JPH0864254A - Charging system for battery pack - Google Patents

Abstract

PURPOSE: To prevent overcharging and over discharging so as to improve safety by including a memory in a battery pack and providing interfaces for a charging device and an electronic device such as a wireless device. CONSTITUTION: A memory 4c is provided in a battery pack 4, while interfaces 4a, 4b for an electronic device 1 and a charging device 5 are arranged, and a time of battery use in the electronic device 1 is counted. The, the counted value is transferred to the pack 4, and consumption of the battery 4a is stored in the memory 4c. In charging, data in the memory 4c is read out by seas of the charging device 5, and a charging time in the charging device 5 is computed, and then, charging is carried out. In other words, when an electric power source is turned on to the electronic device 1 so as to start the action of the electronic device 1, a using time of the electronic device 1 is detected by means of a using time detecting means 2a so as to be transferred and written into the memory 4c via the interface 4a in the pack 4 by seas of a memory access means 2b. On the basis of this data, residual capacity of the battery is found via the memory access means 2b, a residual capacity computing means 2c, and the like so as to be displayed in an indicating unit 3, so that overcharging and over discharging can be prevented.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a charging method for a battery pack used in an electronic device. In recent years, it has come to be used as a power source for electronic devices such as portable radios that use a battery pack having a rechargeable secondary battery. Such a battery pack needs to be charged by a charger when the battery capacity decreases as the electronic device is used, but it is desired to charge the battery properly.

[0002]

2. Description of the Related Art FIG. 5 is an explanatory view of a conventional example. In FIG. 5, 50 is a wireless device, 51 is a wireless circuit, 52 is a detection unit,
53 is a display unit, 54 is a battery pack, and 55 is a charger. The wireless device 50 is mounted on an automobile or the like in a state of being connected to the battery pack 54, and is detached from the installation place when it is separated from the vehicle to be used as a portable wireless device. Radio 5
The zero detection unit 52 detects the voltage value of the battery supplied from the battery pack 54, and displays the voltage value as the remaining battery level in the display unit 53.
To display. When the remaining amount of the battery pack 54 falls to a certain value, the battery pack 54 integrated with the wireless device 50 is attached to the charger 55 and charging is performed. The charging time in this case is executed for a fixed time regardless of the remaining amount of the battery.

[0003]

According to the conventional example, when an electronic device such as a wireless device connected to the battery of the battery pack is used, the battery is charged appropriately by checking the remaining amount. Since accurate remaining battery capacity corresponding to the amount of battery usage is not detected for charging, there is a problem in that overcharging may affect battery life.

Further, some secondary batteries have a property (called a memory effect) that the battery capacity deteriorates and the battery capacity decreases when the operation of charging the battery while discharging the remaining battery is repeated. In that case, deterioration can be prevented by first discharging the battery and then charging it, but it is difficult to determine whether or not it is necessary to discharge the battery, and whether or not discharging has ended Since it could not be ascertained, over-discharge sometimes occurred.

[0005]

FIG. 1 is a block diagram showing the principle of the present invention. In FIG. 1, 1 is an electronic device such as a wireless device, and 2
Is a control unit, 2a is a usage time detection unit, 2b is a memory access unit, 2c is a remaining amount calculation unit, 3 is a display unit, 4 is a battery pack, 4a is a bidirectional interface with an electronic device,
4b is a bidirectional interface with a battery pack, 4c is a memory, 4d is a battery, 5 is a charger, 6 is a control unit, 6a is a data reading means, 6b is a remaining amount calculating means, 6c is a charging time calculating means, 6d. Is a charging control means, and 7 is a charging unit.

According to the present invention, a memory is provided in a battery pack, an interface for an electronic device and a charger is provided, and when the time when the battery is used in the electronic device is counted, the value is transferred to the battery pack so that the battery usage amount is Stored in memory,
At the time of charging, the data in the storage means is read by the charger, and the charging time in the charger is calculated for charging.

[0007]

When the electronic device 1 of FIG. 1 is turned on and the electronic device starts operating, the operating time of the electronic device (the operating time of the battery) is detected by the operating time detecting means 2a. The detected value is transferred to the memory 4c by the memory access means 2b via the interface 4a of the battery pack 4 and written therein. When the electronic device 1 is powered on next, the usage time data stored in the memory 4c is read by the memory access means 2b of the control unit 2 and supplied to the remaining amount calculation means 2c to supply the battery. Is displayed on the display unit 3 to inform the user of the remaining amount.

When the electronic device 1 is used next time without being charged after the previous use and the battery has a large remaining amount, the electronic device 1 is used as it is. In this case, the processing time of this time is detected by the usage time detecting means 2a, and the count value of the current processing time is also the same as the above operation, and the memory 4c of the battery pack 4
Is written to.

When the battery level becomes low, the battery pack 4 (which may be integrated with the electronic device 1) is connected to the charger 5. At this time, the data reading means 6a in the controller 6 of the charger 5 reads the data via the interface 4b of the battery pack 4. When data representing the usage time of the battery is obtained in this way, the remaining amount of the battery is calculated from the data by the remaining amount calculating means 6b, and then the charging time for fully charging the remaining amount is calculated as the charging time calculating means. The charging time calculated by 6c is supplied to the charging control means 6d, and the charging section 7 is controlled by the charging control means 6d. At the end of charging, the usage time data stored in the memory 4c of the battery pack 4 is reset. At this time, data indicating that the memory 4c has been charged can be written.

In the configuration of FIG. 1, the principle configuration for charging a battery is shown. In order to prevent the deterioration of the battery due to the memory effect of the battery, the charger 5 is provided with a discharging function. Control like. That is, the count value of the number of times of charging is stored in the memory 4c of the battery pack 4 by the charger 5, and when the battery pack 4 is connected to the charger 5 during charging,
The count value of the number of times of charging is read together with the data of the processing time from the memory 4c of the battery pack 4, and when the count value reaches a certain number, the battery is first discharged for a time corresponding to the remaining amount of the battery, After that, it may be controlled so that charging is performed. When the count value of the number of times of charging does not reach a fixed number, the count value is updated and the memory 4 of the battery pack 4 is updated.
c.

[0011]

FIG. 2 is a block diagram of an embodiment. This embodiment is an example applied to a wireless device as an example of an electronic device (1 in FIG. 1).

In FIG. 2, reference numeral 20 is a radio device, 21 is an antenna, 22 is a radio unit for transmitting and receiving by radio, and 23 is C.
A control unit including a PU and a memory, 24 is a display unit, 25 is an interface unit that is connected to a battery pack to transfer data, 26 is a battery pack, and 27 is a battery usage amount storage unit E
EPROM (Erectorically Erasable Programmable RO
M) and 28 are interface units that are connected to the wireless device 20 and access the EEPROM 27 under the control of the wireless device 20, 29 is an interface unit that accesses the EEPROM 27 under the control of the charger when connected to the charger, and 30 is It is a battery. Further, 31 is a charger, 32 is an interface unit connected to a battery pack, and 33 is a CPU.
And a memory (program and data), the charging unit 3
The control unit 34 for controlling the charging (and discharging) of 4 is a charging unit. Note that the charging unit 34 uses a circuit having a discharging function when performing control to execute discharging as described later in charging control.

FIG. 3 shows a processing flow in the control unit of the wireless device. Is the main routine, B. Is an interrupt processing routine. The wireless device 20 is used in a state in which it is connected to the battery pack and is disconnected from the charger 31.
In the main routine of (1), it is first determined whether or not the power is turned on (S1 in FIG. 3). This determination is made by identifying the on / off state of a power switch (not shown). When the power is turned on, the control unit 23 reads the data indicating the battery usage amount stored in the EEPROM 27 through the interface unit 25 and the interface unit 28 of the battery pack 26 (at step S2), and the battery remaining amount is determined from the battery usage amount. Is calculated and displayed on the display unit 24 (at step S3).

Referring to FIG. The interrupt processing routine shown in
A certain time after power-on (time shorter than 1 second in this example)
Each time it is started, it is determined whether the transmission process is being executed first (S4 in FIG. 3), and if it is the transmission process, it is determined whether 1 second has elapsed (S5 in the same figure). The counter (provided in the memory of the control unit 23) is incremented (+1) (at step S6), and the processing time is transferred to the battery pack (at step S7). If it is not a transmission process, it is determined whether it is a reception process (at step S8). If it is a reception process, it is determined whether one second has elapsed (at step S9). If it has elapsed, the reception process counter is counted up (at step S10). ), The processing time is transmitted to the battery pack 26 as data. If it does not correspond to either the transmission process or the reception process, it is determined whether one second has elapsed (S.
11) If the time has elapsed, the standby time counter is counted up (at step S12), and the processing time is transferred to the battery pack. If 1 second has not elapsed in any of the transmission processing, reception processing, and standby, interrupt processing is terminated and the time elapsed from the previous time is measured for each processing at the time of the next interrupt processing. Determine.

Referring to FIG. When the processing time of each processing of transmission, reception, and standby (corresponding to the usage time in the configuration of FIG. 1 above) is transferred from the control unit 23 of the wireless device 20 to the battery pack 26 by the processing of FIG. The interface unit 28 controls the EEPRO of the battery pack 26 under the control of
Each data transferred to M27 is written. Radio 2
EEP of the battery pack 26 even when 0 is turned off
The ROM 27 stores data. When the power of the wireless device 20 is turned on next, the A.D. According to the main routine of, the control unit 23 reads the data representing the usage amount stored in the EEPROM 27 of the battery pack, detects the remaining battery amount, and displays it.

When the user wants to charge the battery because the battery level becomes low, etc., the battery pack 26 (or the radio 2
The battery pack 26 in which 0 is connected is connected to the charger 31. At this time, control of charging is started by the control unit 33 of the charger 31.

FIG. 4 is a processing flow in the charger.
When the battery pack is inserted into the charger, the data is read from the battery pack (S1 in FIG. 4). In this case, the read data is data representing the processing time written by the processing of FIG. Next, the total usage time is calculated from the processing time data, and the remaining battery capacity is calculated by subtracting the total usage time from the battery capacity (usable time) (S2 in FIG. 4).

Next, it is determined whether to use the discharge function (at step S3). This step need not be provided when the charger 31 has only the charging function, and the process immediately proceeds from the above S2 to the next step S4. When the charger 31 is provided with a discharging function, it is possible to maintain good characteristics by discharging before charging so that the battery can be used for a long period of time. Allows you to specify the discharge, and if you want to charge quickly, you can specify not to discharge.

When the discharging function is not used, or when the charger does not have the discharging function, the charging time calculation operation is performed (at step S4). This calculation can be obtained based on the remaining battery level. When the charging time is calculated, the control unit 33 causes the charging unit 34 to start the charging process (at step S5). Thereafter, it is monitored whether one minute has elapsed (at step S6). When it has elapsed, the count value of the battery capacity (remaining amount) is increased (at step S7), and the count value data is transferred to the battery pack 26. , EEPROM 27 (see the same S
8). Next, it is determined whether the charging is completed (whether the calculated charging time is reached) (at step S9). If the charging is not completed, the process returns to step S6. When the charging time is reached, the charging is terminated and the data of the battery pack (processing time) (Count data) is reset (at step S10), the charging end time is transferred (at step S11),
It is stored in the EEPROM 27 of the battery pack.

When it is determined in step S3 that the discharge function is to be used, the discharge time is calculated (at step S1).
2). The discharge time is proportional to the battery remaining amount obtained in step S2 above, and can be obtained by multiplying by a predetermined constant. Next, the control unit 33 causes the charging unit (hereinafter, referred to as charging / discharging unit) 34 to start the discharging process (at step S13). After that, it is determined whether or not the discharge has elapsed for 1 minute (at step S14). When it has elapsed, the battery capacity is counted down (at step S15), and the value is transferred to the battery pack (at step S16). Then, it is determined whether or not the discharge time is reached in advance and the discharge is finished (at step S17). If not completed, the process returns to step S14, and if completed, the discharging operation is stopped, the process proceeds to step S4, and the charging control operation is started. In this case, the charge amount is executed with the remaining battery level being zero.

After the charging shown in FIG. 4 is completed, step 1
At 0, the battery data is reset and EEPRO
Although the data of the processing time of M27 is reset, the charging frequency history can be recorded by writing the charging frequency into the EEPROM 27 of the battery pack 26 after this.
The number of times of charging is determined by the above-mentioned discharge function (S3 in FIG. 4)
In the above, the discharge can be performed only when the number of times of charging exceeds a certain value.

[0022]

According to the present invention, since the battery pack has a built-in memory and has an interface with electronic devices such as a charger and a wireless device, the state of the battery being used can be changed from the wireless device to the charger. It becomes possible to recognize it from. Further, by using this battery pack, overcharge and overdischarge can be prevented, and a highly safe charger can be constructed.

[Brief description of drawings]

FIG. 1 is a principle configuration diagram of the present invention.

FIG. 2 is a configuration diagram of an embodiment.

FIG. 3 is a diagram showing a processing flow in a control unit of the wireless device.

FIG. 4 is a diagram showing a processing flow in the charger.

FIG. 5 is an explanatory diagram of a conventional example.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 electronic device 2 control section 2a usage time detection means 2b memory access means 2c residual quantity calculation means 3 display section 4 battery packs 4a, 4b interface 4c memory 4d battery 5 charger 6 control section 6a data reading means 6b residual quantity calculation means 6c Charging time calculation means 6d Charging control means 7 Charging unit

─────────────────────────────────────────────────── ─── Continuation of the front page (51) Int.Cl. ⁶ Identification code Internal reference number FI technical display location H04B 7/26

Claims (3)

[Claims] 1. A charging method for a battery pack that is detachably connected to an electronic device, wherein a control unit of the electronic device has a usage time detecting means for detecting a usage time of the electronic device and a memory of the battery pack memory. The battery pack includes an access unit, a memory, and an interface for transferring data between the electronic device and the charger, and the control unit of the electronic device uses the usage time data detected by the usage time detection unit. Is stored in the memory of the battery pack by the memory access means, and the controller of the charger reads the data in the memory when connected to the battery pack for charging, and reads the remaining amount of the battery from the read data. Is calculated to calculate the charging time, and the battery of the battery pack is charged for the charging time. 2. The charging device according to claim 1,
The charger has a discharging function, the controller of the charger reads the data in the memory, calculates the remaining battery amount, calculates the time for discharging the remaining battery amount, and uses the discharging function for the battery for the calculated time. A charging method for a battery pack, characterized in that the battery is discharged from the battery, the charging time is calculated after the discharging is finished, and the battery is charged by the charging function. 3. The wireless device as claimed in claim 1 or 2, wherein a wireless device is provided as the electronic device, and the control unit of the wireless device is configured to count each transmission processing time, reception processing time, and standby processing time of the wireless device. A method of charging a battery pack, characterized in that each processing time is stored in the memory.