JP2001051030A - Charging battery or changing battery pack - Google Patents

Abstract

PROBLEM TO BE SOLVED: To make outputtable the residual capacity of a battery according to the usage state of the battery by installing a data storage means and referring to the total discharge capacity up to a discharge stop voltage which is changed according to a discharge current value by using a discharge current value at this time. SOLUTION: As an element to judge the degradation of a battery, the degradation can be judged by a reduction in the actual total discharge capacity. At the time of full charging operation of one immediately before, the total discharge capacity which is discharged up to a discharge stop voltage since the full charging operation is integrated by an integrated-discharge-amount calculation program 7a, and the total discharge capacity at this time is stored in a memory 7. The total discharge capacity is divided into ranges at four stages regarding the total discharge capacity to be reduced. It is judged at which stage the battery is degraded, and a degradation degree L is decided. A residual-capacity calculation program 7c refers to a degradation-degree- correspondence total discharge capacity table 7e on the basis of a current value (i), at the present, and a temperature value T, at the present, which are stored in the memory 7 and on the basis of the detected degradation degree L. A table which corresponds to the degradation degree L is selected, and the total discharge capacity Qa which corresponds to the degradation degree L is calculated.

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 for the rechargeable battery pack. The present invention relates to a rechargeable battery and a rechargeable battery pack having an internal circuit capable of outputting the remaining battery capacity to the outside.

[0002]

2. Description of the Related Art Conventionally, a lithium battery or the like is charged with a constant current at first, assuming that the storage battery is in a discharged state, and then charged substantially and then almost fully charged. The charging mode is switched to the constant-voltage charging mode when the charging voltage becomes lower.When the charging current falls below the predetermined value or the charging voltage becomes higher than the predetermined value under this constant-voltage charging, the charging is sufficiently performed. Control is performed to turn off the switch and terminate charging assuming that the charging has been performed. 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. If this is not taken into account, it is necessary to calculate the remaining amount with a margin including the fluctuation of the discharge condition in the calculation of the remaining amount. For this reason, the calculated remaining amount becomes inaccurate, the remaining amount is output in a state where the rechargeable battery is not fully utilized, and charging is repeated many times, and the use efficiency of the rechargeable battery deteriorates. The purpose of this invention is
In order to solve such problems of the prior art,
An object of the present invention is to provide a rechargeable battery or a rechargeable battery pack having an internal circuit capable of outputting the remaining capacity of the battery according to the use state of the battery to the outside and improving the use efficiency of the rechargeable battery. .

[0006]

In order to achieve the above object, the structure of the rechargeable battery or the rechargeable battery pack according to the present invention is from a full charge to a discharge stop voltage depending on a discharge condition for discharging the charged electric charge. Means for integrating the amount of discharge charge from the start of discharge after charging to the present in a rechargeable battery whose total discharge capacity fluctuates, and the total discharge when discharging from a full charge to a discharge stop voltage at a specific discharge current value A discharge current value vs. total discharge capacity data storage means in which a capacity is uniquely associated with a plurality of specific discharge current values and a total discharge capacity up to the discharge stop voltage, and a current discharge current value is detected. Current value detecting means, and data corresponding to the current discharge current value obtained by the data storage means based on the current discharge current value obtained from the current value detecting means. To obtain a total discharge capacity of the nearest discharge stop voltage les, in which and a remaining capacity calculating means for calculating the remaining capacity of the discharge charge from an integrated value obtained by the total discharged capacity and integrating means.

[0007]

DESCRIPTION OF THE PREFERRED EMBODIMENTS A rechargeable battery or a battery pack incorporated in an electronic device has a small discharge current value depending on the data processing content of the electronic device at that time. Is often done continuously and rarely changes rapidly. Therefore, the total discharge capacity when discharging from the full charge to the discharge stop voltage at the specific discharge current value corresponding to the discharge current value at that time is the total discharge capacity up to the discharge stop voltage when discharging at that current value Even if the capacity is predicted and used, no substantial error occurs. For this reason, the data storage means is provided so that the total discharge capacity up to the discharge stop voltage that varies according to the discharge current value can be referred to by the discharge current value at that time, and the current discharge current value Since the remaining discharge capacity is calculated by estimating the total discharge capacity at that time, the remaining amount can be calculated with higher accuracy and dynamically corresponding to the discharge current at that time. 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 diagram of the total discharge capacity table corresponding to the degree of deterioration, and FIG. 4 is an explanatory diagram of characteristics of the total discharge capacity at a specific current value. In FIG. 1, reference numeral 20 denotes an electronic device,
A rechargeable battery 10 having an in-battery charge control circuit detachably mounted therein is provided therein. The rechargeable battery 10
Lithium battery cell (hereinafter referred to as battery body) 1a, 1b, ..., 1
n includes a plurality (three in the figure) of assembled batteries connected in series, and includes a charging / discharging terminal 14a, a charging / discharging power supply line + Vcc (hereinafter, power supply line + Vcc) from a power supply circuit 22 provided in the apparatus main body 21; Upon receiving the charging current via the charge / discharge changeover switch circuit 13, the device main body 21 is supplied with power by the discharge current from the battery main body side via the charging / discharging terminal 14a. The current remaining battery level of the rechargeable battery 10 is read by the MPU 23 provided in the apparatus main body 21 via the SM bus 12. Note that the power supply line + V
cc is connected to the charge / discharge terminal 14a, and is connected to the apparatus main body 21 via this. Also, the ground line GN
DL is connected to the ground terminal 14b, and is connected to the ground GND of the apparatus main body 21 via this. By the way, a built-in circuit built in the rechargeable battery 10 described here is usually a CMOS or the like, and a low power consumption type circuit with 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. The temperature detection circuit 5 has a temperature sensor (not shown), and receives a signal from the temperature sensor to receive a signal from the controller 2.
And outputs the current temperature value to the controller 2 in accordance with the control signal from the controller 2.

The controller 2 includes an MPU 6, a memory 7, an A / D conversion circuit (A / D) 8, and a display device 9, and these circuits are mutually connected via a bus 11. 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 memory 7 includes an integrated discharge amount calculation program 7a, a battery deterioration degree detection program 7b, a remaining amount calculation program 7c, a usable remaining time calculation output program 7d, a deterioration degree corresponding total discharge capacity table 7e, and a parameter storage area 7f. Is provided. The parameter storage area 7f stores a count value N of the number of times of charging and a reference total discharge capacity value Qo (described later). Here, the integrated discharge amount calculation program 7a is called periodically at a predetermined cycle (every time Δt) and the MPU 6
Is executed by When this is executed, the current discharge current value i of the battery is obtained from the current value detection circuit 4 according to the control signal, the discharge current value i is stored in the memory 7, and the immediately preceding discharge capacity Qn-1 Is the current value and time Δt
The integrated value Qn (hereinafter referred to as the integrated discharge amount value) of the discharge amount from the time of full charge to the present is calculated from the sum of the used discharge capacity i × Δt calculated from The deterioration degree detection program 7b is called.

The battery deterioration degree detection program 7b is for making a judgment according to the charge / discharge cycle deterioration. When this program is called and executed by the MPU 6, the temperature detection circuit 5 sends the current temperature value of the rechargeable battery 10 to the battery. Get T,
This is stored in a predetermined area of the memory 7, and when the count value N of the number of times of charging stored in the parameter storage area 7 f is 1 to 100, 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 7c is called. Note that the charge count value N stored in the parameter storage area 7f is incremented by the controller 2 each time charging is performed.
The initial value is “0”.

By the way, a rechargeable battery is generally deteriorated by repeating charge / discharge cycles, and the total discharge capacity is gradually reduced due to the deterioration of the battery. Therefore, the number of times of recharging is used as a factor for determining deterioration. However, the degree of deterioration L can also be determined 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 full charge to the discharge stop voltage is integrated by the integrated discharge amount calculation program 7a, 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 7f in place of the charge count value N, and is read out at the time of discharging from the next full charge to determine the degree of deterioration and 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 7c is called and executed by the MPU 6,
From the current value i, the current temperature value T, and the detected deterioration degree L stored in the memory 7, the table corresponding to the deterioration degree L is selected with reference to the deterioration degree corresponding total discharge capacity table 7e. And the current discharge current value i and the current temperature value T
Then, the correction coefficient Ki corresponding to the discharge current value and the temperature closest to these 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, the remaining amount Qr is calculated from Qr = Qa-Qn based on the accumulated discharge amount Qn up to the present and the total discharge capacity Qa. And
The remaining usable time calculation output program 7d is called.

A usable remaining time calculation output program 7d
When this is called and executed by the MPU 6, the remaining time TL is calculated from the current discharge current value i of the battery to TL =
It is determined by Qr / i. Then, the remaining time TL is displayed on the display device 9.
And outputs the remaining time TL to the MPU 23 of the apparatus main body 21 by interruption via the SM bus 12. In this case, 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. The output data may be the remaining amount Qr, and the remaining time TL
And data of the remaining amount Qr may be output together.

Total discharge capacity characteristic table 7e corresponding to deterioration degree
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 7e 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
e indicates a specific total discharge capacity (stored in the parameter storage area 7f) with Qo of a current value = 0.2c at a temperature of 25 ° every 5 ° C. from a temperature of −20 ° C. to 55 ° 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. First, it is determined whether or not discharging is being performed by the periodic interruption and the start (step 101). If the battery is being charged at the time of NO, a voltage monitoring process or the like is performed on the terminal voltages of the battery bodies 1a, 1b,..., 1n in order to prevent overcharging. When the battery is not used while the charging / discharging terminals 14a and 14b are not connected,
The processing corresponding thereto is performed. If the result is YES and the battery is discharging, the MPU 9 executes the integrated discharge amount calculation program 7a. Thereby, the current discharge current value i is detected (step 102), and the discharge capacity Qn = Qn-1 + i × Δt
Thus, the integrated discharge amount Qn is calculated as the usage amount up to the present (step 103). However, Qn = 0 at the time of starting discharge from full charge. Δt is a time difference from the immediately preceding calculation to the current calculation. When the discharge is not being performed, and when other processing is being performed, the periodic interruption at that time may be stopped. At this time, Δt is set to a specific initial value or increased according to the condition. Become.

Next, the battery deterioration degree detection program 7b
This is executed by the PU 9 to detect the current temperature value T (step 104), determine the current deterioration level L with reference to the charging count value N (step 105), and determine the obtained deterioration level L , The temperature value T, and the discharge current value i, the current deterioration level L, the current temperature value T, and the current discharge current value i (or most). A (close) correction coefficient Ki is obtained (step 106). Therefore, next, the remaining amount calculation program 7c is executed by the MPU 9, and the reference total discharge capacity Qo stored in the parameter storage area 7f is read from the memory 7, and the total discharge capacity at the terminal voltage of 3.0 V which is the discharge end voltage is obtained. The discharge capacity Qa (dischargeable capacity) is obtained by Qa = Qo × Ki (step 107). Then, the remaining amount Qr is calculated from Qr = Qa-Qn based on the discharge capacity Qn and the total discharge capacity Qa (step 108). Further, the usable remaining time calculation output program 7d is executed by the MPU 6 to obtain the remaining time TL = Qr / i from the current discharge current value i of the battery (step 109).
It is transferred to PU23.

As described above, in the embodiment, a plurality of total discharge capacity tables are provided according to the degree of deterioration.
This may be one without corresponding to the degree of deterioration.
The correction coefficient value is stored in the data of the table using the temperature and the current value as parameters, but the total discharge capacity may be directly stored. Further, even if there is only one table storing the total discharge capacity obtained from the characteristic corresponding to the specific current value of about 20 ° C. to about 25 ° C. without being provided in accordance with the temperature, for example, even in a steady state temperature. Good. 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.

[0020]

As described above, according to the present invention, the total discharge capacity up to the discharge stop voltage fluctuating according to the discharge current value can be referred to by the discharge current value at that time, and the present discharge current can be referred to. Since the remaining amount of discharge charge is calculated by predicting the total discharge capacity at that time from the current value, it is possible to calculate the remaining amount with higher accuracy and dynamically according to the discharge current at that time. it can. 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.

[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 ... Integrated discharge amount calculation program, 7b ... Battery deterioration degree detection program, 7c ... Remaining amount calculation program,
7d: available remaining time calculation output program, 7e: total discharge capacity table corresponding to deterioration degree, 7f: parameter storage area, 8: A / D conversion circuit (A / D), 9: display device, 1
0: rechargeable battery, 11: bus, 12: SM bus, 13: charge / discharge changeover switch circuit, 20: electronic device, 21: device body, 22: power supply circuit, 23: MPU.

Continuation of the front page F term (reference) 2G016 CA00 CB12 CB21 CB22 CB31 CC01 CC03 CC04 CC12 CC13 CC16 CC27 CD14 5G003 BA01 CB01 EA05 GC05 5H030 AA08 AA10 AS06 AS11 FF22 FF42 FF44

Claims (6)

[Claims] In a rechargeable battery having a total discharge capacity varying from a full charge to a discharge stop voltage in accordance with a discharge condition for discharging a charged charge, the amount of discharge charge from the start of discharge after charging to the present is integrated. Integrating means for calculating the total discharge capacity when the battery is discharged from the full charge to the discharge stop voltage at a specific discharge current value for the plurality of specific discharge current values and the total discharge capacity up to the discharge stop voltage. Data storage means of the discharge current value and the total discharge capacity stored in association with each other, a current value detection means for detecting a current discharge current value, and the current discharge current value obtained from the current value detection means. Based on the data obtained by the data storage means based on the current discharge current value or to obtain the total discharge capacity up to the nearest discharge stop voltage,
A rechargeable battery comprising: a remaining capacity calculating unit configured to calculate a remaining capacity of a discharge charge from the total discharge capacity and an integrated value obtained by the integrating unit. 2. The data storage means has a table associating a predetermined temperature, the discharge current value, and a total discharge capacity up to the discharge stop voltage. 2. The rechargeable battery according to claim 1, wherein a total discharge capacity up to the discharge stop voltage at another specific discharge current value is stored as a ratio based on a total discharge capacity up to the discharge stop voltage at a specific temperature. 3. The rechargeable battery according to claim 3, further comprising an assembled battery in which a plurality of rechargeable battery bodies are connected in series, and wherein the discharge current value is a current from the plurality of rechargeable battery bodies. 4. A charge battery pack in which a total discharge capacity from a full charge to a discharge stop voltage fluctuates according to a discharge condition for discharging a charged charge, the amount of discharge charge from the start of discharge after charging to the present time. Integrating means for integrating, the total discharge capacity when discharging from the full charge to the discharge stop voltage at a specific discharge current value, the total discharge capacity for the plurality of specific discharge current values and the total discharge capacity up to the discharge stop voltage A discharge current value vs. a total discharge capacity data storage means uniquely associated and stored; a current value detection means for detecting a current discharge current value; and the current discharge current value obtained from the current value detection means And obtaining a total discharge capacity up to the discharge stop voltage corresponding to or closest to the current discharge current value based on the data obtained by the data storage means based on the total discharge capacity. Charging the battery pack characterized by comprising the remaining capacity calculating means for calculating the remaining capacity of the discharge charge from an integrated value obtained by the integration means and. 5. The data storage means has a table in which a predetermined temperature, the discharge current value, and a total discharge capacity up to the discharge stop voltage are associated with each other. 5. The charge battery pack according to claim 4, wherein a total discharge capacity up to the discharge stop voltage at another specific discharge current value is stored as a ratio based on a total discharge capacity up to the discharge stop voltage at a specific temperature. 6. The rechargeable battery pack according to claim 5, further comprising an assembled battery in which a plurality of rechargeable battery bodies are connected in series, wherein said discharge current value is a current from said plurality of rechargeable battery bodies.