the risk of applying a high voltage to the charging connector can be suppressed. For these reasons, the conventional charging device can ensure high operability and safety even for an electric vehicle that does not conform to the normal charging standard.

  The user of the charging device can release the connection of the charging connector at any time. There is a possibility that the charging connector is disconnected from the electric vehicle for some reason. For this reason, it is necessary to determine whether or not an electric vehicle is connected even after charging of the electric vehicle is started.

  The conventional charging device is configured to selectively apply one of two different voltages to the charging connector. If the AC voltage is temporarily applied to the charging connector even after the charging is started, it can be recognized that the electric vehicle has been removed from the charging connector after the charging is started.

  An object to be charged, such as an electric vehicle, generally has a capacitor connected in parallel with a charger in order to suppress an adverse effect due to an excessive AC component. In an electric vehicle having such a capacitor, when applying an AC voltage to the charging connector, it must be assumed that a large current from the capacitor flows to the charging device via the charging connector. The alternating voltage is much smaller than the voltage applied for charging. Therefore, it is necessary to avoid a large current from flowing through a detector that detects an alternating current when an alternating voltage is applied. This effectively means that the conventional charging device cannot apply an AC voltage to the charging connector after the start of charging. That is, the conventional charging device cannot determine whether the electric vehicle is connected after the start of charging. For this reason, it is considered necessary to be able to determine whether or not the electric vehicle is connected even after the start of charging in order to ensure high operability and safety.

JP-A-5-276676 JP 2011-76903 A JP 2011-72104 A

  An object of the present invention is to provide a technique for charging an object (for example, an electric vehicle) that does not comply with the normal charging standard while realizing high operability and safety.

  1 aspect of this invention is a charging device which supplies electric power to the target object provided with the secondary battery, the charging terminal for supplying electric power to the target object, and the charging terminal for charging the secondary battery. 1st supply means which supplies 1 electric power, The power supply means which produces | generates 2nd electric power whose voltage is lower than 1st electric power, The discharge for discharging the inflow electric power which flows in from a target object via a charge terminal And a switching means capable of selectively supplying one of the first power and the second power to the charging terminal and connecting the charging terminal to the discharging means, and applied to the charging terminal. A voltage measuring means for measuring the voltage, and after connecting the discharging means to the charging terminal and then connecting the power supply means to the charging terminal, the voltage measuring means obtained by connecting the power supply means to the charging terminal Judgment to determine whether an object is connected It includes a stage, a.

  Another aspect of the present invention is a method for determining whether or not an object including a secondary battery is connected to a charging device, and the charging terminal for supplying power to the object includes The discharge means for discharging the inflow power flowing from the object through the charging terminal is connected, the connection between the charging terminal and the discharging means is released, and the voltage is higher than the first power for charging the secondary battery. A low second power is supplied to the charging terminal, a voltage applied to the charging terminal is measured in a state where the second power is supplied to the charging terminal, and the charging terminal is measured using the measurement result of the voltage. It is determined whether or not the object is connected.

  Another aspect of the present invention is a charging method for causing a charging device to charge an object including a secondary battery, and the charging terminal for supplying power to the object is connected to the charging terminal. The discharge means for discharging the inflow power flowing from the object through the battery is connected, the connection between the charge terminal and the discharge means is released, and the voltage is lower than the first power for charging the secondary battery. The voltage applied to the charging terminal is measured in a state where the second power is supplied to the charging terminal and the second power is supplied to the charging terminal, and the measurement result of the voltage is used for the charging terminal. Determining whether or not an object is connected, and determining whether or not an object is connected to a charging terminal, and then making a new connection to the charging terminal of the object and the charging terminal of the object When recognizing the disconnection and recognizing a new connection to the charging terminal of the object, It performs supply to power the charging terminal, when recognizing the release of the connection between the charging terminal of the object to terminate the supply to the charging terminal of the first power.

  In the present invention, it is possible to charge an object (for example, an electric vehicle) that does not conform to the normal charging standard while ensuring high operability and safety.

It is a figure explaining the structure of the charging device by this embodiment. It is a figure explaining the connection determination method by this embodiment. It is a figure explaining the structure of the charging device by the modification of this embodiment. It is a figure explaining the connection determination method by the modification of this embodiment.

Hereinafter, embodiments of the present invention will be described with reference to the drawings.
FIG. 1 is a diagram illustrating the configuration of the charging apparatus according to the present embodiment.
This charging device 1 assumes that a vehicle 2 equipped with a secondary battery such as an electric vehicle is an object to be charged, and is installed as a charging facility in a charging stand (charging station) or the like. We will call it “charging equipment”).

  The vehicle 2 includes a connector (hereinafter referred to as “connection connector”) 21 for connection to a charging connector 11 that is a charging terminal for supplying power from the charging facility 1. By connecting the capacitor C1 and a vehicle charger (not shown) to the connection connector 21, the capacitor C1 and the vehicle charger are connected in parallel. Thereby, the electric power supplied via the connection connector 21 is supplied to the capacitor C1 and the on-vehicle charger (not shown). The other end of the capacitor C1 is connected to the ground.

  The charging facility 1 receives power supplied from the power supply system 3 for charging the vehicle 2 and receives AC power from the AC power supply 4 for operation. Electric power from the power supply system 3 (hereinafter referred to as “charging power”) is supplied to one contact of the switch SW1, and the common contact of the switch SW1 is connected to the charging connector 11. Thereby, the charging power from the power supply system 3 is supplied to the charging connector 11 via the switch SW1.

  AC power from the AC power supply 4 is supplied to an AC-DC converter (not shown), and is applied as a DC internal power supply voltage to a power supply waveform measurement unit 13 and a vehicle connection determination unit 14 described later. The AC power is supplied to the temporary side of the transformer 12, whereby an AC voltage value Vs (amplitude value or AC voltage having a maximum absolute value of Vs. Here, the amplitude is supplied to the secondary side of the transformer 12. (Assuming the value is Vs). The AC voltage value Vs is a very small value compared with that of the charging power. For example, the voltage value of the charging power is about 200V, and the AC voltage value Vs is about 5V.

  The 0 contact of the switch SW1 is connected to the common contact of the switch SW2. The 0 contact of the switch SW2 is connected to one end of the resistor R1, and the 1 contact is connected to one end of the resistor R2. The other end of the resistor R1 is connected to the ground, and the other end of the resistor R2 is connected to the secondary side of the transformer 12.

  The two switches SW1 and SW2 function as switching means that can selectively supply one of charging power and AC power to the charging connector 11. Therefore, the transformer 12 functions as a power supply means that can supply power having a voltage lower than the charging power to the charging connector 11.

  When the common contact of the switch SW1 is connected to the 0 contact and the common contact of the switch SW2 is connected to the 0 contact, the charging connector 11 is connected to the ground via the resistor R1. For this reason, when the vehicle 2 is connected to the charging connector 11, the resistor R <b> 1 functions as a discharging unit that discharges the electric charge stored in the capacitor C <b> 1 of the vehicle 2. Thereby, the two switches SW1 and SW2 also have a function of connecting the charging connector 11 to the resistor R1 as a discharging means. The discharging means is not limited to this embodiment. Another configuration may be adopted.

  The voltage waveform measuring unit 13 is capable of measuring voltage waveforms at a node B between the common contact of the switch SW1 and the charging connector 11 and a node A between one contact of the switch SW2 and one end of the resistor R2. It is. The measurement result by the voltage waveform measurement unit 13 is output to the vehicle connection determination unit 14.

  The vehicle connection determination unit 14 is a determination unit that determines whether or not the vehicle 2 is connected to the charging connector 11 using the measurement result by the voltage waveform measurement unit 13. The vehicle connection determination unit 14 individually controls switching of the two switches SW1 and SW2, and controls the measurement of the voltage waveform by the voltage waveform measurement unit 13.

  The voltage waveform measurement by the voltage waveform measurement unit 13 is normally performed in a state where the common contact of the switch SW1 is connected to the 0 contact. This is because the vehicle 2 is often not connected to the charging connector 11, and the common contact of the switch SW1 should not be connected to one contact in the situation where the vehicle 2 is not connected to the charging connector 11. is there.

  When the voltage waveform measuring unit 13 measures the voltage waveform at the node A, the vehicle connection determining unit 14 determines that the common contact of the switch SW1 is connected to the 0 contact and the common contact of the switch SW2 is connected to the 0 contact. Continue for a certain time. Thereafter, the vehicle connection determination unit 14 connects the common contact of the switch SW2 to one contact, thereby shifting to a state in which power is supplied to the node A from the secondary side of the transformer 12 via the resistor R2. The waveform measuring unit 13 is caused to measure the voltage waveform at the node A. Before measuring the voltage waveform of the node A, the state in which power can be supplied to the resistor R1 via the switch SW1 and the switch SW2 is continued for a certain time, so that the capacitor C1 of the vehicle 2 connected to the charging connector 11 Even if a large charge is accumulated, the charge is discharged through the resistor R1. For this reason, by causing the voltage waveform measuring unit 13 to measure the voltage at the node A as described above, it is possible to avoid measuring an excessive voltage for the voltage waveform measuring unit 13.

  The voltage waveform measurement unit 13 and the vehicle connection determination unit 14 can be realized by, for example, one microcomputer (hereinafter abbreviated as “microcomputer”). When realizing the voltage waveform measurement unit 13 and the vehicle connection determination unit 14 on the microcomputer, it is necessary to reliably avoid application of an excessive voltage. In this embodiment, it is possible to reliably avoid applying an excessive voltage to the node A using the switches SW1 and SW2 and the resistor R1. Therefore, even when a microcomputer is used, high reliability can be realized.

  As described above, the power from the power supply system 3 is very large compared to the AC voltage value Vs of the AC power generated on the secondary side of the transformer 12. For this reason, the voltage at the node B is applied to the voltage waveform measuring unit 13 via a decompression circuit (not shown). Thereby, the voltage waveform measurement part 13 and the vehicle connection determination part 14 are realizable on a microcomputer.

  FIG. 2 is a diagram for explaining the connection determination method according to the present embodiment. The determination method is a method for determining whether the vehicle 2 is connected to the charging connector 11 applied to the vehicle connection determination unit 14.

  In FIG. 2, SW1 and SW2 represent switches SW1 and SW2, respectively, and 0 and 1 represent the types of contacts connected to the common contacts, respectively. FIG. 2A shows an example of measurement results of voltages at nodes A and B when the vehicle 2 is connected to the charging connector 11. FIG. 2B shows an example of measurement results of voltages at nodes A and B when the vehicle 2 is not connected to the charging connector 11.

  The vehicle connection determination unit 11 has a situation in which the common contact of the switch SW1 is connected to the 0 contact and the common contact of the switch SW2 is connected to the 1 contact (in FIG. 2, this situation is “SW1 =“ 0 ”and SW2 = Focusing on the result of the voltage waveform measurement unit 13 measuring the voltage of the node A or B by “1” ”, it is determined whether or not the vehicle 2 is connected. Hereinafter, this state is referred to as a “determination implementation period”, and the state during that period is referred to as a “determination implementation possible state”.

  Immediately before the determination execution period, the common contact of the switch SW1 is connected to the 0 contact, and the common contact of the switch SW2 is connected to the 0 contact. Thereby, the charging connector 11 is connected to the resistor R1 via the switches SW1 and SW2. For this reason, even if the vehicle 2 having a large charge stored in the capacitor C1 is connected to the charging connector 11, the charge is discharged through the resistor R1. As a result, it is reliably avoided that the voltage waveform measuring unit 13 measures an excessive voltage during the determination execution period. The state immediately before the determination execution period is referred to as a “dischargeable state”.

  Within the determination execution period, each voltage of the nodes A and B can be regarded as a voltage applied to the charging connector 11. Therefore, as shown in FIG. 2B, when the vehicle 2 is not connected to the charging connector 11, the voltage waveforms at the nodes A and B are both supplied to the voltage waveform measuring unit 13 as an AC voltage waveform with an amplitude value Vs. Measured.

  However, when the vehicle 2 is connected to the charging connector 11, as shown in FIG. 2A, the voltage waveforms at the nodes A and B are both AC voltage waveforms whose amplitude is smaller than the amplitude value Vs. This is because the AC voltage is divided by the impedances of the resistor R2 and the capacitor C1, and the amplitude values of the voltages at the nodes A and B are smaller than the amplitude value Vs. Accordingly, in this embodiment, the amplitude value Vs and the threshold value Vth in consideration of the impedances of the resistor R2 and the capacitor C1 are determined, and when the amplitude value of the voltage waveform at the node A or B is less than the threshold value Vth, the vehicle 2 is determined to be connected. Since the electric charge stored in the capacitor C1 of the vehicle 2 is discharged in the dischargeable state immediately before the determination execution period, in FIG. 2A, the voltage of the node B in the dischargeable state is the ground ( GND) level.

  The impedance C1 of the capacitor C1 is calculated by C1 = 1 / j2πfC = 1 / jωC, where C is the capacitance and f is the frequency of the AC power. When the determination execution period elapses, the common contact of the switch SW2 is connected to the 0 contact regardless of the determination result of the connection of the vehicle 2, and returns to a dischargeable state. The connection between the common contact and the zero contact of the switch SW2 is maintained even if the common contact of the switch SW1 is connected to the one contact. This is to discharge the current flowing from the charging connector 11 when the common contact of the switch SW1 is connected to the 0 contact again.

  The vehicle connection determination unit 14 changes the state in the order of dischargeable state → determinable state → dischargeable state before charging is started (period from when charging is finished to when the next charging is started). To recognize the new connection of the vehicle 2. Accordingly, when a new connection of the vehicle 2 can be recognized, the common contact of the switch SW1 is connected to one contact, and the supply of charging power is automatically started via the charging connector 11. At this time, the switch SW2 connects the common contact to, for example, the 0 contact. The state in which the switches SW1 and SW2 are connected in this way is referred to as a “chargeable state”.

  After starting charging as described above, the vehicle connection determination unit 14 determines whether or not the vehicle 2 is connected at any time in order to recognize the disconnection of the vehicle 2. Thereby, when recognizing that the vehicle 2 is not connected, the vehicle connection determination unit 14 connects the common contact of the switch SW1 to the 0 contact, that is, transitions to the dischargeable state, to the charging connector 11. The supply of charging power is terminated. Therefore, from the start of charging until the vehicle 2 is recognized to be disconnected, the vehicle connection determination unit 14 changes the state in the order of chargeable state → dischargeable state → determinable state → chargeable state. Transition.

  The vehicle connection determination unit 14 recognizes the vehicle 2 connected to the charging connector 11 as described above, and automatically supplies charging power and ends the supply according to the recognition result. Therefore, for the user of the charging facility 1, charging can be performed automatically only by connecting the vehicle 2 to the charging connector 11, and high operability is realized. Further, even if the connection with the vehicle 2 is released during charging, the supply of charging power to the charging connector 11 is automatically stopped, so that safety can be ensured.

  In the present embodiment, the object to be charged is the vehicle 2, but the object may be other than the vehicle 2. The type of the object is not particularly limited. The selective supply of charging power or AC power to the charging connector 11 and the connection between the charging connector 11 and the resistor R1 are made possible by the switches SW1 and SW2. However, the configuration that makes such switching possible is the present. The present invention is not limited to the embodiment. For example, when one switch having three contacts is employed, such switching can be performed using the one switch.

  In the present embodiment, the transformer 12 generates power having a lower voltage than the charging power. However, generation of the power having the lower voltage may be performed by other than the transformer 12. The method for determining whether or not the vehicle 2 is connected may be changed according to the power source that generates low-voltage power. Hereinafter, the modification will be specifically described with reference to FIGS. 3 and 4.

  FIG. 3 is a diagram illustrating a configuration of a charging device according to a modification of the present embodiment. In FIG. 3, the same reference numerals are assigned to basically the same components as in the present embodiment. Thus, the description will be made in a manner that focuses only on portions that are different from the present embodiment.

  As in the present embodiment, the charging device 1 ′ assumes that the vehicle 2 equipped with a secondary battery such as an electric vehicle is an object to be charged, and is installed as a charging facility in a charging stand or the like. In this charging facility 1 ′, the DC power generated by the DC power supply 31 can be supplied to the charging connector 11 by replacing the transformer 12 with the DC power supply 31. Thereby, the voltage waveform measurement unit 32 measures the DC voltage waveform of the node A or B. The vehicle connection determination unit 33 determines whether or not the vehicle 2 is connected to the charging connector 11 using the measurement result of the DC voltage waveform by the voltage waveform measurement unit 32.

  As the DC power supply 31, a power supply circuit (for example, an AC-DC converter) that applies an internal power supply voltage to the voltage waveform measurement unit 32 and the vehicle connection determination unit 33 can be used. Thereby, an existing power supply circuit may be used as the DC power supply 31. Since it is not necessary to newly prepare the DC power supply 31, the manufacturing cost of the charging equipment 1 'can be further suppressed as compared with the present embodiment.

  FIG. 4 is a diagram for explaining a connection determination method according to a modification of the present embodiment. The determination method is a method for determining whether or not the vehicle 2 is connected to the charging connector 11, which is applied to the vehicle connection determination unit 33.

  In FIG. 3, as in FIG. 2, SW1 and SW2 represent switches SW1 and SW2, respectively, and 0 and 1 represent types of contacts connected to the common contacts. FIG. 3A shows an example of measurement results of voltages at nodes A and B when the vehicle 2 is connected to the charging connector 11. FIG. 3B shows an example of measurement results of voltages at nodes A and B when the vehicle 2 is not connected to the charging connector 11.

  Since the DC power supply 31 generates direct-current power, when the vehicle 2 is not connected to the charging connector 11, as shown in FIG. Both are measured by the voltage waveform measuring unit 32 as a DC voltage waveform of the voltage value Vs. However, when the vehicle 2 is connected to the charging connector 11, as shown in FIG. 3A, both voltage waveforms in the node A and B determination enable state are both lower than the voltage value Vs from the ground level. The waveform rises relatively slowly up to the voltage value.

  The reason why the voltage waveforms at the nodes A and B do not reach the voltage value Vs is that the DC voltage is divided by the impedances of the resistor R2 and the capacitor C1. The reason why the waveform levels of the nodes A and B are gradually increased is that there is a time constant obtained from the resistor R2 and the capacitor C1 of the vehicle 2. From this, when DC power is supplied to the charging connector 11, in addition to the voltage values of the voltage waveforms of the nodes A and B, the voltage value of the voltage waveform is changed after the transition to the determination executable state. It is possible to determine whether or not the vehicle 2 is connected by paying attention to the time until the set voltage value is reached, that is, the time change in the voltage value. In FIG. 3A, the determined voltage value is represented by Vth, and the time for which the threshold value to be regarded as the vehicle 2 being connected is represented by Tth.

  The vehicle connection determination unit 33 monitors the measurement result (voltage value) of the node A or B input from the voltage waveform measurement unit 32 after shifting to the determination executable state, and until the voltage value reaches the voltage value Vth. Time is measured. Thereby, when the voltage value of the node A or B does not reach the voltage value Vth before the time Tth is measured, the vehicle connection determination unit 33 determines that the vehicle 2 is not connected to the charging connector 11. The charging control based on the determination result is the same as that in the present embodiment.

1, 1 'charging device 2 vehicle (electric vehicle)
3 Power System 4 AC Power Supply 11 Charging Connector 12 Transformer 13, 32 Voltage Waveform Measurement Unit 14, 33 Vehicle Connection Determination Unit 21 Connection Connector C1 Capacitor R1, R2 Resistance SW1, SW2 Switch

Claims (8)

In a charging device for supplying power to an object equipped with a secondary battery,
A charging terminal for supplying the power to the object;
First supply means for supplying a first power for charging the secondary battery to the charging terminal;
Power supply means for generating second power having a voltage lower than that of the first power;
Discharging means for discharging the charge stored in the object through the charging terminal;
Switching means capable of selectively supplying one of the first power and the second power to the charging terminal, and connecting the charging terminal to the discharging means;
Voltage measuring means for measuring a voltage applied to the charging terminal;
After connecting the discharging means to the charging terminal, the object is connected to the charging terminal based on the measurement result of the voltage by the voltage measuring means obtained by connecting the power supply means to the charging terminal. Determining means for determining whether or not
A charging device comprising: The determination means pays attention to at least one of a voltage value of the voltage and a time change of the voltage value as a measurement result of the voltage by the voltage measurement means, and the object is connected to the charging terminal. Determine whether or not
The charging device according to claim 1. When the determination means recognizes that the object is newly connected to the charging terminal by determining whether or not the object is connected to the charging terminal, the first means via the switching means When supplying power to the charging terminal and recognizing that the object is disconnected from the charging terminal, the supply of the first power to the charging terminal via the switching unit is terminated. ,
The charging device according to claim 1 or 2, wherein A method for determining whether an object including a secondary battery is connected to a charging device,
Connecting a discharging means for discharging the charge stored in the object through the charging terminal to a charging terminal for supplying power to the object;
Disconnecting the charging terminal and the discharging means, supplying the charging terminal with second power having a voltage lower than the first power for charging the secondary battery;
Measuring a voltage applied to the charging terminal in a state where the second power is supplied to the charging terminal;
Using the measurement result of the voltage, determine whether the object is connected to the charging terminal,
A connection determination method characterized by the above. In a charging method for causing a charging device to charge an object including a secondary battery,
Connecting a discharging means for discharging the charge stored in the object through the charging terminal to a charging terminal for supplying power to the object;
Disconnecting the charging terminal and the discharging means, supplying the charging terminal with second power having a voltage lower than the first power for charging the secondary battery;
Measuring a voltage applied to the charging terminal in a state where the second power is supplied to the charging terminal;
Using the measurement result of the voltage, determine whether the object is connected to the charging terminal,
Through the determination of whether the object is connected to the charging terminal, recognizing a new connection of the object to the charging terminal, and release of the connection of the object with the charging terminal;
When recognizing a new connection of the object to the charging terminal, supply the first power to the charging terminal,
When recognizing the release of the connection of the object with the charging terminal, the supply of the first power to the charging terminal is terminated.
A charging method characterized by that. The determination means includes
Before starting charging, a dischargeable state in which the charge stored in the object is discharged through the charging terminal using the discharging means, and the second power having a voltage lower than the first power is applied to the second power. A state in which the determination can be performed via the charging terminal to the next battery and the state is changed in the order of the dischargeable state.
The charging device according to claim 1. The determination means includes
After starting charging, a chargeable state in which the first power can be supplied from the first supply means to the secondary battery via the charging terminal, the dischargeable state, the determination feasible state, Transition states in the order of the chargeable states;
The charging device according to claim 6. In a charging device for charging a secondary battery included in an object,
A charging terminal used to charge the object;
Voltage measuring means for measuring a voltage applied to the charging terminal;
Discharging means for discharging the charge stored in the object;
A chargeable state in which first power can be supplied from the first supply means to the secondary battery via the charging terminal, and second power having a voltage lower than the first power is supplied to the secondary battery. The circuit configuration includes a determination feasible state in which supply is possible through the charging terminal, and a dischargeable state in which the charge stored in the object can be discharged through the charging terminal using the discharging means. Switching means for switching;
After the dischargeable state is configured and the charge is discharged by the discharging unit, the determination is performed, and the object is placed on the charging terminal based on the measurement result of the voltage by the voltage measuring unit. Determining means for determining whether or not connected,
A charging device comprising: