JP4764971B2 - Battery level measuring device - Google Patents

Description

  TECHNICAL FIELD The present invention relates to a battery remaining amount measuring device that measures the remaining amount of electricity stored in a secondary battery, and in particular, to measure the remaining amount of a battery for accurately measuring the amount of electricity stored in a lithium ion battery. Relates to the device.

  Conventionally, the lithium ion battery can store the current amount of dischargeable electric charge (remaining amount) in a charge / discharge state where the lithium ion battery is connected to an external load device or charging device, or in a rest state where the lithium ion battery is left unused. As a measuring device for accurately measuring the amount of charge or the amount of electricity that can be charged, for example, a battery remaining amount measuring device such as a secondary battery remaining amount display device described in Patent Document 1 described later is used. .

FIG. 20 is a block diagram illustrating an example of a conventional battery remaining amount measuring apparatus.
In the remaining amount measuring device shown in FIG. 20, the lithium ion battery 31 in the battery pack 3 is a rechargeable secondary battery. Usually, in the battery pack 3, a current sensor 32 for detecting a charge / discharge current flowing in the lithium ion battery 31 and a temperature sensor 33 for detecting the temperature of the lithium ion battery 31 are integrally stored. Detection signals from the current sensor 32 and the temperature sensor 33 are taken into the computing device 1 by the detection device 2, and the computing device 1 is activated to calculate the amount of electricity stored in the lithium ion battery 31. The remaining amount recognized by the remaining amount measuring device.

  A charging efficiency memory table 401, a discharge efficiency memory table 501, a self-discharge amount memory table 601, a timer 7, and a memory 8 are connected to the arithmetic device 1. The calculation result of the calculation device 1 is output to the external device 9, and the remaining amount of electricity stored in the lithium ion battery 31 can be displayed by the electricity amount display unit 10 provided there. The remaining amount stored in the lithium ion battery 31 is stored in the memory 8. In the arithmetic unit 1, the remaining discharge time (dischargeable time) is calculated by dividing the remaining amount by the discharge current detected by the current sensor 32 at the time of discharging the lithium ion battery 31 or a predetermined current value. The This remaining discharge time is displayed by a time display unit 11 provided in the external device 9.

  When the lithium ion battery 31 is charged, a chargeable amount of electricity is obtained by subtracting the remaining amount stored in the memory 8 from the full charge amount, and a charge current detected by the current sensor 32 or a predetermined current value. The remaining charge time (chargeable time) is obtained by dividing by. This remaining charge time is displayed on the time display unit 11 provided in the external device 9. As the predetermined current value in the calculation of the chargeable / dischargeable time, an average current value that has flowed within the predetermined time or a scheduled current value that is about to flow to an external load or the like can be used.

  In the calculation algorithm 101, different algorithms are executed at the time of charging / discharging when current flows through the lithium ion battery 31 and at the time of non-charging / discharging when current is not flowing. That is, at the time of charging / discharging, a new remaining amount is obtained by adding the amount of charged electricity and subtracting the amount of discharged electricity to the previous remaining amount recorded in the memory 8. The current remaining amount is obtained by subtracting a predetermined self-discharge amount from the previous remaining amount recorded in FIG.

FIG. 21 is a graph showing an example of the relationship between temperature and charging efficiency in a conventional battery remaining amount measuring apparatus.
Here, the charge electricity amount is the product of the charge current value detected by the current sensor 32 and the charge time measured by the timer 7, that is, the charge electricity amount for a predetermined time is multiplied by the charge efficiency (ampere hour efficiency). It is obtained by. The charging efficiency is the ratio of the amount of electricity actually stored to the amount of electricity that can be charged in the lithium ion battery 31 (the amount of charge that can be charged), and this value is the temperature of the lithium ion battery 31, the lithium ion battery It varies depending on the current flowing through 31 and the amount of electricity (remaining amount) stored therein. In the graph shown in FIG. 21, the charging efficiency decreases as the temperature decreases.

FIG. 22 is a graph showing an example of the relationship between temperature and discharge efficiency in a conventional remaining amount measuring apparatus.
The amount of discharge electricity is obtained by dividing the product of the discharge current value detected by the current sensor 32 and the time measured by the timer 7, that is, the amount of discharge electricity for a predetermined time by the discharge efficiency. In the graph shown in FIG. 22, the discharge efficiency decreases as the temperature decreases and the current increases. The discharge efficiency is based on the total discharge charge amount (rated capacity C _N ; hereinafter simply referred to as C) at a normal temperature (20 ° C.) and a discharge current value of 0.2 C [A]. This is a ratio indicating the ratio of the amount of charge [mAH] discharged with a predetermined discharge current, and this value varies with temperature and current. The magnitude of the discharge current is expressed by adding a unit of current to a multiple of the rated capacity, such as I = 1.0 CmA or I = 0.2 CmA.

  For example, when the charge electricity amount obtained by integrating the detected current with a charge efficiency of 0.9 is 1000 C, the recognized actual charge electricity amount is 900 C (1000 C × 0.9). For example, when the discharge electric quantity obtained by integrating the detected current with a discharge efficiency of 0.9 is 1000 C, the recognized actual discharge electric quantity is 1111 C (1000 C / 0.9). Become.

FIG. 23 is a graph showing the relationship between the leaving period and the remaining rate with the temperature as a parameter of the fully charged battery in the remaining amount measuring device.
Generally, the remaining amount of a secondary battery such as the lithium ion battery 31 decreases even when left in a state where it is not used. This is a phenomenon called self-discharge, and the magnitude of the self-discharge depends on the temperature, the standing period, and the remaining amount. FIG. 23 shows a state in which the remaining amount rate is reduced by self-discharge, with the amount of electricity (full charge amount) of the battery in a fully charged state being 100%. Between the remaining rate and the temperature of the lithium ion battery 31 left in a fully charged state, and the leaving period, the higher the temperature, the larger the self-discharge amount of the lithium ion battery 31, and the self-discharge with the leaving period. There is a relationship that increases the amount.

  The charge efficiency, discharge efficiency, and self-discharge amount values shown in FIGS. 21, 22, and 23 are stored in the charge efficiency memory table 401, the discharge efficiency memory table 501, and the self-discharge amount memory table 601 of FIG. 20, respectively. A value corresponding to various conditions detected by the detection device 2 is selected and used in the calculation in the calculation device 1.

Note that Japanese Patent Application No. 2002-1000035 (filed on April 2, 2002) is a prior application related to the above-described prior art. Further, Patent Document 2 describes a power source residual capacity measuring device that can accurately measure the residual capacity of a secondary battery both during discharging and during charging.
JP-A-6-20723 Japanese Patent Laid-Open No. 5-152006

  By the way, the conventional remaining amount measuring apparatus is based on the idea that the charge / discharge efficiency changes depending on the temperature and current. However, as a result of the experiment, when the conditions (temperature, current, etc.) change in charging / discharging of the secondary battery, the charging / discharging efficiency does not change, and charging and discharging cannot be temporarily performed according to each charging / discharging condition. It has been found that the idea that there is an amount of electricity and that the amount changes is appropriate.

FIG. 24 is a graph showing the amount of charge electricity with respect to the preceding charge temperature in the conventional battery remaining amount measuring apparatus.
In FIG. 24, after complete discharge, until the battery is fully charged at a predetermined temperature (for example, until the charging current reaches 0.05 C [A]), the result of charging at a constant voltage / constant current is the result of preceding charging. Shown as a graph. Further, the additional charge graph is obtained by charging again at normal temperature (20 ° C.) until it is fully charged again. When charging is performed continuously under two different charging conditions (temperature and current), each is fully charged at a predetermined temperature (−20 ° C. and 0 ° C.), and then the temperature is set to room temperature (20 ° C.). As a result, a certain amount of electricity is charged. Moreover, it can be seen that the total amount of electricity is equal to the amount of electricity when continuously charged at normal temperature from the fully discharged state to the fully charged state.

  In this way, the charging efficiency (charged electricity amount) of the secondary battery is constant, and when the charging conditions change, a part of the electricity amount cannot be charged temporarily according to the ambient temperature. Yes. That is, when the remaining amount is measured based on the concept of the conventional remaining amount measuring device, for example, assuming that the temperature becomes room temperature after charging at 0 ° C., the amount of electricity stored at 0 ° C. is estimated to be small. Therefore, there arises a problem that the remaining amount at room temperature is smaller than the actual remaining amount (actual remaining amount).

FIG. 25 and FIG. 26 are graphs showing an example of a result of continuous discharge under two types of discharge conditions (temperature / current) in a conventional battery remaining amount measuring apparatus.
The result of constant current discharge after complete charge until complete discharge at a predetermined temperature (for example, until the battery voltage reaches 2.5 V) is shown as a graph of preceding discharge. Further, the additional discharge graph is obtained by discharging until complete discharge once again at normal temperature (20 ° C.).

  In the graph of FIG. 25, if the current value of the preceding discharge is 0.2 C [A] and the temperature is 0 ° C., for example, the remaining amount becomes zero when the amount of electric discharge becomes 5250 C, and the temperature Is −20 ° C., the remaining amount becomes zero when the amount of electric discharge becomes 4800C. However, if additional discharge is performed at a normal temperature (20 ° C.) after that, additional discharge can be performed by 100 C in the former and 550 C in the latter.

  In the graph of FIG. 26, if the current value of the preceding discharge is 1 C [A] and the temperature is 0 ° C., for example, the amount of electricity that can be discharged (remaining amount) at the time when the amount A of discharged electricity reaches 4550 C. However, if additional discharge is performed at a normal temperature (20 ° C.) after that, the remaining amount B becomes 800 C, and additional discharge can be performed by that amount.

  As described above, in the conventional remaining amount measuring device, even after recognizing that the secondary battery is completely discharged under the predetermined condition, a certain amount of electricity is discharged at room temperature (20 ° C.), and the total electricity is completely charged. It is equal to the amount of electricity when discharged continuously at normal temperature (20 ° C.) from the state to the complete discharge state.

  Thus, in the secondary battery such as the lithium ion battery 31, when the temperature rises or the discharge current decreases, an apparent remaining amount is generated even if no new charging is performed. Therefore, in the conventional remaining amount measuring device, although the amount of electricity that can be discharged increases and the remaining discharge time increases, the remaining amount recognized by the computing device is maintained at zero, and the remaining discharge time is also zero. There was a problem of calculating.

  In addition, the remaining amount calculation considering the self-discharge amount is performed at the time of non-charging / discharging, but since the self-discharge amount was indirectly obtained from the detected plural state amounts (remaining amount, temperature, leaving period), When the non-charge / discharge state is repeated, there is a problem that the remaining amount recognized by the remaining amount measuring device is greatly different from the actual remaining amount due to accumulation of errors.

  Furthermore, the secondary battery deteriorates by repeatedly charging and discharging electricity, and the rated capacity itself decreases. However, the conventional remaining amount measuring device has a problem that it cannot accurately measure the remaining amount by accurately recognizing the degree of deterioration.

An object of the present invention is to provide a battery remaining amount measuring device capable of accurately measuring a remaining capacity rate of a secondary battery by correcting the remaining capacity based on a direction of a current flowing through the secondary battery before entering a resting state. There is.

In order to achieve the above object, the battery remaining amount measuring device calculates a remaining amount value of the secondary battery according to a voltage sensor that detects a voltage of the secondary battery and a voltage signal detected by the voltage sensor. An arithmetic device that stores the remaining amount value calculated by the arithmetic device and the direction of the current flowing through the secondary battery, a voltage value in a resting state in which no current flows through the secondary battery, and the second As the remaining rate characteristics indicating the relationship with the ratio of the amount of electricity stored in the secondary battery, the remaining amount differs depending on whether the current direction immediately before entering the resting state is the charging direction or the discharging direction. Correction data for correcting the voltage value of the secondary battery in the hibernation state, and a remaining capacity rate in which the current direction immediately before the hibernation state is either the charge direction or the discharge direction holding the data Composed of the remaining rate memory table - the open-circuit voltage.

In this battery remaining amount measuring device, the remaining amount of electricity is measured during charging / discharging of the secondary battery, and based on the remaining rate of the secondary battery when charging / discharging of the secondary battery is stopped for a predetermined time. When executing the remaining amount correction, the remaining amount value stored in the memory can be corrected based on the remaining amount data read from the open-circuit voltage-remaining rate memory table in accordance with the current direction stored in the memory.
In order to achieve the above object, the remaining amount of electricity is measured during charging / discharging of the secondary battery, and when the charging / discharging of the secondary battery is stopped for a predetermined time, the remaining rate of the secondary battery is calculated. In the battery remaining amount measuring device that performs the remaining amount correction based on the voltage sensor that detects the voltage of the secondary battery, and calculates the remaining amount value of the secondary battery according to the voltage signal detected by the voltage sensor An arithmetic device that stores the remaining amount value calculated by the arithmetic device and the direction of the current flowing through the secondary battery, a voltage value in a resting state in which no current flows through the secondary battery, and the second As the remaining rate characteristics indicating the relationship with the ratio of the amount of electricity stored in the secondary battery, the remaining amount differs depending on whether the current direction immediately before entering the resting state is the charging direction or the discharging direction. Rate data, said When the current direction immediately before the stop state is the remaining rate data for either the charge direction or the discharge direction, and when the current direction immediately before the sleep state is the charge direction and the discharge direction An open-circuit voltage-remaining rate memory table storing difference data of the remaining rate characteristic in the memory, and the remaining amount read from the open-circuit voltage-remaining rate memory table according to the current direction stored in the memory According to the rate data, there is provided a battery remaining amount measuring device that corrects the remaining amount value stored in the memory.

According to the amount measuring apparatus of a battery of this invention, the open circuit voltage according to the current direction stored in the memory - the read-out remaining quantity ratio data from the remaining amount rate memory table, the stored residual value in the memory Since the correction can be made, the remaining rate and the remaining amount in the hibernation state can be corrected with high accuracy regardless of the state (charging or discharging) before the hibernation state.

Embodiments of the present invention will be described below with reference to the drawings.
(First embodiment)
FIG. 1 is a block diagram showing the overall configuration of the battery remaining amount measuring apparatus according to the first embodiment.

  The arithmetic device 1 includes an arithmetic algorithm 12 for measuring the remaining amount of the secondary battery, to which a battery pack 3 including a lithium ion battery 31 is connected via the detection device 2. In addition to the lithium ion battery 31, the battery pack 3 includes a current sensor 32 that detects a charge / discharge current flowing through the lithium ion battery 31, a temperature sensor 33 that detects the ambient temperature of the lithium ion battery 31, and a lithium ion battery 31. A voltage sensor 34 for detecting the voltage is accommodated. The signal detected here is taken into the calculation device 1 by the detection device 2, and the calculation device 1 detects the charging state in which the current flowing in by the current sensor 32 is detected by the internal calculation algorithm 12 and the flowing out current. The determined discharge state and the rest state other than that are respectively determined, and the amount of electricity (remaining amount) stored in the lithium ion battery 31, the remaining charge / discharge time (remaining charge time, remaining discharge time) and the like are calculated.

  The computing device 1 includes a temperature-non-charge amount memory table 4 that stores the relationship between the temperature of the lithium ion battery 31 and the amount of electricity (non-charge amount) that is considered to be temporarily unchargeable, and the temperature of the lithium ion battery 31. And the temperature / current-non-discharge amount memory table 5 that preserves the relationship between the current and the amount of electricity (non-discharge amount) that is considered to be temporarily undischargeable, the voltage (open voltage) of the lithium ion battery 31 in the rest state, and lithium An open-circuit voltage-remaining rate memory table 6 that stores a relationship with a ratio (remaining rate) of the amount of electricity stored in the ion battery 31, a timer 7 that measures the charging time or discharging time of the lithium ion battery 31, and lithium A memory 8 that stores the remaining amount and the full charge amount stored in the ion battery 31 is connected.

  At the time of charging / discharging when the lithium ion battery 31 is charged / discharged, the calculation algorithm 12 adds the amount of charged electricity to the previous remaining amount stored in the memory 8 or the amount of discharged electricity from the previous remaining amount. A new remaining amount is obtained by subtraction. Here, the amount of charged electricity is calculated at the time of charging as the product of the charging current detected by the current sensor 32 and the time measured by the timer 7 (the amount of charged electricity for a predetermined time). The product of the detected discharge current and the time measured by the timer 7 (amount of discharge electricity for a predetermined time) can be calculated during discharge. In addition, the non-charge amount is obtained from the detected temperature with reference to the temperature-non-charge amount memory table 4, the chargeable amount is calculated using the remaining amount / full charge amount stored in the memory 8, and the detected temperature The non-discharge amount is obtained from the current by referring to the temperature / current-non-discharge amount memory table 5, and the dischargeable amount is calculated using the remaining amount stored in the memory 8. Further, the remaining charge / discharge time is obtained by dividing the chargeable amount and the dischargeable amount by a predetermined current value.

  At the time of non-charging / discharging when the current stops flowing in the lithium ion battery 31, the remaining amount calculation is performed in consideration of the self-discharge amount. That is, when the non-charge / discharge state has been in a resting state (resting state), the open voltage is detected by the voltage sensor 34 and the remaining voltage of the lithium ion battery 31 is determined by referring to the open voltage-remaining rate memory table 6. Find the quantity rate. Further, the remaining amount of the lithium ion battery 31 is obtained by multiplying the remaining amount rate by the full charge amount stored in the memory 8, and the remaining amount is corrected.

  These calculation results by the calculation device 1 are output to the external device 9, and the remaining amount of electricity stored in the lithium ion battery 31 can be displayed on the electricity display unit 10. Further, the remaining discharge time can be displayed on the time display unit 11 provided in the external device 9.

Next, the operation of the battery remaining amount measuring apparatus according to the first embodiment will be described.
In the remaining amount measuring device of FIG. 1, the processing contents by the calculation algorithm 12 are different in the charged state, the discharged state, and the rest state. That is, the computing device 1 determines what state the lithium ion battery 31 is currently in, and a series of processes corresponding to the state is executed.

  FIG. 2 is a flowchart showing state determination by the arithmetic algorithm 12 of FIG. In this state determination, first, it is checked whether or not a current flows through the lithium ion battery 31 from the measured value of the current sensor 32 (step S1). If a current is flowing, the current direction is checked (step S2). Here, when the current direction is the positive direction, it is determined as a charged state, and when the current direction is the negative direction, it is determined as a discharged state.

FIG. 3 is a flowchart illustrating an example of calculation processing in a charged state.
In the charged state, the computing device 1 first obtains the corresponding non-charge amount of the lithium ion battery 31 from the temperature measured by the temperature sensor 33 and the temperature-non-charge amount memory table 4 (step S11). Next, the remaining charge and the non-charge amount are subtracted from the full charge amount to obtain the chargeable electric amount of the lithium ion battery 31 (step S12). Further, the chargeable amount of electricity is divided by the current to obtain the chargeable time of the lithium ion battery 31 (step S13).

  Next, the voltage value of the lithium ion battery 31 measured by the voltage sensor 34 is not less than a predetermined value (for example, 4.15 V in the case of 1 cell), and the current value measured by the current sensor 32 is a predetermined value. (For example, 50 mA) or less is checked (steps S14 and S15), and if so, the process proceeds to step S16. In step S <b> 16, the full charge amount is corrected by replacing the full charge amount value with the remaining amount value stored in the memory 8.

FIG. 4 is a flowchart illustrating an example of calculation processing in a discharged state.
In the discharged state, the arithmetic device 1 first obtains the non-discharge amount of the corresponding lithium ion battery 31 from the temperature, current, and temperature / current-non-discharge amount memory table 5 measured by the temperature sensor 33 and the current sensor 32. (Step S17). Next, the non-discharge amount is subtracted from the remaining amount to obtain the dischargeable electricity amount of the lithium ion battery 31 (step S18). Further, the amount of electricity that can be discharged is divided by the current to determine the dischargeable time of the lithium ion battery 31 (step S19).

  Here, as the data of the temperature-non-charge amount memory table 4, the amount of charge that can be additionally charged shown in the graph of FIG. 24 is used, and the data of the temperature-current-non-discharge amount memory table 5 is used. Uses the amount of electric discharge that enables the additional discharge shown in the graphs of FIGS. 25 and 26 described above. In this case, when the temperature is higher than the normal temperature (20 ° C.), the charge more than the charge at the normal temperature (20 ° C.) is charged / discharged regardless of the charge or discharge. Therefore, the value obtained by subtracting the amount of electricity at normal temperature (20 ° C.) from the amount of electricity at a predetermined temperature is set as a non-charge amount and a non-discharge amount, respectively, and these values are shown as negative values for convenience. However, the reference value of the amount of electricity to be additionally charged / discharged may be set to a high temperature such as 60 ° C. instead of room temperature (20 ° C.). All values of discharge amount can be shown as positive values.

FIG. 5 is a flowchart illustrating an example of the calculation process in the sleep state.
In the rest state of the lithium ion battery 31, the arithmetic device 1 determines whether or not the voltage (open voltage) measured by the voltage sensor 34 is equal to or higher than a predetermined value (for example, 4.15V in the case of one cell) ( Step S21). If the open circuit voltage is equal to or higher than the predetermined value, the full charge amount value is replaced by the remaining amount value stored in the memory 8 to correct the full charge amount in the memory 8 (step S25).

  When the open circuit voltage is less than or equal to a predetermined value, it is checked whether or not the duration time of the resting state has exceeded a predetermined time, for example, 1 hour (step S22). The corresponding remaining rate of the lithium ion battery 31 is obtained from the open voltage and the open voltage-remaining rate memory table 6 (step S23). Furthermore, a new remaining amount value is calculated by multiplying the full charge amount of the memory 8 by the remaining amount rate (step S24) and replaced with the remaining amount value stored in the memory 8 (remaining amount correction).

  As described above, in the battery remaining amount measuring apparatus according to the first embodiment, the current sensor 32 that detects the current flowing through the lithium ion battery 31 and the current flowing into the lithium ion battery 31 are detected by the current sensor 32. The charging device, the discharging state in which the current flowing out from the lithium ion battery 31 is detected, and the resting state, and calculating the chargeable / dischargeable amount of electricity and the chargeable / dischargeable time according to the determination result; A temperature sensor 33 that detects the temperature of the lithium ion battery 31; a voltage sensor 34 that detects the voltage of the lithium ion battery 31; and an arithmetic unit 1 that calculates the remaining amount of the lithium ion battery 31 based on signals from the sensors. A timer 7 for measuring the duration of the charged state, a memory 8 for storing the remaining amount of the lithium ion battery 31 and the full charge amount of the lithium ion battery 31, The temperature-non-charge amount memory table 4 that stores the relationship between the ambient temperature of the lithium ion battery 31 and the amount of electricity (non-charge amount) that is considered to be temporarily unchargeable, and the temperature and current of the lithium ion battery 31 temporarily. The temperature / current-non-discharge amount memory table 5 that stores the relationship between the amount of electricity (non-discharge amount) that is considered to be undischargeable, the voltage (open voltage) of the lithium ion battery 31 in the rest state, and the lithium ion battery 31 An open-circuit voltage-remaining rate memory table 6 that stores the relationship with the ratio (remaining rate) of the stored electricity amount is provided. Therefore, even when the ambient temperature or current value of the lithium ion battery 31 at the time of discharge changes, it is displayed by obtaining the amount of electricity (non-discharge amount) considered to be temporarily unable to discharge from the changed temperature or current. This solves the problem that the remaining amount does not match the amount of electricity that can actually be discharged. Further, since the remaining rate is obtained from the open voltage and the open voltage-remaining rate memory table 6 when no current flows in the lithium ion battery 31 (zero current state), the battery voltage that fluctuates at no load is stabilized. Thus, the remaining amount can be accurately obtained.

(Second Embodiment)
FIG. 6 is a block diagram showing the overall configuration of the battery remaining amount measuring apparatus according to the second embodiment.

  In the battery remaining amount measuring apparatus according to the second embodiment, the processing content of the arithmetic algorithm 13 executed by the arithmetic device 1 when the lithium ion battery 31 is in the charged state and the resting state is the same as that of the first embodiment. It is different from the form. However, the configuration of the remaining amount measuring device is the same as that of the first embodiment shown in FIG.

  The state determination by the calculation algorithm 13 is the same as the state determination by the calculation algorithm 12 shown in FIG. 2, and the discharge processing in the discharge state is performed at the time of discharge by the calculation algorithm 12 shown in FIG. It is the same as arithmetic processing. In addition, in the remaining amount measuring apparatus in FIG. 6, the same reference numerals as those in FIG. 1 are given to portions corresponding to those in the first embodiment, and detailed description thereof will be omitted.

  In the description of the calculation algorithm 12 of the first embodiment, the non-charge amount is based on the charge amount at normal temperature (20 ° C.), and the charge amount under the reference condition (= the full charge amount at normal temperature). It shows how much the charge amount at a given temperature is small. The non-discharge amount is also based on the discharge amount of 0.2C at normal temperature (20 ° C), and the discharge amount under the standard condition (= full charge at normal temperature) The amount of discharge at a predetermined temperature at a predetermined temperature with respect to the amount) shows how much the discharge amount becomes small. Further, the amount of electricity that can be discharged in the discharge process is obtained in step S18 in which the non-discharge amount is subtracted from the remaining amount, and the amount of the remaining amount is a value obtained by integrating the charge / discharge electricity amount regardless of the temperature (calculation algorithm). 12 calculation formulas) was used. Therefore, in the calculation of the amount of electricity that can be discharged, the accuracy is lowered because the remaining amount (discharge amount under the reference condition) includes the influence of temperature. Regarding the calculation of the chargeable electricity amount in the charging process, since the remaining amount and the non-charge amount are similarly related, the accuracy is lowered.

  That is, in the first embodiment, the correction of the full charge amount in the charging process shown in FIG. 3 (step S16) and the correction of the full charge amount in the pause process shown in FIG. Since it was executed regardless of the temperature, the corrected full charge amount contained an error due to a temperature change. Here, considering the case where the amount of electricity that can be discharged is calculated after correcting the full charge amount under conditions other than the reference conditions, the effect of temperature is further added to the full charge amount including the effect of temperature. become. That is, the calculated value of the dischargeable electric quantity is an error in which the temperature influence is included in the original electric quantity.

FIG. 7 is a flowchart illustrating an example of calculation processing in a charged state.
Compared with the flowchart of the charging process shown in FIG. 3, the calculation process in the charging state of FIG. 7 includes a temperature check step S31 after the charging process step S15.

  In the second embodiment, the voltage value of the lithium ion battery 31 is also determined after a series of calculation (chargeable amount, chargeable time) processing is finished in step S11 to step S13 even when it is determined that the battery is in the charged state. Is equal to or higher than a predetermined value (for example, 4.15 V in the case of one cell) and the current value is equal to or lower than a predetermined value (for example, 50 mA), the temperature of the lithium ion battery 31 is checked in step S31. Only when it is determined to be in the range (for example, 15 to 30 ° C.), the full charge amount is corrected by replacing the full charge amount value with the remaining amount value stored in the memory 8 in step S16. If it is determined in step S31 that the temperature is other than room temperature, the full charge correction is not performed and the process returns to the state determination shown in FIG.

FIG. 8 is a flowchart illustrating an example of the calculation process in the hibernation state.
Compared with the flowchart of the pause process shown in FIG. 5, the temperature check step S32 is added after the open circuit voltage is determined to be greater than or equal to a predetermined value in step S21 of the pause process.

  In the second embodiment, when the lithium ion battery 31 is determined to be in a resting state and the voltage (open voltage) measured by the voltage sensor 34 is equal to or higher than a predetermined value (in the case of one cell, for example, 4.15 V). However, only when it is determined in step S32 that the temperature is in the normal temperature range (for example, 15 ° C. to 30 ° C.), the full charge amount value is replaced with the remaining amount value stored in the memory 8 and the full charge amount correction is performed. If it is determined in step S32 that the temperature is other than room temperature, the full charge amount correction is not performed and the process returns to the state determination shown in FIG.

FIG. 9 is a graph showing the temperature / current characteristics of the non-discharge amount, and FIG. 10 is a graph showing the temperature characteristics of the non-charge amount.
Looking at these temperature characteristics, there is a large change in the current characteristics of the non-discharge amount and the current characteristics of the non-charge amount for temperatures below room temperature (20 ° C.). However, there is little change in both the non-charge amount and the non-discharge amount in a temperature range above room temperature. That is, when the temperature is equal to or higher than normal temperature, both the discharge amount and the charge amount are substantially equal to those at normal temperature. Therefore, in the remaining amount measuring device of the lithium ion battery 31, the temperature check at step S31 and step S32 is performed. It can be seen that the temperature condition in is not limited to room temperature, and may be replaced with a condition of room temperature or higher.

  As described above, in the battery remaining amount measuring apparatus according to the second embodiment, the voltage value detected by the voltage sensor 34 is equal to or greater than a predetermined value, and the current value detected by the current sensor 32 is equal to or less than the predetermined value. In this case, when the temperature detected by the temperature sensor 33 is in the temperature range above room temperature, the full charge amount of the lithium ion battery 31 stored in the memory 8 is replaced with the remaining amount calculated by the arithmetic device 1. Therefore, when the charging process is performed, the full charge amount of the lithium ion battery 31 is corrected in the temperature range of room temperature or higher so that the corrected full charge amount does not always include the influence of the error due to the temperature. In the rest process, when the voltage value of the open circuit voltage is equal to or higher than a predetermined value and the temperature detected by the temperature sensor 33 is in the temperature range equal to or higher than normal temperature, the lithium ion battery 31 stored in the memory 8 is fully charged. The charge amount is replaced with the remaining amount value calculated by the arithmetic device 1. Therefore, when the discharge state is determined in the state determination after correcting the full charge amount, in step S18 for calculating the dischargeable amount of electricity in the discharge process of the lithium ion battery 31, the calculated remaining amount is doubled. Errors due to temperature effects can be eliminated.

(Third embodiment)
The configuration of the remaining battery level measuring apparatus according to the third embodiment is the same as that of the first embodiment shown in FIG. However, in the state determination by the arithmetic algorithm 12, the processing content is different. Note that the calculation algorithm 12 executed by the arithmetic device 1 when the lithium ion battery 31 is in the charge state, the discharge state, and the hibernation state are the charge processing and discharge processing already described in FIGS. 3, 4, and 5. , And pause processing.

  The state in which the current consumption of the battery pack 3 becomes the smallest during battery operation (connected to the AC power source) of the notebook personal computer is a state in which the personal computer is turned off. In this state, since the apparatus main body is not operating, current consumption in the battery pack 3 is considered to be zero. However, when the current values when a plurality of notebook personal computers were turned off were measured, it was confirmed that a minute current of about 5 mA was flowing in all the personal computers.

  From the open-circuit voltage-remaining rate characteristic, the remaining amount change rate at the practical minimum level (about 40% remaining rate) is about 0.35% / mV, and when considering that the remaining amount accuracy is within 1%, The allowable change amount of the open circuit voltage is 2.8 mV.

  FIG. 11 is a graph showing changes in the magnitude of the minute current flowing through the lithium ion battery and the open circuit voltage. This graph shows how a change in the amount of electricity of the lithium ion battery 31 affects the open-circuit voltage when a minute current continuously flows through the lithium ion battery 31 having a remaining rate of 40% for one hour. . According to this graph, it can be seen that if the magnitude of the current is within 13 mA, the amount of change in the open circuit voltage is within 2.8 mV, and the remaining capacity accuracy is 1%. If the remaining amount accuracy is considered to be within 2%, the current allowed from the same calculation is 26 mA or less. That is, considering that the remaining amount accuracy is about 1 to 2%, it can be said that there is no problem even if a minute current within 13 to 26 mA flows.

  FIG. 12 is a flowchart showing state determination by the arithmetic algorithm according to the third embodiment. Here, step S1 and step S2 correspond to the flowchart (FIG. 2) showing the state determination by the calculation algorithm 12 of FIG.

  In the state determination flowchart shown in FIG. 12, after determining whether or not a current flows through the lithium ion battery 31 in step S <b> 1, step S <b> 3 is executed and the magnitude of the current is a predetermined value (for example, 20 mA) or less. Whether or not the current value is checked. In this state determination, even if a current is flowing, it is checked whether it is a minute current. Process. For example, when the current exceeds 20 mA, the process proceeds to step S2 in which the current direction is checked, and any one of the charge / discharge processes is performed.

  As described above, in an electronic device in which a minute current flows even when the power is turned off, such as a notebook computer, when the remaining amount measuring device of the present invention is used, it can be recognized as a resting state even if a minute current is flowing. Therefore, in the battery remaining amount measuring apparatus according to the third embodiment, even if the current is not zero, the battery is in the resting state, and the remaining amount is corrected when the resting state has exceeded a predetermined time.

  In addition, when this remaining amount measuring device is applied to a notebook computer, even if a minute current is always flowing, it is recognized as a hibernation state, so the remaining amount is corrected appropriately, and this remaining amount correction and full charge amount correction are performed. Capacity learning can be performed through collaboration. For this reason, even when the actual capacity of the battery changes due to cycle deterioration or the like, there is an advantage that the accuracy of the remaining battery capacity to be measured does not deteriorate.

(Fourth embodiment)
The battery remaining amount measuring apparatus according to the fourth embodiment is different from the second embodiment shown in FIG. 6 in the processing contents of the arithmetic algorithm for executing the pause process. The configuration of the remaining amount measuring device is the same as that of the first embodiment. In addition, regarding the calculation algorithm executed by the calculation device 1 when the lithium ion battery 31 is in the state determination, charge state, or discharge state, the state determination, the charging process described above with reference to FIG. 2, FIG. 3, or FIG. It is the same as the discharge process.

  In the pause processing in the first embodiment, as shown in FIG. 5, the remaining amount correction (step S24) is performed regardless of the remaining amount rate of the battery. However, as will be described below, the open-circuit voltage change with respect to the remaining rate change is small at a low remaining rate of about 40% or less, and the characteristics of the lithium ion battery 31 after charging (charging characteristics) and after discharging (discharging characteristics). Therefore, the remaining amount error after correction when the remaining amount is corrected in this range becomes a problem.

FIG. 13 is a graph of the remaining rate characteristic showing the relationship between the open circuit voltage and the remaining rate.
Here, experimental data of charging characteristics and discharging characteristics are shown as two remaining rate characteristics. Charging characteristic data is charged from the state of zero remaining amount to a predetermined remaining amount rate, and then left for a certain period of time, when the battery voltage becomes substantially constant, a pause in which no current flows through the lithium ion battery 31 It shows the relationship between the voltage value (open circuit voltage) in a state and a predetermined remaining amount rate. In addition, the discharge characteristic data is obtained by discharging the battery from the fully charged state to the predetermined remaining capacity rate, and then leaving it for a certain period of time. When the battery voltage becomes substantially constant, It shows the relationship.

  When the remaining rate is about 40% or less, the change in the open-circuit voltage with respect to the change in the remaining rate is small. In this case, the difference in the remaining rate corresponding to the open circuit voltage becomes large. That is, when the remaining amount of the lithium ion battery 31 is corrected in the low remaining rate range, the remaining amount error after the correction is large. Further, in a normal notebook computer or the like, the battery pack 3 is shipped in a low charge state of about 30%, not in a fully charged state or a fully discharged state. Therefore, when the remaining amount is corrected only with a predetermined capacity (for example, 40%) or more, which always has a relatively high remaining amount accuracy, the remaining amount correction and the full charge amount correction are performed after the remaining amount measuring device is first activated. Until the capacity learning is carried out by cooperation with, the accuracy of the remaining amount display becomes very poor.

FIG. 14 is a flowchart illustrating an example of a calculation process in the sleep state by the calculation algorithm according to the fourth embodiment.
In the battery remaining amount measuring apparatus according to this embodiment, after the calculation of the remaining amount ratio in the pause process (step S23) in FIG. 5, a new activation number check (step S33) and a remaining amount ratio check (step S34) are performed. ). In the operation of the suspension process, when the suspension state continues for a predetermined time in step S22, the number of activations is checked after the remaining amount ratio is obtained in step S23 (step S33). When the rest process in the remaining amount measuring device is executed first, the process proceeds to step S24, and the remaining amount correction (remaining amount = full charge amount × remaining rate) is performed regardless of the remaining amount rate. However, if the remaining amount measuring apparatus is activated for the second time or later, the process proceeds to step S34. In this step S34, it is determined whether or not the remaining amount rate calculated in step S23 is equal to or greater than a predetermined value (for example, 40%). Correction (step S24) is performed. If it is determined in step S34 that the remaining amount rate is equal to or less than the predetermined value, the process returns to the state determination without newly calculating the remaining amount.

  As described above, when the battery remaining amount measuring apparatus according to the fourth embodiment is initially in the dormant state and the suspension process is executed in the computing device 1, the remaining amount ratio and Regardless of the remaining amount, the remaining amount is corrected only when the remaining rate is equal to or greater than a predetermined value in the second and subsequent pause states. Thereby, when the unused battery pack 3 is first activated, the remaining amount can be measured with a certain degree of accuracy, and the remaining amount can be measured with a relatively high accuracy during the second and subsequent pause processing. .

(Fifth embodiment)
FIG. 15 is a block diagram showing an overall configuration of a battery remaining amount measuring apparatus according to the fifth embodiment.

  In the battery remaining amount measuring apparatus according to the fifth embodiment, the processing content of the arithmetic algorithm 14 executed by the arithmetic device 1 when the lithium ion battery 31 is in a discharged state is different from that of the first embodiment. ing. However, the configuration of the remaining amount measuring device is the same as that of the first embodiment shown in FIG.

  The state determination by the calculation algorithm 14 is the same as the state determination by the calculation algorithm 12 shown in FIG. 2, and the calculation algorithm executed when the lithium ion battery 31 is in the charged state and the resting state is: This is the same as the charging process and the pause process already described with reference to FIGS. In addition, in FIG. 15, parts corresponding to those of the first embodiment are denoted by the same reference numerals as those in FIG. 1, and detailed description thereof is omitted.

  Next, processing of the calculation algorithm 14 executed at the time of discharging will be described. The computing device 1 refers to the temperature / current-non-discharge amount memory table 5 from the temperature and current at that time to obtain the non-discharge amount at the time of discharge, and subtracts this non-discharge amount from the remaining amount. The possible amount of electricity is calculated. Further, the dischargeable time is obtained by dividing the dischargeable amount of electricity by the current value. Furthermore, when the actual remaining amount is zero at the time of discharge, the remaining amount is replaced with a non-discharge amount and updated.

FIG. 16 is a diagram showing a change over time in the amount of electricity that can be discharged in the fifth embodiment.
As shown in FIG. 26, the characteristics of the lithium ion battery 31 used here are such that when the battery is fully charged at 20 ° C./0.2 C [A], the discharge amount is A + B = 5400C≈1500 mAH, 0 ° C. / The amount of discharge after becoming fully charged at 1 C [A] is A = 4500C≈1250 mAH.

  A case where charging / discharging is repeated at a temperature of 0 ° C., and the actual remaining amount matches the amount of dischargeable electricity recognized by the computing device 1 by the learning function, and then discharged from the fully charged state (1250 mAH). Is assumed.

  When the lithium ion battery 31 is repeatedly charged and discharged at 0 ° C. and in a fully charged state, the actual remaining amount is 1250 mAH (corresponding to A in FIG. 26). Further, the remaining amount recognized by the arithmetic device 1 is a value (1500 mAH) obtained by adding the actual remaining amount to the non-discharge amount (corresponding to B in FIG. 26), and the dischargeable electric amount is obtained by subtracting the non-discharge amount from the remaining amount. Value (1250 mAH). From this state, if the discharge with a discharge current value of 1 C [A] is started at timing t1, both the actual remaining amount and the amount of electricity that can be discharged are reduced.

  In the present invention, since the remaining discharge time is obtained by dividing the amount of electricity that can be discharged by the current value, the remaining discharge time at this time shows the same value as the remaining amount / current value obtained by the conventional method. . Then, at the timing t2 after the lapse of T1 from the start of discharge, the lithium ion battery 31 is in a completely discharged state, and the actual remaining amount, the amount of electricity that can be discharged, and the remaining discharge time are all zero, but at this time, The remaining amount recognized by the computing device 1 is replaced with the non-discharge amount. For this reason, the magnitude | size of residual amount corresponds with the non-discharge amount (equivalent to B of FIG. 26) determined by temperature and an electric current.

  Therefore, when the temperature changes to 20 ° C. at the next timing t 3 and additional discharge at 20 ° C./0.2 C [A] starts at timing t 4, the apparent remaining amount (actual remaining amount, ie, FIG. 26). Is equivalent to A). The arithmetic unit 1 recognizes that the remaining amount is 250 mAH when the previous preceding discharge is completed (timing t2), and the non-discharge amount in the temperature and current conditions at this time is 0 mAH. The amount of electricity that can be discharged is 250 mAH (250 mAH-0 mAH). That is, the apparent remaining amount (actual remaining amount) matches the amount of electricity that can be discharged, and the calculated remaining discharge time (dischargeable time) also matches the actual remaining discharge time T2.

  As described above, in the remaining amount measuring apparatus according to the fifth embodiment, when the temperature and the discharge current change in a state where the remaining amount is zero, the remaining discharge time displayed on the external device 9 and the actual discharge can be performed. Time matches. Further, in the display of the remaining discharge time in the external device 9, there is no difference from the actual dischargeable time, so that the user is not confused or distrusted. Furthermore, the amount of electricity stored in the lithium ion battery 31 can be used up until it is completely discharged, the substantial usage time is increased, and the frequency of charging is reduced.

(Sixth embodiment)
FIG. 17 is a block diagram showing a battery remaining amount measuring apparatus according to the sixth embodiment.
In the figure, reference numeral 1 denotes an arithmetic device, and 2 denotes a detection device that captures various sensor signals built in the battery pack 3. The battery pack 3 includes a lithium ion battery 31 as a secondary battery, and a current sensor 32 detects a current flowing through the lithium ion battery 31. The battery pack 3 further includes a temperature sensor that detects the temperature of the lithium ion battery 31 and a voltage sensor 34 that detects the voltage of the lithium ion battery 31.

  The computing device 1 calculates the remaining battery level based on the sensor signal captured by the detection device 2 from the battery pack 3. This computing device 1 includes a memory table (temperature-non-charge amount memory table) 4 that stores the relationship between the ambient temperature of the lithium ion battery 31 and the amount of electricity (non-charge amount) that is considered to be temporarily unchargeable, lithium A memory table (temperature / current-non-discharge amount memory table) 5 that stores the relationship between the ambient temperature and current of the ion battery 31 and the amount of electricity (non-discharge amount) considered to be temporarily unable to discharge; Memory table (open voltage-remaining memory table) storing the relationship between the battery voltage (open voltage) in a state where no current flows in the battery (open state) and the amount of electricity (remaining amount) stored in the lithium ion battery 31 61, 62, a timer 7 for measuring time, a memory 8 for storing the remaining amount and the full charge amount, a memory 81 for storing the current direction before the suspension, and an external device It is connected, such as 9. The external device 9 is connected to the computing device 1 and displays the remaining amount of electricity that can be supplied to an electronic device operated by the lithium ion battery 31, as well as the remaining charge time (rechargeable time) of the lithium ion battery 31, and discharge. The remaining time (dischargeable time) can be displayed.

  When compared with the remaining amount measuring device shown in FIG. 1, instead of the open-circuit voltage-remaining rate memory table 6, it is used when the direction of the current flowing through the lithium ion battery 31 immediately before entering the resting state is the charging direction. Open voltage (after charging) -remaining rate memory table 61 and open voltage (after discharging) -remaining rate memory table 62 used when the current direction is the discharging direction. The open-circuit voltage (after charging) -remaining rate memory table 61 and the open-circuit voltage (after discharging) -remaining rate memory table 62 store different remaining rate data.

  That is, in the remaining amount measuring apparatus according to the first embodiment shown in FIG. 1, only one type of remaining rate data is stored in the open-circuit voltage-remaining rate memory table 6 and is in a dormant state. The previous current direction was not memorized. Therefore, the open-circuit voltage-remaining rate memory table 6 has an open-circuit voltage after charging or after discharging as a characteristic that simultaneously represents an open-circuit voltage-remaining rate characteristic after charging and an open-circuit voltage-remaining rate characteristic after discharging. Only one of the remaining rate data of the remaining rate characteristic is set, or an intermediate value of the two remaining rate characteristics is set as the remaining rate data. On the other hand, here, a memory 81 for storing the direction of the current flowing in the lithium ion battery 31 before the suspension is added, and the calculation algorithm 15 stored in the calculation device 1 is slightly changed from the calculation algorithm 12. The current direction storage process at the time of charging / discharging and the remaining rate calculation process at the time of rest are executed. Since the configuration other than the memory tables 61 and 62 and the memory 81 is the same as that of the first embodiment shown in FIG. 1, detailed description thereof will be omitted.

Next, the operation of the battery remaining amount measuring apparatus according to the sixth embodiment will be described.
In the remaining amount measuring device in FIG. 17, the computing device 1 determines what state the lithium ion battery 31 is currently in, and a series of processes according to the state is performed.

  At the time of charging, the arithmetic unit 1 obtains the non-charge amount of the corresponding lithium ion battery 31 from the temperature measured by the temperature sensor 33 and the temperature-non-charge amount memory table 4. Next, the remaining charge and the non-charge amount are subtracted from the full charge amount to obtain the chargeable electric amount of the lithium ion battery 31. Further, the chargeable electricity amount is divided by the current to obtain the chargeable time of the lithium ion battery 31. At the time of discharging, the computing device 1 obtains the non-discharge amount of the corresponding lithium ion battery 31 from the temperature, current, and temperature / current-non-discharge amount memory table 5 measured by the temperature sensor 33 and the current sensor 32. . Next, the non-discharge amount is subtracted from the remaining amount to obtain the dischargeable electric amount of the lithium ion battery 31. Further, the amount of electricity that can be discharged is divided by the current to determine the remaining discharge time (dischargeable time) of the lithium ion battery 31 and sent to the external device 9 for display along with the remaining amount and remaining charge time (chargeable time). To do.

  The calculation algorithm 15 includes a calculation process for storing the direction of the current flowing in the lithium ion battery 31 in the memory 81 when the lithium ion battery 31 is being charged / discharged (during charging / discharging). In other words, the memory 81 stores the current direction data before the suspension when the state in which the charging / discharging current stops flowing to the lithium ion battery 31 enters the suspension state after a predetermined time.

  When the lithium ion battery 31 is stopped, the remaining rate data is obtained by using the open voltage detected by the voltage sensor 34 and the memory tables 61 and 62. Here, unlike the calculation processing method in the hibernation state shown in FIG. 14, two memory tables, that is, open voltage (after charging) −remaining rate by current direction data before the lithium ion battery 31 enters the hibernation state. The memory table 61 and the open-circuit voltage (after discharge) -remaining rate memory table 62 are properly used. Specifically, when the battery is charged before the hibernation state, the open circuit voltage (after charging) -remaining rate memory table 61. From the memory ratio 61 before the hibernation state, the open circuit voltage (after discharging) -remaining The remaining rate is read from the quantity rate memory table 62 and the remaining value stored in the memory 8 is corrected. Here, the remaining amount value stored in the memory 8 is corrected when the hibernation state continues for a predetermined time.

  As described above, the battery remaining amount measuring apparatus according to the sixth embodiment is an open-circuit voltage storing the remaining amount data when the current direction immediately before the lithium ion battery 31 enters the resting state is the charging direction. -Since there is a remaining capacity ratio memory table 61 and an open-circuit voltage-remaining capacity ratio memory table 62 that stores remaining capacity ratio data when the current direction immediately before entering the resting state is the discharging direction, the resting state Regardless of the state prior to (charging or discharging), the remaining amount ratio and remaining amount correction in the rest state of the lithium ion battery 31 can be performed with high accuracy. Accordingly, since the remaining amount (remaining time) is highly accurate and the time that the device can actually be used matches the usage time displayed on the external device 9, the user can trust the displayed usage time and feel at ease. There is an advantage that can be used. In addition, the remaining amount (remaining time) is highly accurate, and the time that the device can actually be used matches the usage time displayed on the device, so that the amount of electricity stored in the battery can be used up to the end. There is an advantage that the execution time of the apparatus becomes long.

  The open-circuit voltage (after charging) -remaining rate memory table 61 is constituted by remaining-rate data obtained by digitizing the charging characteristic data of FIG. 13, and the open-circuit voltage (after discharging) -remaining rate memory table 62 is It is the table comprised by the remaining rate data which digitized the discharge characteristic data of FIG.

(Seventh embodiment)
FIG. 18 is a block diagram showing a battery remaining amount measuring apparatus according to the seventh embodiment.
When compared with the remaining amount measuring device shown in FIG. 17, the open voltage (after discharge) -remaining rate ratio memory table 62 is eliminated, and an open voltage correction memory table 63 is added instead. The open voltage correction memory table 63 stores correction data for correcting the voltage value of the lithium ion battery 31 in the resting state.

  Further, a memory 81 for storing the direction of the current flowing through the lithium ion battery 31 before the suspension is added in the same manner, and the computation algorithm 16 stored in the computing device 1 is also slightly different from the processing during the suspension. The configuration other than the memory tables 61 and 63 and the memory 81 is the same as that of the first embodiment, and detailed description thereof is omitted.

  As for the operation of the remaining amount measuring device, the same arithmetic processing as that of the remaining amount measuring device in FIG. 17 is executed at the time of charging / discharging, but the calculating operation in the rest state is slightly different. That is, the current direction data is checked immediately before the rest state stored in the memory 81 at the time of rest, and when the current direction stored in the memory 81 is the discharge direction, the current direction data is stored in the open-circuit voltage correction memory table 63. Using the correction data, the open circuit voltage detected by the voltage sensor 34 is corrected.

  For example, in this open-circuit voltage correction memory table 63, for each open-circuit voltage, a voltage value corresponding to the voltage difference from the charge characteristic based on the discharge characteristic is stored, and the current direction immediately before the rest state is the discharge direction. Assume that the open-circuit voltage at that time is 3.797V. In that case, assuming that the lithium ion battery 31 has the remaining rate characteristic shown in FIG. 13, the set value of the open-circuit voltage correction memory table 63 corresponding to the open-circuit voltage 3.797V is 11 mV, The open circuit voltage at that time is corrected to 3.808 V (3.797 + 0.011).

  In this example, the actual remaining amount is 40%. When the open-circuit voltage is not corrected, the remaining amount ratio obtained from the open-circuit voltage at the time of discharge is determined according to the charging characteristics, so that the error is 4% ( The remaining capacity rate (36%) is also generated, but by correcting the open circuit voltage, the remaining capacity rate along the charging characteristic curve can be obtained after conversion into the open circuit voltage during charging, and the accurate remaining capacity rate (40 %). In the case where the current direction stored in the memory 81 is the charging direction, no error occurs in the remaining rate even if correction is not performed.

  As described above, in the battery remaining amount measuring apparatus according to the seventh embodiment, the open circuit voltage-remaining rate memory table includes correction data for correcting the voltage value of the lithium ion battery 31 in the resting state, and the resting state. Since the current direction immediately before entering the state is composed of the remaining rate data for either the charging direction or the discharging direction, the lithium ion battery 31 regardless of the state (charging or discharging) before the resting state. The remaining amount rate correction and remaining amount correction in the resting state can be performed with high accuracy.

  Here, the open voltage correction method based on the charging characteristic data has been described. However, instead of the open voltage (after charging) -remaining rate memory table 61, the open voltage (after discharging) -remaining rate memory table 62. May be used to store the voltage value corresponding to the difference voltage from the discharge characteristic with reference to the charging characteristic for each open circuit voltage in the open circuit voltage correction memory table 63 to correct the open circuit voltage of the lithium ion battery 31.

(Eighth embodiment)
FIG. 19 is a block diagram showing a battery remaining amount measuring apparatus according to the eighth embodiment.
When compared with the remaining amount measuring device shown in FIG. 18, the open circuit voltage correction memory table 63 is eliminated, and a remaining rate correction memory table 64 is added instead. The remaining rate correction memory table 64 stores difference data of remaining rate characteristics when the current direction immediately before entering the resting state is the charging direction and when the current direction is the discharging direction.

  Further, a memory 81 for storing the direction of the current flowing through the lithium ion battery 31 before the suspension is added in the same manner, and the computation algorithm 17 stored in the computing device 1 is also slightly different from the processing at the suspension. The configuration other than the memory tables 61 and 64 and the memory 81 is the same as that of the first embodiment, and a detailed description thereof will be omitted.

  As for the operation of the remaining amount measuring device, the same arithmetic processing as that of the remaining amount measuring device in FIG. 1 is executed during charging / discharging, but the calculating operation in the resting state is slightly different. That is, the remaining rate data is obtained by using the open circuit voltage and the open voltage (after charging) -remaining rate memory table 61 detected by the voltage sensor 34 during the pause. Next, the current direction data stored in the memory 81 is checked immediately before the hibernation state. If the current direction stored in the memory 81 is discharge, the difference stored in the remaining rate correction memory table 64 is stored. The remaining rate data is corrected using the data.

  For example, the remaining amount correction memory table 64 stores, for each open circuit voltage, differential data based on the discharge characteristics based on the charge characteristics, and the current direction immediately before the rest state is the discharge direction, and at that time Is an open circuit voltage of 3.797V. In this case, assuming that the lithium ion battery 31 has the remaining rate characteristic shown in FIG. 13, the remaining rate is obtained as 36% from the open circuit voltage (after charging) -remaining rate memory table 61. Since it was in the discharge state immediately before the resting state, the remaining amount data is corrected with reference to the remaining amount correction memory table 64. That is, since the set value of the remaining rate correction memory table 64 corresponding to the open circuit voltage 3.797V is + 4%, the remaining rate data is corrected to 40% (36 + 4).

  In this example, the actual remaining amount is 40%, and when the remaining rate data is not corrected, the value is in accordance with the charging characteristics, so that an error of 4% (remaining rate 36%) also occurs. However, since the remaining amount rate along the discharge characteristic curve can be obtained by correcting the remaining amount rate data, the remaining amount (remaining time) with high accuracy based on the accurate remaining rate (40%). Can be recognized.

  Here, the method of correcting the remaining rate based on the charging characteristic data has been described. However, instead of the open voltage (after charging) -remaining rate memory table 61, the open voltage (after discharging) -the remaining rate memory table. 62 is used to store the difference data from the charge characteristic data with reference to the discharge characteristic data for each open circuit voltage in the remaining rate correction memory table 64 to correct the remaining rate of the lithium ion battery 31. .

It is a block diagram which shows the whole structure of the battery residual amount measuring apparatus which concerns on 1st Embodiment. It is a flowchart which shows the state determination by the arithmetic algorithm of FIG. It is a flowchart which shows an example of the arithmetic processing in a charge condition. It is a flowchart which shows an example of the arithmetic processing in a discharge state. It is a flowchart which shows an example of the arithmetic processing in a dormant state. It is a block diagram which shows the whole structure of the battery residual amount measuring apparatus which concerns on 2nd Embodiment. It is a flowchart which shows an example of the arithmetic processing in a charge condition. It is a flowchart which shows an example of the arithmetic processing in a dormant state. It is a graph which shows the temperature-current characteristic of non-discharge amount. It is a graph which shows the temperature characteristic of the non-charging amount. It is a graph which shows the magnitude | size of the micro electric current which flows into a lithium ion battery, and the change of an open circuit voltage. It is a flowchart which shows the state determination by the arithmetic algorithm which concerns on 3rd Embodiment. It is a graph of the remaining rate characteristic which shows the relationship between an open circuit voltage and a remaining rate. It is a flowchart which shows an example of the arithmetic processing in the hibernation state by the arithmetic algorithm which concerns on 4th Embodiment. It is a block diagram which shows the whole structure of the battery residual amount measuring apparatus which concerns on 5th Embodiment. It is a figure which shows the time change of the electric quantity which can be discharged in 5th Embodiment. It is a block diagram which shows the whole structure of the battery residual amount measuring device which concerns on 6th Embodiment. It is a block diagram which shows the whole structure of the battery residual amount measuring apparatus which concerns on 7th Embodiment. It is a block diagram which shows the whole structure of the battery residual amount measuring device which concerns on 8th Embodiment. It is a block diagram which shows an example of the conventional residual amount measuring apparatus of a battery. It is a graph which shows an example of the relationship between the temperature in a conventional battery remaining amount measuring apparatus and charging efficiency. It is a graph which shows an example of the relationship between the temperature and discharge efficiency in the conventional battery remaining amount measuring apparatus. It is a graph which shows the relationship between a leaving period and a remaining rate with the temperature as a parameter of the battery made into the full charge state in the conventional battery remaining amount measuring device. It is a graph which shows the magnitude | size of the amount of charge electricity with respect to the prior charge temperature in the conventional battery remaining amount measuring apparatus. It is a graph which shows an example of the result of having discharged continuously by two types of discharge conditions (temperature and electric current) in the conventional battery remaining amount measuring apparatus. It is another graph which shows an example of the result of having discharged continuously by two types of discharge conditions (temperature and electric current) in the conventional battery remaining amount measuring apparatus.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Computation device 2 Detection device 3 Battery pack 4 Temperature-non-charge amount memory table 5 Temperature / current-non-discharge amount memory table 6 Open voltage-Remaining rate memory table 7 Timer 8 Memory 9 External device 10 Electricity amount display unit 11 hours Display unit 12 to 17 Arithmetic algorithm 31 Lithium ion battery 32 Current sensor 33 Temperature sensor 34 Voltage sensor 61 Opening voltage (after charging) -remaining rate memory table 62 Opening voltage (after discharging) -Residual rate memory table 63 Opening voltage correction Memory table 64 Remaining rate correction memory table

Claims (6)

A battery that measures the remaining amount of electricity at the time of charging / discharging of the secondary battery, and executes the remaining amount correction based on the remaining rate of the secondary battery when the charging / discharging of the secondary battery is stopped for a predetermined time. In the remaining amount measuring device,
A voltage sensor for detecting a voltage of the secondary battery;
An arithmetic unit that calculates a remaining value of the secondary battery according to a voltage signal detected by the voltage sensor;
A memory for storing the remaining amount value calculated by the arithmetic unit and a current direction flowing through the secondary battery, respectively;
As a remaining rate characteristic indicating a relationship between a voltage value in a resting state in which no current flows in the secondary battery and a ratio of the amount of electricity stored in the secondary battery, the current direction immediately before the resting state is charged. Different remaining rate data when the direction is the direction and when the direction is the discharge direction, correction data for correcting the voltage value of the secondary battery in the rest state, and immediately before the rest state An open-circuit voltage-remaining rate memory table storing remaining rate data for either the charging direction or the discharging direction of the current direction ,
And a remaining capacity value stored in the memory is corrected by remaining capacity data read from the open-circuit voltage-remaining capacity ratio memory table in accordance with a current direction stored in the memory. Remaining amount measuring device.   2. The battery remaining amount measuring device according to claim 1, wherein the remaining amount value stored in the memory is corrected when the hibernation state continues for a predetermined time.   2. The remaining battery level according to claim 1, wherein when the voltage value of the secondary battery in the hibernating state is equal to or greater than a predetermined value, the full charge amount stored in the memory is replaced with a new remaining amount value. Measuring device.   The battery remaining amount measuring device according to claim 1, further comprising a current sensor that detects a direction of a current flowing through the secondary battery.   The battery residual quantity measuring device according to any one of claims 1 to 4, wherein the secondary battery is a lithium ion battery.   A battery that measures the remaining amount of electricity at the time of charging / discharging of the secondary battery, and executes the remaining amount correction based on the remaining rate of the secondary battery when the charging / discharging of the secondary battery is stopped for a predetermined time. In the remaining amount measuring device,
  A voltage sensor for detecting a voltage of the secondary battery;
  An arithmetic unit that calculates a remaining value of the secondary battery according to a voltage signal detected by the voltage sensor;
  A memory for storing the remaining amount value calculated by the arithmetic unit and a current direction flowing through the secondary battery, respectively;
  As a remaining rate characteristic indicating a relationship between a voltage value in a resting state in which no current flows in the secondary battery and a ratio of the amount of electricity stored in the secondary battery, the current direction immediately before the resting state is charged. The remaining amount rate data is different depending on whether the current direction is the discharge direction or the discharge direction, and the current direction immediately before the sleep state is the remaining amount rate data for either the charging direction or the discharging direction. An open-circuit voltage-remaining rate memory table storing difference data of the remaining rate characteristics when the current direction immediately before entering the resting state is a charging direction and a discharging direction;
  And a remaining capacity value stored in the memory is corrected by remaining capacity data read from the open-circuit voltage-remaining capacity ratio memory table in accordance with a current direction stored in the memory. Remaining amount measuring device.

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