JP2003199261A - Charge controller for secondary battery and electrical apparatus using such - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a charge controller for secondary battery and an electrical apparatus using the charge controller wherein insufficient charging which occurs when the temperature of a secondary battery immediately after its discharging is high is corrected in a short time according to an ambient temperature, and further reduction in charging capacity is prevented. <P>SOLUTION: The charge controller comprises a current supply means 3 which supplies a charging current to a secondary battery 10; a temperature detecting means 11 which detects the temperature of the secondary battery 10 under charging; a secondary battery voltage detecting means 4 which detects the voltage of the secondary battery 10; a control means 6 which controls the charging of the secondary battery 10; and a minimum temperature determination means 12 which determines a minimum temperature during fast charging. The ambient temperature is determined from the minimum temperature, and a temperature at which additional charging is started is set based on the ambient temperature. Thus, the insufficiency of charging can be eliminated, and charging can be performed in a short time. <P>COPYRIGHT: (C)2003,JPO

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a charging control device for a secondary battery, and more particularly to the start of additional charging after charging.

[0002]

2. Description of the Related Art A nickel-hydrogen secondary battery or a secondary battery represented by a nickel-cadmium secondary battery has been widely put into practical use as an operating power source for various device systems such as a mobile phone and a portable camera. Further, in recent years, a large current can be discharged, and it has been used as a power source for electric tools and vacuum cleaners.

FIG. 10 is a block diagram of a conventional charge control device for a secondary battery of this type. In the figure, the charger 1 is connected to a power supply 2. The charger 1 is a power source for the constant current circuit 3 which is a current supply unit, the secondary battery voltage detection unit 4, and a charging control circuit 6 which is a control unit including an arithmetic unit 5 including a microcomputer and the arithmetic unit 5. DC power supply 7
It is composed of Further, 8 is a dividing resistor inserted between the temperature detecting means 11 and the DC power supply 7.

Reference numeral 9 denotes a secondary battery pack to which a plurality of nickel-hydrogen secondary batteries or nickel-cadmium secondary batteries 10 are connected in series or in parallel,
It is connected so that the output of the constant current circuit 3 of the charger 1 is applied. Further, reference numeral 11 is a temperature detecting means arranged near the secondary battery 10 to detect the temperature of the secondary battery 10 during charging and standby.

The conventional charge / discharge will be described below. The secondary battery 10 is generally charged by a constant current circuit 3 at a constant current as shown in FIG. While the information from the temperature detecting means 11 such as a thermistor for detecting the temperature of the secondary battery and the secondary battery voltage detecting means 4 for detecting the secondary battery voltage is taken into the charging control circuit 6, the constant current circuit 3 is controlled. Done. That is, when the temperature detecting means 11 detects that the secondary battery 10 is connected to the charger 1,
Based on the criteria determined in advance according to the type of secondary battery or the specifications of the device, it is determined whether the secondary battery voltage and secondary battery temperature are suitable for charging, and if they are suitable, rapid charging is started. When it is not suitable, a small current is passed until the voltage rises or the secondary battery temperature cools down, and the standby state is entered. The voltage of the rechargeable battery 10 and the rechargeable battery temperature are checked at any time even during rapid charging, and it is detected from the values such as −ΔV value and dT / dt obtained in advance whether or not the battery is fully charged. . When the fully charged state can be detected, the rapid charging is terminated and the self-discharged portion is intermittently replenished, so that the so-called trickle charging is performed. This trickle charging also aims to supplement the amount of charge that has not been fully charged at the reference temperature, for example, room temperature, because the temperature of the secondary battery has risen at the completion of charging. FIG. 11 shows a characteristic diagram of the secondary battery temperature and the secondary battery voltage during charging. Regarding the discharge control, there are various controls such as detecting the secondary battery voltage and the secondary battery temperature and stopping the operation when a certain voltage value is reached so as not to cause overdischarge, and displaying the remaining amount. In addition, various discharge control measures have been made in order to extend the life of the secondary battery, such as detecting the secondary battery temperature and stopping it when the temperature exceeds a predetermined temperature.

[0006]

However, there are some secondary batteries of recent years that have a large current and a large capacity, and those whose exterior is covered with a resin, and the conventional configuration requires a large amount of electricity. Regarding a battery that uses a large number of secondary batteries 10, the secondary battery 10 immediately after being discharged has a high temperature due to a large amount of heat generation due to a large current, or poor heat dissipation due to the use of resin for the exterior. However, even if an attempt is made to compensate for the self-discharged amount by trickle charging, the battery will be charged while the temperature is high, and there is a problem that the charging will be substantially insufficient.

Further, when the charging / discharging in the insufficient charging state is repeated, the amount of electricity that can be charged gradually (hereinafter referred to as charging capacity) decreases, and there is a problem that the operating time for discharging becomes short. .

The present invention solves the above-mentioned problems by solving the shortage of charge of the secondary battery due to the temperature rise of the secondary battery due to rapid charging, preventing the decrease of the charge capacity, and
An object of the present invention is to provide a charge control device for a secondary battery that can be charged in a necessary minimum time and an electric device using the same.

[0009]

In order to solve the above-mentioned conventional problems, current supply means for supplying a charging current to a secondary battery, temperature detection means for detecting the temperature of the secondary battery during charging, and Secondary battery voltage detection means for detecting the voltage of the secondary battery, control means for controlling the charging of the secondary battery, and full charge after the secondary battery starts charging based on the output from the temperature detection means. When the temperature detected by the temperature detection means reaches a predetermined temperature determined by the minimum temperature of the secondary battery after full charge detection, the minimum temperature determination means for determining the minimum temperature until charging detection is provided. The configuration is such that additional charging is started. With this configuration, depending on the ambient temperature of the device, when the ambient temperature is low, the start temperature of additional charging is lowered to increase the charge electricity amount (charge electricity amount priority), and when it is high, the start temperature of additional charge is raised. Since the additional charging time is shortened while ensuring the amount of electricity to be charged (charging time priority), it is possible to compensate for the capacity that cannot be fully charged by charging the secondary battery at high temperature in the shortest time and prevent the capacity from decreasing. . Further, when the secondary battery charged in this way is used in a device, the usage time of the device can be extended.

[0010]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS The invention according to claim 1 is a current supply means for supplying a charging current to a secondary battery, a temperature detection means for detecting the temperature of the secondary battery during charging, and a voltage of the secondary battery. Secondary battery voltage detection means for detecting the, the control means for controlling the charging of the secondary battery, from the start of charging the secondary battery based on the output from the temperature detection means until full charge detection A minimum temperature determining means for determining a minimum temperature between the two, and when the temperature detected by the temperature detecting means reaches a predetermined temperature determined by the minimum temperature of the secondary battery after full charge detection, additional charging is performed. It has a configuration to start. With this configuration, additional charging is performed according to the ambient temperature of the device,
It is possible to compensate for the capacity that could not be fully charged due to the high temperature of the secondary battery in the shortest time and prevent the capacity from decreasing.

According to a second aspect of the present invention, there is provided a power source for supplying electric power to the electric equipment, a current supplying means for supplying a charging current to the secondary battery, and a temperature detecting means for detecting the temperature of the secondary battery during charging. A secondary battery voltage detection means for detecting the voltage of the secondary battery and a control means for controlling the charging of the secondary battery, and the temperature of the secondary battery at the time when the power is turned on after the detection of the full charge. When the temperature detected by the temperature detecting means reaches the predetermined temperature determined by the above, the additional charging is started. With this configuration, when the temperature before quick charging at power-on is low, the temperature at which additional charging is started is determined by the temperature equivalent to the ambient temperature, and if it becomes lower than this temperature, additional charging after full charge detection is started. Accurately judge the ambient temperature in the state before the temperature rises before using the device,
It is possible to supplement the capacity that cannot be fully charged by charging the secondary battery at a high temperature in the shortest time and prevent the capacity from decreasing.

According to a third aspect of the present invention, a current supply means for supplying a charging current to the secondary battery, a temperature detecting means for detecting the temperature of the secondary battery during charging, and a secondary voltage detecting means for detecting the voltage of the secondary battery. A secondary battery voltage detection means, a control means for controlling charging of the secondary battery, and an attachment / detachment detection means for detecting attachment / detachment of the secondary battery to / from an electric device are provided, and the attachment / detachment detection means detects attachment of the secondary battery. When the temperature detected by the temperature detecting means reaches a predetermined temperature determined by the temperature of the secondary battery at the time of detection, additional charging is started. With this configuration, when the secondary battery is installed, the temperature at which additional charging is started is determined by the temperature equivalent to the ambient temperature before quick charging, and if it falls below this temperature, additional charging after full charge detection is started. The capacity that cannot be fully charged by charging the secondary battery at high temperature can be compensated for in the shortest time so that the capacity does not decrease.

According to a fourth aspect of the present invention, a current supplying means for supplying a charging current to the secondary battery, a temperature detecting means for detecting the temperature of the secondary battery during charging, and a secondary voltage detecting means for detecting the voltage of the secondary battery. A secondary battery voltage detection means, a control means for controlling the charging of the secondary battery, and a peak voltage detection means for detecting the peak voltage of the voltage of the secondary battery are provided, and the voltage of the secondary battery is detected after full charge detection. When the temperature detected by the temperature detecting means reaches a predetermined temperature determined by the temperature when the peak voltage is reached, the additional charging is started. With this configuration, the temperature equivalent to the ambient temperature is set by the temperature at the time of the voltage peak, and by starting additional charging, the capacity that cannot be fully charged by charging the secondary battery at high temperature is supplemented in the shortest time.
It is possible to prevent the capacity from decreasing.

According to a fifth aspect of the present invention, a current supplying means for supplying a charging current to the secondary battery, a temperature detecting means for detecting the temperature of the secondary battery during charging, and a secondary voltage detecting means for detecting the voltage of the secondary battery. A secondary battery voltage detection means, a control means for controlling the charging of the secondary battery, and a timekeeping means for timing the elapsed time from the full-charge detection time, the secondary battery of the predetermined time after the full-charge detection When the temperature detected by the temperature detecting means reaches a predetermined temperature determined by the temperature, the additional charge after the full charge is detected is started. With this configuration, by charging the secondary battery at a high temperature by setting the temperature to a temperature equivalent to the ambient temperature at the time when the secondary battery is cooled before the start of additional charging after the rapid charging is completed. It is possible to compensate for the unreachable capacity in the shortest time and prevent the capacity from decreasing.

According to a sixth aspect of the present invention, current supply means for supplying a charging current to the secondary battery, temperature detecting means for detecting the temperature of the secondary battery during charging, and second voltage detecting means for detecting the voltage of the secondary battery. A secondary battery voltage detection means, a control means for controlling the charging of the secondary battery, and a temperature change detection means for detecting a change in the temperature of the secondary battery are provided, and the change in the secondary battery temperature after the end of charging is When the temperature detected by the temperature detecting means reaches a predetermined temperature determined from the temperature when the temperature reaches a predetermined value,
It is configured to start additional charging. With this configuration, it is possible to set the start temperature of the additional charge by setting the temperature at the time when the temperature decreases and stabilizes after the end of the rapid charge as the temperature corresponding to the ambient temperature.

According to a seventh aspect of the present invention, a temperature change detecting means for detecting a change in the temperature of the secondary battery is provided, and the temperature change detecting means detects the temperature change when the change in the secondary battery temperature after the completion of the additional charging reaches a predetermined value. When the temperature detected by the temperature detecting means reaches the predetermined temperature to be determined, the additional charging is started next time.
With this configuration, the amount of change can be set to be smaller than that after the end of rapid charging, and the start temperature of additional charging can be set from a temperature closer to the ambient temperature.

According to an eighth aspect of the present invention, a current supplying means for supplying a charging current to the secondary battery, a temperature detecting means for detecting the temperature of the secondary battery during charging, and a secondary voltage detecting means for detecting the voltage of the secondary battery. A secondary battery voltage detection unit, a control unit that controls charging of the secondary battery, and a storage unit that stores the temperature at the start of charging, and the temperature detection unit stores the temperature stored in the storage unit after full charge detection. When the temperature to be detected reaches, the additional charging is started. With this configuration, the secondary battery can be charged at a high temperature and at least at a temperature lower than the temperature at which quick charging can be started even when the secondary battery is attached to the device, and the secondary battery can be charged at a high temperature. It is possible to supplement the capacity that cannot be fully charged and prevent the capacity from decreasing.

The invention as defined in claim 9 is particularly defined by claims 1 to 1.
In the configuration described in 8, the additional charging is configured to maximize the predetermined time, so that overcharging due to the additional charging can be prevented.

According to a tenth aspect of the present invention, the temperature of the secondary battery is provided when the time measuring means for measuring the elapsed time from the full charge detection time is provided, and the time measured by the time measuring means has passed a predetermined time. Since the maximum time is determined by, the predetermined time is set as the cooling time when the quick charge is finished, and the maximum time is set longer if the temperature is lower than the ambient temperature and short if it is low. It is possible to prevent overcharge while ensuring an optimum charge capacity with respect to the ambient temperature of the secondary battery.

According to the eleventh aspect of the present invention, there is provided a minimum temperature judging means for detecting the minimum temperature from the start of charging of the secondary battery to the detection of full charge, and the minimum temperature judging means detects the minimum temperature. Since the maximum time is determined by the temperature, if the minimum temperature is low, the maximum time is set longer, and if it is low, the maximum time is set longer to ensure the optimum charging capacity for the ambient temperature of the secondary battery while overcharging. Can be prevented.

According to a twelfth aspect of the present invention, there is provided peak voltage detecting means for detecting the peak voltage of the voltage of the secondary battery, and the maximum time is determined by the temperature at the peak voltage point detected by the peak voltage detecting means. The maximum time is set longer when the temperature at the peak voltage is low, and set shorter when the peak voltage is low to prevent overcharging while ensuring the optimum charge capacity for the ambient temperature of the secondary battery. You can

According to a thirteenth aspect of the present invention, temperature change detecting means for detecting a change in the temperature of the secondary battery is provided, and when the change in the temperature of the secondary battery after completion of charging reaches a predetermined value. Since the maximum time is determined from the temperature of, the maximum temperature is set as the ambient temperature of the secondary battery by setting the temperature at the time when the temperature drops and stabilizes after the rapid charging as the temperature equivalent to the ambient temperature. On the other hand, it is possible to prevent overcharging while ensuring the optimum charging capacity.

According to a fourteenth aspect of the present invention, a temperature change detecting means for detecting a temperature change of the secondary battery is provided, and the temperature change of the secondary battery after the completion of the additional charging reaches a predetermined value. Since the maximum time for the next additional charge is determined from the temperature at the time, the temperature at the time when the temperature drops and stabilizes after the additional charge is detected as the temperature equivalent to the ambient temperature with higher accuracy and the maximum It is possible to prevent overcharging while setting the time and securing the optimum charge capacity with respect to the ambient temperature of the secondary battery.

A fifteenth aspect of the present invention is an electric device charged by using the charge control device for a secondary battery according to any one of the first to fourteenth aspects. It is possible to provide an electric device that eliminates insufficient charging of a secondary battery due to an increase in battery temperature, prevents a decrease in charging capacity, and charges in the shortest time required for charging.

[0025]

Embodiments of the present invention will be described below with reference to the drawings.

(Embodiment 1) FIG. 1 is a circuit block diagram of a charge control device for a secondary battery according to a first embodiment of the present invention, FIG. 2 is a charge characteristic diagram of the charge control device for a secondary battery, and FIG. 3 is the same. It is an additional charge characteristic figure of the charge control device of a secondary battery. Since the basic configuration is the same as that of the conventional example, the same components as those of the conventional example are designated by the same reference numerals and the description thereof will be omitted.

In FIG. 1, 1 is a charger, which is a constant current control circuit 3 which is a current supply means, a secondary battery voltage detection means 4,
A charging control circuit 6 which is a control means that incorporates a computing unit 5 having a microcomputer and a DC power supply 7 which is a power source of the computing unit 5 are provided. Further, reference numeral 12 is a minimum temperature determination means for detecting the minimum temperature of the secondary battery 10 during rapid charging, and is incorporated in the charge control circuit 6. The constant current circuit 3 can obtain the output of the computing unit 5 and can turn on / off the charging and output a plurality of constant current values.

Further, 9 is a secondary battery pack, which is a secondary battery 1
0 and a temperature detecting means 11 for detecting the temperature of the secondary battery 10 arranged in the vicinity thereof are connected to the DC power source 7 of the charger 1 via the dividing resistor 8. The signal from the temperature detecting means 11 is transmitted to the calculator 5 of the charge control circuit 6 and the minimum temperature determining means 12 via the attachment / detachment detecting means 14.

If the temperature signal from the temperature detecting means 11 is input, the attachment / detachment detecting means 13 determines that the secondary battery pack 9 is attached to the charger 1. If the temperature signal is not input, the attachment / detachment detecting means 13 determines It is determined that the next battery pack 9 is not attached.
Further, the computing unit 5 obtains the information on the secondary battery voltage and the secondary battery temperature to determine the transition to the rapid charging, the transition to the trickle charging due to the detection of the full charge, the transition to the additional charging, and the charging control circuit 6 Output a signal. Receiving the signal, the secondary battery 10 is charged with each constant current.

The operation of the secondary battery charge control device configured as described above will be described below.

In FIG. 1 and FIG. 2, the secondary battery pack 9 is connected to the charger 1. The attachment / detachment detection unit 13 recognizes the temperature information from the temperature detection unit 11 in the charger 1 and determines that the secondary battery pack 9 is connected, and the charging control circuit 6 starts charging control.

The charge control circuit 6 determines from the temperature detecting means 11 whether the temperature of the secondary battery pack 9 is high. Further, the secondary battery voltage detection means 4 also determines whether or not the secondary battery pack 9 is over-discharged. The temperature of the secondary battery pack 9 is low and is not over-discharged. The secondary battery pack 9 shifts to rapid charging and is charged, but when the temperature of the secondary battery pack 9 is high immediately after discharging, or when over-discharge occurs. If it is, the secondary battery waits for quick charging until it is ready to be charged. Then, when the temperature of the secondary battery pack 9 becomes low and reaches a preset temperature, it is rapidly charged,
The temperature set here is set to 15 to 20 degrees higher than the room temperature, for example, when the room temperature is set to 30 ° C., it is set to 50 ° C. in order to shorten the waiting time of the quick charge as much as possible. The full-charge detection in the rapid charging is performed by detecting the change of the secondary battery voltage by utilizing the charge characteristic of the secondary battery voltage, -ΔV detection, and the change of the secondary battery temperature per unit time ΔT / Δt. Performed by detection. These -ΔV detection and ΔT / Δt detection are performed based on a value determined in advance depending on the type of secondary battery, the specifications of the device, and the surrounding environment.

However, if the temperature at the start of rapid charging is increased in order to shorten the standby time as much as possible, the charging capacity at the time of detecting the full charge becomes less than 100%.
The full charge here is the maximum charge amount at a certain temperature, and is different from the rated charge amount at the reference temperature. Generally, the higher the temperature, the smaller the maximum charge amount compared to the rated charge amount. Therefore, when the temperature of the secondary battery having the rated charge amount is increased to a high temperature, assuming that there is no discharge such as self-discharge, the charge capacity of the secondary battery becomes larger than the maximum charge amount at that temperature. That is, overcharge occurs at this temperature. However, it is designed so that practically, there is almost no problem even if the charging capacity becomes larger than the maximum charging capacity at a high temperature such as when performing rapid charging.

Therefore, after the rapid charge is completed by detecting the full charge, the trickle charge for supplementing the self-discharge is not performed and the secondary battery pack 9 is kept on standby until it cools down.
When the temperature of the secondary battery pack 9 reaches a predetermined value, for example, 40 ° C., the rapid charging (hereinafter referred to as additional charging) is performed again.

However, if the temperature at which the additional charging is started is lowered, the time from the end of the quick charging to the end of the additional charging becomes long, and conversely, if the temperature is raised, the additional charging is performed. Nevertheless, the charge capacity is insufficient,
That is, it will be less than the rated capacity.

The ambient temperature is 20 ° C. throughout the year.
If there is a change of ± 15 ° C. and the temperature at the start of charging is constant, depending on the time, it may take a very long time to finish the additional charging, or the effect of the additional charging may not be sufficiently brought out.

FIG. 2 shows the characteristics of the Ni-Cd secondary battery during charging. During rapid charging, the endothermic reaction of the secondary battery causes
It has the characteristic that the temperature once drops and then rises again when fully charged, and the minimum temperature at that time is T2 if the ambient temperature is high and T2 if the ambient temperature is low. It will be lower as shown. Charge control circuit 6
The minimum temperature determination means 12 detects the minimum temperature at the time of rapid charging based on the temperature information from the temperature detection means 11, and the calculator 5 determines the additional charging start temperature based on the minimum temperature detected by the minimum temperature determination means 12. After the rapid charging ends, when the temperature of the secondary battery rises and then drops to this temperature, additional charging starts. If the minimum temperature of the calculator 5 is low,
When it is determined that the ambient temperature is low, the additional charge start temperature is set to be low, and when the minimum temperature is high, it is determined that the ambient temperature is high and the additional charge start temperature is set to be high.

As a result, when the ambient temperature is high, it is possible to secure the charge capacity commensurate with the ambient temperature while shortening the time until the end of the additional charging, and when the ambient temperature is low, the cooling time is also short. Also, since the additional charging is started at a lower temperature, almost 100% charge capacity can be obtained.

Further, the time until the full charge is detected in the additional charge becomes shorter if the additional charge start temperature is higher, and becomes longer if the additional charge start temperature is low, and the calculator 5 determines the maximum temperature of the additional charge to be the minimum temperature detected by the minimum temperature determination means 12. When the ambient temperature is high, it is set to be short, and when the ambient temperature is low, it is set to be long, and when the full charge cannot be detected for some reason, the additional charging is completed in the longest time. It is possible to protect against overcharging in an optimal charging state.

Before the charging control circuit 6 starts the charging operation by the attachment / detachment detection means 13 detecting the attachment of the secondary battery pack 9 to the charger 1, the calculator 5 sets the temperature at that time to the ambient temperature. If the temperature at that time is low, the additional charge start temperature is set to be low, and if it is high, the additional charge start temperature is set to be high. In this way, since the start temperature of additional charging is determined before the start of rapid charging, it is possible to reliably detect the ambient temperature and secure the charging capacity, and set the maximum time for additional charging at that temperature. As a result, it is possible to reliably protect against overcharge against the ambient temperature.

Further, when the power supply 2 is turned on, the computing unit 5 judges the temperature at that time as the ambient temperature, and if the temperature at that time is low, the additional charging start temperature is set to a low temperature, and if it is higher, the additional charging starts. Set the temperature higher. In this way, by setting the temperature at the start of use of the charger 1 as the reference temperature, the ambient temperature can be more reliably prevented without being affected by the temperature from the temperature detecting means 11 due to the repeated use of the charger. It is possible to set the maximum temperature for additional charging and the additional charging start temperature by detecting the temperature.

(Embodiment 2) Hereinafter, Embodiment 2 of the present invention will be described with reference to FIGS. 2 and 3 described in Embodiment 1 and FIG. FIG. 4 is a circuit block diagram in the second embodiment of the present invention. Since the basic configuration of this embodiment is the same as that of the first embodiment, the description thereof is omitted and the different points will be mainly described. Further, the same components as those of the first embodiment are designated by the same reference numerals and the description thereof will be omitted.

The present embodiment is different from the first embodiment in that a peak voltage detecting means 14 for detecting the peak of the secondary battery voltage is provided in the charge control circuit 6.

The operation will be described below.

As shown in FIG. 2, the voltage of the secondary battery 10 during rapid charging reaches a peak at the end of full charging, and the temperature at the peak of the voltage is the same as the minimum temperature described in the first embodiment. Depending on the ambient temperature, the higher the ambient temperature, the higher this temperature, and the lower the ambient temperature, the lower this temperature. The peak voltage detection means 14 of the charge control circuit 6 detects the peak voltage based on the voltage information from the secondary battery voltage detection means 4. As a result, the calculator 5 uses the temperature information input from the temperature detecting means 11 to determine the temperature at the peak voltage time, the temperature T3 at the peak voltage V1 if the ambient temperature is high, and the temperature at the peak voltage V2 if the ambient temperature is low. T4 is stored, the additional charging start temperature is determined based on this temperature, and after the rapid charging ends, when the secondary battery temperature rises to this temperature, the additional charging starts.

With this, the ambient temperature is accurately detected,
The charge capacity can be secured, and by setting the maximum time of additional charge at the temperature at that time, overcharge can be reliably protected against ambient temperature.

(Third Embodiment) FIG. 5 is a circuit block diagram of a charge control device for a secondary battery according to a third embodiment of the present invention.
FIG. 6 is a charge characteristic diagram of the charge control device for the secondary battery.
Since the basic configuration of this embodiment is the same as that of the first embodiment, the description thereof is omitted and the different points will be mainly described. Also,
The same components as those in the first embodiment are designated by the same reference numerals and the description thereof will be omitted.

The present embodiment is different from the first embodiment in that the charging control circuit 6 is provided with a time measuring means 15 for measuring the elapsed time from the time of detecting the full charge.

The operation will be described below.

In the figure, when the computing unit 5 detects a full charge during the rapid charging and ends the rapid charging, the time measuring means 15
Starts the period measurement. When the time measured by the timer 15 reaches a preset time t1, the calculator 5 subtracts the preset temperature ΔT from the temperature T5 input from the temperature detector 11 at that time (T5-ΔT). ) Is determined as the ambient temperature, the temperature at which the additional charge starts can be determined based on the ambient temperature immediately before the additional charge, and the time can be shortened and the charge capacity can be secured more reliably. Further, by setting the maximum time of additional charging at the temperature at that time, it is possible to reliably protect against overcharge against ambient temperature.

(Fourth Embodiment) FIG. 7 is a circuit block diagram of a charge control device for a secondary battery according to a fourth embodiment of the present invention.
FIG. 8 is a charge characteristic diagram of the charge control device for the secondary battery.
Since the basic configuration of this embodiment is the same as that of the first embodiment, the description thereof is omitted and the different points will be mainly described. Also,
The same components as those in the first embodiment are designated by the same reference numerals and the description thereof will be omitted.

The present embodiment differs from the first embodiment in that a temperature change detecting means 16 for detecting the amount of change in temperature detected by the temperature detecting means 11 is provided in the charge control circuit 6.

The operation will be described below.

In the figure, when the calculator 5 detects the full charge and terminates the quick charge, the temperature change detecting means 16 calculates the temperature change amount at predetermined intervals based on the temperature detected by the temperature detecting means 11. Since the charging current is not supplied in the standby after the end of the rapid charging, the temperature of the secondary battery 10 decreases, and when the temperature decreases to the ambient temperature, the temperature change amount per predetermined time becomes small.

When the amount of temperature change detected by the temperature change detecting means 16 becomes smaller than a preset value, the computing unit 5 judges that the temperature T6 at that time is the ambient temperature, and the ambient temperature immediately before the additional charging is added. The temperature at which charging starts can be determined, the ambient temperature can be detected more accurately, and the time can be shortened and the charging capacity can be secured more reliably. Further, by setting the maximum time of additional charging at the temperature at that time, it is possible to reliably protect against overcharge against ambient temperature.

Further, the temperature change detecting means 16 detects the amount of temperature change by detecting the amount of change after the completion of the additional charging, and further reduces the temperature change amount of the ambient temperature determination to detect it. By determining the start temperature of additional charging during additional charging, the ambient temperature can be detected more accurately, and the time can be shortened and the charging capacity can be secured with higher accuracy. Also, by setting the maximum time of additional charging at the temperature at that time, it is possible to reliably protect against overcharge against ambient temperature.

(Fifth Embodiment) FIG. 9 is a circuit block diagram of a charge control device for a secondary battery according to a fifth embodiment of the present invention.
Since the basic configuration of this embodiment is the same as that of the first embodiment, the description thereof is omitted and the different points will be mainly described. Also,
The same components as those in the first embodiment are designated by the same reference numerals and the description thereof will be omitted.

In the figure, the difference from the first embodiment is that a storage means 17 for storing the temperature detected by the temperature detection means 11 is provided in the charge control circuit 6.

The operation will be described below.

In the figure, the storage means 17 stores the temperature detected by the temperature detection means 11 at the time of starting the rapid charging, and after the completion of the rapid charging, the calculator 5 stores the temperature and the temperature stored in the storage means 17. The temperature detected by the detection unit 11 is compared, and if the temperature detected by the temperature detection unit 11 is high, the process waits, and if it becomes low, additional charging is started. As a result, the temperature at which the rapid charge can be started, that is, the temperature at which the charge capacity can be secured by the quick charge is lowered before the additional charge is performed, so that a larger charge capacity can be obtained by the additional charge.

(Embodiment 6) The charge control device for a secondary battery described in any one of Embodiments 1 to 5 was used for electric equipment. As a result, it is possible to solve an insufficient charging of the secondary battery due to the temperature rise of the secondary battery due to the rapid charging, prevent a decrease in the charging capacity, and provide an electric device that performs charging in the shortest time required for charging.

[0062]

As described above, according to the invention described in claims 1 to 14, the insufficient charging of the secondary battery caused by the temperature rise of the secondary battery due to the rapid charging is eliminated, and the charge capacity is reduced. In addition to preventing, charging can be performed in the shortest necessary time. Further, according to the invention described in claim 15, it is possible to provide an electric device which can be charged in a short time without causing insufficient charging.

[Brief description of drawings]

FIG. 1 is a circuit block diagram of a charge control device for a secondary battery according to a first embodiment of the present invention.

FIG. 2 is a charging characteristic diagram of a charging control device for a secondary battery according to Examples 1 and 2 of the present invention.

FIG. 3 is an additional charging characteristic diagram of the charging control device for the secondary battery.

FIG. 4 is a circuit block diagram of a charge control device for a secondary battery according to a second embodiment of the present invention.

FIG. 5 is a circuit block diagram of a charge control device for a secondary battery according to a third embodiment of the present invention.

FIG. 6 is a charging characteristic diagram of the secondary battery charging control device.

FIG. 7 is a circuit block diagram of a charge control device for a secondary battery according to a fourth embodiment of the present invention.

FIG. 8 is a charging characteristic diagram of the secondary battery charging control device.

FIG. 9 is a circuit block diagram of a charge control device for a secondary battery according to a fifth embodiment of the present invention.

FIG. 10 is a circuit block diagram of a conventional secondary battery charge control device.

FIG. 11 is a charging characteristic diagram of the charge control device for the secondary battery.

[Explanation of symbols]

2 power supplies 3 constant current circuit (current supply means) 4 Secondary battery voltage detection means 6 Charge control circuit (control means) 10 secondary battery 11 Temperature detection means 12 Minimum temperature determination means 13 Attachment / detachment detection means 14 Peak voltage detection means 15 Timekeeping means 16 Temperature change detection means 17 storage means

   ─────────────────────────────────────────────────── ─── Continued front page    (72) Inventor Masakazu Fukushima             1006 Kadoma, Kadoma-shi, Osaka Matsushita Electric             Sangyo Co., Ltd. (72) Inventor Hiroyuki Senoo             1006 Kadoma, Kadoma-shi, Osaka Matsushita Electric             Sangyo Co., Ltd. F-term (reference) 5G003 AA01 BA01 CA02 CA14 CB01                       CB07 CB10 FA07                 5H030 AA02 AA06 AS11 BB01 FF22                       FF41 FF43 FF51 FF52

Claims (15)

[Claims] 1. A current supply means for supplying a charging current to a secondary battery, a temperature detection means for detecting the temperature of the secondary battery during charging, and a secondary battery voltage detection means for detecting the voltage of the secondary battery. A minimum temperature determination for determining the minimum temperature from the start of charging of the secondary battery to the detection of full charge based on the output from the temperature detecting means and a control means for controlling the charging of the secondary battery Means for charging the secondary battery configured to start additional charging when the temperature detected by the temperature detecting means reaches a predetermined temperature determined by the minimum temperature of the secondary battery after detection of full charge. Control device. 2. A power source for supplying electric power to an electric device, a current supplying means for supplying a charging current to a secondary battery, a temperature detecting means for detecting a temperature of the secondary battery during charging, and a voltage of the secondary battery. A secondary battery voltage detecting means for detecting the charge of the secondary battery, and a control means for controlling the charging of the secondary battery, and a predetermined value determined by the temperature of the secondary battery when the power is turned on after detecting the full charge. A secondary battery charge control device configured to start additional charging when the temperature detected by the temperature detecting means reaches the temperature. 3. Current supply means for supplying a charging current to the secondary battery, temperature detection means for detecting the temperature of the secondary battery during charging, and secondary battery voltage detection means for detecting the voltage of the secondary battery. A control means for controlling charging of the secondary battery, and an attachment / detachment detection means for detecting attachment / detachment of the secondary battery to / from an electric device,
A configuration for starting additional charging when the temperature detected by the temperature detection unit reaches a predetermined temperature determined by the temperature of the secondary battery when the attachment / detachment detection unit detects attachment of the secondary battery; Charge control device for secondary battery. 4. A current supply means for supplying a charging current to the secondary battery, a temperature detection means for detecting the temperature of the secondary battery during charging, and a secondary battery voltage detection means for detecting the voltage of the secondary battery. A control means for controlling the charging of the secondary battery and a peak voltage detecting means for detecting the peak voltage of the voltage of the secondary battery, and the voltage of the secondary battery reaches the peak voltage after full charge detection. A secondary battery charging control device configured to start additional charging when the temperature detected by the temperature detecting means reaches a predetermined temperature determined by the temperature at the time. 5. A current supply means for supplying a charging current to the secondary battery, a temperature detection means for detecting the temperature of the secondary battery during charging, and a secondary battery voltage detection means for detecting the voltage of the secondary battery. A control means for controlling the charging of the secondary battery, and a timekeeping means for measuring the elapsed time from the point of full charge detection,
When the temperature detected by the temperature detecting means reaches a predetermined temperature determined by the temperature of the secondary battery after a lapse of a predetermined time after the detection of full charge, the secondary charging is configured to start additional charge after the detection of full charge. Battery charge control device. 6. A current supply means for supplying a charging current to the secondary battery, a temperature detection means for detecting the temperature of the secondary battery during charging, and a secondary battery voltage detection means for detecting the voltage of the secondary battery. , A control means for controlling the charging of the secondary battery and a temperature change detecting means for detecting a change in the temperature of the secondary battery are provided, and the change in the secondary battery temperature after the end of charging reaches a predetermined value. A secondary battery charge control device configured to start additional charging when a temperature detected by the temperature detecting means reaches a predetermined temperature determined by the temperature at the time. 7. A temperature change detection means for detecting a change in temperature of the secondary battery is provided, and the temperature is determined to be a predetermined temperature determined from the temperature when the change in the secondary battery temperature after the end of additional charging reaches a predetermined value. 7. The charge control method for a secondary battery according to claim 6, wherein when the temperature detected by the temperature detecting means reaches a temperature, the next additional charge is started. 8. A current supply means for supplying a charging current to the secondary battery, a temperature detection means for detecting the temperature of the secondary battery during charging, and a secondary battery voltage detection means for detecting the voltage of the secondary battery. A control unit for controlling the charging of the secondary battery and a storage unit for storing the temperature at the start of charging, and the temperature detected by the temperature detection unit reaches the temperature stored by the storage unit after full charge detection. A charging control device for a secondary battery configured to start additional charging when the charging is performed. 9. The charge control device for a secondary battery according to claim 1, wherein the additional charge has a maximum time. 10. The longest time is determined according to the temperature of the secondary battery when the timekeeping means for measuring the time elapsed from the time of detecting the full charge is provided, and the time measured by the timekeeping means has passed a predetermined time. A secondary battery charge control device as described. 11. A structure comprising: a minimum temperature determination means for detecting a minimum temperature from the start of charging of the secondary battery to the detection of full charge, and determining the maximum time according to the minimum temperature detected by the minimum temperature determination means. The charge control device for a secondary battery according to claim 9. 12. The secondary battery according to claim 9, further comprising peak voltage detecting means for detecting the peak voltage of the voltage of the secondary battery, and determining the maximum time according to the temperature at the time of the peak voltage detected by the peak voltage detecting means. Charge control device. 13. A temperature change detection means for detecting a change in the temperature of the secondary battery is provided, and the maximum time is determined from the temperature when the change in the temperature of the secondary battery after completion of charging reaches a predetermined value. The charge control device for the secondary battery according to claim 9. 14. A temperature change detecting means for detecting a change in temperature of the secondary battery is provided, and the temperature at the time when the change in the temperature of the secondary battery reaches a predetermined value after the completion of the additional charging is determined by the next additional charging. 10. The charging control device for a secondary battery according to claim 9, wherein the maximum time of charging is determined. 15. An electric device using a secondary battery that is charged using the charge control method for a secondary battery according to claim 1. Description: