JPH07241044A - Charge control system for secondary battery - Google Patents

Abstract

PURPOSE:To detect a fully charged state of a secondary battery, being charged with constant voltage and constant current, accurately based on the charging current and the battery voltage. CONSTITUTION:The charging control system for secondary battery comprises a battery measuring section 12 for monitoring the voltage of a secondary battery 11, a current measuring section 13 for monitoring the charging current, and a full-charge detecting/controlling section 14 for turning a switch 15 inserted into a charging path OFF when the charging current drops below a set level thus interrupting the charging operation temporarily and detecting a fully charged state when the battery voltage measured at the voltage measuring section 12 reaches a prescribed level.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a charging control system for a battery pack containing a secondary battery.

[0002]

2. Description of the Related Art In a battery pack containing a lithium-ion secondary battery, charge control of the secondary battery is performed by constant current charging at first, and when the battery voltage rises to reach a set maximum charging voltage. , Switch to constant voltage charging, detect full charge and terminate charging.

In detecting the full charge of the secondary battery in such charge control, conventionally, the charge current during constant voltage charging was measured, and if the charge current was less than a specified current value, the charge was considered to be full charge.
However, in such a full charge detection means,
There was a problem that full charge was detected even when the charging current did not flow due to a defect such as battery open.

Further, when such an erroneous full-charge detection is performed, the battery pack is erroneously recognized as the operable time, and the device is driven by the battery pack (when the battery is driven).
In addition, there is an inconvenience that the processing (for example, application software processing) has to be terminated halfway.

Some of the above-mentioned battery packs are provided with a storage device for storing charge / discharge information of the built-in secondary battery. The battery capacity of this type of battery pack is managed by adding or subtracting the corresponding battery capacity to the battery capacity stored in the storage device when the battery is charged or discharged.

However, such a battery capacity management means has the following problems. That is, when a fully charged battery (100% in the storage device) is left alone, discharged to some extent, and then charged again, the actual capacity is reduced, but the battery stored in the storage device is reduced. Since the capacity information remains 100%, it is recognized that the battery is in a fully charged state, and as a result, there is an inconvenience that the battery cannot be fully charged even if the battery is charged. Further, even when discharging is performed in that state, if the information in the storage device remains 100%, the information on the storage device capacity does not become zero even if the actual capacity becomes zero. Occurs.

Further, the charging method of the secondary battery in the above-mentioned battery pack is such that the charge amount of the battery being charged is added at a constant interval and the charging is terminated when the full charge is detected, or the charging current is changed. A method has been adopted in which charging is terminated when it is detected that the current is below a certain reference current value.

Therefore, conventionally, when the secondary battery (battery A) being charged is replaced with another secondary battery (battery B) while the secondary battery (battery A) is being charged, the battery B is not charged. Since it holds the fully charged battery capacity data detected by Battery A,
If the charging capacity of the battery A being charged is lower than that of the battery B, the charging capacity is insufficient, and conversely, the capacity of the battery B is less than that of the battery A.
There was a problem that it would be overcharged if it was higher than the capacity. Also, if the battery replaced during charging is an abnormal battery, the replacement of the battery pack cannot be detected.
There was a problem of charging as it was.

In addition, a plurality of lithium ion secondary batteries
When individually charging one lithium ion secondary battery, another lithium ion secondary battery is charged after detecting the full charge of one lithium ion secondary battery. Each secondary battery ends charging when it detects full charge.

However, in such conventional charging control, after the secondary battery is fully charged, the secondary battery is not charged, so that the secondary battery is discharged and the full charge is maintained. Therefore, when the discharge progresses, there arises an inconvenience that correct secondary battery management cannot be performed.

[0011]

As described above, the charging control of the secondary battery in the battery pack containing the lithium ion secondary battery is performed by charging the battery voltage which is set by the constant current charging. When the maximum voltage is reached, switching to constant voltage charging is performed, and the charging current during constant voltage charging is measured, and when it is below the specified current value, it is considered to be fully charged.Therefore, when the charging current does not flow due to a defect such as battery open However, there was a problem that full charge was detected. Further, when such an erroneous full-charge detection is performed, there is an inconvenience such as an incorrect recognition of the operable time by the battery pack, and the process having to be terminated halfway when the device is driven by the battery pack.

Further, in a battery pack provided with a storage device for storing charge / discharge information of the built-in secondary battery, the battery capacity is stored in the storage device when the charge / discharge occurs. It is managed by adjusting the battery capacity that is set, but in such battery capacity management means,
When a fully charged battery is left for a while, discharged to some extent, and then recharged, the actual capacity is reduced, but the battery capacity information stored in the storage device indicates that the battery is full. It is recognized that the battery is in a charged state, and as a result, there is an inconvenience that the battery cannot be fully charged even if it is charged. Furthermore, if discharging is performed in that state, even if the actual capacity becomes zero, the storage device There was a problem that the capacity information of was not zero.

Further, the charging method of the secondary battery in the above-mentioned battery pack is such that the charge amount of the battery being charged is added at a constant interval and the charging is terminated when the full charge is detected, or the charging current is changed. A method of terminating charging when it detects that the current has dropped below a certain reference current value is adopted.
Conventionally, when the secondary battery (A) being charged is replaced with another secondary battery (B) while the secondary battery (A) is being charged, the battery B is charged to the full charge detected by the battery A. Since the battery capacity data of the battery is stored, if the charging capacity of the battery A during charging is lower than the charging capacity of the battery B, the charging capacity is insufficient, and conversely,
If the capacity of the battery B is higher than the capacity of the battery A, there is a problem of overcharging. Further, if the battery replaced during charging is an abnormal battery, replacement of the battery pack cannot be detected, and the battery is charged as it is.

In addition, a plurality of lithium ion secondary batteries
In the case of individually charging each one, conventionally, after detecting the full charge of one lithium ion secondary battery, another lithium ion secondary battery is charged, and the charging is terminated when the full charge of each secondary battery is detected. Therefore, after the secondary battery is fully charged, the secondary battery is not charged, so the secondary battery is discharged and the full charge is not maintained. There was an inconvenience that it could not be managed.

The present invention has been made in view of the above circumstances,
An object of the present invention is to provide a secondary battery charge control method capable of accurately detecting a fully charged state of a secondary battery charged by constant voltage and constant current.

Further, according to the present invention, in a battery pack having a built-in storage means for storing the secondary battery and the remaining capacity of the battery, the remaining capacity (charge amount) of the secondary battery is always correct in the storage means of the battery pack. It is an object of the present invention to provide a battery capacity management system for a secondary battery, which can store the information stored therein and can accurately recognize the remaining capacity of the secondary battery.

Further, the present invention provides a charge control method for a secondary battery, which is capable of always performing a safe and correct charge even when the battery pack is replaced during charging, in charge control of a battery pack having a built-in secondary battery. The purpose is to provide.

Further, the present invention is a system for charging a plurality of secondary batteries one by one with a constant current and a constant voltage, and when the secondary battery being charged is charged with a constant voltage, another It is an object of the present invention to provide a secondary battery charge control method capable of charging a fully charged battery and always maintaining the secondary battery in a fully charged state.

[0019]

The present invention relates to a secondary battery which is charged with a constant current and a constant voltage, as shown in FIG. 1, and a voltage measuring unit 12 for monitoring the battery voltage of the secondary battery 11, The current measuring unit 13 that monitors the charging current, and when the charging current becomes less than or equal to a set value, the switch 15 interposed in the charging path is turned off to temporarily stop the charging, and the battery voltage measured by the voltage measuring unit 12 becomes It is characterized by comprising a full-charge detection control unit 14 for detecting full-charge when the voltage reaches the specified voltage.

Further, according to the present invention, in a system using a battery pack incorporating a secondary battery and a storage means for storing the remaining capacity of the battery, as shown in FIG.
Capacity detection device 2 for detecting the remaining capacity from the battery voltage of
2 and the remaining capacity information detected by the remaining capacity detecting device 22 is compared with the remaining capacity information of the storage device 24 in the battery pack 21, and when the difference is equal to or more than a specified value, the remaining capacity detecting device 22 remains. And a battery capacity storage control device 23 for writing capacity information into the storage device 24.

Further, the present invention is a system for controlling the charging of a battery pack having a built-in secondary battery, as shown in FIG. 3, the battery pack 31 has a built-in secondary battery (BATT) charging state, and A storage device 32 that stores identification information unique to each battery pack is provided, and a secondary battery (BATT) of the battery pack 31 is provided.
The identification information peculiar to the battery pack is read from the storage device 32 of the battery pack 31 and stored in the charger 33 that controls the charging of the battery, and the battery being charged is checked by comparing the identification information read this time with the identification information read last time. In addition to detecting whether the pack has been replaced,
When it is detected that the battery pack 31 has been replaced during charging, the switch 36 interposed in the charging path is turned off to cancel the continuation of the charging operation, and the built-in storage device 32 of the replaced battery pack 31 is used. It is characterized in that a charging control unit 34 is provided which reads information on the next battery (BATT) and starts charging from the beginning according to the state of the replaced battery pack 31.

Further, the present invention relates to a charging control system for controlling charging of a plurality of battery packs each having a built-in secondary battery for constant current / constant voltage charging, one by one, as shown in FIG. When each battery pack 41a is in a fully charged state and the other battery pack 41b has finished the constant current charging, the switches 44a and 44b interposed in the charging paths of the battery packs 41a and 41b are turned on to turn on the constant charge. Voltage / constant current source 4
The constant voltage charging power output from 2 is supplied to each battery pack 41.
a, 41b to control each battery pack 41a, 41b at a constant voltage, and has a full-charge detection function.
3 is provided.

[0023]

In the structure shown in FIG. 1, the lithium ion secondary battery 11 is charged with a constant current and a constant voltage. At the end of charging, the charging current decreases. When the charging current measured by the current measuring unit 13 becomes equal to or less than the set charging current value for full charge detection, the full charge detection control unit 14 turns off the switch 15,
It is determined whether or not the battery voltage measured by the voltage measuring unit 12 is equal to or higher than the set voltage, and when the measured battery voltage is equal to or higher than the set voltage, full charge is detected, and the full charge detection state is indicated by, for example, the full charge display unit. 16 is displayed.

By adopting such a structure that the full charge is detected by the charging current and the battery voltage, the inconvenience of erroneously detecting the full charge when the charging current does not flow due to a defective battery is avoided, and the constant voltage constant current is maintained. The fully charged state of the secondary battery to be charged can be accurately detected.

In the structure shown in FIG. 2, the battery pack 21
The remaining capacity of the secondary battery (BATT) built in the battery is stored in the storage device 24 in the battery pack 21, and the remaining capacity detection device 22 determines the remaining capacity from the battery voltage of the secondary battery (BATT). It is calculated. The remaining capacity information detected by the remaining capacity detection device 22 and the remaining capacity information stored in the storage device 24 are sent to the battery capacity storage control device 23 for comparison, and when the difference in the remaining capacity is equal to or more than a specified value, the remaining capacity information remains. The information of the capacity detection device 22 is written in the storage device 24 as accurate remaining capacity information, and if the difference in the remaining capacity does not reach the specified value, the writing in the storage device 24 is not performed.

As a result, the storage device 2 in the battery pack 21
An accurate remaining capacity can always be stored in 4. In the configuration shown in FIG. 3, the charge control device 34 controls the storage device 3 of the battery pack 31 at regular intervals while the battery pack 31 is being charged.
The identification information unique to the battery pack is read from 2, and it is detected whether or not the battery pack is being replaced during charging. Further, the charging control device 34
When it detects that the battery pack 31 has been replaced during charging, it turns off the switch 36 interposed in the charging path, cancels (stops) the continuation of the charging operation, and stores the replaced battery pack 31. The information of the built-in secondary battery (BATT) is read from the device 32, and charging is started from the beginning according to the state of the replaced battery pack 31.

In this way, when it is detected that the battery pack has been replaced during charging, the continuation of the charging operation, which was being performed on the battery pack before replacement, is interrupted and a new battery pack is newly added to the replaced battery pack. By including the charging control means that starts the charging operation, even if the battery pack being charged is replaced during charging, it can be charged accurately according to the state of each battery, and the chargeable capacity of the battery can be reduced. It can be used without exhaustion. Further, even if the battery pack replaced during charging has a battery abnormality, the battery abnormality can be recognized at the time of battery replacement, so that reliable and accurate charging can be maintained.

In the configuration shown in FIG. 4, the charging control section 43
Determines that one battery pack 41a is fully charged by constant current constant voltage charging and the other battery pack 41b has finished constant current charging, each battery pack 41a,
Switches 44a, which are respectively interposed in the charging path of 41b,
Both 44b are switched on. Constant voltage / constant current source 4
No. 2 outputs the charging power in the constant voltage mode when the charging current is reduced to the specified value or less. As a result, each battery pack 4
1a and 41b are each controlled by constant voltage charging to maintain a fully charged state.

[0029]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the present invention will be described below with reference to the drawings. FIG. 1 is a block diagram showing a first embodiment of the present invention. In FIG. 1, 11 is a lithium-ion secondary battery (BATT) that is charged with a constant current and a constant voltage. Reference numeral 12 is a voltage measuring unit (V) that measures the charging voltage of the lithium ion secondary battery 11, and 13 is a current measuring unit (A) that measures the charging current of the lithium ion secondary battery 11.

Reference numeral 14 is a full-charge detection control unit for detecting the full charge of the lithium-ion secondary battery 11 from the measured voltage of the voltage measuring unit 12 and the measured current of the current measuring unit 13, and the charging current measured by the current measuring unit 13 Is less than the specified current value, the switch 15 is turned off once and the battery voltage measured by the voltage measuring unit 12 is checked. If the measured voltage reaches the specified voltage, full charge detection is performed.

Reference numeral 15 denotes a switch interposed in the charging current path of the lithium-ion secondary battery 11, which is turned on / off by the full-charge detection control unit 14, and the measured charging current of the current measuring unit 13 is below a specified value. When it becomes, it is controlled off.

Reference numeral 16 denotes a full-charge display section which, when the full-charge detection control section 14 detects full charge, outputs a display indicating that the lithium-ion secondary battery 11 is in a fully-charged state. Here, the operation of the first embodiment shown in FIG. 1 will be described.

When charging the lithium ion secondary battery 11,
Charging power is supplied to the lithium ion secondary battery 11 from a constant current / constant voltage source (not shown) via the switch 15, and the lithium ion secondary battery 11 is charged with constant current / constant voltage.

The charging current of the lithium-ion secondary battery 11 decreases as it approaches the end of charging, and at the end of charging, a predetermined current value, that is, the full-charge detection controller 14
Below the specified current value set in.

The full charge detection control unit 14 includes a current measuring unit 13
When recognizing that the charging current measured in step 1 has become equal to or less than the specified current value, the switch 15 is turned off once and the voltage measuring unit 1
Check the battery voltage measured in 2. That is, the open battery voltage of the lithium ion secondary battery 11 is checked. Then, it is determined whether or not the measured voltage has reached a predetermined specified voltage, and if it has reached the specified voltage, full charge detection is performed and the fact is notified to the full charge display unit 16. As a result, the lithium-ion secondary battery 11 is displayed on the full-charge display unit 16.
Information indicating the fully charged state of is displayed.

As described above, according to the first embodiment, since the full charge detection is performed by the charging current and the battery voltage, it is possible to avoid the inconvenience of falsely detecting the full charge when the battery is defective and the charging current does not flow. , Can always detect correct full charge.

FIG. 2 is a block diagram showing a second embodiment of the present invention. In FIG. 2, reference numeral 21 is a battery pack, which has a built-in secondary battery (BATT) and a storage device 24 for storing the remaining capacity of the built-in secondary battery (BATT).

Reference numeral 22 is a remaining capacity detecting device for detecting the remaining capacity of the battery pack 21 (the remaining capacity of the secondary battery (BATT) built in the battery pack 21). Built-in secondary battery (BATT)
The remaining capacity of the battery pack 21 is detected based on the battery voltage).

Reference numeral 23 denotes a battery capacity storage control device having a battery capacity comparison function, which displays the remaining capacity of the battery pack 21 detected by the remaining capacity detection device 22 and the remaining capacity stored in the storage device 24 in the battery pack 21. In comparison, when the difference between the remaining capacities is equal to or larger than a predetermined value set in advance, the remaining capacity information is written in the storage device 24 using the information of the remaining capacity detection device 22 as accurate remaining capacity information, When the difference does not reach the specified value, writing to the storage device 24 is not performed, and after a certain period, the above-described operation including battery capacity comparison is repeated.

A storage device 24 provided in the battery pack 21 is read / write controlled under the control of the battery capacity storage control device 23 and stores the remaining capacity information of the built-in secondary battery (BATT).

Now, the operation of the second embodiment shown in FIG. 2 will be described. In the storage device 24 in the battery pack 21, under the control of the battery capacity storage control device 23, the remaining capacity of the battery pack 21 (remaining capacity of the secondary battery (BATT) built in the battery pack 21 is maintained at regular intervals. Capacity) is stored.

The remaining capacity detecting device 22 includes a battery pack 21.
Battery voltage of the secondary battery (BA
The actual remaining capacity of the battery pack 21 is detected from the battery voltage of (TT)), and the detected remaining capacity is supplied to the battery capacity storage control device 23.

The battery capacity storage control device 23 accesses the storage device 24 of the battery pack 21 at a constant cycle, reads the remaining capacity stored in the storage device 24, and detects the remaining capacity with the remaining capacity detection device 22. It is determined whether or not the difference is equal to or more than a specified value by comparing with the actual battery remaining capacity.

If the difference between the remaining capacities is equal to or greater than the specified value in this comparison, the remaining capacity information actually detected by the remaining capacity detection device 22 is written in the storage device 24 as an accurate remaining capacity, and again after a fixed period. The operation including the battery capacity comparison described above is repeated.

If the difference between the remaining capacities obtained by the above comparison has not reached the specified value, writing to the storage device 24 is not performed, and the operation including the battery capacity comparison described above is repeated after a certain period.

By having such a battery capacity management mechanism, an accurate remaining capacity can always be stored in the storage device 24 of the battery pack 21. FIG. 3 is a block diagram showing a third embodiment of the present invention.

In FIG. 3, 31 is a battery pack,
A storage device that has a built-in secondary battery (BATT) composed of an assembled battery, and that stores the remaining capacity of the built-in secondary battery (BATT), identification information unique to the pack for identifying each battery pack, and the like. With 32.

Reference numeral 33 denotes a charger for controlling the charging of the battery pack 31, which is provided with a charging control section 34, a power source section 35, a charging on / off switch 36 and the like. The charging control unit 34 reads the identification information unique to the battery pack from the storage device 32 of the battery pack 31 at a constant cycle, updates and stores it each time, and stores the identification information read just now and the identification information read last time and stored. By comparison, it is detected whether or not the battery pack is being replaced during charging, and when it is detected that the battery pack 31 is replaced during charging, the switch 36 interposed in the charging path is once turned off to change the battery pack before replacement. After canceling the continuation of the charging operation for, the information of the built-in secondary battery (BATT) is read from the storage device 32 of the replaced battery pack 31, and the battery is charged from the beginning according to the state of the replaced battery pack 31. To start.

The operation of the third embodiment shown in FIG. 3 will be described here. The storage device 32 of the battery pack 31 stores status information such as the remaining capacity of the built-in secondary battery (BATT) and identification information unique to the battery pack.

In addition, the built-in secondary battery (BAT
T) is supplied with charging power from the power supply unit 35 of the charger 33 via the charging on / off switch 36, and charging is continued until the built-in secondary battery (BATT) of the battery pack 31 is fully charged. Will be performed. The charging method at this time is a charging method that continues charging until the charge amount of the battery pack being charged reaches a specified value, or a charging method that continues charging until the charging current falls below a specified value, or a charging time is set. Any charging method or the like in which charging is continued until the time is reached may be used.

The charging control unit 34 reads the identification information peculiar to the battery pack from the storage device 32 of the battery pack 31 at a constant cycle, stores the identification information each time, and the identification information read just now and the identification information read last time and stored. Check if the battery pack is being replaced during charging by comparing with. At this time, when it is detected that the battery pack 31 has been replaced during charging, the switch 36 interposed in the charging path is temporarily turned off to cancel the continuation of the charging operation for the battery pack before replacement, and the replaced battery is replaced. Information on the built-in secondary battery (BATT) is read from the storage device 32 of the pack 31, and charging is started from the beginning according to the state of the replaced battery pack 31.

As described above, when it is detected that the battery pack is replaced during charging, the continuation of the charging operation, which was being performed on the battery pack before replacement, is interrupted and a new one is newly installed on the replaced battery pack. Since the charging control means for starting the charging operation is provided, even if the battery pack being charged is replaced during charging, it can be accurately charged according to the state of each battery, and the chargeable capacity of the battery pack. Can be used without exhaustion. Further, even if the battery pack replaced during charging has a battery abnormality, the battery abnormality can be recognized at the time of battery replacement, so that reliable and accurate charging can be maintained.

In the embodiment shown in FIG. 3 described above, when it is detected that the battery pack 31 has been replaced during charging, the continuation of the charging operation is canceled, and the secondary battery built in the storage device 32 of the replaced battery pack 31 is used. The battery (BATT) information was read and charging was started from the beginning according to the state of the replaced battery pack 31, but a storage unit for storing the charging state information of the battery pack is provided outside the battery pack. , When it is detected that the battery pack has been replaced during charging, the storage unit is initialized, a new charging operation is started for the replaced battery pack, and the charging status information associated with the charging operation is displayed. It may be configured to be stored in the storage unit. Even in this case, as in the above embodiment, even if the battery pack being charged is replaced during charging,
Accurate charging can be performed according to each battery state, the full chargeable capacity of the battery pack can be used, and even if the battery pack replaced during charging is abnormal, Since battery abnormality can be recognized at the time of battery replacement, accurate charging with high reliability and safety can be maintained.

FIG. 4 is a block diagram showing a fourth embodiment of the present invention, and FIG. 5 is an operation explanation diagram of the fourth embodiment. Figure 4
In the above, 41a and 41b are battery packs each incorporating a secondary battery to be charged. Reference numeral 42 is a constant voltage / constant current source for supplying a constant voltage charging power source to the battery packs 41a and 41b.

Reference numeral 43 denotes a charge control unit for controlling the battery packs 41a and 41b at a constant voltage, which has a full-charge detection function, and when the battery pack being charged (for example, 41a) is fully charged. 41a) is temporarily stopped and another battery pack (41a) requiring constant current charging
b) The charge control function for starting the constant current charging, and when the constant current charging of each of the battery packs 41a, 41b targeted for charging is completed, the battery packs 41a, 4 targeted for charging are charged.
1b has a charging control function of forming a charging path in each of the battery packs 41a and 41b so as to maintain a fully charged state and performing constant voltage charging control.

That is, as shown in FIG. 5, when the constant current charging of the battery packs 41a, 41b is completed, the charging control unit 43 turns on the switches 44a, 44b interposed in the charging paths of the battery packs 41a, 41b. Both are turned on to form a charging path in each battery pack 41a, 41b. On this occasion,
The constant voltage / constant current source 42 outputs the charging power in the constant voltage mode when the charging current is reduced to a specified value or less. As a result, each of the battery packs 41a and 41b is charged with a constant voltage, and the fully charged state is maintained.

44a and 44b are battery packs 41a and 41
The switches are individually interposed in the charging path b, and are turned on / off by the charging control unit 43. Here, the operation of the fourth embodiment shown in FIG. 4 will be described with reference to FIG.

The charge control unit 43 controls the battery packs 4 on one side.
When it is determined that 1a is fully charged by constant current constant voltage charging and the other battery pack 41b has finished constant current charging, the switches 44a and 44b interposed in the charging paths of the respective battery packs 41a and 41b are turned on. Switch on both.

On the other hand, the constant voltage / constant current source 42 outputs the charging power in the constant voltage mode when the charging current decreases below a specified value. As a result, the battery packs 41a and 41b are controlled by constant voltage charging, respectively, and the battery packs 41a and 41b are controlled.
The fully charged state of b is maintained.

FIG. 5 shows the battery packs 41a, 41 at this time.
The charge state of b is shown. From TE shown in FIG. 5 to each battery pack 4
1a, 41b are controlled by constant voltage charging, and each battery pack 41
Since a and 41b are kept in a fully charged state, battery management can always be performed in a correct charged state.

FIG. 6 is a block diagram showing a fifth embodiment of the present invention. In FIG. 6, reference numeral 51 denotes a battery pack composed of an assembled battery, and has a storage device 52 for storing identification information unique to the own pack inside the pack.

Reference numeral 61 denotes a charger, which has a function of storing identification information unique to the battery pack 51 read from the battery pack 51 and detecting whether or not the battery pack is replaced during charging. Reference numeral 62 denotes a data collating device provided in the charger 61, which periodically reads identification information unique to the battery pack 51 from the battery pack 51, and the read identification information and the identification information previously read and stored. Whether or not the battery pack has been exchanged is detected by checking and.

Reference numeral 63 denotes a power source section of the charger 61, which outputs charging power for the battery pack 51. Reference numeral 64 denotes a charge amount storage device provided in the charger 61. The charge amount storage device 64 adds the charge amount according to the charge, and stops the charge when the preset charge amount is reached.

Reference numeral 65 denotes a reference charge amount storage device provided in the charger 61, which stores the charge amount when the battery pack 51 is fully charged. Reference numeral 66 is a comparator provided in the charger 61, and compares the charge amount of the battery pack 51 being charged with the reference charge amount stored in the reference charge amount storage device 65.

Reference numeral 67 denotes a switch provided in the charger 61, which is switched off when the exchange of the battery pack is detected by the data collating device 62 and when the charge amount reaches the reference charge amount. Stop charging to 51.

The operation of the fifth embodiment shown in FIG. 6 will be described here. The data collating device 62 of the charger 61 periodically reads the identification information unique to the battery pack 51 from the storage device 52 of the battery pack 51 being charged, and reads and stores the read identification information last time. Whether the battery pack is replaced or not is detected by collating with the identification information.

When the data collating device 62 detects that the battery pack has been replaced during charging, it turns off the switch 67 and further clears the added charge amount stored in the charge amount storage device 64. After that, the switch 67 is turned on to start charging the replaced battery pack 51.

In detecting whether or not the battery pack has been replaced,
When it is not detected that the battery pack is replaced during charging, the added charge amount stored in the charge amount storage device 64 in the comparator 66 and the reference charge amount storage device 65 are stored. The reference charge amount is compared, and when it is detected that the charge amount reaches the reference charge amount in this comparison,
The switch 67 is turned off to stop charging the battery pack 51.

In this way, when it is detected that the battery pack has been replaced during charging, the continuation of the charging operation, which was being performed on the battery pack before replacement, is interrupted and a new battery pack is newly added to the replaced battery pack. Since the charging control means for starting the charging operation is provided, even if the battery pack being charged is replaced during charging, it can be accurately charged according to the state of each battery, and the chargeable capacity of the battery pack. Can be used without exhaustion. Further, even if the battery pack replaced during charging has a battery abnormality, the battery abnormality can be recognized at the time of battery replacement, so that reliable and accurate charging can be maintained.

[0070]

As described above in detail, according to the present invention, in a secondary battery charged with a constant current and a constant voltage, a voltage measuring unit for monitoring the battery voltage of the secondary battery and a charging current are monitored. When the current measuring unit and the charging current are below the set value, turn off the switch interposed in the charging path to temporarily stop charging,
By providing a full-charge detection control unit that detects full-charge when the battery voltage measured by the voltage measuring unit has reached a specified voltage, and by performing a full-charge detection with the charging current and the battery voltage, It is possible to avoid the inconvenience of erroneously detecting the full charge when the charging current does not flow due to a defective battery, and it is possible to accurately detect the full charge state of the secondary battery charged with a constant voltage and constant current.

Further, according to the present invention, in a system using a battery pack having a secondary battery and a storage means for storing the remaining capacity of the battery, the remaining capacity for detecting the remaining capacity from the battery voltage of the battery pack. The remaining capacity information detected by the detection device and this remaining capacity detection device is compared with the remaining capacity information of the storage device in the battery pack, and if the difference is more than a specified value, the remaining capacity information of the remaining capacity detection device is displayed. By including a battery capacity storage control device for writing in the storage device and realizing a function of always storing the correct remaining capacity of the battery pack in the storage means of the battery pack, the remaining capacity of the battery pack can always be recognized accurately. The battery capacity can be managed with high reliability.

Further, according to the present invention, in a charging control system for a battery pack having a built-in secondary battery, a battery pack having a storage device for storing identification information capable of identifying each battery pack, Identification means is read from the storage device of the battery pack at a fixed cycle, stored each time, and compared with the identification information read this time and the identification information read last time to detect whether or not the battery pack is being replaced during charging. A configuration including charge control means for canceling the continuation of the charging operation when detecting that the battery pack is replaced during charging and for newly starting the charging operation for the replaced battery pack. By doing so, even if the battery pack is replaced during charging, safe and correct charging can always be performed.

Further, according to the present invention, in the charging control system for the secondary battery, which controls the charging of each of a plurality of battery packs each having a built-in secondary battery for constant current / constant voltage charging, A full-charge detection unit that detects the fully charged state of a battery pack, and when the battery pack that is being charged becomes fully charged, the charging of the battery pack is temporarily stopped and the constant current charging of other battery packs that require constant current charging is performed. Charge control means for starting current charging, and charge control for performing constant voltage charging for maintaining a fully charged state in each of the plurality of battery packs to be charged when constant current charging of each of the plurality of battery packs to be charged is completed And a means for maintaining constant charge of each battery pack in a fully charged state, the secondary battery after charging is always kept in a fully charged state, and battery management is promoted by the progress of discharge. Nozu The lost, it is possible to handle the battery pack is always in the correct state of charge.

[Brief description of drawings]

FIG. 1 is a block diagram showing the configuration of a first embodiment of the present invention.

FIG. 2 is a block diagram showing the configuration of a second embodiment of the present invention.

FIG. 3 is a block diagram showing the configuration of a third embodiment of the present invention.

FIG. 4 is a block diagram showing the configuration of a fourth embodiment of the present invention.

FIG. 5 is an operation explanatory diagram of the fourth embodiment.

FIG. 6 is a block diagram showing the configuration of a fifth embodiment of the present invention.

[Explanation of symbols]

11 ... Lithium ion secondary battery (BATT), 12 ... Voltage measuring unit (V), 13 ... Current measuring unit (A), 14 ... Full charge detection control unit, 15 ... Switch. 21 ... Battery pack, 22 ...
Remaining capacity detection device, 23 ... Battery capacity storage control device, 24
…Storage device. 31 ... Battery pack, 32 ... Storage device, 33
... charger, 34 ... charge control unit, 35 ... power supply unit, 36 ... switch. 41a, 41b ... Battery pack, 42 ... Constant voltage
Constant current source, 43 ... Charging control unit, 44a, 44b ... Switch. 51 ... Battery pack, 52 ... Storage device, 61 ... Charger, 62 ... Data collating device, 63 ... Power supply, 64 ... Charge amount storage device, 65 ... Reference charge amount storage device, 66 ... Comparator,
67 ... switch.

 ─────────────────────────────────────────────────── ─── Continuation of front page (72) Inventor Shizuo Morioka 1381 Shinmachi, Ome-shi, Tokyo Within Toshiba Computer Engineering Co., Ltd. (72) Inventor Yoshiaki Ukitani 1381 Shinmachi, Ome-shi, Tokyo 1 Toshiba Computer In Ta Engineering Co., Ltd. (72) Inventor Masayasu Tanaka 1381 Shinmachi, Ome-shi, Tokyo Inside Toshiba Computer Engineering Co., Ltd. (72) Inventor Akihiko Uchida 1381 Shinmachi, Ome-shi, Tokyo Toshiba Computer Within Engineering Co., Ltd. (72) Inventor Keiichi Mitsui 1381 Shinmachi, Ome-shi, Tokyo 1 Toshiba Computer Engineering Co., Ltd.

Claims (6)

[Claims] 1. In a secondary battery charge control system for controlling charging of a secondary battery by constant current constant voltage charging, current measuring means for monitoring the charging current of the secondary battery and measurement by this current measuring means. A charging current determining means for determining whether or not the charging current has become less than or equal to the set value for determining the state of charge, and this charging current determining means detects that the measured charging current has become less than or equal to the set value for determining the fully charged state. At this time, the charging control means for temporarily controlling the charging of the secondary battery, the battery voltage measuring means for measuring the released battery voltage of the secondary battery when the charging is suspended by the charging control means, and the battery voltage measuring means It has a full-charge determination means for determining whether or not the measured battery voltage has reached the full-charge set voltage.When the charging current of the secondary battery falls below a specified value, charging is temporarily stopped and the battery voltage Reach set voltage A charging control method for a secondary battery, which is characterized by detecting a full charge when the battery is charged. 2. A battery pack including a secondary battery and a storage unit that stores the remaining capacity of the battery, and a detection unit that detects the remaining capacity of the secondary battery included in the battery pack.
The remaining capacity detected by the detection means is compared with the remaining capacity stored in the storage means. When the difference is equal to or more than a set value, the remaining capacity detected by the detection means is stored in the storage means. When the remaining capacity of the secondary battery contained in the battery pack is greater than the detected remaining capacity of the secondary battery by a specified value or more, the remaining capacity stored in the battery pack is stored in the battery pack. A battery capacity management method for a secondary battery, characterized in that the remaining capacity value of the means is updated. 3. A charging control method for a battery pack containing a secondary battery, comprising: a battery pack having a storage device for storing identification information capable of identifying each battery pack; and a storage device for the battery pack. The identification information is read at regular intervals, stored each time, and the identification information read this time is compared with the identification information read last time to detect the presence or absence of replacement of the battery pack during charging, and the battery pack during charging. When it is detected that the battery pack has been replaced, the battery pack is provided with a charging control means for canceling the continuation of the charging operation and newly starting the charging operation for the replaced battery pack. Charge control method. 4. A storage unit for storing charging status information of the battery pack is provided in the battery pack, and when it is detected that the battery pack has been replaced during charging, the charging stored in the storage unit of the replaced battery pack. The charging control method for a battery pack according to claim 3, wherein a charging operation is newly started for the replaced battery pack according to the status information. 5. A storage unit for storing the charging status information of the battery pack is provided outside the battery pack, and when it is detected that the battery pack has been replaced during charging, the storage unit is initialized to replace the replaced battery pack. To start a new charging operation,
The charge control method for a battery pack according to claim 3, wherein charge state information associated with the charging operation is stored in a storage unit. 6. A charging control method for a secondary battery, which controls charging of a plurality of battery packs each having a built-in secondary battery for constant current / constant voltage charging, in a fully charged state of the battery pack during charging. Full-charge detection means to detect the charge, and when the battery pack being charged is fully charged, the charging of the battery pack is temporarily stopped and the constant-current charging of another battery pack that requires constant-current charging is started. And a charge control means for performing constant voltage charging for maintaining a fully charged state in each of the plurality of battery packs to be charged when constant current charging of each of the plurality of battery packs to be charged is completed, A charging control method for a secondary battery, wherein each battery pack that has been charged with a constant current maintains a fully charged state.