JP2002050408A - Rechargeable battery, rechargeable battery pack, and method for calculating remaining amount of rechargeable battery - Google Patents

Abstract

(57) [Summary] A rechargeable battery or rechargeable battery pack having an internal circuit capable of outputting the remaining capacity of a battery according to the use state of the battery to the outside and calculating the remaining amount with high accuracy. Is to provide. A correction value for a reference total discharge capacity Qo corresponding to a charge end voltage at a full charge at that time is stored, and the total discharge capacity at that time calculated at the time of calculating the remaining amount is corrected by the correction value. The remaining amount is calculated, and even if the full-charge voltage of the charging device built in the electronic device fluctuates occasionally, the remaining amount can be calculated with high accuracy.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a rechargeable battery, a rechargeable battery pack, and a method for calculating the remaining amount of a rechargeable battery, and more particularly, to a lithium-ion secondary storage battery (hereinafter referred to as a lithium battery) having a charge controller or a rechargeable battery pack thereof. The present invention relates to a rechargeable battery and a rechargeable battery pack capable of outputting the remaining capacity of the battery according to the use state of the battery to the outside and performing highly accurate remaining amount calculation.

[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 capacity) is calculated, and the obtained used charge amount is calculated as a total discharge capacity up to a preset discharge stop 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 The fixed total discharge capacity value Qo is calculated as follows:
It is a reference total discharge capacity value when the battery is discharged from a full charge at 25 ° C. to a discharge stop voltage at 0.2 c. The voltage value of the full charge at this time is usually 4.2 V (reference charge end voltage). Moreover, the reference total discharge capacity value Qo is an average value measured for many rechargeable batteries. for that reason,
The full-charge voltage of the charging device built into the electronic device varies depending on the operation of the device individually or at that time. If the voltage is 4.1 V or 4.3 V, naturally, the remaining charge voltage will be reduced. The accuracy of the calculated value is reduced. 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 battery according to the usage state of the battery to the outside, and to obtain a highly accurate remaining capacity. It is to provide a rechargeable battery or a rechargeable battery pack having an internal circuit capable of performing calculations. Still another object of the present invention is to provide a method for calculating the remaining capacity of a charged battery, which can output the remaining capacity of the battery according to the usage state of the battery to the outside and can calculate the remaining capacity with high accuracy. It is in.

[0006]

The structure of a rechargeable battery or a rechargeable battery pack according to the present invention for achieving the above object has a structure from a full charge to a discharge stop voltage according to a discharge condition for discharging a charged charge. In a rechargeable battery of which total discharge capacity fluctuates, the battery body or an assembled battery in which a plurality of battery bodies are connected in series, and the integration of the amount of discharge charge from the start of discharge after charging to the present according to the discharge current value Means, charge end voltage value detecting means for detecting a voltage value of the battery body at full charge as a charge end voltage value, voltage value detecting means for detecting a current voltage value of the battery body, and total discharge at a reference charge end voltage. Correction value storage means for storing a difference between the charge amount and the total discharge charge amount at the charge end voltage before and after the reference charge voltage at the time of full charge as a correction value corresponding to the charge end voltage; The total discharge capacity when discharging from the full charge of the reference charge end voltage to the discharge stop voltage at the discharge current value is uniquely associated with a plurality of specific discharge current values and the total discharge capacity up to the discharge stop voltage. A correction value for obtaining a correction value corresponding to the charge end voltage value from the correction value storage means based on the stored discharge current value / total discharge capacity data storage means and the charge end voltage value detected by the charge end voltage value detection means. Obtaining the total discharge capacity up to the discharge stop voltage corresponding to the current discharge current value or the closest to the current discharge current value by the data obtained by the data storage means based on the current discharge current value obtained from the acquisition means and the current value detection means. A remaining capacity calculator for calculating the remaining capacity of the discharge charge from the total discharge capacity, the amount of the discharge charge integrated by the integrating means, and the correction value obtained by the correction value obtaining means. It is intended and means.

A feature of the method of calculating the remaining amount of a rechargeable battery according to the present invention is that the total discharge charge amount at a charge end voltage before and after the reference charge voltage at full charge with respect to the total discharge charge amount at the reference charge end voltage is Correction value storage means for storing the difference between the two as a correction value corresponding to the charge end voltage, and a specific discharge current value indicating the total discharge capacity when discharging from the full charge of the reference charge end voltage to the discharge stop voltage at the specific discharge current value A discharge current value vs. a total discharge capacity data storage means for storing a plurality of discharge current values and a total discharge capacity up to the discharge stop voltage in a unified manner, and discharging the battery body after charging; The amount of discharge charge from the start to the present is integrated according to the discharge current value, the voltage value of the battery body at full charge is detected as a charge end voltage value, the current voltage value of the battery body is detected, and the charge end is detected. The correction value obtained from the correction value storage means based on the voltage value and the data obtained from the data storage means based on the current discharge current value indicate the total value up to the discharge stop voltage corresponding to or closest to the current discharge current value. The remaining capacity of the discharge charge is calculated from the discharge capacity and the integrated amount of the discharge charge.

[0008]

As described above, according to the present invention, the correction value for the reference total discharge capacity Qo corresponding to the charge end voltage at the time of full charge at that time is stored and calculated at the time of calculating the remaining amount. Since the remaining total is calculated by correcting the total discharge capacity at that time with the correction value, even if the full charge voltage of the charging device built in the electronic device varies from the reference discharge end voltage. , It is possible to calculate the remaining amount with high accuracy.

[0009]

FIG. 1 is a circuit diagram mainly showing a lithium rechargeable battery according to an embodiment of the prior invention relating to the rechargeable battery of the present invention.
FIG. 2 is a flowchart of the total discharge capacity correction value calculation process, FIG. 3 is a flowchart of the remaining amount calculation process, and FIG.
FIG. 5 is an explanatory diagram of a total discharge capacity table corresponding to the degree of deterioration, and FIG.
Is an explanatory diagram of the characteristics of the total discharge capacity at the specific current value, and FIG. 6 is an explanatory diagram of the charge end voltage correction charge amount table. FIG. 4 is an explanatory diagram of the deterioration degree-corresponding total discharge capacity table, and FIG. 6 is an explanatory diagram of the charge end voltage correction charge amount table. In FIG. 1, 20 is
The electronic device includes 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. The charging / discharging terminal 14a, the charging / discharging power supply line + Vcc (hereinafter referred to as the power supply line + Vcc), and the charging current from the charging / discharging changeover switch circuit 13 receive the charging current from the device body 21.
Is supplied with power by a discharge current from the battery main body side via the charge / discharge terminal 14a. The rechargeable battery 10 is supplied to the SM bus 12 by the MPU 23 provided in the apparatus main body 21.
, The current remaining battery level of the rechargeable battery 10 is read. 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.

Incidentally, the built-in circuit built in the rechargeable battery 10 described here is usually constituted by CMOS or the like.
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 detection of full charge when the rechargeable battery 10 is fully charged is when the charge current value becomes equal to or less than a predetermined value and the state continues for a certain period. The terminal voltage of the battery body detected at this time is the charging end voltage,
It is designed to be a voltage at full charge, usually 4.2V (reference charge end voltage).

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 controller 2 controls ON / OFF of the charge-side switch and the discharge-side switch in accordance with charging and discharging. The charge / discharge changeover switch circuit 13 may be omitted, and the charge / discharge power supply line + Vcc may be directly connected to the positive electrode side of the battery body 1a. In such a case, the charging / discharging switching control is performed by the charging device on the device main body 21 side. Inside the rechargeable battery 10, in addition to the controller 2, a voltage value detection circuit 3, a current value detection circuit 4, and a temperature detection circuit 5 are provided.

The voltage value detection circuit 3 comprises a battery body 1a, 1
b,..., 1n are respectively connected to the positive electrode side and the negative electrode side, 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 causes the MPU 9 to execute various programs, which will be described later, to generate the above-described control signals, and to obtain the terminal voltages of the battery bodies 1a, 1b,..., 1n from the voltage value detection circuit 3 for each battery body. In addition, the charging current value or the discharging current value at that time is obtained from the current value detecting circuit 4, and the current temperature is obtained from the temperature detecting circuit 5, and a predetermined process described later is performed. Aside from this,
.., 1 according to the detected voltage value.
When any one of n is overcharged or overdischarged, the charge / discharge switch circuit 13 is controlled to turn off the charge-side switch when overcharged and to turn off the discharge-side switch when overdischarged. Then, the charge / discharge operation is stopped for each.

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. Then, according to a control signal from the controller 2, the current value of the current charge / discharge is output to the controller 2.
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), receives a signal from the temperature sensor, and operates according to a control signal from the controller 2.
To output the current temperature value.

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 interconnected via a bus 11. Further, each control signal is sent to each circuit via the bus 11. And a voltage value detection circuit 3;
The detection signal values of 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 has a total discharge capacity correction value calculation program 7a, an integrated amount calculation program 7b, a battery deterioration degree detection program 7c, a remaining amount calculation program 7d, a deterioration degree corresponding total discharge capacity characteristic table 7e, a full charge voltage correction charge amount. A table 7f and a parameter storage area 7g are provided. The parameter storage area 7g stores a charge count N, a reference total discharge capacity Qo (described later), and the like. Here, the total discharge capacity correction value calculation program 7a is periodically called at a predetermined cycle when charging is being performed, and is executed by the MPU 6. When this is executed by the MPU 6, the current charging current value i of the battery is obtained from the current value detection circuit 4, and when the current value equal to or less than the predetermined value continues for a certain time or more, the completion of charging is detected. Of each current battery body 1
a, 1b,..., 1n are obtained from the voltage value detection circuit 4, and the highest voltage value is selected from the voltage values V of the battery bodies 1a, 1b,. And referring to the full charge voltage correction charge amount table 7f,
The correction charge amount ΔQv (correction value as a percentage of the reference discharge amount Qo or the total discharge amount Qa) in the column corresponding to the voltage value closest to the current charging end voltage is obtained and stored in the parameter storage area 7g.

The integrated amount calculation program 7b is called periodically at predetermined intervals (every time Δt) and executed by the MPU 6. 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 Then, an integrated value Qn (integrated discharge amount value) of the discharge amount from the time of full charge to the present is calculated based on the sum of the used discharge capacity i × Δt calculated from the current value and the time Δt, and stored in the memory. 7 and calls the deterioration degree corresponding total discharge amount calculation program 7b. The battery deterioration degree detection program 7c is for making a determination in accordance with the charge / discharge cycle deterioration. When this is called and executed by the MPU 6, the charge number count value N stored in the parameter storage area 7g is referred to. And that's 1
In the case of up to 100, the deterioration degree L = 1, 101 to 2
Up to 00, the degree of deterioration L = 2, from 201 to 300, from the degree of deterioration L = 3, 301 or more,
It is determined whether the deterioration degree L is 4 or any of the 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. The number-of-charges count value N stored in the parameter storage area 7g is incremented by the controller 2 each time charging is performed, and the initial value is "0".

In general, a rechargeable battery is 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, a total discharge capacity at the time of discharging from the time of the full charge to the discharge stop voltage is provided with an integrated discharge amount calculation program, and the total discharge capacity is integrated by executing this program. The total discharge capacity at the time
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.
Also, this is stored in the parameter storage area 7g in place of the charge count value 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 this program is called and executed by the MPU 6, the remaining capacity calculation program 7d degrades from the current current value i and the current temperature value T stored in the memory 7 and the detected deterioration degree L. The table corresponding to the degree of deterioration L is selected with reference to the total discharge capacity table 7e corresponding to the degree, 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. The coefficient Ki is obtained, and the total discharge capacity Qa up to the discharge stop voltage according to the deterioration of the rechargeable battery is calculated by Qa = reference total discharge capacity Qo × Ki (the relationship between the total discharge capacity Qa and the reference total discharge capacity Qo is See below). Then, the remaining amount Qr is calculated from Qr = Qa−Qn + ΔQv × Qa / 100 based on the accumulated discharge amount Qn up to the present and the total discharge capacity Qa. Then, the available remaining time calculation output program 7d is called. Note that ΔQv is a correction value (Qo or% with respect to Qa) stored in the parameter storage area 7g.

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. The data to be output may be the remaining amount Qr, or both the remaining time TL and the remaining amount Qr data may be output. In this case, the remaining time TL or the remaining amount Qr is stored in the memory 7, and when a request for transmitting the remaining time TL or the remaining amount Qr from the MPU 23 of the apparatus main body 21 is within a predetermined time from the calculation time. In response to this request, MPU9
May be output to the apparatus main body 21 side.

Total discharge capacity characteristic table 7e corresponding to the degree of deterioration
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.
2.0c, the total discharge capacity from the time of full charge of the reference charge end voltage (4.2V) to the discharge stop voltage (correction coefficient K
is stored separately for each predetermined temperature.
The vertical axis is a specific discharge current value, and the horizontal axis is temperature. The temperature is data collected every 5 ° C. Among these data, FIG. 5 shows the relationship between the total discharge capacity when discharging at a specific discharge current value from the full charge of the reference charge end voltage at the temperature of 25 ° 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. Qo, Q1, and Q2 obtain the total discharge capacity by using these current values as specific current values.

The charge end voltage correction charge amount table 7f is
FIG. 6 shows that after the charging is completed at the charging end voltage of 4.2 V, the discharge current value is equal to or less than the discharge stop voltage of 3.0 V.
With respect to the reference discharge capacity value Qo obtained as 0.2c and a temperature of 25 ° C, 0.05V centered on the charge end voltage 4.2V.
The difference between the discharge current value at each charge termination voltage before and after the reference charge termination voltage (4.2 V) in units of 0.2 C and the total discharge capacity Q obtained at a temperature of 25 ° C. is ΔQv = (Q−Qo).
/ Qo is made into a table corresponding to the discharge stop voltage. When Q> Qo, ΔQv becomes positive, and when Q <Qo, ΔQv becomes negative. In the table, column 75 is the discharge stop voltage, and column 76 is the correction value ΔQv. In addition,
As for the correction value ΔQv, the difference from the total discharge capacity Q is represented by ΔQ =
Calculated as Q-Qo and further multiplied by ΔQ by a correction coefficient Ki to obtain a total discharge amount Q corresponding to the current temperature and the degree of deterioration.
ΔQ × K as the ratio of each total discharge amount Qa
The ratio of i / Qa may be represented by%, and a table may be tabulated corresponding to the discharge stop voltage for each total discharge amount Qa.

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. The correction coefficient Ki of each table is such that the voltage at the time of full charge is the reference charge end voltage (4.2 V), and FIG.
Battery body 1 (battery body 1
a, 1b,..., 1n) and a discharge capacity Qo of 25 ° C. at a terminal voltage of 3.0 V.
Are taken as 1 as a reference of the total discharge capacity, and the ratios Q1 / Qo, Q2 / Qo of the characteristics Q1, Q2,.
The correction coefficient Ki at 5 ° C. is used, and the correction coefficient Ki is obtained and stored for other temperatures. Thus, the data storage capacity can be reduced by storing the discharge capacity Qo separately as the reference discharge capacity without storing the total discharge capacity directly and storing the correction coefficient Ki in the table. As shown in FIG. 4, the total discharge capacity characteristic table 7e corresponding to the degree of deterioration indicates that the temperature range is from -20 ° C to 55 ° C.
The Qo of the current value = 0.2c at 25 ° every 5 ° C. is taken as a reference total discharge capacity (stored in the parameter storage area 7g) and the total discharge capacity of each specific discharge current value is sampled as a ratio. Therefore, when referring to this, the ratio corresponding to the current temperature value T and the current current value i, or if there is no such value, the closest ratio is referred to as the correction coefficient Ki.

Next, the process of calculating the total discharge capacity correction value will be described with reference to FIG. Note that this process is a process of calculating the total discharge capacity correction value in step 102a when it is determined that the battery is being charged in the remaining amount calculation process of FIG. 3 described below. First, the process is started by a periodic interrupt process, and the current charging current value is detected (step 201). Then, it is determined whether or not the battery is fully charged (step 202). Here, if the answer is NO, the process ends and the process stops until the next interrupt process. Here, if YES, the highest voltage value among the current voltage values of the plurality of battery bodies is detected as the charge end voltage (step 20).
3). Then, the correction charge amount ΔQv corresponding to the charge end voltage value is obtained with reference to the full charge voltage correction charge amount table 7f (step 204), and the correction value ΔQv is stored in the parameter storage area 7g (step 205). This processing ends.

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 NO, it is determined whether or not charging is being performed (step 101a). During charging, the total discharge capacity correction value calculation program 7a is called and executed by the MPU 6, the above-described total discharge capacity correction value calculation processing of FIG. 2 is performed, and the correction value ΔQv is stored in the memory (step 102a). . If the result is YES and the battery is being discharged, the integrated amount calculation program 7a is executed by the MPU 9, and the MPU 6 performs a process for detecting the current value (i) (step 102). Then, in step 103, ΔQd is calculated by ΔQd = i × Δt. Δt is a time difference from the immediately preceding calculation time point determined according to the interrupt cycle to the current calculation time. Next, as step 104, a process of calculating the integrated discharge amount Qn is performed. The integrated discharge amount Qn is based on Qn = Qn-1 + ΔQd. Where Q
n-1 is the previous integrated discharge amount, and ΔQd is
This is the current discharge amount calculated in 02. The default value is
Qn = 0. The calculated Qn is stored in the memory 7.

In the next step 105, the current temperature value T is detected. Next, the battery deterioration degree detection program 7
b is executed by the MPU 9 to determine the current degree of deterioration L with reference to the count value N of the number of times of charging (step 106). Then, the obtained degree of deterioration L, the temperature value T detected in step 105, and With reference to the deterioration degree corresponding total discharge capacity table 7e, the current deterioration degree L, the current temperature value T, and the current discharge current value i correspond to the current discharge current value i detected in step 102 (or A (closest) correction coefficient Ki is obtained (step 107). 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 7g.
Is read from the memory 7, and the total discharge capacity Qa (dischargeable capacity) at the terminal voltage of 3.0 V, which is the discharge stop voltage, is Qa.
= Qo × Ki (step 108). next,
Based on the corrected charge amount ΔQv, the accumulated discharge amount Qn, and the total discharge capacity Qa stored in step 204, Qr = Qa−
The remaining amount Qr is calculated from Qn + ΔQv × Qa / 100 (step 109). 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 110), which is transferred to the MPU 23 of the apparatus body 21 side. (Step 111).

As described above, in order to further improve the accuracy of calculating the remaining amount, the charging end voltage correction electric charge amount table 7f in the embodiment stores the correction value corresponding to the temperature in addition to the temperature as a parameter. May be used. In the embodiment, a plurality of total discharge capacity tables are provided according to the degree of deterioration. However, the number of total discharge capacity tables 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 the steady state temperature, for example, about 20 ° C. to 25 ° C., without providing the table according to the temperature. Good. Further, in the embodiment,
Since the battery bodies 1a, 1b, and 1c are in series, the remaining battery capacity is calculated as the remaining battery capacity of one battery body, but when the battery bodies 1a, 1b, and 1c are in parallel, , The divided value of the parallel number is the remaining battery power. However,
It is a matter of course that in the case of parallel operation, the remaining battery amounts may be individually calculated and the sum thereof may be used as the remaining battery amount. further,
Although the present invention describes only the rechargeable battery or the rechargeable battery pack, it is a matter of course that a part of the controller and the function of calculating the remaining amount can be assigned to the apparatus main body side. In such a case, It can be considered as an invention of a method for calculating the remaining amount.

[0026]

As described above, according to the present invention, the correction value for the reference total discharge capacity Qo according to the charge end voltage at the time of full charge at that time is stored and calculated at the time of calculating the remaining amount. Since the remaining total is calculated by correcting the total discharge capacity at that time with the correction value, even if the full charge voltage of the charging device built in the electronic device varies from the reference discharge end voltage. , It is possible to calculate the remaining amount with high accuracy. As a result, the accuracy of the calculated remaining amount output to the outside does not need to be reduced, and the use efficiency of the rechargeable battery can be improved.

[Brief description of the drawings]

FIG. 1 is a circuit diagram mainly showing a lithium rechargeable battery according to an embodiment of the prior invention relating to the rechargeable battery of the present invention.

FIG. 2 is a flowchart of a total discharge capacity correction value calculation process.

FIG. 3 is a flowchart of the remaining amount calculation process.

FIG. 4 is an explanatory diagram of a total discharge capacity table corresponding to the degree of deterioration.

FIG. 5 is an explanatory diagram of characteristics of a total discharge capacity at a specific current value.

FIG. 6 is an explanatory diagram of the charge end voltage correction charge amount table.

[Explanation of symbols]

1, 1a, 1b, 1n: lithium battery body (battery body), 2: controller, 3: voltage value detection circuit, 4, current value detection circuit, 5, temperature detection circuit, 6, 23: MPU, 7: memory, 7a: total discharge capacity correction value calculation program, 7c: battery deterioration degree detection program, 7d: remaining amount calculation program, 7d: usable remaining time calculation output program, 7e, 77: deterioration degree corresponding total discharge capacity table, 7f: full 7g: Parameter storage area, 8: A / D conversion circuit (A / D), 9: Display device, 10: Rechargeable battery, 11: Bus, 12: SM bus, 13: Charge / discharge switching Switch circuit, 20: electronic device, 21: device body, 22: power supply circuit, 23: MPU.

 ──────────────────────────────────────────────────続 き Continuing on the front page (72) Inventor Masato Suzuki 1-88 Ushitora, Ibaraki-shi, Osaka F-term in Hitachi Maxell, Ltd. (Reference) 2G016 CA00 CB12 CB13 CB21 CB31 CC01 CC06 CC12 CC13 CC16 CC27 CC28 CE00 5G003 BA03 CA03 CA06 CB02 DA07 EA05 5H030 AS20 FF22 FF42 FF43

Claims (5)

[Claims] 1. A rechargeable battery in which the total discharge capacity from a full charge to a discharge stop voltage fluctuates according to a discharge condition for discharging a charged charge, comprising: a battery body or an assembled battery in which a plurality of battery bodies are connected in series. Integration means for integrating the amount of discharge charge from the start of discharge after charging to the present according to the discharge current value; and a charge end voltage for detecting a voltage value of the battery body in the full charge as the charge end voltage value. Value detection means, voltage value detection means for detecting a current voltage value of the battery body, and a total charge end voltage before and after the reference charge voltage at the time of full charge with respect to a total discharge charge amount at a reference charge end voltage. Correction value storage means for storing a difference from the discharge charge amount as a correction value corresponding to the charge end voltage; and The discharge current value vs. the total discharge capacity stored in such a manner that the total discharge capacity when discharging to the power stop voltage is uniquely associated with the specific discharge current value for the plurality of specific discharge current values and the total discharge capacity up to the discharge stop voltage. Storage means; correction value acquisition means for obtaining a correction value corresponding to the charge end voltage value from the correction value storage means based on the charge end voltage value detected by the charge end voltage value detection means; Based on the current discharge current value obtained from the detection means, the data obtained by the data storage means obtains a total discharge capacity corresponding to the current discharge current value or up to the nearest discharge stop voltage, A remaining capacity for calculating the remaining capacity of the discharge charge from the total discharge capacity, the amount of the discharge charge integrated by the integration means, and the correction value obtained by the correction value obtaining means. A rechargeable battery comprising: an amount calculating 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. A battery pack or a battery pack in which a plurality of battery bodies are connected in series, wherein a total discharge capacity from a full charge to a discharge stop voltage fluctuates according to a discharge condition for discharging a charged charge. A battery, integrating means for integrating the amount of discharge charge from the start of discharge after charging to the present according to a discharge current value, and a charge end detecting the voltage value of the battery body in the full charge as the charge end voltage value Voltage value detecting means, voltage value detecting means for detecting a current voltage value of the battery main body, and a charge end voltage before and after the reference charge voltage at the time of full charge with respect to a total discharge charge amount at a reference charge end voltage. Correction value storage means for storing a difference from the total discharge charge amount as a correction value corresponding to the charge end voltage, and whether or not the full charge of the reference charge end voltage at a specific discharge current value The total discharge capacity when discharging to the discharge stop voltage is defined as the discharge current value vs. the total discharge capacity, which is stored for each of the plurality of specific discharge current values and uniquely associated with the total discharge capacity up to the discharge stop voltage. Data storage means; correction value acquisition means for obtaining a correction value corresponding to the charge end voltage value from the correction value storage means based on the charge end voltage value detected by the charge end voltage value detection means; The data obtained by the data storage means based on the current discharge current value obtained from the value detection means obtains the total discharge capacity corresponding to the current discharge current value or up to the nearest discharge stop voltage. Calculating the remaining capacity of the discharge charge from the total discharge capacity, the amount of the discharge charge integrated by the integration means, and the correction value obtained by the correction value obtaining means. And a remaining capacity calculating means. 4. 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. 4. The rechargeable battery pack according to claim 3, 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. 5. A method for calculating a remaining amount of a charged battery 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 method comprising: Correction value storage means for storing, as a correction value, a difference between the total discharge charge amount at a charge end voltage before and after the reference charge voltage at the time of the full charge as a correction value, and a reference value at a specific discharge current value. The total discharge capacity at the time of discharging from the full charge to the discharge stop voltage of the charge end voltage is stored for each of the plurality of specific discharge current values in a manner uniquely associated with the total discharge capacity up to the discharge stop voltage. Means for storing data on the discharge current value versus the total discharge capacity, and accumulating the amount of discharge charge from the start of discharge after charging the battery body to the present in accordance with the discharge current value. Detecting the voltage value of the battery body in the battery as the charge end voltage value, detecting the current voltage value of the battery body, and a correction value obtained from the correction value storage unit based on the charge end voltage value. The total discharge capacity up to the discharge stop voltage corresponding to the current discharge current value or the closest to the current discharge current value by the data obtained by the data storage means based on the current discharge current value, and the integrated discharge charge A method for calculating the remaining capacity of a rechargeable battery, comprising calculating a remaining capacity of a discharge charge from the amount.