JP3771451B2 - Secondary battery unit and remaining capacity display device - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a secondary battery unit including a rechargeable battery cell such as a lithium polymer battery and a remaining capacity display device suitable for use in displaying the remaining battery capacity.
[0002]
[Prior art]
For example, in a device using a secondary battery such as a mobile phone, a small video camera, a digital camera, a portable audio device, a portable personal computer, etc., for the purpose of displaying the charging time, charging state or replacement time of the secondary battery, It is required to measure the electric capacity of the secondary battery, that is, the remaining capacity. One method for measuring the remaining capacity of the secondary battery is to uniquely define the correlation between the battery voltage and the remaining capacity, detect the voltage of the battery cell and estimate the remaining capacity, There is known a method of calculating a remaining capacity by integrating charge / discharge currents.
[0003]
[Problems to be solved by the invention]
However, since the remaining capacity and the battery voltage do not always correspond one-to-one, it is difficult to accurately measure the remaining capacity of the battery cell by the above-described method of detecting the battery cell voltage and calculating the remaining capacity. There is a problem of being. On the other hand, the method of calculating the remaining capacity by integrating the charge / discharge current of the secondary battery can calculate the remaining capacity of the battery cell with high accuracy, but requires a large number of parts and circuits as the current integrating circuit. There is a problem that the cost required for measuring the capacity increases.
[0004]
The present invention was devised in view of such problems, and provides a secondary battery unit and a remaining capacity display device that can be configured at low cost and can detect the remaining capacity of a battery cell with high accuracy. For the purpose.
[0005]
[Means for Solving the Problems]
  For this reason, the secondary battery unit of the present invention is a secondary battery unit configured with rechargeable battery cells and memory elements,The battery cell is a lithium secondary battery;The memory element defines a plurality of current value data corresponding to various current values flowing through the battery cell, and a voltage defining a plurality of voltage data corresponding to various voltages of the battery cell. A data storage unit, and a remaining capacity data storage unit that defines corresponding remaining capacity data for each combination of the plurality of current value data and the plurality of voltage data;A deterioration correction data storage unit that stores a plurality of deterioration correction data corresponding to various deterioration states of the battery cell, and a deterioration state data storage that defines a plurality of deterioration state data corresponding to the various deterioration states of the battery cell. Each of the plurality of deterioration state data and each of the plurality of deterioration correction data are associated with each other, and the deterioration state data is once set to a predetermined voltage after being charged during charging. It is defined from the voltage drop value calculated by discharging for a time and measuring the voltage value after the lapse of the predetermined time.(Claim 1).
[0006]
  In addition, the memory element may include a temperature correction data storage unit that stores a plurality of temperature correction data corresponding to various temperatures at predetermined positions of the secondary battery unit. The memory element includes a temperature data storage unit that defines a plurality of temperature data corresponding to various temperatures at a predetermined position of the secondary battery unit, and the temperature correction data storage unit corresponds to each of the plurality of temperature data. The temperature correction data to be stored may be stored (claim 3)..
[0008]
  MaThe remaining capacity display device of the present invention is a remaining capacity display device for displaying the remaining capacity of the battery cell in the secondary battery unit on a display unit, and a current value measuring unit for measuring a current value flowing through the battery cell. And a voltage measuring unit that measures the voltage of the battery cell, a voltage measured by the voltage measuring unit, and a current value measured by the current value measuring unit, corresponding from the remaining capacity data storage unit The remaining capacity data acquisition unit for acquiring the remaining capacity data to be calculated, a calculation unit for calculating the remaining capacity of the battery cell based on the remaining capacity data acquired by the remaining capacity data acquisition unit, and the calculation unit And a display control unit for displaying the remaining capacity of the battery cell on the display unit.The battery cell is a lithium secondary battery, and the memory element of the secondary battery unit stores a plurality of deterioration correction data corresponding to various deterioration states of the battery cell; A deterioration state data storage unit that defines a plurality of deterioration state data corresponding to various deterioration states of the battery cell, and each of the plurality of deterioration state data and each of the plurality of deterioration correction data are associated with each other; The deterioration state data is defined by a voltage drop value calculated by discharging for a predetermined time after reaching a predetermined voltage and measuring a voltage value after the predetermined time has elapsed during charging. Unit calculates the remaining capacity of the battery cell using the deterioration correction data corresponding to the deterioration state data.(Claims)4).
[0009]
  Furthermore, the remaining capacity display device of the present invention is a remaining capacity display device for displaying the remaining capacity of the battery cell in the secondary battery unit on the display unit, and a current value measuring unit for measuring the current value flowing through the battery cell. And a voltage measuring unit for measuring the voltage of the battery cell;,in frontA remaining capacity data acquisition unit that acquires the corresponding remaining capacity data from the remaining capacity data storage unit based on the voltage measured by the voltage measuring unit and the current value measured by the current value measurement unit; A calculation unit for calculating the remaining capacity of the battery cell based on the remaining capacity data acquired by the remaining capacity data acquisition unit, and a display for displaying the remaining capacity of the battery cell calculated by the calculation unit on the display unit With a control unit,The battery cell is a lithium secondary battery, and the memory element of the secondary battery unit stores a plurality of deterioration correction data corresponding to various deterioration states of the battery cell, and the battery A plurality of deterioration state data storage units defining a plurality of deterioration state data corresponding to various deterioration states of the cell, and each of the plurality of deterioration state data and each of the plurality of deterioration correction data are associated with each other; The deterioration state data is defined by a voltage drop value calculated by discharging a predetermined time after reaching a predetermined voltage and measuring a voltage value after the predetermined time has elapsed during charging,The calculation unit isThe deterioration correction data corresponding to the deterioration state data;The temperature correction data stored in the temperature correction data storage unitWhenThe remaining capacity of the battery cell is calculated using5).
[0013]
DETAILED DESCRIPTION OF THE INVENTION
FIG. 1 is a block diagram showing a configuration of a secondary battery unit as an embodiment of the present invention, and is a diagram showing a simplified example of the circuit configuration.
A secondary battery unit (hereinafter also referred to as a battery unit) 1 according to an embodiment of the present invention is substantially the same as a secondary battery such as a so-called battery pack in appearance, and includes a mobile phone, a small video camera, It is used as a drive power source for external devices (hereinafter referred to as “power consuming devices”) that consume power, such as digital cameras, portable audio devices, and portable personal computers. The battery unit 1 includes a rechargeable battery cell 11 and a circuit unit 12 as shown in FIG.
[0014]
The battery cell 11 is comprised by secondary batteries, such as a lithium polymer battery and a lithium ion battery. Examples of the lithium polymer battery and lithium ion battery include those using a lithium transition metal composite oxide such as lithium cobalt composite oxide as the positive electrode and a carbon material such as graphite as the negative electrode. The battery cell 11 does not have any calculation function.
[0015]
The circuit unit 12 includes an EEPROM (memory element) 13, a protection circuit 14, a fuse (FUSE) 15, a thermistor (temperature measurement unit) 16, low-pass filters (LPF) 17 and 18, and a resistor 19.
The memory element 13, the protection circuit 14, the thermistor 16, the LPFs 17 and 18, and the resistor 19 constituting the circuit unit 12 are provided on the printed circuit board, and the fuse 15 is in the middle of wiring between the printed circuit board and the battery cell 11. Is provided.
[0016]
The protection circuit 14 is for preventing overcharge and overdischarge of the battery cell 11, and the FUSE 15 is for protecting the circuit from overcurrent. The thermistor 16 is for measuring the temperature at a predetermined position in the battery unit 1, and is disposed, for example, in the middle of the wiring connected to the terminal of the battery cell 11, and outputs the measurement result to the T terminal. It has become. The thermistor 16 functions as a temperature measuring unit that measures the temperature at a predetermined position of the battery unit 1.
[0017]
The LPFs 17 and 18 are filter circuits for preventing the malfunction due to noise and protecting the EEPROM 13 from EMI (Electro Magnetic Interference) and ESD (Electro Static Discharge).
The memory element 13 is configured by a nonvolatile memory such as an EEPROM, for example. In the present embodiment, the case where an EEPROM is used as a memory element is shown, and hereinafter, the reference numeral 13 is attached and indicated as EEPROM 13.
[0018]
The EEPROM 13 is electrically separated from the battery cell 11 so that the power of the battery cell 11 is not consumed. The battery cell 11 and the EEPROM 13 are configured as independent circuits. That is, in the battery unit 1, in addition to the output terminals (see “+ terminal” and “− terminal” in FIG. 1) of the battery cell 11 for supplying power to the power consuming device as described above, the EEPROM 13 Are separately provided with DI / O terminals for reading / writing information and Vcc terminals for supplying driving power to the EEPROM 13. In the present invention, “electrically separated” does not deny that the ground (GND) is shared.
[0019]
The EEPROM 13 is connected to the Vcc terminal, and when connected to the power consuming device or the charger 2 (described later) and the remaining capacity display device 4 (described later), these power consuming device and charger are connected via the Vcc terminal. 2 and the remaining capacity display device 4 are supplied with electric power.
The EEPROM 13 and the thermistor 16 are connected to the G terminal for signal ground. The S terminal (sense terminal) is a terminal for measuring the voltage of the battery cell 11 via the resistor 19, and is used for measuring the voltage with the + terminal when connected to the charger 2 described later. It has come to be used. The reason for using the S terminal instead of the-terminal for measuring the voltage of the battery cell 11 is that the internal resistance of the circuit is large between the + terminal and the-terminal, so the voltage of the battery cell 11 is accurately measured. Because it is difficult.
[0020]
Further, the EEPROM 13 is connected to the DI / O terminal via the LPF 18, and various data is exchanged between the power consuming device, the charger 2 and the remaining capacity display device 4 via the DI / O terminal. It is supposed to be. The SK terminal is for supplying a clock from the power consuming device, the charger 2 and the remaining capacity display device 4 to the EEPROM 13.
[0021]
1, the EEPROM 13 includes a current value data storage unit 31, a voltage data storage unit 32, a remaining capacity data storage unit 33, a temperature data storage unit 34, a temperature correction data storage unit 35, and a deterioration state data storage unit. 36 and a deterioration correction data storage unit 37.
The current value data storage unit 31 defines a plurality of current value data corresponding to various current values flowing through the battery cell 11, and the voltage data storage unit 32 includes a plurality of current value data corresponding to various voltages of the battery cell 11. The remaining capacity data storage unit 33 defines corresponding remaining capacity data for each combination of a plurality of current value data and a plurality of voltage data.
[0022]
The temperature data storage unit 34 defines a plurality of temperature data corresponding to various temperatures at a predetermined position (attachment position of the thermistor 16) in the battery unit 1, and the temperature correction data storage unit 35 includes a plurality of temperature correction data storage units 35. The temperature correction data corresponding to each of the temperature data is stored, and the deterioration state data storage unit 36 defines a plurality of deterioration state data corresponding to various deterioration states of the battery cell 11, and is deteriorated. The correction data storage unit 37 stores deterioration correction data corresponding to each of a plurality of deterioration state data.
[0023]
FIG. 2 is a diagram partially showing an example of the data structure of the EEPROM in the secondary battery unit as an embodiment of the present invention. As shown in FIG. (Current value data), deterioration state data, deterioration correction data, temperature data, temperature correction data, voltage data and remaining capacity data are stored.
[0024]
When the current rate measurement is performed within a predetermined range, the current rate data is represented by n types of current value data (n is a natural number; in this embodiment, n = 4) representing the range (current rate value ( (Unit: 0.01C) is defined as a table, and is set in advance within a possible range as a measured value of the current rate of the battery cell 11. For example, when the current rate measurement is performed in the range of 0.2 to 2C, the data string {20, 50, 100, 200} has various values that can be taken as the current rate (current value). It is recorded in advance as a representative value. Thereby, the EEPROM 13 functions as the current value data storage unit 31.
[0025]
In the example shown in FIG. 2, the current rate data is registered as a 16-bit unsigned integer (hereinafter, such a data format is referred to as “A type”). The deterioration state data is specified by a discharge test result (details will be described later) performed when the battery cell 11 is charged by the charger 2. The deterioration state of the battery cell 11 is determined by devising a method for charging the battery cell 11. Specifically, at the time of charging, the voltage drop value is obtained by discharging the battery for a predetermined time (for example, 1 second) after reaching a predetermined voltage (for example, fully charged) and measuring the voltage value after the predetermined time has elapsed. Is calculated.
[0026]
When the IR drop value is measured within a predetermined range, the degradation state data is represented by q types (q is a natural number; q = 4 in the present embodiment) representing the range (in units of mV). Is defined as a table. Here, the IR drop indicates a voltage drop due to the internal resistance of the battery cell 11. The voltage drop (internal resistance) increases according to the degree of deterioration of the battery cell 11, but defines q values between the minimum value and the maximum value of the battery voltage after the voltage drop.
[0027]
For example, in the case of a battery cell 11 having a full charge voltage of 4.1 V (= 4100 mV), a data string {3600, 3700, 3800, 3950} is previously stored as representative values of various values that can be taken as voltage drop values. It is to be recorded. Thereby, the EEPROM 13 functions as the deterioration state data storage unit 36. In the example shown in FIG. 2, the deterioration state data is registered as A type.
[0028]
The deterioration correction data is a table that defines a ratio (0 to 100%) of irreversible battery deterioration capacity corresponding to the IR drop data string (four in this embodiment) of the table defining the deterioration state data. is there. The value stored in the deterioration correction data is a value when there is no correction by temperature.
As the deterioration correction data, for example, a data string such as {10, 50, 75, 100} is recorded. When the deterioration state data string is {3600, 3700, 3800, 3950}, the IR drop voltage is At 3.6 V, it indicates that 10% of the initial capacity is the battery capacity after deterioration.
[0029]
Similarly, when the IR drop voltage is 3.7V, 50% of the initial capacity, and when the IR drop voltage is 3.8V, 75% of the initial capacity is the battery capacity after deterioration. Further, when the IR drop voltage is 3.95 V, 100% of the initial capacity is the battery capacity after deterioration, indicating that the battery cell 11 has not deteriorated. Thereby, the EEPROM 13 functions as the deterioration correction data storage unit 37. In the example shown in FIG. 2, the degradation state data is registered as an 8-bit unsigned integer (hereinafter, such a data format is referred to as “B type”).
[0030]
When the battery cell 11 is charged by the charger 2 described later, the IR drop value is measured, and the measurement result is recorded at a predetermined position (not shown) of the EEPROM 13 by the charger 2. It has become so.
When the battery unit 1 is used by the power consuming device, the power consuming device uses the deterioration correction data stored in the deterioration correction data storage unit 33 based on the IR drop value written by the charger 2. Then, a correction calculation of the remaining capacity of the battery cell 11 is performed.
[0031]
The temperature data defines p types of temperatures (p is a natural number; in this embodiment, p = 16) representing this range as a table in a predetermined temperature range. Is 0 to 80 ° C., a data string such as {0, 1, 2, 4, 6, 8, 10, 15, 20, 25, 30, 40, 50, 60, 70, 80} These are defined in advance as representative values of various values that can be taken as the detected temperature.
[0032]
Thereby, the EEPROM 13 functions as the temperature data storage unit 34. Note that these temperature values defined as temperature data are not limited to integers of 0 or more. In the example shown in FIG. 2, the temperature data is registered as type B.
The temperature correction data defines the ratio (0 to 100%) of the reversible battery deterioration capacity corresponding to the temperature data string (16 in this embodiment) of the table defining the temperature data. The value stored in the temperature correction data is a value when there is no deterioration due to use of the battery cell 11.
[0033]
As this temperature correction data, for example, a data string such as {5, 10, 20, 40, 50, 60, 70, 80, 90, 95, 100, 95, 90, 80, 60, 40} is recorded. When the temperature data string is {0, 1, 2, 4, 6, 8, 10, 15, 20, 25, 30, 40, 50, 60, 70, 80}, the temperature of the battery cell 11 is 0. It shows that 5% of the initial capacity is the battery capacity after deterioration due to temperature at the time of ° C.
[0034]
Similarly, when the temperature of the battery cell 11 is 1 ° C., 10% of the initial capacity, and when the temperature of the battery cell 11 is 2 ° C., 20% of the initial capacity,. When the temperature of the battery is 10 ° C., 70% of the initial capacity,... (On the way, omitted)... When the temperature of the battery cell 11 is 80 ° C., 40% of the initial capacity is the battery capacity after deterioration due to temperature. Indicates that there is. Thereby, the EEPROM 13 functions as the temperature correction data storage unit 35. In the example shown in FIG. 2, the temperature correction data is registered as type B.
[0035]
The voltage data defines m kinds of voltage ranges (m is a natural number; m = 16 in the present embodiment) representative of this range when voltage measurement is executed within a predetermined range. When the voltage range of the battery cell 11 is 2.7 V to 4.2 V, {2700, 2800, 2900, 3000, 3100, 3200, 3300, 3400, 3500, 3600, 3700, 3800, 3900, 4000, 4100, 4200} is defined in advance as representative values of various values that can be taken as voltage values. As a result, the EEPROM 13 functions as the voltage data storage unit 32. In the example shown in FIG. 2, the voltage data is registered as A type.
[0036]
The remaining capacity data is a combination of a current rate data string (four in this embodiment) in a table defining current rate data and a voltage data string (16 in this embodiment) in a table defining voltage data. On the other hand, the ratio (0 to 100%) of the remaining capacity of the battery cell 11 is defined. As a result, the EEPROM 13 functions as the remaining capacity data storage unit 33. FIG. 3 is a diagram showing an example of remaining capacity data, and shows a relationship among current value data, voltage data, and remaining capacity data as a matrix.
[0037]
Although the remaining capacity data is not described in the matrix shown in FIG. 3, the remaining capacity is actually stored as a% value (0 to 100) in this matrix. The remaining capacity data is not limited to the% value, and may be stored as a ratio (0 to 1), for example.
These remaining capacities are values in the case where an apparent change of the remaining capacity due to temperature and deterioration due to use of the battery cell 11 are not taken into consideration. In addition, secondary batteries such as lithium polymer batteries and lithium ion batteries have different electrical characteristics depending on design specifications such as material configuration, electrode structure, maximum charge capacity, and generated voltage. In order to accurately calculate the capacity, it is desirable to store individual values corresponding to the characteristics of the battery cell 11 in the EEPROM 13. In the example shown in FIG. 2, the remaining capacity data is registered as type B.
[0038]
FIG. 4 is a block diagram showing a configuration of a secondary battery unit charger as one embodiment of the present invention, and shows a simplified example of the circuit configuration.
As shown in FIG. 4, the charger 2 includes a charge control circuit 21, a constant current discharge circuit 22, an MPU 23, an A / D converter 24, and a power supply circuit 25. The battery unit 1 and each terminal ( The connection is made through “+ terminal”, “− terminal” and “CM terminal” in FIG.
[0039]
The charge control circuit 21 applies a predetermined voltage to the battery cells 11 of the battery unit 1. The MPU 23 includes an arithmetic element and a storage element such as a ROM or a RAM, and controls the charge control circuit 21. The EEPROM 13 of the battery unit 1 is connected to the MPU 23 through a CM terminal so as to be communicable.
The CM terminal constitutes the above-mentioned DI / O terminal, S terminal, SK terminal, T terminal, G terminal and Vcc terminal together for convenience.
[0040]
The A / D converter 24 detects the output voltage of the battery cell 11 and outputs a detection signal to the MPU 23, and is connected to the anode output side of the charge control circuit 21.
The constant current discharge circuit 22 is for generating a constant current load, and is connected in parallel with the charge control circuit 21 on the output side of the charge control circuit 21.
Further, power is supplied from the power supply circuit 25 to each element or circuit of the charger 2. The constant current discharge circuit 22 may include a plurality of constant current switching mechanisms in order to enable measurement with higher accuracy.
[0041]
Next, the process in which the charger charges the secondary battery unit as one embodiment of the present invention will be described with reference to the flowchart (steps A10 to A90) shown in FIG.
When the battery unit 1 is connected to the charger 2 and charging is started, the charger 2 first charges the battery cell 11 until it reaches a predetermined voltage (for example, 4.00 V) value (step A10). The charger 2 once sets Timer = 0 (step A20), and then starts discharging using the constant current discharge circuit 22 or the constant resistance voltage circuit (not shown) (step A30).
[0042]
And after performing this discharge for a predetermined time (for example, 1 second) (step A40), the voltage value of the battery cell 11 is measured (step A50), and discharge is stopped (step A60). The MPU 23 calculates an IR drop value based on the measurement result, and writes this IR drop value in a predetermined position (not shown) of the battery unit 1 (step A70).
[0043]
Thereafter, the charger 2 resumes charging (step A80) and performs charging until the battery cell 11 is fully charged (step A90).
FIG. 6 is a block diagram showing a configuration of a remaining capacity display device as one embodiment of the present invention, and is a diagram showing a simplified example of the circuit configuration.
The remaining capacity display device 4 displays the remaining capacity of the battery cell 11 in the battery unit 1 on a remaining capacity display section (display section) 41. As shown in FIG. 6, the D / IO terminal, the SK terminal, The battery unit 1 is connected via a T terminal, a G terminal, a + terminal, a − terminal, and a Vcc terminal.
[0044]
  As shown in FIG. 6, the remaining capacity display device 4 includes a remaining capacity display section (display section) 41 and a microcomputer 42 (hereinafter referred to as a microcomputer 42. The microcomputer 42 includes a remaining capacity data acquisition section and a calculation section. , Each function of the display control unit), A / D converter 43, A / D converter (electricalPressureMeasurement unit) 44, differential amplifier and A / D converter (electricFlow valueA measurement unit 45, a voltage regulator 46, and a drive unit 47 are provided.
[0045]
The remaining capacity display device 4 is often used by being incorporated in the above-described power consuming device. For example, the remaining capacity display device 4 is incorporated in a mobile phone or a small video camera, and the remaining capacity of the battery (secondary battery) is reduced. It is displayed in various forms on a display (remaining capacity display unit 41) or the like.
The remaining capacity display unit 41 is communicably connected to the microcomputer 42, and is for displaying information obtained by the microcomputer 42 and the remaining capacity of the battery cell 11. For example, display on a liquid crystal display, lighting of an LED, etc. Thus, the remaining capacity of the battery cell 11 is displayed.
[0046]
The voltage regulator 46 converts the power supplied from the battery cell 11 of the battery unit 1 into a predetermined voltage. For example, the battery voltage of 3 to 4 V input from the battery cell 11 is stabilized to 3.3 V. It is designed to output.
The A / D converter 44 is disposed on the input side of the voltage regulator 46, detects the output voltage of the battery cell 11, outputs a detection signal to the microcomputer 42, and measures a voltage of the battery cell 11. It is supposed to function as. The power from the A / D converter 44 is supplied to the EEPROM 13 of the battery unit 1 through the Vcc terminal.
[0047]
The differential amplifier and A / D converter 45 is disposed on the input side of the voltage regulator 46, detects the output current of the battery cell 11 from the potential difference between both ends of the resistor 48, and outputs a detection signal to the microcomputer 42. In addition, it functions as a current value measuring unit that measures the current value flowing through the battery cell 11. The resistance value of the resistor 48 for measuring the potential difference is set as small as possible in order to suppress the voltage drop. Therefore, the A / D converter 45 is provided with a differential amplifier for performing signal amplification.
[0048]
The A / D converter 43 converts temperature information (analog signal) measured by the thermistor 16 of the battery unit 1 into a digital signal and outputs it to the microcomputer 42.
The microcomputer 42 includes a storage element, an arithmetic element, a clock oscillation unit, and the like (not shown) and controls the entire circuit. The EEPROM 13 of the battery unit 1 is communicably connected to the microcomputer 42 via the DI / O terminal. The remaining capacity data storage unit 31, the temperature correction data storage unit 32, and the deterioration in the EEPROM 13 are connected. The remaining capacity data, the temperature correction data, and the deterioration correction data respectively stored in the correction data storage unit 33 are transmitted to the microcomputer 42.
[0049]
The microcomputer 42 is defined in advance in the current value data storage unit 31 of the EEPROM 13 in the battery unit 1 based on the actual value of the current rate (current value) measured by the A / D converter (current value measurement unit) 45. The current rate (current value data) corresponding to the measured current value is selected from the plurality of current value data.
[0050]
Further, the microcomputer 42 stores a plurality of voltage data defined in advance in the voltage data storage unit 32 of the EEPROM 13 in the battery unit 1 based on the actual measurement value of the voltage measured by the A / D converter (voltage measurement unit) 44. The voltage data corresponding to the actually measured value of the voltage is selected from the inside.
Further, the microcomputer 42 corresponds to the measured value from a plurality of temperature data defined in advance in the temperature data storage unit 34 of the EEPROM 13 in the battery unit 1 based on the measurement result of the thermistor 16 in the battery unit 1. The temperature data to be selected is selected.
[0051]
Furthermore, the microcomputer 42 selects from among a plurality of deterioration state data defined in advance in the deterioration state data storage unit 36 of the EEPROM 13 in the battery unit 1 based on the IR drop value stored in the EEPROM 13 in the battery unit 1. The deterioration state data corresponding to the IR drop value is selected.
[0052]
As a method for the microcomputer 42 to select current value data, voltage data, temperature data, and deterioration state data, for example, each value closest to the actual measurement value may be selected and acquired. , Current value data, voltage data, temperature data, and deterioration state data are associated in advance as representative values for each predetermined range of each value, and these representative values (current value data, voltage Data, temperature data, and deterioration state data) may be selected, and various modifications can be made without departing from the spirit of the present invention.
[0053]
The microcomputer 42 then determines the voltage value and the current based on the voltage data obtained from the voltage measured by the A / D converter 44 and the current rate data obtained from the current rate measured by the A / D converter 45. The remaining capacity data corresponding to the combination with the rate is acquired from the EEPROM 13 (remaining capacity data storage section 35) of the battery unit 1 via the DI / O terminal, and functions as a remaining capacity data acquisition section. It has become.
[0054]
Furthermore, the microcomputer 42 calculates the remaining capacity of the battery cell 11 based on the acquired remaining capacity data, and functions as a calculation unit. Further, the microcomputer 42 functions as a display control unit for displaying the calculated remaining capacity of the battery cell 11 on the remaining amount display unit (display unit) 41.
The microcomputer 42 outputs a clock for driving the EEPROM 13 of the battery unit 1 to the SK terminal.
[0055]
The drive unit 47 is for realizing various functions other than the display of the remaining capacity. For example, when the remaining capacity display device 4 is incorporated in a mobile phone, the drive unit 47 functions as a telephone. A circuit or the like for realizing this corresponds to the drive unit 47.
A method of displaying the remaining capacity of the battery cell in the secondary battery unit as one embodiment of the present invention by the remaining capacity display device 4 configured as described above will be described according to the flowchart (steps B10 to B130) shown in FIG. To do.
[0056]
When the battery unit 1 is connected to the remaining capacity display device 4, the microcomputer 42 measures the voltage of the battery cell 11 by the A / D converter 44 (step B10). The microcomputer 42 refers to the voltage data storage unit 32 of the EEPROM 13 in the battery unit 1 and acquires voltage data (for example, 3700 mV) based on the measured value (for example, 3680 mV) of the voltage (step B20).
[0057]
Moreover, the microcomputer 42 measures the current rate of the battery cell 11 by the A / D converter 45 (step B30). Then, the microcomputer 42 refers to the current value data storage unit 31 of the EEPROM 13 in the battery unit 1 and acquires current rate data (for example, 50 C / 100) based on the measured value of the current rate (for example, 45 C / 100). (Step B40).
[0058]
The microcomputer 42 refers to the remaining capacity data storage unit 33 of the EEPROM 13 in the battery unit 1, and the remaining capacity data corresponding to the combination of the voltage data (3700 mV) and the current rate data (50 C / 100) selected as described above. 70%) is acquired (step B50).
Further, the microcomputer 42 acquires the temperature at a predetermined position of the battery cell 11 from the thermistor 16 of the battery unit 1 (step B60), and refers to the temperature data storage unit 34 of the EEPROM 13 in the battery unit 1 to determine the battery cell 11 Temperature data (for example, 10 ° C.) is acquired based on the actually measured value (for example, 12 ° C.) (step B70).
[0059]
Then, the microcomputer 42 refers to the temperature correction data storage unit 35 of the EEPROM 13 in the battery unit 1 and acquires temperature correction data (for example, 70% or 0.7) (step B80).
Further, the microcomputer 42 obtains the IR drop value recorded in the EEPROM 13 by the charger 2 (step B90), and refers to the deterioration state data storage unit 36 of the EEPROM 13 in the battery unit 1 to refer to the IR drop value of the battery cell 11. Degradation state data (for example, 3800 mV) is acquired based on the value (step B100).
[0060]
Then, the microcomputer 42 refers to the deterioration correction data storage unit 37 of the EEPROM 13 in the battery unit 1 and acquires deterioration correction data (for example, 75% or 0.75) (step B110).
The microcomputer 42 uses the temperature correction data (0.7) acquired in step B80 and the deterioration correction data (0.75) acquired in step B110 for the remaining capacity data (70%) acquired in step B50. Then, correction (for example, 70% × 0.7 × 0.75≈40%) is performed (step B120), and the microcomputer 42 displays the remaining capacity data thus calculated on the remaining amount display unit 41 (step B120). B130).
[0061]
Thus, according to the secondary battery unit and the remaining capacity display device as one embodiment of the present invention, the EEPROM 13 in the battery unit 1 includes the current value data storage unit 31 and the voltage data storage unit 32. Instead of directly using the current values and voltages measured by the A / D converters 45 and 44, based on the current rate data and voltage data set in advance in the current value data storage unit 31 and the voltage data storage unit 32. The remaining capacity can be acquired, and the remaining capacity of the battery cell 11 can be acquired quickly.
[0062]
Further, since the remaining capacity data storage unit 33 is provided, the remaining capacity data can be acquired based on the current rate data and the voltage data, and the display of the remaining capacity of the battery cell can be speeded up. In addition, since it is not necessary to perform calculation when acquiring the remaining capacity, the apparatus configuration can be simplified and the manufacturing cost can be reduced.
In particular, since the remaining capacity data is recorded in the EEPROM 13 as a table, the memory element can be configured using a small capacity and inexpensive one such as an EEPROM.
[0063]
Further, even when the relationship between the current rate and the voltage is nonlinear, the remaining capacity of the battery cell 11 can be accurately calculated by using the remaining capacity data corresponding to the combination of the current rate data and the voltage data. it can.
In the present invention, since the remaining capacity is obtained based on the relationship table between the current rate and the voltage that are considered to have the greatest influence on the measurement value, the remaining capacity of the battery cell 11 is simply increased. It can be measured with accuracy.
[0064]
Further, in the present invention, it can be said that the remaining capacity data is corrected in advance by the current rate that is assumed to be the largest as an error factor, and it can be said that the accuracy of the remaining capacity is high. .
Therefore, it is not always necessary to perform correction based on the temperature or the deterioration state, and it may be left to the user of the battery unit 1 (remaining capacity display device 4) to determine whether or not to perform the correction based on the temperature or the deterioration state. And the degree of freedom of the user can be improved.
[0065]
In other words, in the above-described embodiment, the remaining capacity data acquired from the remaining capacity data storage unit 33 is corrected based on the temperature and the deterioration state. However, the present invention is not limited to this, for example, based on the temperature. The remaining capacity data acquired from the remaining capacity data storage unit 33 may be directly used without performing only the correction or the correction based on the deterioration state, or without performing these corrections.
[0066]
In addition, since a memory element (EEPROM or the like) for storing current value data, voltage data, remaining capacity data, etc. is inexpensive, a conventional secondary battery unit is implemented when implementing the secondary battery unit as one embodiment of the present invention. Compared to the above, the manufacturing cost does not increase greatly.
Furthermore, in general, the correlation between the battery voltage and the remaining capacity varies depending on the current rate flowing at that time. However, in the present invention, the remaining capacity data is not limited to the battery voltage, Therefore, the remaining capacity of the battery cell 11 can be measured more accurately.
[0067]
Further, since the EEPROM 13 stores temperature correction data defining a plurality of temperature correction data corresponding to various temperatures at predetermined positions of the battery unit 1, the remaining capacity of the battery cell 11 taking into account the influence of temperature is obtained. And the accuracy of the remaining capacity can be improved.
Furthermore, since the temperature data storage unit 34 and the temperature correction data storage unit 35 are provided, it is not necessary to perform calculation processing using the measured temperature directly, and the remaining capacity is corrected based on preset temperature data. The remaining capacity with high accuracy can be acquired quickly, the burden on the remaining capacity display device 4 can be reduced, and the device configuration can be simplified.
[0068]
In addition, since the EEPROM 13 stores a plurality of deterioration correction data corresponding to various deterioration states of the battery cell 11, based on the influence of the deterioration of the battery cell 11 by performing correction using the deterioration correction data. Further, the remaining capacity of the battery cell 11 can be obtained, and the accuracy of the remaining capacity can be improved.
Further, since the degradation state data storage unit 36 and the degradation correction data storage unit 37 are provided, it is not necessary to perform arithmetic processing by directly using the measured degradation state (voltage drop value), and the preset degradation state data is obtained. Since the remaining capacity is corrected based on this, a highly accurate remaining capacity can be acquired quickly, and the burden on the remaining capacity display device can be reduced, and the device configuration can be simplified.
In the present invention, the remaining capacity can be corrected by temperature and deterioration by the arithmetic processing of the microprocessor on the side where the battery unit 1 such as the remaining capacity display device or the power consuming device is mounted. The structure of 1 can be simplified.
[0069]
The present invention is not limited to the above-described embodiment, and various modifications can be made without departing from the spirit of the present invention.
For example, in the above-described embodiment, the voltage measured by the A / D converter 44 or the current rate measured by the A / D converter 45 does not match the voltage data or current rate data stored in the EEPROM 13 in advance. In addition, the remaining capacity data corresponding to the combination of the voltage data and the current rate data is forcibly approximated to the voltage data and the current rate data registered in advance, but the present invention is limited to this. is not.
[0070]
For example, when the measured current rate does not match the voltage data or current rate data stored in the EEPROM 13 in advance, the remaining capacity data may be linearly corrected. For example, when the voltage data is defined as a data string {2700,..., 3600, 3700,..., 4200}, and the measured voltage is 3650 mV, the remaining capacity data at 3600 mV And the remaining capacity data at 3700 mV may be the remaining capacity data corresponding to this measured value.
[0071]
That is, when the voltage measurement result by the A / D converter (voltage measurement unit) 44 is not stored in the EEPROM 13 (voltage data storage unit 32), or when the current rate (current) by the A / D converter (current value measurement unit) 45 is stored. Value) is not stored in the EEPROM 13 (current value data storage unit 31), the microcomputer (remaining capacity data acquisition unit) 42 registers the voltage data, current value data, and these stored in the EEPROM 13 The remaining capacity data corresponding to the measurement result may be obtained by performing linear correction using the corresponding remaining capacity data.
[0072]
Further, the method for detecting the deterioration state of the battery cell 11 is not limited to the method using the IR drop value defined by the voltage of the battery cell 11 after being discharged for a certain time as described above. The deterioration state of the battery cell 11 may be detected based on the difference in the discharge time when discharged to the maximum.
Furthermore, in the battery unit 1 of the present invention of each aspect described above, the writing of the IR drop value to the EEPROM 13 and the calculation of the remaining capacity are not limited to the charger or the power consuming device, and the battery unit 1 can be connected. Any device can be used as long as it is a proper device.
[0073]
In the above-described embodiment, the current value data storage unit 31, the voltage data storage unit 32, the remaining capacity data storage unit 33, the temperature data storage unit 34, the temperature correction data storage unit 35, the deterioration state are stored in the EEPROM 13 of the battery unit 1. Although the data storage unit 36 and the deterioration correction data storage unit 37 are provided, the present invention is not limited to this, and all or at least a part of these may be provided on the remaining capacity display device 4 side. .
[0074]
Further, in the above-described embodiment, the remaining capacity display device 4 includes the current value measuring unit (A / D converter 45) and the voltage measuring unit (A / D converter 44), but the present invention is not limited thereto. Instead of this, the battery unit 1 may have such a configuration.
In addition, if each embodiment of this invention is disclosed, it can be manufactured by those skilled in the art.
[0075]
【The invention's effect】
  As described above in detail, the secondary battery unit and the remaining capacity display device of the present invention have the following effects or advantages.
  (1) A memory element in the secondary battery unit defines a plurality of current value data corresponding to various current values flowing through the battery cells, and a plurality of voltages corresponding to various voltages of the battery cells. Since it has a voltage data storage section that defines data, instead of directly using the measured current value and voltage, the remaining capacity can be obtained based on preset current value data and voltage data, and the battery cell Can be obtained quickly (Claim 1, Claim)4, Claim5).
[0076]
  (2) Since each of the combinations of the plurality of current value data and the plurality of voltage data has a remaining capacity data storage section that defines the corresponding remaining capacity data, the remaining capacity data is based on the current value data and the voltage data. And the display of the remaining capacity of the battery cell can be speeded up. Further, since it is not necessary to perform an operation when acquiring the remaining capacity, the apparatus configuration can be simplified and the manufacturing cost can be reduced.4, Claim5).
[0077]
  (3) Since the memory element has a temperature correction data storage unit that stores a plurality of temperature correction data corresponding to various temperatures at predetermined positions of the secondary battery unit, the remaining capacity of the battery cell taking into account the influence of temperature is reduced. And the accuracy of the remaining capacity can be improved.5).
  (4) A temperature data storage unit that defines a plurality of temperature data corresponding to various temperatures at a predetermined position of the battery cell, and a temperature correction data storage unit that stores temperature correction data corresponding to each of the plurality of temperature data. Therefore, it is not necessary to perform calculation processing directly using the measured temperature, and the remaining capacity is corrected based on preset temperature data, so that a highly accurate remaining capacity can be quickly acquired. The load on the remaining capacity display device can be reduced, and the device configuration can be simplified.5).
[0078]
  (5) Since it has a deterioration correction data storage unit that stores a plurality of deterioration correction data corresponding to various deterioration states of the battery cell, the remaining capacity of the battery cell can be obtained based on the influence of the deterioration of the battery cell, The accuracy of the remaining capacity can be improved.1, contractClaim4, Claim5).
  (6) A deterioration state data storage unit that defines a plurality of deterioration state data corresponding to various deterioration states of the battery cell, and a deterioration correction data storage unit that stores deterioration correction data corresponding to each of the plurality of deterioration state data, Therefore, it is not necessary to perform calculation processing directly using the measured degradation state (voltage drop value), and the remaining capacity is corrected based on preset degradation state data. In addition, the load on the remaining capacity display device can be reduced, and the device configuration can be simplified.1, contractClaim4, Claim5).
[Brief description of the drawings]
FIG. 1 is a block diagram showing a configuration of a secondary battery unit as one embodiment of the present invention.
FIG. 2 is a diagram partially showing an example of the data structure of an EEPROM in the secondary battery unit as one embodiment of the present invention.
FIG. 3 is a diagram illustrating an example of remaining capacity data.
FIG. 4 is a block diagram showing a configuration of a charger of the secondary battery unit 1 as one embodiment of the present invention.
FIG. 5 is a flowchart for explaining processing in which a charger charges a secondary battery unit as one embodiment of the present invention.
FIG. 6 is a block diagram showing a configuration of a remaining capacity display device as one embodiment of the present invention.
FIG. 7 is a flowchart for explaining a method of displaying a remaining capacity of a battery cell in a secondary battery unit as an embodiment of the present invention by a remaining capacity display device.
[Explanation of symbols]
1 Secondary battery unit
2 charger
4 Remaining capacity display device
11 battery cells
12 Circuit part
13 EEPROM (memory element)
14 Protection circuit
15 FUSE
16 Thermistor (temperature measurement unit)
17, 18 LPF
19 Resistance
21 Charge control circuit
22 Constant current discharge circuit
23 MPU
24 A / D converter
25 Power supply circuit
31 Current value data storage
32 Voltage data storage
33 Remaining capacity data storage
34 Temperature data storage
35 Temperature correction data storage
36 Degradation state data storage
37 Deterioration correction data storage
41 Remaining display
42 Microcomputer (remaining capacity data acquisition unit, calculation unit, display control unit)
43 A / D Converter
44 A / D converter (voltage measurement unit)
45 A / D converter (current value measurement unit)
46 Voltage regulator
47 Drive unit
48 resistance

Claims (5)

A rechargeable battery unit comprising a rechargeable battery cell and a memory element,
The battery cell is a lithium secondary battery;
The memory element is
A current value data storage for defining a plurality of current value data corresponding to various current values flowing through the battery cell;
A voltage data storage for defining a plurality of voltage data corresponding to various voltages of the battery cell;
For each combination of the plurality of current value data and the plurality of voltage data, a remaining capacity data storage section that defines corresponding remaining capacity data ,
A deterioration correction data storage unit for storing a plurality of deterioration correction data corresponding to various deterioration states of the battery cell;
A deterioration state data storage unit defining a plurality of deterioration state data corresponding to various deterioration states of the battery cell;
Each of the plurality of deterioration state data is associated with each of the plurality of deterioration correction data,
The deterioration state data, at the time of charge, once a predetermined time discharge after reaching a predetermined voltage, and wherein Rukoto defined than the voltage drop value calculated by measuring the voltage value after the predetermined time has elapsed A secondary battery unit. The memory element is
The secondary battery unit according to claim 1, further comprising a temperature correction data storage unit that stores a plurality of temperature correction data corresponding to various temperatures at predetermined positions of the secondary battery unit. The memory element is
A temperature data storage unit for defining a plurality of temperature data corresponding to various temperatures at predetermined positions of the secondary battery unit;
3. The secondary battery unit according to claim 2, wherein the temperature correction data storage unit stores the temperature correction data corresponding to each of the plurality of temperature data. A remaining capacity display device that displays the remaining capacity of the battery cell in the secondary battery unit according to any one of claims 1 to 3 on a display unit,
A current value measuring unit for measuring a current value flowing through the battery cell;
A voltage measuring unit for measuring the voltage of the battery cell;
Based on the voltage measured by the voltage measurement unit and the current value measured by the current value measurement unit, a remaining capacity data acquisition unit that acquires the corresponding remaining capacity data from the remaining capacity data storage unit;
A calculation unit for calculating the remaining capacity of the battery cell based on the remaining capacity data acquired by the remaining capacity data acquiring unit;
A display control unit for displaying the remaining capacity of the battery cell calculated by the calculation unit on the display unit ;
The battery cell is a lithium secondary battery;
A memory element of the secondary battery unit stores a plurality of deterioration correction data storing a plurality of deterioration correction data corresponding to various deterioration states of the battery cell, and a plurality of deterioration corresponding to various deterioration states of the battery cell. With a degradation state data storage that defines state data,
Each of the plurality of deterioration state data is associated with each of the plurality of deterioration correction data,
The deterioration state data is defined by a voltage drop value calculated by discharging a predetermined time after reaching a predetermined voltage and measuring a voltage value after elapse of the predetermined time at the time of charging,
The calculation unit is characterized that you calculate remaining capacity of the battery cell with the deterioration correction data corresponding to the degradation state data, the remaining capacity display. A remaining capacity display device for displaying the remaining capacity of the battery cell in the secondary battery unit according to claim 2 or 3 on a display unit,
A current value measuring unit for measuring a current value flowing through the battery cell;
A voltage measuring unit for measuring the voltage of the battery cell;
Based on the voltage measured by the voltage measurement unit and the current value measured by the current value measurement unit, a remaining capacity data acquisition unit that acquires the corresponding remaining capacity data from the remaining capacity data storage unit;
A calculation unit for calculating the remaining capacity of the battery cell based on the remaining capacity data acquired by the remaining capacity data acquiring unit;
A display control unit for displaying the remaining capacity of the battery cell calculated by the calculation unit on the display unit;
The battery cell is a lithium secondary battery;
A memory element of the secondary battery unit stores a plurality of deterioration correction data storing a plurality of deterioration correction data corresponding to various deterioration states of the battery cell, and a plurality of deterioration corresponding to various deterioration states of the battery cell. With a degradation state data storage that defines state data,
Each of the plurality of deterioration state data is associated with each of the plurality of deterioration correction data,
The deterioration state data is defined by a voltage drop value calculated by discharging a predetermined time after reaching a predetermined voltage and measuring a voltage value after elapse of the predetermined time at the time of charging,
The operational unit, characterized in that for calculating the remaining capacity of the battery cell by using the the deterioration correction data and the temperature correction data storage unit to the stored temperature correction data corresponding to the degradation state data, Remaining capacity display device.

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