JP2005265682A - Battery status detecting apparatus and method - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a battery state detecting apparatus and its related technologies, capable of accurately and easily detecting the state of a lead battery, even during traveling. <P>SOLUTION: When the lead battery 7 is charged and discharged with close timings, the charge and the discharge are detected by a detection processing part 5 via a current-detecting part 1 to acquire both a charge internal resistance value based on the charge and a discharge internal resistance value, based on the discharge. The charge internal resistance value and the discharge internal resistance value are derived and acquired via the use of Ohm's relational expression etc., on the basis of both charge and discharge current values detected via the current-detecting part 1 at the charge and the discharge and the amount of change in terminal voltages, before and after the start of the charge and the discharge detected via a voltage-detecting part 3. A ratio between the internal resistance values is derived by the detection processing part 5, and the battery residual quantity of the lead battery 7 at that time is detected, on the basis of the derived ratio between the internal resistance values. <P>COPYRIGHT: (C)2005,JPO&NCIPI

Description

  The present invention relates to a battery state detection device for detecting a state (remaining battery level or degree of deterioration) of a lead battery mounted on a vehicle and related technology.

  Various technologies have been proposed for detecting the state of lead batteries installed in vehicles, but the state of lead batteries in use (during traveling, etc.) that are frequently charged and discharged are accurately detected. It is difficult to do. For example, as a conventional technique, there is a technique for detecting the remaining battery level by detecting the open terminal voltage of a lead battery. However, since the lead battery is frequently charged and discharged during traveling, the concentration gradient in the solution of the lead battery, etc. As a result, the open terminal voltage is not stable and the remaining battery level cannot be detected accurately.

  Therefore, the problem to be solved by the present invention is to provide a battery state detection device and related technology capable of accurately and easily detecting the state of a lead battery even during traveling.

  In order to solve the above-mentioned problem, in the invention of claim 1, a battery state detection device for detecting a state of a lead battery mounted on a vehicle, wherein a current charged or discharged to the lead battery is detected. A current detection means; a voltage detection means for detecting a terminal voltage of the lead battery; and a charge / discharge current value detected via the current detection means when charging or discharging of the lead battery is started. And a detection processing means for detecting the state of the lead battery based on the amount of change in the terminal voltage before and after the start of the charge / discharge detected via the voltage detection means.

  According to a second aspect of the present invention, in the battery state detection device according to the first aspect of the invention, the detection processing unit is configured to control the lead battery based on the charge / discharge current value and the change amount of the terminal voltage. An internal resistance value is derived, and the state of the lead battery is detected based on the internal resistance value.

  According to a third aspect of the present invention, in the battery state detection device according to the second aspect of the present invention, the detection processing means is a charge internal resistance that is the internal resistance value derived when the lead battery is charged. The state of the lead battery is detected based on the value and a discharge internal resistance value that is the internal resistance value derived when the lead battery is discharged.

  According to a fourth aspect of the present invention, in the battery state detection device according to the third aspect of the present invention, the detection processing means is configured to determine the state of the lead battery based on a ratio between the charge internal resistance value and the discharge internal resistance value. Is detected.

  According to a fifth aspect of the present invention, in the battery state detection device according to any one of the first to fourth aspects, the detection processing means is based on the current value of the charge / discharge and the amount of change in the terminal voltage. Then, at least one of the remaining battery level and the deterioration level of the lead battery is detected.

  The invention of claim 6 is a battery state detection method for detecting a state of a lead battery mounted on a vehicle, wherein the current detection means detects a current charged or discharged to the lead battery, and Voltage detection means for detecting a terminal voltage of the lead battery, and when charging or discharging the lead battery is started, the charge / discharge current value detected via the current detection means, and the voltage detection The state of the lead battery is detected based on the change amount of the terminal voltage before and after the start of the charge / discharge detected through the means.

  According to the first to sixth aspects of the present invention, when charging or discharging of the lead battery is started, the charge / discharge current value and the change amount of the terminal voltage of the lead battery before and after the start of the charge / discharge. Since the state of the lead battery is detected based on the above, the state of the lead battery can be detected accurately and easily in accordance with a desired charge / discharge timing even during traveling.

  According to the second aspect of the present invention, the internal resistance value of the lead battery is derived based on the charge / discharge current value and the change amount of the terminal voltage, and the state of the lead battery is detected based on the internal resistance value. Therefore, the state of the lead battery can be detected accurately and easily.

  According to the third aspect of the present invention, the charging internal resistance value that is derived when the lead battery is charged and the internal resistance value that is derived when the lead battery is discharged. Since the state of the lead battery is detected based on a certain discharge internal resistance value, the state of the lead battery can be detected accurately and easily.

  According to the invention described in claim 4, since the state of the lead battery is detected based on the ratio between the charge internal resistance value and the discharge internal resistance value, the state of the lead battery can be detected accurately and easily.

  FIG. 1 is a block diagram of a battery state detection device (hereinafter simply referred to as “state detection device”) according to an embodiment of the present invention. As shown in FIG. 1, the state detection device includes a current detection unit (current detection unit) 1, a voltage detection unit (voltage detection unit) 3, a detection processing unit (detection processing unit) 5 including a CPU and the like. The state of the lead battery 7 (at least one of the remaining battery level and the degree of deterioration) mounted on the vehicle is detected. Here, the remaining battery level indicates the amount of charge that can be discharged with reference to when the lead battery 7 is fully charged, and the degree of deterioration indicates the degree of deterioration of the lead battery 7 due to secular change.

  The current detection unit 1 is inserted in a charging / discharging energization path 9 connected to the plus terminal of the lead battery 7 and detects a current charged or discharged to the lead battery 7. The voltage detector 3 detects the terminal voltage of the lead battery 7.

  When the charging or discharging of the lead battery 7 is started, the detection processing unit 5 detects the charge / discharge current value detected via the current detection unit 1 and the charge detected via the voltage detection unit 3. Based on the amount of change in the terminal voltage before and after the start of discharge, the remaining battery level and the degree of deterioration of the lead battery 7 are detected. Detection by the detection processing unit 5 to start charging or discharging the lead battery 7 is performed based on, for example, detection of a charge / discharge current by the current detection unit 1.

  Below, the principle of the state detection of the lead battery 7 which concerns on this embodiment is demonstrated.

  FIG. 2 is a graph showing the results of measuring the change state of the terminal voltage when charging / discharging the lead battery at various current values. In the test of FIG. 2, the open terminal voltage (remaining battery level) is varied in various ways with respect to the lead battery 7 in which the open terminal voltage is stable at a value corresponding to the remaining battery level. The terminal voltage immediately after the start of each charge / discharge (for example, 100 ms after the start of charge / discharge (charging / discharging is continuing)) was measured. The horizontal axis of the graph of FIG. 2 corresponds to the open terminal voltage, and the vertical axis corresponds to the terminal voltage immediately after the start of charging / discharging. Each series of the graphs G1a to G1c in FIG. 2 shows the terminal voltage measurement results after a minute time (for example, after 100 ms) from the start of charging when charging 5A, 10A, and 15A at each open terminal voltage. Each series of graphs G2a to G2c corresponds to the measurement result of the terminal voltage after a minute time (for example, after 100 ms) from the start of discharge when discharging 5A, 10A, and 15A at each open terminal voltage. It corresponds. The series of graph G3 shows the state when charging / discharging is not performed (when there is no change in terminal voltage) as a reference.

  From the test results of FIG. 2, in a state where the open terminal voltage is relatively high (a state where the remaining battery level is large) (for example, a region indicated by A1 in FIG. 2), the higher the open terminal voltage (the greater the remaining battery level). It turns out that the variation | change_quantity of the terminal voltage of the lead battery 7 with respect to charging / discharging (especially charge) is large. From this, it can be seen that at least the remaining battery level of the lead battery 7 can be estimated based on the current value during charging and discharging and the amount of change in the terminal voltage.

  Moreover, these quantity values are greatly related to the deterioration degree of the lead battery 7 as described below, and the deterioration degree of the lead battery 7 can be estimated based on these quantity values. FIG. 3 is a graph comparing the amount of change in terminal voltage associated with charging / discharging for two types of lead batteries having different degrees of deterioration. More specifically, the graph G11 in FIG. 3 shows the amount of change in the terminal voltage during charging / discharging by charging / discharging the new lead battery 7 with about 80% remaining battery power while changing the current value. The graph G12 shows the amount of change in the terminal voltage during charging / discharging by charging / discharging the deteriorated lead battery 7 whose remaining battery level is about 75% while changing the current value. The measurement result is shown. From the graph of FIG. 3, it can be seen that if the remaining battery level is the same, the amount of change in the terminal voltage with respect to charge and discharge at each level is greater in the degraded product than in the new product.

In the present embodiment, in order to obtain a more advantageous quantity index for estimating the remaining battery level and the degree of deterioration of the lead battery 7, the detection processing unit 5 is provided with a current value and a change amount of the terminal voltage during charging / discharging. Based on this, the internal resistance value of the lead battery 7 at that time is derived. The derivation of the internal resistance value Rin is based on Ohm's law using, for example, the current value I during charge / discharge and the terminal voltage variation dV.
Rin = dV / I
The following relational expression can be used.

  FIG. 4 is a graph showing the relationship between the open terminal voltage and the derived internal resistance value when charge / discharge of a predetermined current value is performed on a lead battery (new lead battery), and the horizontal axis of the graph is Corresponding to the open terminal voltage, the vertical axis corresponds to the internal resistance value. More specifically, a graph G21 in FIG. 4 shows an internal resistance value (charging internal resistance value) derived based on a measurement result when charging is performed at 10 A at different open-circuit voltages, and the graph G22 These show the internal resistance value (discharge internal resistance value) derived based on the measurement result when discharging 10 A at different open terminal voltages. From the graph of FIG. 4, particularly in a relatively high open terminal voltage state, there is a strong correlation between the internal resistance value (particularly the charge internal resistance value derived at the time of charging) and the open terminal voltage (remaining battery level). I understand that.

  Further, since the internal resistance value is a very effective quantity index for evaluating the degree of deterioration of the lead battery 7 (generally, the internal resistance value increases as the deterioration progresses), and thus the derived internal resistance value is used. The degree of deterioration of the lead battery 7 can be estimated. Therefore, for example, the detection processing unit 5 can detect the degree of deterioration of the lead battery 7 based on one or both of the derived charge internal resistance value and discharge internal resistance value. In this case, for example, when a predetermined threshold level is provided and it is detected that the charge internal resistance value or the discharge internal resistance value exceeds the threshold level, the detection processing unit 5 is notified of the deterioration of the lead battery 7. A notification signal may be output.

  Further, in the present embodiment, in order to obtain a more effective quantity index for detecting the state of the lead battery 7, the state detection is performed by calculating the ratio between the charging internal resistance value and the discharging internal resistance value acquired at timings close to each other. I am trying to use it. FIG. 5 is a graph showing a value of a ratio between a charge internal resistance value and a discharge internal resistance value acquired when a lead battery (new lead battery) is charged / discharged with a predetermined current value at different open terminal voltages. is there. More specifically, the value of the ratio between the charging internal resistance value and the discharging internal resistance value in FIG. 5 is obtained by charging and discharging a predetermined current value (for example, 10 A) at approximate timings at different open terminal voltages. This is performed for the lead battery 7, and the charge internal resistance value and the discharge internal resistance value are obtained by the above-described method at the time of charge / discharge, and the charge internal resistance value is divided by the discharge internal resistance value. Yes. From the graph of FIG. 5, in a state where the open terminal voltage is relatively high (a state where the battery remaining amount is relatively large), the ratio of both internal resistance values and the open terminal voltage (remaining battery amount) are significantly close to a proportional relationship. It can be seen that the remaining battery level can be estimated from the ratio between the two internal resistance values.

  Therefore, in the present embodiment, when the lead battery 7 is charged and discharged at close timing, the detection processing unit 5 detects the charge / discharge via the current detection unit 1 and is based on the charging. A charge internal resistance value and a discharge internal resistance value based on discharge are acquired. As described above, the charge internal resistance value and the discharge internal resistance value are the charge / discharge current value detected via the current detector 1 during the charge / discharge and the charge / discharge detected via the voltage detector 3. Based on the amount of change in terminal voltage before and after the start of charging (for example, the difference between the terminal voltage before the start of charge / discharge and the terminal voltage 100 ms after the start of charge / discharge) Is obtained and obtained. Then, the detection processing unit 5 is caused to derive a ratio between the internal resistance values (for example, a value obtained by dividing the charging internal resistance value by the discharge internal resistance value), and based on the derived ratio between the internal resistance values, The state of the lead battery 7 (particularly the remaining battery level) is detected.

  Here, the detection of the remaining battery level based on the ratio between the two internal resistance values is, for example, data (data table or the like) indicating a correspondence relationship between the internal resistance value and the remaining battery amount obtained in advance by a test. Can be registered in the storage unit of the detection processing unit 5 and the correspondence data can be used. In this case, the detection processing unit 5 may display information regarding the detected remaining battery level via a predetermined display unit (not shown).

  In the present embodiment, the charging / discharging of the lead battery 7 is detected and the state of the lead battery 7 is detected at that timing. However, the detection processing unit 7 includes a load, an alternator, a regulator, and the like. By controlling the charge / discharge of the lead battery 7 at a predetermined level, the detection processing unit 5 may positively control the charge / discharge timing for the lead battery 7 that can be used for state detection.

  As described above, according to the present embodiment, when charging or discharging of the lead battery 7 is started, the current value of the charge / discharge and the change in the terminal voltage of the lead battery 7 before and after the start of the charge / discharge. Since the state of the lead battery 7 is detected based on the amount, the state of the lead battery 7 can be detected accurately and easily in accordance with the desired charge / discharge timing even during traveling.

  In particular, in the present embodiment, the lead battery 7 is determined based on the ratio between the charge internal resistance value and the discharge internal resistance value derived based on the measurement associated with the charge and discharge performed on the lead battery 7 at approximate timing. Since the state (particularly, the remaining battery level) is detected, the state can be detected more accurately and easily.

It is a block diagram of the battery state detection apparatus which concerns on one Embodiment of this invention. It is a graph which shows the result of having measured the change state of the terminal voltage at the time of charging / discharging with various electric current values with respect to a lead battery. It is the graph which compared the variation | change_quantity of the terminal voltage accompanying charging / discharging about two types of lead batteries from which a deterioration degree differs. It is a graph which shows the relationship between the open terminal voltage at the time of charging / discharging of a predetermined electric current value with respect to a lead battery, and the derived | led-out internal resistance value. It is a graph which shows the value of the ratio of the charge internal resistance value acquired when charging / discharging a lead battery with a predetermined current value in a different open terminal voltage, and a discharge internal resistance value.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Current detection part 3 Voltage detection part 5 Detection processing part 7 Lead battery

Claims (6)

A battery state detection device for detecting a state of a lead battery mounted on a vehicle,
Current detecting means for detecting current charged or discharged with respect to the lead battery;
Voltage detecting means for detecting a terminal voltage of the lead battery;
When charging or discharging of the lead battery is started, the current value of the charge / discharge detected via the current detection means and before and after the start of the charge / discharge detected via the voltage detection means Based on the amount of change in the terminal voltage, detection processing means for detecting the state of the lead battery,
A battery state detection device comprising: The battery state detection device according to claim 1,
The detection processing means includes
A battery characterized in that an internal resistance value of the lead battery is derived based on the charge / discharge current value and an amount of change in the terminal voltage, and a state of the lead battery is detected based on the internal resistance value. Condition detection device. The battery state detection device according to claim 2,
The detection processing means includes
The charge internal resistance value that is the internal resistance value derived when the lead battery is charged and the discharge internal resistance value that is the internal resistance value derived when the lead battery is discharged. A battery state detection device for detecting a state of the lead battery based on the battery. The battery state detection device according to claim 3,
The detection processing means includes
A battery state detection device that detects a state of the lead battery based on a ratio between the charge internal resistance value and the discharge internal resistance value. In the battery state detection device according to any one of claims 1 to 4,
The detection processing means detects at least one of a remaining battery level and a degree of deterioration of the lead battery based on the charge / discharge current value and the amount of change in the terminal voltage. Condition detection device. A battery state detection method for detecting a state of a lead battery mounted on a vehicle,
Using current detection means for detecting current charged or discharged with respect to the lead battery, and voltage detection means for detecting a terminal voltage of the lead battery,
When charging or discharging of the lead battery is started, the current value of the charge / discharge detected via the current detection means and before and after the start of the charge / discharge detected via the voltage detection means A battery state detection method, comprising: detecting a state of the lead battery based on a change amount of the terminal voltage.

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