JPH11122839A - Battery-charging controller - Google Patents

Abstract

PROBLEM TO BE SOLVED: To secure charging capacitance and shorten actual charging time at the same time, without causing decline in the performance of a battery or the reduction in life, when the battery temperature is relatively high. SOLUTION: This requipment is provided with a residual capacitance calculating means 21 for finding the residual capacitance of a battery 5, and a temperature-detecting means 22 for detecting the temperature of the battery. Also provided are a charger-controlling means 23 which sets the output of a charger 4, based on the residual capacitance and the battery temperature and a charging stopping means 24 for stopping charging. The charger controlling means 23 controls the charger 4 so that the output of the charger becomes smaller, the higher the battery temperature and the smaller the residual capacitance are, when the battery temperature is higher than the one determined beforehand.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

TECHNICAL FIELD The present invention relates to, for example, nickel
The present invention relates to a battery charge control device used to charge a battery whose temperature rises during charging such as a hydrogen battery.

[0002]

2. Description of the Related Art Conventionally, as a charger for charging a battery (for example, a nickel-metal hydride battery) whose temperature rises during charging, the battery temperature at the start of charging is detected, and this battery temperature falls within a predetermined temperature range. In general, charging is performed only when the charging is performed. That is, in this type of battery, charging is not performed when the battery temperature is above the upper limit or below the lower limit of the temperature range in order to improve the life and performance of the battery.

[0003] Charging by this type of charger is performed by passing a constant current through the battery, and when the battery temperature reaches a predetermined charging stop temperature, or when the battery temperature does not reach the charging stop temperature, the battery is fully charged. The battery is charged until the charging state is reached, and the process ends when a phenomenon peculiar to the end of charging occurs. The specific phenomena include a phenomenon in which the battery voltage of the nickel-metal hydride battery decreases at the end of charging, and a phenomenon in which the rate of increase in the battery temperature becomes extremely high. The charging current is set to a value such that a battery having a remaining capacity of substantially zero and a battery temperature relatively low such as room temperature can be quickly fully charged.

[0004]

However, the conventional charger configured as described above has a high ambient temperature at the time of charging and a high temperature at which the battery temperature at the start of charging is close to the upper limit temperature at the start of charging. Thus, there is a problem in that the charging is completed before the battery reaches a fully charged state, and the battery cannot be sufficiently charged. For example, when charging the discharged battery until the remaining capacity becomes substantially zero, and when the temperature is high and the battery temperature is close to the upper limit of the chargeable temperature range, the battery is fully charged. Can not do. This is because the nickel-metal hydride battery generates heat during charging and rises in temperature, and the battery temperature reaches the charge stop temperature even before reaching full charge.

In order to solve such a problem, the following three methods can be considered. (1) The output (charge current) of the charger is reduced to reduce the amount of heat generated by the battery. (2) The upper limit temperature of the charging start temperature range is shifted to a lower temperature side. That is, charging cannot be performed unless the battery temperature is sufficiently lower than the charging stop temperature. (3) The charge stop temperature is increased. However, reducing the output of the charger increases the charging time. If the upper limit temperature of the charging start temperature range is lowered, it is necessary to wait until the battery is cooled to a temperature at which the battery can be charged. As a result, the actual charging time including the standby time becomes longer. Furthermore, if the charging stop temperature is increased, the battery is likely to be overcharged at a high temperature, and in that state, the hydrogen storage alloy constituting the negative electrode of the nickel-metal hydride battery is oxidized and the separator is deteriorated, and the battery performance is reduced. And the life is shortened.

Further, in the conventional charger, since the charging current and the stop control method are constant, it is difficult to optimally charge other batteries of different types and capacities so as not to be overcharged. For this reason, a charger must be prepared according to the type and capacity of the battery. In order to solve this problem and allow a single charger to charge multiple types of batteries, the charger must be stopped before overcharging any type or capacity of battery. .

SUMMARY OF THE INVENTION The present invention has been made to solve the above-mentioned problems, and it is necessary to secure the charging capacity and shorten the actual charging time when the temperature of the battery is relatively high. A first object is to achieve compatibility while preventing the service life from being shortened. A second object is to enable a single charger to charge batteries of different types and capacities. further,
A third object is to stop the charger before overcharging any type and capacity of battery.

[0008]

In order to achieve this object, a battery charge control device according to the present invention comprises: a remaining capacity calculating means for obtaining a remaining capacity of a battery; a temperature detecting means for detecting a temperature of the battery; A charger control means for setting a charging current based on the remaining capacity of the battery and the battery temperature; and a charging stopping means for stopping charging when the battery is charged to a full charge state, provided in the battery case, Means for reducing the charging current as the battery temperature is higher and the remaining capacity is smaller when the battery temperature at the start of charging is higher than a predetermined temperature, and transmitting the charging current to the charger as a charging instruction signal. And output control means for controlling the output in accordance with the charging instruction signal is provided in the charger.

[0009] Since the battery temperature can be prevented from rising during charging by lowering the charger output, according to the present invention, when the battery temperature at the start of charging is higher than a predetermined temperature, The higher the battery temperature, the smaller the charging current and the more difficult it is for the battery temperature to rise during charging. Therefore, the upper limit of the chargeable temperature range does not need to be set low, so that the actual charging time can be shortened. In addition, when the remaining capacity is relatively small, the charging current is smaller than when the battery temperature is the same and the remaining capacity is large, so that sufficient charging can be performed while suppressing heat generation. When the remaining capacity is relatively large, the charged amount of electricity is small even when the charging current is relatively large, so that the battery can be fully charged before the battery temperature reaches the charging stop temperature.

[0010] Further, since the charging current can be set in accordance with the type and capacity of the battery in the battery case on the battery case side, a single charger can use various types of batteries under optimum conditions for each battery. Can be charged.

According to another aspect of the present invention, there is provided a battery charge control device comprising: a remaining capacity calculating means for calculating a remaining capacity of a battery; and a charge stopping means for stopping charging by a charger when the battery is charged to a fully charged state. In addition to being provided in the battery case and connected to the charger via the signal transmission means, the charger is provided with a timer for measuring the elapsed time after the start of charging, and the remaining capacity and the charge of the battery determined by the remaining capacity calculation means are provided. Self-stop means is provided for stopping charging when the elapsed time after the start of charging exceeds the longest charging time set by the current.

According to the present invention, since the function of stopping charging can be provided on each of the battery case side and the charger side, overcharging can be reliably prevented.

[0013]

BEST MODE FOR CARRYING OUT THE INVENTION

First Embodiment Hereinafter, an embodiment of a battery charge control device according to the present invention will be described in detail with reference to FIGS. FIG.
FIG. 2 is a block diagram showing a configuration of a battery charge control device according to the present invention, FIG. 2 is a block diagram showing a configuration inside a battery case, FIG. 3 is a graph serving as a map for setting an output of a charger, and FIG. 5 is a flowchart for explaining the operation of the CPU, and FIG. 5 is a flowchart for explaining the operation of the charger.

In these figures, reference numeral 1 denotes a charge control device according to this embodiment. This charge control device 1
Is for charging a battery of an electric vehicle such as an electric bicycle or an electric wheelchair, is housed in a battery case 2, and has a configuration in which a CPU 3 controls a charger 4. The battery case 2 houses a battery 5 and is formed so as to be detachable from a battery mounting portion of an electric vehicle (not shown) and a battery connecting portion (not shown) of the charger 4.

The battery 5 is constituted by connecting a plurality of cells of a nickel-metal hydride battery in series, and terminals 6 and 7 are connected to a positive electrode and a negative electrode. These terminals 6 and 7 are connected to the charger 4 at the time of charging, and are connected to the motor control unit 8 of the electric vehicle at the time of discharging. The terminals 6 and 7 have a structure in which the contacts are brought into contact with each other when the battery case 2 is mounted on the charger 4 or the electric vehicle to conduct electricity. A display device 9 connected to the motor control unit 8 is for displaying the remaining capacity of the battery 5 during traveling, and is disposed on the body of the electric vehicle at a position that is easy for a driver to see.

The battery case 2 includes a thermistor 10 for detecting the temperature of the battery 5, current detecting means 11 for detecting a current flowing through the battery 5 during charging and discharging, and a voltage between terminals of the battery 5. And a display device 13 with a switch for displaying the remaining capacity of the battery 5.

As shown in FIG. 2, the CPU 3 is connected to the charger 4 or the motor control unit 8 of the electric vehicle via a communication interface 14 and signal terminals 15 and 16. The signal transmission system between the CPU 3 and the charger 4 constitutes a signal transmission unit according to the present invention. The terminals 15 and 16 are of a contact type similarly to the terminals 6 and 7.

As shown in FIG. 2, the CPU 3 has a remaining capacity calculating means 21 for calculating the remaining capacity of the battery 5.
A temperature detecting means 22 for detecting the temperature of the battery 5, a charger controlling means 23 for setting an output of the charger 4, and a charging stopping means 24 for stopping charging.
And a discharge control means 25 for refreshing the battery 5, a connection determination means 26 for determining whether or not the charger 4 is connected, and a charge time calculation means 27 for determining the longest charge time. doing. The CPU 3 is connected to the battery 5 via a power supply circuit 28 so that power is supplied from the battery 5.

The remaining capacity calculating means 21 calculates the integrated value of the current detected by the current detecting means 11, that is,
The remaining capacity of the battery 5 is obtained by adding / subtracting the current flowing during discharging. The obtained remaining capacity is stored in a memory (not shown). The temperature detecting means 22 is configured to detect the temperature of the battery 5 based on the output of the thermistor 10.

The charger control means 23 sets a charging current based on the remaining capacity of the battery 5 obtained by the remaining capacity calculating means 21 and the battery temperature at the start of charging obtained by the temperature detecting means 22, This charging current is used as a charging instruction signal by the charger 4 and the communication interface 14.
Is transmitted via the Internet. In this embodiment, the charging current is set by the map shown in FIG.

The map is formed by assigning the charging current to the remaining capacity of the battery 5 and the battery temperature at the start of charging. The remaining capacity is represented by DOD (depth of discharge) in this embodiment. In FIG. 3, a large DOD indicates that the remaining capacity is 0%, and a small DOD indicates that the remaining capacity is 100%.
%, And DOD indicates that the capacity is intermediate between large DOD and small DED.

The map shown in FIG. 3 shows that when the battery temperature at the start of charging is lower than the current control starting temperature indicated by T1 in FIG. 3, the charging current becomes maximum irrespective of the battery temperature and the current control starting temperature T1 When the charging temperature is higher, the charging current is continuously reduced according to the battery temperature and the value of DOD. For example, when the battery temperature at the start of charging is T2 in FIG. 3, the charging current decreases according to a DOD value in a range from 0% (large DOD) to about 50% (during DOD). Also,
If the battery temperature at the start of charging is higher than T3 in FIG. 3, the higher the battery temperature, the more D
The smaller the OD value, the smaller the charging current.

In this embodiment, the charge stopping means 24 is configured to transmit a charge stop signal to the charger 4 via the communication interface 14 when detecting a specific phenomenon occurring at the end of charging at the time of constant current charging. I have. The specific phenomena occurring at the end of charging are a phenomenon in which the battery voltage decreases at the end of charging and a phenomenon in which the rate of increase in the battery temperature increases significantly. The voltage drop is detected by the voltage drop amount calculating means 29 connected to the voltage detecting means 12, and the temperature rise rate is obtained by the temperature rise rate calculating means 30.

The connection judging means 26 sends a signal for judging connection to the charger 4 and judges whether or not the battery case 2 is connected to the charger 4. When a signal indicating the connection confirmation is returned from the charger 4, it is determined that the battery is connected to the charger 4. Further, the connection determination means 26 executes the connection confirmation, thereby making the CPU 3
It is also possible to determine whether there is an abnormality in the signal transmission means between the battery and the charger 4.

The charging time calculating means 27 calculates a maximum charging time (hereinafter referred to as a total timer) which can be charged based on the remaining capacity obtained by the remaining capacity calculating means 21 and the charging current set by the charger controlling means 23. Value), and the total timer value is sent to the charger 4 together with the charge instruction signal as a charge control signal.
In this embodiment, the charging time is calculated by the charging time calculating means 27 and the charger 4 respectively. That is,
The charging time calculating means 27 outputs a charging stop signal to the charger 4 when the elapsed time after the start of charging exceeds the total timer value.
When the elapsed time from the start of charging exceeds the total timer value, the charger 4 stops itself even if a charge stop signal is not sent from the battery case 2. More specifically, the total timer value is sent to the charger 4 together with the charge instruction signal as a charge control signal, so that the charger 4 also measures the elapsed time from the start of charging, and when the total timer value is exceeded. Even if the charge stop signal is not sent from the battery case 2, the charger 4 stops itself. The elapsed time is measured by a timer 31 and a timer 40 of the charger 4 described later. The total timer value is obtained by the following equation (1). {(Battery capacity−remaining capacity) / charging current} × constant (1) Here, the value recorded in the EEPROM 32 is used as the battery capacity.

The discharge control means 25 includes a battery case 2
When the switch of the display device 13 with a switch is turned on while the charger 4 is mounted on the charger 4, the charger 4 is turned on.
, A refresh start signal is transmitted.
The refresh is performed by discharging the battery 5 with the charger 4. Further, the discharge control means 25
Sends a refresh stop signal to the charger 4 when the voltage between the terminals of the battery 5 reaches a predetermined refresh end value during refresh.

As shown in FIG. 1, the charger 4 converts AC power supplied from an outlet plug 33 into DC by an AC / DC converter 34 and supplies the DC power to the charging terminal 6 as a charging current. I have. Also, this charger 4
The receiving means 35, the comparing / calculating means 36, and the output controlling means 37 for passing the charging current set by the CPU 3
And the like, and further includes a discharger 38 for refreshing the battery 5 and discharge control means 39 for controlling the discharger 38.

The receiving means 35 receives the signal C via the signal terminal 15.
It is provided for receiving a signal from the PU 3 or transmitting a signal to the CPU 3, and is configured to receive a charge instruction signal and a charge stop signal and transmit these signals to the comparison / calculation signal 36. The elapsed time (charging time) after the start of charging is measured by the timer 40, and a charging stop signal is sent to the comparing / calculating means 36 when the charging time exceeds the total timer value sent from the CPU 3. I have.
The self-stopping means according to the present invention is constituted by the receiving means 35 in this embodiment. Further, the receiving means 35 has a reply means 41 for sending a signal indicating connection confirmation to the CPU 3 when receiving the signal for connection determination sent by the CPU 3.

Further, the receiving means 35 includes a CPU
3 receives the refresh start signal or the refresh stop signal transmitted by the discharge control means 39.
To be sent to. Refreshing of the battery 5 is started by the discharge control unit 39 sending a discharge start signal to the discharger 38, and is ended by sending a discharge stop signal. At the time of refreshing, the receiving means 35 sends a charge stop signal to the comparing / calculating means 36. In FIG. 1, what is indicated by reference numeral 42 connected to the receiving means 35 is an LED driver for turning on the LED 43 at the time of charging or refreshing.

The comparing / calculating means 36 includes the receiving means 35
A target charging current is determined from the charging instruction signal transmitted by the DC / DC converter, and based on the outputs of the current detecting means 44 and the voltage detecting means 45 provided on the downstream side of the AC / DC converter 34, the charging current matches the target charging current. The output control means 37 is configured to perform feedback control. The output control means 37 controls the output of the AC / DC converter 34 according to the control signal sent from the comparison / calculation means 36.

Next, the operation of the charging control device 1 configured as described above will be described with reference to the flowcharts shown in FIGS. The CPU 3 in the battery case 2 determines whether or not the charger 4 is connected as shown in step S1 of FIG. This determination is performed by the connection determination unit 26 transmitting a connection determination signal to the charger 4 and detecting whether the charger 4 returns a connection confirmation signal. Since the connection confirmation signal is returned from the charger 4 by attaching the battery case 2 to the charger 4, the connection is determined in step S1, and the connection is determined in step S2.
Proceed to.

In step S2, the CPU 3 reads the remaining capacity of the battery 5 from the memory, and then determines in step S3 whether the battery temperature falls within a temperature range between the lower limit temperature for starting charging and the upper limit temperature for starting charging. . If it is out of the range, charging is awaited in step S4.
If it is within the range, the CPU 3 sets the charging current in step S5.

The charging current is read from the map shown in FIG. 3 based on the remaining capacity and the battery temperature. That is, the battery temperature at the start of charging is equal to the predetermined current control start temperature (T
1) When the temperature is higher, the lower the battery temperature is and the smaller the remaining capacity is, the smaller the battery temperature becomes.

Next, the CPU 3 obtains the total timer value in step S6, confirms whether or not the communication function is normal in step S7, and sends the charging current and the total timer value to the charger 4 in step S8. When the charger 4 receives these signals, the charger 4 starts charging as shown in step S9.

After the start of charging, as shown in step S10, the CPU 3 determines whether or not the charging time has reached the total timer value. When the determination is NO, that is, the charging time has reached the total timer value. If not,
In step S11, it is determined whether or not charging is completed. If the charging has not been completed, the process returns to step S10. If the charging time has reached the total timer value or if it is determined that charging has been completed, the CPU 3 sends a charging stop signal to the charger 4 in step S12.

On the other hand, the charger 4 determines the connection of the battery 5 in step P1 shown in FIG. 5 by mounting the battery case 2, and determines in step P2 whether the battery voltage is significantly reduced. . In this embodiment, when the battery voltage is 16 V or lower, the process proceeds to Step P3, and when the battery voltage is higher than 16V, the process proceeds to Step P4. In step P3, time measurement is started using the timer 40 as a pre-charge timer, and pre-charge is performed. This preliminary charging is performed until the battery voltage becomes 16 V or more in Step P5. When the pre-charge time exceeds a predetermined pre-charge timer value, it is determined that the battery is abnormal, the process proceeds from step P6 to step P7, and the LED 43 is turned on so that an abnormal state can be determined.

After the pre-charging is completed, at step P4 C
Confirmation of the communication function is performed by transmitting and receiving signals to and from the PU3, and then, in step P8, the charging current and the total timer value are received. When the receiving means 35 sends the charging current to the comparing / calculating means 36, charging is started as shown in step P9. After the start of charging, the charger 4 determines whether or not a charging stop signal has been received as shown in Step P10, and if not, determines in Step P11 whether or not the charging time has exceeded the total timer value. . If the charging time does not exceed the total timer value, the process returns to Step P10. When the charging time exceeds the total timer value or when the charging stop signal is received, the charger 4 proceeds to Step P12 and stops charging.

Therefore, the above-described charge control device 1
When the battery temperature at the start of charging is higher than a predetermined current control start temperature (T1), the higher the battery temperature and the smaller the remaining capacity, the smaller the charging current and the lower the battery temperature during charging. it can.

For this reason, since the upper limit temperature of the charging start temperature range does not need to be set low, the charging standby time becomes short,
The actual charging time can be shortened. In addition, when the remaining capacity is relatively small, the charging current is smaller than when the battery temperature is the same and the remaining capacity is large, so that sufficient charging can be performed while suppressing heat generation. When the remaining capacity is relatively large, the charged amount of electricity is small even when the charging current is relatively large, so that the battery can be fully charged before the battery temperature reaches the charging stop temperature.

Further, the charging control device 1 stops charging when the charging time exceeds the total timer value in each of the CPU 3 and the charger 4 in the battery case 2. It is possible to reliably prevent self-stopping and overcharging. That is, since the charger 4 can have a self-stop function, the reliability is high even in a configuration in which charging control is performed on the battery case side.

Further, the charging control device 1 is configured to be accommodated in the battery case 2 and to transmit a charging instruction signal to the charger 4 via a signal transmission means. Output control means 37 for controlling the output
Is provided, it is possible to set a charging current according to the type and capacity of the battery 5 in the battery case 2 on the battery case 2 side. As a result, a single charger 4 can charge various types of batteries under optimal conditions.

Second Embodiment In order for the CPU 3 to set the charger output, it can be implemented as shown in FIGS. FIG. 6 and FIG. 7 are graphs each serving as a map for setting the output of the charger. Even if these maps are replaced with the map of FIG. 3, the same effect as when the first embodiment is adopted can be obtained.

In the map shown in FIG. 6, the vertical axis indicates the DOD (depth of discharge), and the output (charge current) of the charger is represented by A to C.
It is shown in stages. The outputs have a relationship of output A> output B> output C. The larger the value of the depth of discharge, the smaller the remaining capacity. When the map shown in FIG. 6 is adopted, when the battery temperature at the start of charging is lower than the current control start temperature TA, the battery is charged at the maximum output regardless of the remaining capacity. When the battery temperature is higher than the temperature TA, the higher the battery temperature is, The smaller the capacity (the larger the DOD), the lower the charger output.

The map shown in FIG. 7 is adopted when the charger 4 is operated so that the ON state and the OFF state occur repeatedly to change the output of the charger. In this map, the ON state time is changed in three stages as pulse A to pulse C. Pulse A> pulse B
> Pulse C. Even if this map is adopted, the same effect as in the case of using the maps of FIGS. 3 and 6 can be obtained.

Third Embodiment In order to provide the charger 4 with a self-stop function, the charger 4 can be configured as shown in FIGS. 8 to 11 show another embodiment, FIG. 8 is a block diagram showing a configuration inside a charger, FIG. 9 is a block diagram showing a configuration inside a battery case, and FIG.
FIG. 11 is a flowchart for explaining the operation of U, and FIG. 11 is a flowchart for explaining the operation of the charger. In these figures, the same or equivalent members as those described in FIG. 1 and FIG. 2 are denoted by the same reference numerals, and detailed description is omitted.

When adopting this embodiment, the CPU 3
The point that there is no means for setting the charging current;
The second embodiment employs the same configuration as that of the above embodiment, except that the configuration for transmitting the remaining battery data is adopted.

In this embodiment, a value stored in a memory 51 provided in the charger 4 is used as the charging current. Further, the charger 4 is provided with a charger-side charging time calculating means 52 for obtaining a total timer value based on the remaining battery data sent from the CPU 3 and the charging current read from the memory 51. In this embodiment, the charging is stopped when the elapsed time after the start of charging exceeds the total timer value obtained by the charger-side charging time calculating means 52. This control is executed by the receiving means 35 of the charger 4.

The operation of the CPU 3 and the charger 4 in this embodiment will be described with reference to the flowcharts shown in FIGS. In the flowcharts of these drawings, when performing the same or the same operations as those described in the flowcharts of FIGS. 4 and 5, the same reference numerals are given and the detailed description is omitted. First, the operation of the CPU 3 of the battery case 2 will be described with reference to FIG.

First, as shown in steps S1 to S4 in FIG. 10, the CPU 3 determines whether or not the charger 4 is connected, and then reads the remaining capacity data of the battery 5, and sets the battery temperature to the charging start lower limit temperature. It is determined whether the temperature falls within a temperature range between the charging start upper limit temperature and the charging start upper limit temperature. If the battery temperature is within the above temperature range, the communication function is confirmed (step S7), and then the remaining capacity data of the battery 5 is sent to the charger 4 as shown in step 101.

Thereafter, the CPU 3 obtains a total timer value from the remaining capacity data and the charging current (constant value) (step S6).
Start timing by. Then, charging by the charger 4 is started (step S9), and as shown in steps S10 and S11, when the charging time exceeds the total timer value or when it is determined that the charging is completed, step S12 is performed.
Sends a charge stop signal to the charger 4 to end charging.

On the other hand, the charger 4 operates in step P1 of FIG.
After performing the preliminary charging and the communication function determination shown in Step P7, the remaining capacity data of the battery 5 transmitted from the CPU 3 is received in Step P101. Then, the charger 4 obtains a total timer value from the remaining capacity data and the charging current (constant value) in Step P102, and starts charging after the timer 40 starts counting time in Step P103 (Step P9). After charging starts, CP
When the charging stop signal transmitted by U3 is received, or when the elapsed time after the start of charging exceeds the total timer value, charging is stopped (steps P10 to P1).
2).

Thus, even if the charger 4 is configured to obtain the total timer value based on the remaining capacity data, the charger 4 can be provided with a self-stop function, and the embodiment shown in FIGS. The same operation and effect as in the case of adopting the form are obtained.

In each of the above-described embodiments, an example in which a nickel-metal hydride battery is used has been described. However, any type of battery 5 may be used as long as the temperature rises due to heat generation during charging. Can be.

[0054]

As described above, according to the present invention, when the battery temperature at the start of charging is higher than the predetermined temperature, the higher the battery temperature, the more difficult it is for the battery temperature to rise during charging. . Therefore, the upper limit temperature of the charging start temperature range does not need to be set low, and the actual charging time can be shortened. In addition, when the remaining capacity is relatively small, the charging current is smaller than when the battery temperature is the same and the remaining capacity is large, so that sufficient charging can be performed while suppressing heat generation. When the remaining capacity is relatively large, the charged amount of electricity is small even when the charging current is relatively large, so that the battery can be fully charged before the battery temperature reaches the charging stop temperature.

Therefore, the battery can be charged with the optimum charger output in the state at the start of charging the battery, and when the battery temperature is relatively high, it is possible to secure both the charging capacity and the shortening of the actual charging time. it can. Moreover, since the output of the charger is lowered to secure the charging capacity for the high-temperature battery, the battery does not overheat as compared with the case where the method of increasing the maximum temperature for stopping charging is adopted. Therefore, the performance of the battery is not reduced and the life is not shortened.

Further, since the charge control device is housed in the battery case, the output of the charger according to the type and capacity of the battery in the battery case can be set on the battery case side. Can be detachably attached to the charger, and a single charger can charge various types of batteries under optimal conditions.

According to another invention, the self-stop means for stopping charging when the elapsed time after the start of charging reaches the longest charging time is also provided on the charger side. By the charger stopping means, the charger stops charging when the longest charging time is reached. For this reason, the charger can be provided with a self-stop function, and overcharging can be reliably prevented.

[Brief description of the drawings]

FIG. 1 is a block diagram showing a configuration of a battery charge control device according to the present invention.

FIG. 2 is a block diagram showing a configuration inside a battery case.

FIG. 3 is a graph showing a map for setting an output of a charger.

FIG. 4 is a flowchart illustrating an operation of a CPU in a battery case.

FIG. 5 is a flowchart for explaining the operation of the charger.

FIG. 6 is a graph showing a map for setting the output of the charger.

FIG. 7 is a graph showing a map for setting the output of the charger.

FIG. 8 is a block diagram showing a configuration inside the charger.

FIG. 9 is a block diagram showing a configuration inside a battery case.

FIG. 10 is a flowchart illustrating an operation of a CPU in a battery case.

FIG. 11 is a flowchart for explaining the operation of the charger.

[Explanation of symbols]

DESCRIPTION OF SYMBOLS 1 ... Charge control device, 2 ... Battery case, 3 ... CP
U, 4 charger, 5 battery, 21 remaining capacity calculation means, 22 temperature detection means, 23 charger control means, 2
4 ... Charge stopping means, 27 ... Charge time calculating means, 35 ... Receiving means, 37 ... Output control means, 52 ... Charger side charging time calculating means

Claims (2)

[Claims] 1. A remaining capacity calculating means for obtaining a remaining capacity of a battery, a temperature detecting means for detecting a temperature of a battery, a remaining capacity of a battery obtained by the remaining capacity calculating means, and a battery temperature detected by the temperature detecting means. Charger control means for setting a charging current based on the above, and charging stop means for stopping charging by the charger when the battery is charged to a fully charged state are provided in a battery case, and the charger control means When the battery temperature at the start of charging is higher than a predetermined temperature, the charging current is set smaller as the battery temperature is higher and the remaining capacity is smaller, and the charging current is used as a charging instruction signal by a signal transmitting means to the charger. And output control means for controlling the output in accordance with the charging instruction signal is provided in the charger. A charge control device for a battery. 2. A battery capacity calculating means for calculating a remaining capacity of a battery, a charging stopping means for stopping charging by a charger when the battery is charged to a full charge state, and a signal transmitting means. And a timer for measuring the elapsed time after the start of charging, and charging the longest charging time set by the remaining capacity of the battery and the charging current determined by the remaining capacity calculating means. A charge control device for a battery, comprising: a self-stop means for stopping charging when an elapsed time after the start is exceeded.