JP2001056362A - Charge battery or pack thereof - Google Patents

Abstract

PROBLEM TO BE SOLVED: To accurately calcullate the amount of integration in the case of a next discharge by periodically integrating the amount of self discharge when no charge battery is in actual use and updating the amount of integration discharge. SOLUTION: An MPU 6 executes an operation mode setting/monitoring program 7a by the interrupt signal of a current value detection circuit 4 or a timer interrupt signal from a timer qb. In that case, in the case of discharging mode, the MPU 6 periodically executes a program 7b for calculating the amount of integration discharge at each time Δt (for example, 30 seconds). More specifically, by adding amount of used discharge ix Δt being calculated from a current discharge current value (i) and current time Δt to previous amount of integration discharge Qn-1, amount of integration discharge Qn from the time of full charging to current time is calculated, and a storage value in a memory 7 is updated. Then, the current amount of integration discharge Qn is subtracted from a total discharge capacity Qa for obtaining remainder Qr, or the remainder Qr and remaining time, for displaying them on a display 9a and for outputting to the MPU of a device 21, thus accurately detecting the remainder Qr and remaining time and improving the usage efficiency of a photocell.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a rechargeable battery or a rechargeable battery pack, and more particularly to a rechargeable lithium-ion battery (hereinafter referred to as a lithium battery) having a charge controller or a rechargeable battery pack in which the rechargeable battery is actually used. The present invention relates to a rechargeable battery and a rechargeable battery pack having an internal circuit capable of outputting the remaining capacity of a rechargeable battery in consideration of self-discharge when the rechargeable battery is not being used.

[0002]

2. Description of the Related Art Conventionally, a lithium battery or the like is charged at a constant current at first, and then substantially charged to almost full charge, assuming that the storage battery is in a discharged state. When it becomes, it switches to the charging mode with constant voltage,
Under the constant voltage charging, when the charging current becomes equal to or less than a predetermined value, or when the charging voltage becomes equal to or more than a predetermined value, it is determined that the charging has been sufficiently performed and the switch is turned off to terminate the charging. Has been done. A charge control controller (or a part thereof) is built in or integrated with the lithium ion battery or its rechargeable battery pack side to prevent overcharge.

[0003] Rechargeable batteries and rechargeable battery packs of this type (hereinafter referred to as rechargeable batteries) are incorporated in electronic devices such as portable computers and hand-held electronic devices. When the voltage of the rechargeable battery drops below a predetermined value, the electronic devices are recharged. The charging is performed by the charging circuit on the side, the charging current is received, the charging is terminated when the charging is completed, and the discharging is performed to supply power to the electronic device when the battery is driven. For this purpose, the controller of the charging control switches the current direction by providing a relay or a relay device that allows current to flow bidirectionally between the positive electrode side of the rechargeable battery and the charging terminal. In addition, there is a diode switching circuit that inserts a diode in series in each of the charging and discharging directions to select a current in one direction and block a current in the opposite direction. In an electronic device having this type of rechargeable battery, when the electronic device is connected to an AC power supply and the electronic device is not operating or is operating, the rechargeable battery is charged and the AC power supply is removed. When the electronic device is operated by operation, the electronic device is operated by electric power from the rechargeable battery.

[0004] Recently, a battery according to the smart battery standard has been developed and used as a battery built in this kind of electronic device. According to the smart battery standard, a processor (MPU) in an electronic device and a control circuit having a processor provided as an internal circuit in a rechargeable battery are connected by an SM bus to determine the state of the rechargeable battery in a processor (MPU) in the electronic device. ) Can be sent as data. One of the data transferred as the state of the battery is data indicating the remaining capacity (hereinafter referred to as remaining capacity) of the rechargeable battery. Normally, the remaining data of the rechargeable battery is used to determine whether data processing scheduled in the electronic device can be processed without malfunction due to the current remaining amount of the rechargeable battery.

[0005]

Conventionally, in a battery according to the smart battery standard, when the remaining amount of a rechargeable battery is sent to an electronic device, a discharge current value is detected each time the battery is used and the battery is fully charged. From the current value used up to the present, the used charge amount (used discharge amount) is calculated, and the obtained used charge amount is calculated as a total discharge capacity up to a preset discharge end voltage (for example, when the voltage of the rechargeable battery is 3.0 V). Is obtained by subtracting from the fixed total discharge capacity value Qo) when However, if the other discharge conditions, such as the discharge current value and the temperature at that time, are different, the total discharge capacity up to the stop of the discharge is accordingly different, so that the remaining amount also fluctuates. Also, the power of the electronic device with the built-in rechargeable battery is
When the battery is in the state and has not been used for a long time, the remaining amount of the rechargeable battery decreases due to self-discharge. As a result, the value of the accumulated discharge amount up to the previous time differs from the actual value.
This appears as an error in the integrated discharge amount calculated next. As a result, the remaining amount calculated from the integrated discharge amount is not accurate. Further, in a device used in a state where an electronic device with a built-in rechargeable battery is hardly carried, the rechargeable battery is usually removed from the electronic device using an AC power source and is often stored separately. In such a case, when it is necessary to use the rechargeable battery, the stored rechargeable battery is attached to the device and used.However, even under the special condition of storage, self-discharge proceeds. It is similarly difficult to calculate an accurate remaining amount. An object of the present invention is to solve such a problem of the related art, and it is possible to output the remaining capacity of a rechargeable battery in consideration of self-discharge when the rechargeable battery is not actually used. It is to provide a rechargeable battery and a rechargeable battery pack having a possible internal circuit.

[0006]

The structure of the rechargeable battery or the rechargeable battery pack according to the present invention for achieving the above object is as follows. Calculate and store the integrated discharge amount of the discharge charge up to and calculate the remaining amount of the discharge charge of the charge battery based on the integrated discharge amount and the total discharge capacity from the full charge to the discharge stop voltage of the charge battery. In a rechargeable battery having an internal circuit for outputting, a discharge amount storage means for storing a discharge amount or a discharge rate in relation to at least a remaining capacity corresponding to a predetermined elapsed time when the rechargeable battery is not actually used, When the rechargeable battery is not actually used, the discharge amount or the discharge rate stored in the discharge amount storage means is obtained every predetermined elapsed time or every integral multiple of this, and
An integrated discharge amount updating means for updating the integrated discharge amount at every predetermined elapsed time or an integral multiple of time based on the integrated discharge amount is provided.

[0007]

As described above, when the rechargeable battery is not actually used, the discharge amount storage means for storing the discharge amount or the discharge rate corresponding to the predetermined elapsed time at least in relation to the remaining capacity is provided. The integrated discharge amount updating means updates the integrated discharge amount already stored when the rechargeable battery is not actually used. The amount of discharge is periodically integrated, and a more accurate integrated amount can be calculated when the next charge battery is discharged. As a result, it is possible to detect the remaining amount and the remaining time with higher accuracy, and it is possible to improve the use efficiency of the rechargeable battery.

[0008]

FIG. 1 is a circuit diagram mainly showing a lithium rechargeable battery incorporated in an electronic apparatus according to an embodiment to which the rechargeable battery of the present invention is applied, FIG.
FIG. 3 is an explanatory view of a deterioration degree-corresponding total discharge capacity table, and FIG.
Is an explanatory diagram of the characteristics of the total discharge capacity at a specific current value, and FIG. 5 is an explanatory diagram of a self-discharge rate table. FIG.
In the figure, reference numeral 20 denotes an electronic device having a rechargeable battery 10 having a rechargeable in-battery control circuit which is detachably mounted therein. The rechargeable battery 10 includes a plurality of (three in the figure) lithium battery cells (hereinafter referred to as battery bodies) 1a, 1b,..., 1n, and a battery pack connected in series. 22 to charge / discharge terminal 14
a, charge / discharge power supply line + Vcc (hereinafter power supply line + Vc
c), the charging current is received via the charge / discharge changeover switch circuit 13, and the device main body 21 is supplied with power by the discharging current from the battery main body side via the charging / discharging terminal 14a. Also,
The rechargeable battery 10 includes an MPU 23 provided in the apparatus main body 21.
Thus, the current remaining battery level of the rechargeable battery 10 is read via the SM bus 12. The power supply line + Vcc is connected to the charging / discharging terminal 14a, and is connected to the apparatus main body 21 via this. In addition, the ground line GNDL is connected to the ground terminal 14b, and is connected to the ground GND of the device main body 21 via this. By the way, the built-in circuit built in the rechargeable battery 10 described here usually has C
A low power consumption type circuit composed of a MOS or the like and having a low clock frequency is used. The operating power is very small, and the built-in circuit here operates on the power from the rechargeable battery except when it is in a charged state. The full charge detection when the rechargeable battery 10 is fully charged is detected when the terminal voltage of the battery body reaches a predetermined value corresponding to the full charge or more, for example, when the terminal voltage becomes 4.3 V. Is done.

The power supply circuit 22 includes a rechargeable battery 10 and a commercial AC
It has a switching circuit with the power supply,
The power from the power supply is supplied, and the apparatus main body 21 operates.
A charge / discharge changeover switch circuit 1 provided between a positive electrode of a battery body 1a of a rechargeable battery 10 and a power supply line + Vcc.
Reference numeral 3 denotes a charge-side switch and a discharge-side switch. The charge-side switch and the discharge-side switch are turned on and off by the controller 2 in response to charging and discharging.
F control is performed. The charge / discharge changeover switch circuit 13
May be deleted, and the charge / discharge power supply line + Vcc may be directly connected to the positive electrode side of the battery body 1a. Inside the rechargeable battery 10, in addition to the controller 2, a voltage detection circuit 3, a current value detection circuit 4, and a temperature detection circuit 5 are provided.

The voltage detection circuit 3 includes battery bodies 1a, 1b,
, 1n are connected to the positive electrode side and the negative electrode side, respectively, and detect the respective terminal voltages and output the current voltage value of the battery body to the controller 2 according to the control signal from the controller 2. The controller 2 is provided for each battery body 1
, 1n from the voltage detection circuit 3 according to the control signal corresponding to each battery body, and any one of the battery bodies 1a, 1b,..., 1n according to the detected voltage value.
When one of them is overcharged or overdischarged, the charge / discharge changeover switch circuit 13 is controlled to turn off the charge-side switch when overcharged, and turn off the discharge-side switch when overdischarged to charge each one. Stop the discharging operation. The current value detection circuit 4 has a detection resistor Rs, which is inserted in series between the negative electrode of the battery body 1n and the ground line GNDL. And
Controller 2 according to the control signal from controller 2
The current value of the current charge / discharge is output to. The charge current or the discharge current depends on the polarity of the terminal voltage of the detection resistor Rs. Further, the current value detection circuit 4 changes the detected current value from a state of substantially “0” or less than a predetermined value (a state of a minute current value that is not substantially in a charged or discharged state) to a predetermined value or a fixed value. (Current value corresponding to the operating state of charging or discharging) or more, and conversely, from the above-mentioned predetermined value or more than a certain value to less than a certain value or to a state of substantially “0” And MP for each
An interrupt signal is generated for U6. When the MPU 6 is in the sleep state, the current value detection circuit 4 activates the MPU 6 by the former interrupt signal to set an operation mode setting /
The MPU 6 executes the processing of the monitoring program 7a. When the latter interrupt signal is received, the MPU 6 executes the processing of the operation mode setting / monitoring program 7a and
U6 itself enters the sleep state. The temperature detection circuit 5 has a temperature sensor (not shown), and receives a signal from the temperature sensor and outputs a current temperature value to the controller 2 according to a control signal from the controller 2.

The controller 2 includes an MPU 6, a memory 7, an A / D conversion circuit (A / D) 8, a display device 9 a, and a timer 9 b, which are interconnected via a bus 11. Have been. Further, each control signal is sent to each circuit via the bus 11. Then, the detection signal values of the voltage detection circuit 3, the current value detection circuit 4, and the temperature detection circuit 5 are passed to the MPU 6 via the A / D 8. The timer 9b generates a timer interrupt signal every time Δt, for example, every 30 seconds. When the MPU 6 is in a sleep state, the timer 9b activates the MPU 6 by the timer interrupt signal to execute processing of an operation mode setting / monitoring program 7a described later. Causes MPU 6 to execute. The memory 7 includes an operation mode setting / monitoring program 7a, an integrated discharge amount calculation program 7b, a battery deterioration degree detection program 7c, a remaining amount calculation program 7d, a self-discharge integrated amount calculation program 7e, and a deterioration degree corresponding total discharge capacity table 7f. , Self-discharge rate table 7
g, parameter storage area 7h, and time counter 7i
(A so-called soft counter). The parameter storage area 7h has a count value N of the number of times of charging, a reference total discharge capacity value Qo (described later), and a 2-bit value indicating whether the rechargeable battery 10 is currently being charged, discharged, or in a sleep state. The status flag is stored.

Here, the operation mode setting / monitoring program 7a is executed by the MPU 6 in response to an interrupt signal of the current value detection circuit 4 or a timer interrupt signal. This program receives the interrupt signal of the current value detection circuit 4 and
6, the current discharge current value i (including its polarity) of the battery is obtained from the current value detection circuit 4 according to the control signal, and the discharge current value i is stored in the memory 7 while the battery is being charged. , Discharging, or in a sleep state, based on the detected discharge current value i. That is, according to the current discharge current value i, when the current is equal to or more than a predetermined value and the polarity is positive, it is determined that the battery is being charged. If it is less than the value, it is determined to be in the sleep state. The 2-bit status flag provided in the parameter storage area 7h is set to one of charging (for example, 01), discharging (10), and sleep state (11) according to the determination result. Set to one of the modes. Then, in the charging mode according to the set status flag, the charging state is monitored, and in the discharging mode, the MPU 6 calls and executes the integrated discharge amount calculation program 7b. In the sleep mode, the MPU 6 is set to the sleep mode.

On the other hand, when the operation mode setting / monitoring program 7a is executed by the MPU 6 in response to the timer interrupt signal, the state of charge is monitored with reference to the status flag in the parameter storage area 7h to monitor the state of charge. In the discharging mode, the MPU 6 calls the integrated discharge amount calculation program 7b and executes it. In the sleep mode, the MPU 6 is activated in response to a timer interrupt signal from the timer 9b. Then, the MPU 6 is caused to execute a self-discharge integrated amount calculation program 7e (described later), and thereafter, the MPU 6 is set to the sleep mode again. The integrated discharge amount calculation program 7b is periodically called at a predetermined cycle (each time Δt = every 30 seconds) during discharge and is executed by the MPU 6. When this is executed, the current discharge current value i of the battery is detected and stored in the memory 7 (however, if the current discharge current value i is already stored by the operation mode setting / monitoring program 7a, it is stored in the memory 7). 7), the previous discharge capacity Qn-1 is calculated from the sum of the current discharge value i and the used discharge capacity i.times..DELTA.t calculated from the current .DELTA.t and the time .DELTA.t. Integrated value Qn (hereinafter integrated discharge amount value)
Is calculated and stored in the memory 7, and the battery deterioration degree detection program 7c is called.

The battery deterioration degree detection program 7c is for making a judgment in accordance with the charge / discharge cycle deterioration. When this program is called and executed by the MPU 6, the temperature detection circuit 5 outputs the current temperature value of the rechargeable battery 10. Get T,
This is stored in a predetermined area of the memory 7, and when the count N is 1 to 100 with reference to the count value N of the number of times of charge stored in the parameter storage area 7h, the degree of deterioration L = 1, 101 to 200 Sometimes, the degree of deterioration L =
2, when the range is from 201 to 300, the degree of deterioration L = 3, 3
When it is equal to or greater than 01, it is determined whether the deterioration degree is L = 4 and it is one of four levels, and the deterioration degree L at that time is stored in the memory 7. Then, the remaining amount calculation program 7d is called. Note that the charging count value N stored in the parameter storage area 7h is incremented by the controller 2 each time charging is performed.
The initial value is substantially “0”.

By the way, a rechargeable battery generally deteriorates due to repeated charge / discharge cycles, and the total discharge capacity is gradually reduced due to the deterioration of the battery. Therefore, the number of times of charging is used as a factor for determining deterioration. However, the degree of deterioration L is
The determination can also be made based on a decrease in the actual total discharge capacity.
That is, at the time of the previous full charge, the total discharge capacity when discharging from the time of the full charge to the discharge stop voltage is integrated by the integrated discharge amount calculation program 7b, and the total discharge capacity at that time is stored in the memory. 7, the total discharge capacity is divided into four ranges with respect to the total discharge capacity decreasing in the same manner as described above, and the degree of deterioration is determined to determine the degree of deterioration. This is stored in the parameter storage area 7h in place of the charge count N, read out at the time of discharging from the next full charge, and the degree of deterioration is determined to determine the next degree of deterioration. It may be determined in discharging. The following processing is performed using the battery deterioration degree L determined in this way.

When the remaining amount calculation program 7d is called and executed by the MPU 6, the remaining current calculation value 7 and the current temperature value T stored in the memory 7 and the detected degree of deterioration L The table corresponding to the deterioration level L is selected with reference to the total discharge capacity table 7f corresponding to the temperature, and the correction corresponding to the discharge current value and the temperature closest to the current discharge current value i and the current temperature value T is selected from the current discharge current value i and the current temperature value T. The coefficient Ki is obtained, and the total discharge capacity Qa according to the deterioration of the rechargeable battery is calculated by Qa = reference total discharge capacity Qo × Ki. Then, based on the accumulated discharge amount Qn up to the present and the total discharge capacity Qa, Qr = Qa
The remaining amount Qr is calculated from -Qn. Further, the remaining amount Qr
And the remaining time TL from the current discharge current value i of the battery and TL = Qr
/ I. Then, this remaining amount QR or this and the remaining time TL are output to the display device 9a.
The data is output to the MPU 23 on the device main body 21 side by an interrupt through 2. In this case, the remaining amount Qr or the remaining time TL and the remaining time TL may be stored in the memory 7 and output by the MPU 9 in response to a request from the MPU 23 of the apparatus main body 21.

When the self-discharge integrated amount calculation program 7e is called and executed by the MPU 6,
The value of the time counter 7i is incremented, and it is determined whether or not the value exceeds 2 × 60 minutes × 24 hours = 2880. When the value exceeds this value (YES), one day has elapsed (30 seconds × 2880 = One day), the current temperature value T of the rechargeable battery 10 is obtained from the temperature detection circuit 5, and it is determined whether the temperature value T is equal to or higher than 21 ° C. And the temperature value T
Is greater than or equal to 21 ° C. (YES), this temperature value is stored in a predetermined area of the memory 7, and the Qmax ratio is calculated from the latest remaining amount Qr and the latest total discharge capacity Qa stored in the parameter storage area 7h. = Qr / Qa, thereby searching and referring to the self-discharge rate table 7g, and further searching for a column in which the current temperature value T falls within the range, and calculating the daily self-discharge amount coefficient Ks ( Daily discharge rate).
Then, the self-discharge amount Qm = the remaining amount Qr × the self-discharge amount coefficient Ks is obtained, and the stored integrated value Qn is updated as the present integrated value Qn = the stored integrated value Qn + the self-discharge amount Qm. If the result of the determination is negative (NO) in either of the above two determinations, this processing ends, the process returns to the operation mode setting / monitoring program 7a, and the MPU 6 is again set to the sleep state.

As shown in FIG. 5, the self-discharge rate table 7g has a ratio of Qmax = remaining amount Qr / value of total discharge capacity Qa (Qa
Is a table in which each row is provided in accordance with the ratio of Qr to the row corresponding to the Qmax ratio.
x ratio = 100% to 80% (not including 80% itself), Qmax ratio = 80% to 50% (but not including 50% itself), and temperature of 21 ° C. in each of three rows where Qmax ratio = 50% or less. 5 is a table in which the self-discharge amount coefficients Ks are stored at temperatures divided into five units in units of 10 ° C. from a temperature of C or more. That is, the first column 75 is a column from 21 ° C. or more to less than 30 ° C., and the next column 76 is a column from 31 ° C. or more to less than 40 ° C.
The next column 77 is a column from 41 ° C or more to less than 50 ° C,
The next column 78 is a column from 51 ° C. or higher to less than 60 ° C., and the next column 79 is a column at 61 ° C. or higher. For example, in a row where the Qmax ratio = 100% to 80%, Ks = 0.02 and Ks = 0.0
4, Ks = 0.07, Ks = 0.15, Ks = 0.30 are stored. These self-discharge amount coefficients Ks are:
When the battery body 1 (one battery cell) is not actually used as a rechargeable battery, that is, it is not in a charged state,
The average value of the values measured as the amount of self-discharge in one day under the respective temperature conditions in a state where each circuit is connected when there is no discharge state. However, at this time, the MPU 6 is in the sleep state, and each circuit is in the operation stop state. Note that, although the accuracy is slightly lowered, the self-discharge amount coefficient Ks when only the battery main body 1 (one battery cell) alone is spontaneously discharged (self-discharged) every day is not under such a condition. May be measured and assigned to each of the columns 75 to 79 in accordance with the temperature and the Qmax ratio.

Deterioration degree corresponding total discharge capacity characteristic table 7f
Is, as shown in FIG. 3, a four-stage battery deterioration degree L (=
1 to 4), four tables 71, 72, 73,
Consists of 74. Each table includes specific discharge current values 0.2c, 0.5c,... Obtained corresponding to the degree of deterioration.
For 2.0c, the total discharge capacity (as a correction coefficient Ki) from the time of full charge to the discharge stop voltage is stored separately for each predetermined temperature. The vertical axis is a specific discharge current value,
The horizontal axis is temperature. The temperature is data collected every 5 ° C. Of these data, temperature 2
FIG. 4 shows the relationship of the total discharge capacity when discharging at a specific discharge current value from the full charge at 5 ° C. to the discharge stop voltage. The vertical axis represents the voltage value of one battery body (cell), and the horizontal axis represents the discharge capacity (mAh). Qo, Q1,
Q2 is current value = 0.2c, current value = 0.5c,
This is the total discharge capacity up to a discharge stop voltage of 3.0 V at a current value of 1.0 c. Note that 1.0c is a current value at which all the design capacities can be discharged in one hour.
For a battery of 00 mAh, 1.0c is 1200 mA. 0.5c is 600 mA, and 0.2c is 24 mA.
0 mA. It is Qo, Q1, Q2 that obtained the total discharge capacity using these current values as specific current values.

The total discharge capacity table 7f corresponding to the degree of deterioration shown in FIG.
Is a table provided with four sheets corresponding to the degree of deterioration L, and the correction coefficient Ki of each table is shown in FIG.
Battery body 1 (battery body 1
a, 1b,..., 1n), the ratio Q1 / Qo, Q2 / Qo of the characteristics Q1, Q2,.
.. Are the correction coefficients Ki at 25 ° C., and the correction coefficients Ki are obtained and stored for other temperatures. By storing the correction coefficient Ki without directly storing the total discharge capacity, the data storage capacity can be reduced. As shown in FIG. 3, the total discharge capacity characteristic table 7 corresponding to the deterioration degree
f indicates a specific total discharge capacity (stored in the parameter storage area 7h) as a reference total discharge capacity (stored in the parameter storage area 7h) from a temperature of −20 ° C. to 55 ° C. and a current value of 0.2c at 25 ° every 5 ° C. Since the total discharge capacity of the current value is sampled as a ratio, when referring to this, the one corresponding to the current temperature value T and the current current value i or the closest one when there is no such value. The ratio is referred to as a correction coefficient Ki.

Next, the remaining amount calculation process will be described with reference to FIG. The remaining amount calculation process is started by an interrupt signal of the current value detection circuit 4 or a periodic interrupt (for each Δt) by the timer 9a, and first, the MPU 6 executes the operation mode setting / monitoring program 7a. When this program is executed and started by an interrupt signal of the current value detection circuit 4, the current discharge current value i is detected (step 101), and it is determined whether the battery is discharging, charging, or sleeping. (Step 102). If the battery is being charged, a current that is equal to or more than a predetermined current value that is predetermined as a positive polarity discharge current value i is flowing. Therefore, it is determined that the battery is being charged, and a status flag during the charging is set (step 103a), each battery body 1 to prevent overcharge
The terminal voltage of a, 1b,..., 1n is subjected to a voltage monitoring process of each battery body 1 (step 104a).

During the discharge, a current equal to or greater than a predetermined current value that is predetermined as the negative polarity discharge current value i is flowing. Therefore, it is determined that the battery is discharging, and the status flag during the discharge is set. (Step 103), the integrated discharge amount calculation program 7b is called and executed by the MPU 6. Accordingly, based on the current discharge current value i obtained in step 101, the discharge capacity Qn = Qn-1 + i ×
The integrated discharge amount Qn is calculated from Δt as the usage amount up to the present (step 104). Then, the calculated integrated discharge amount Qn is stored in the memory 7. However, Qn = 0 at the time of starting discharge from full charge. Δt is 1
This is the time difference from the previous calculation to the current calculation. When the discharge is not being performed, and when other processing is being performed, the periodic interrupt at that time may be stopped.
At that time, it is set to a specific initial value or increased according to conditions. On the other hand, the current discharge current value i is substantially “0”.
If it is less than the predetermined value, the sleep state is determined in step 102, the status flag is set to the sleep state (step 103b), the value of the time counter 7i is reset (step 104b), and the MPU is set.
6 is set to the sleep state (step 105b), and this processing ends.

After the step 104, the MPU 6 executes the battery deterioration degree detection program 7c, detects the current temperature value T (step 105), and refers to the charge count number N to determine the current temperature value T. The deterioration degree L is determined and detected (step 106), and the current deterioration state is determined by referring to the deterioration degree corresponding total discharge capacity table 7f based on the obtained deterioration degree L, the temperature value T, and the discharge current value i. The degree L, the current temperature value T, and the correction coefficient Ki corresponding to (or closest to) the current discharge current value i are obtained (step 10).
7). Therefore, next, the remaining amount calculation program 7d
And reads the reference total discharge capacity Qo stored in the parameter storage area 7h from the memory 7 to obtain the total discharge capacity Qa at the terminal voltage of 3.0 V which is the discharge end voltage.
(Dischargeable capacity) is obtained by Qa = Qo × Ki, and the total discharge capacity Qa is stored in the memory 7 (step 108). Then, the discharge capacity Qn and the total discharge capacity Qa are used as Qr = Qa.
The remaining amount Qr is calculated from -Qn and stored. Next, the remaining amount Qr is transferred to the MPU 23 of the apparatus main body 21 (step 109). In this case, the remaining amount Qr and the remaining time TL are calculated as described above, and these are
May be forwarded to

When the operation mode setting / monitoring program 7a is executed by the MPU 6 in response to a timer interrupt signal and started, the status flag in the parameter storage area 7h is referred to (step 101a) to determine whether the battery is being charged or discharged. Or sleep state (step 1).
02a), when discharging, the process proceeds to step 104, and in step 104, the current discharge current value i of the battery is detected and stored in the memory 7, and the discharge capacity Qn is determined based on the detected current discharge current value i. = Qn-1 + i × Δt, the integrated discharge amount Qn is calculated as the usage amount up to the present.
Then, the above-described processing after step 105 is executed.
When the battery is being charged, the process proceeds to step 104a and the above-described processing is performed. When the sleep state is determined in step 101a, the self-discharge integrated amount calculation program 7e is called and executed by the MPU 6, and the value of the time counter 7i is incremented (step 1).
03c), it is determined whether or not the time has elapsed by one day, based on whether or not the value of the time counter 7i has exceeded 2880 (step 104c). If the determination here is NO, this processing is terminated. On the other hand, when the value of the time counter 7i exceeds 2880, the result is YES, and the current temperature value T of the rechargeable battery 10 is obtained from the temperature detection circuit 5 (step 105c).
It is determined whether or not the temperature value T is equal to or higher than 21 ° C. (Step 1)
06c). Here, if the determination is NO, this process ends. When the temperature value T is 21 ° C. or more, the answer is YES here,
Latest remaining amount Q stored in parameter storage area 7h
The Qmax ratio = Qr / Qa is calculated from r and the latest total discharge capacity Qa (step 107c), and the self-discharge rate table 7g is calculated.
The self-discharge amount coefficient Ks in the column where the current temperature value T falls within the range is obtained (step 108c), and the self-discharge amount Qm is calculated as the remaining amount Qr × the self-discharge amount coefficient Ks. (Step 109c), the current integrated value Qn = the stored integrated value Qn + the self-discharge amount Qm is calculated (step 110c), and the integrated value Qn stored in the memory 7 is updated (step 109c). 111c). Then, the process returns to step 105b, sets the MPU 6 to the sleep state, and ends the processing.

As described above, the self-discharge rate table of the embodiment shows that the discharge rate (coefficient) for calculating the amount of self-discharge in units of one day is expressed by the relationship of Qmax ratio = remaining amount Qr / total discharge capacity Qa. It is possible to store the self-discharge amount in the unit of time or in an integral multiple of the coefficient by using another time unit. Of course, it may be calculated as Further, instead of the coefficient of the relationship of Qmax ratio = remaining amount Qr / total discharge capacity Qa, the remaining amount may be simply used as a coefficient for the discharge amount or the discharge amount itself. In addition, the accuracy of the self-discharge amount calculation is increased as the time is shortened, but the power of the rechargeable battery is consumed correspondingly. Therefore, an appropriate unit time should be selected in relation to this. . Further, in the embodiment, the MPU or the rechargeable battery is set to the sleep state in a state other than during charging or discharging, that is, when the rechargeable battery is not actually used. According to the present invention, it is not necessary to set the MPU or the rechargeable battery to the sleep state in a state other than the state in which the battery is not discharging or discharging. Further, each circuit may or may not be in the operation stop state. The sleep state is equivalent to the stop state, and in this sense, the MPU may be set to the stop state instead of the sleep state. In the embodiment, the example of the assembled battery is given, but it goes without saying that the number of the battery main body may be one. Further, in the embodiment, a rechargeable battery in which a circuit including a battery main body and a controller is integrated as a rechargeable battery is described. However, the present invention relates to a so-called rechargeable battery pack in which a recharging circuit and a battery are individually separated in advance. Needless to say, the present invention can be applied to a rechargeable battery pack formed integrally.

[0026]

As described above, according to the present invention, when the rechargeable battery is not actually used, the amount of discharge or the discharge rate corresponding to the predetermined elapsed time is at least in relation to the remaining capacity. There is provided a discharge amount storage means for storing, and when the charge battery is not actually used, the integrated discharge amount already stored is updated by the integrated discharge amount update means, so that the charge battery is not actually used. Even when the self-discharge is not performed, the self-discharge amount is periodically integrated, and a more accurate integrated amount can be calculated when the next charge battery is discharged. As a result, it is possible to detect the remaining amount and the remaining time with higher accuracy, and it is possible to improve the use efficiency of the rechargeable battery.

[Brief description of the drawings]

FIG. 1 is a circuit diagram mainly showing a lithium rechargeable battery built in an electronic device of an embodiment to which a rechargeable battery of the present invention is applied.

FIG. 2 is a flowchart of a remaining amount calculation process.

FIG. 3 is an explanatory diagram of a deterioration degree-corresponding total discharge capacity table.

FIG. 4 is an explanatory diagram of characteristics of a total discharge capacity at a specific current value.

FIG. 5 is an explanatory diagram of a self-discharge rate table.

[Explanation of symbols]

1, 1a, 1b, 1n: Lithium battery body (battery body), 2: controller, 3: voltage detection circuit, 4, current value detection circuit, 5, temperature detection circuit, 6, 23: MPU, 7
... Memory, 7a ... Operation mode setting / monitoring program, 7
b: integrated discharge amount calculation program, 7c: battery deterioration degree detection program, 7d: remaining amount calculation program, 7e: self-discharge integrated amount calculation program, 7f: deterioration degree-corresponding total discharge capacity table, 7g: self-discharge rate table, 7h ... A parameter storage area, 8 ... A / D conversion circuit (A / D), 9a ... Display device, 9b ... Timer, 10 ... Charge battery, 11 ... Bus,
12 SM bus, 13 charge / discharge changeover switch circuit, 20
... Electronic device, 21 ... Device main body, 22 ... Power supply circuit, 23 ...
MPU.

 ──────────────────────────────────────────────────続 き Continued on the front page F term (reference) 2G016 CA00 CB12 CB22 CB31 CC01 CC04 CC06 CC07 CC10 CC13 CC15 CC16 CC27 CC28 CE00 5G003 AA01 BA01 DA07 EA05 GC05 5H030 AA10 AS06 FF27 FF41 FF52

Claims (6)

[Claims] When the rechargeable battery is in a discharged state, an integrated discharge amount of discharge charge from the start of discharge after charging of the rechargeable battery to the present is calculated and stored, and the integrated discharge amount and the full charge of the rechargeable battery are calculated. In a rechargeable battery having an internal circuit for calculating and outputting a remaining capacity of the discharge charge of the rechargeable battery based on a total discharge capacity from a charge to a discharge stop voltage, a predetermined value when the rechargeable battery is not actually used Discharge amount storage means for storing a discharge amount or a discharge rate at least in relation to the remaining capacity in correspondence with the elapsed time, and the predetermined elapsed time or an integer thereof when the rechargeable battery is not actually used. The discharge amount or the discharge rate stored in the discharge amount storage means is obtained at every double time, and based on this, the integrated discharge amount is calculated when the predetermined elapsed time or the integral multiple. Rechargeable battery characterized by comprising an integrating discharge amount updating means for updating each. 2. The discharge amount storage means stores the discharge rate in a relationship between the remaining capacity and the ratio of the total discharge capacity. The integrated discharge amount update means stores the discharge amount in the ratio. The rechargeable battery according to claim 1, wherein the discharge rate is obtained by referring to a storage unit. 3. The apparatus further comprises a processor, a memory, a timer, and a temperature detecting means for detecting a current temperature.
Each of the plurality of temperature ranges is divided and stored in the memory in accordance with the ratio, and the integrated discharge amount updating unit is realized by the processor and a program executed by the processor. Is in a sleep state or stopped state when it is not actually used, is activated by a signal of the timer every predetermined time, obtains the current temperature from the temperature detecting means, calculates the ratio at the present time 3. The rechargeable battery according to claim 2, wherein the discharge rate is obtained in a temperature range in which the current temperature falls within the plurality of temperature ranges corresponding to the ratio. 4. When the rechargeable battery is in a discharged state, an integrated discharge amount of discharge charge from the start of discharge after charging of the rechargeable battery to the present is calculated and stored, and the integrated discharge amount and the full charge of the rechargeable battery are calculated. In a charge battery pack having an internal circuit that calculates and outputs a remaining capacity of discharge charge of the charge battery based on a total discharge capacity from a charge to a discharge stop voltage, when the charge battery is not actually used. Discharge amount storage means for storing a discharge amount or a discharge rate corresponding to a predetermined elapsed time at least in relation to the remaining capacity; and when the rechargeable battery is not actually used, the predetermined elapsed time or The discharge amount or the discharge rate stored in the discharge amount storage means is obtained for each integer multiple of time, and based on this, the integrated discharge amount is calculated for the predetermined elapsed time or the integer. Charging the battery pack characterized by comprising the accumulated discharge amount updating means for updating every time. 5. The discharge amount storage means stores the discharge rate in a relationship between the remaining capacity and the ratio of the total discharge capacity, and the integrated discharge amount update means stores the discharge amount in the ratio. 5. The rechargeable battery pack according to claim 4, wherein the discharge rate is obtained by referring to a storage means. 6. The apparatus further includes a processor, a memory, a timer, and temperature detecting means for detecting a current temperature, wherein the discharge rate is:
Each of the plurality of temperature ranges is divided and stored in the memory in accordance with the ratio, and the integrated discharge amount updating unit is realized by the processor and a program executed by the processor. Is in a sleep state or a stop state when it is not actually used, is activated by a signal at predetermined time intervals of the timer, obtains a current temperature from the temperature detecting means, calculates the ratio at the present time, and The rechargeable battery pack according to claim 5, wherein the discharge rate is obtained in a temperature range in which the current temperature falls among the plurality of temperature ranges corresponding to the ratio.