JP4983513B2 - Vehicle battery management device - Google Patents

Description

  The present invention relates to a battery management device that manages a battery mounted on a vehicle.

2. Description of the Related Art Conventionally, a battery management device mounted on a vehicle has been developed that manages its charge state and deterioration state by calculating the internal resistance value and open circuit voltage of the battery.
For example, in Patent Document 1, in an output deterioration calculation device for a secondary battery mounted on a hybrid electric vehicle, an open-circuit voltage of the battery is detected when the generator motor is not operated, and an internal resistance is determined using a preset map. A configuration for calculating a value is disclosed. Thereby, the internal resistance value of the battery can be obtained without using a current sensor.

Further, in Patent Document 2, in the battery remaining capacity estimation device, a relational expression (V ₀ = V−R · I) of the open circuit voltage V ₀ , the terminal voltage V, the internal resistance value R, and the current I of the battery is used. A method for estimating the battery internal resistance value R is disclosed. In this technique, the open-circuit voltage V ₀ and the internal resistance value R are estimated by detecting data of the terminal voltage V and the current I under two different load conditions.

For example, two different terminal voltages detected in such a short time that the open voltage V _{0 of the} battery and the internal resistance value R do not change, and the load current at that time (positive during discharging and negative during charging) are respectively (V ₁ , I ₁ ), (V ₂ , I ₂ ), the internal resistance value R is estimated based on the following formula A.

With such a method, the internal resistance value R of the battery can be easily estimated.
JP 2003-018756 A JP 2001-330654 A

However, the characteristics of the battery vary greatly depending on the remaining capacity of the battery power, the temperature condition, and the deterioration state. Therefore, general-purpose map setting as described in Patent Document 1 is difficult, and the battery cannot be managed accurately.
On the other hand, when the relational expression as described in Patent Document 2 is used, the denominator of the above-described expression A becomes small if the difference between the values of two different detected terminal voltages and load currents is small. The calculation error becomes large and the reliability of the calculation result is lowered. On the other hand, if two data are collected after a time that increases the difference between the terminal voltage and the load current, the actual internal resistance value R will fluctuate during that time, and an accurate calculation cannot be expected. In addition, the fluctuation of the calculated internal resistance value R tends to be large, and filtering may be necessary.

  The present invention has been devised in view of such problems, and an object of the present invention is to provide a vehicle battery management device that can accurately grasp the state of the battery with a simple configuration.

A battery management device for a vehicle according to the present invention (Claim 1) is a management device for a battery mounted on a vehicle, and detects voltage between terminals of the battery and voltage detection means for detecting a voltage between terminals of the battery. Current detection means for determining, open-circuit voltage determination means for determining an open-circuit voltage of the battery, current between the terminals detected by the current detection means, voltage between the terminals detected by the voltage detection means, and determination of the open-circuit voltage An internal resistance value calculating means for calculating the internal resistance value of the battery based on the open circuit voltage determined by the means , and a torque detecting means for detecting the torque of the electric motor driven by the power of the battery, The internal resistance value calculating means calculates the internal resistance value when the absolute value of the torque detected by the torque detecting means exceeds a predetermined torque value set in advance .

According to the vehicle battery management apparatus (claim 2) of the present invention, in addition to the configuration according to claim 1, the open-circuit voltage determining means is configured such that the inter-terminal current is less than a preset current value. The voltage between the terminals detected by the voltage detecting means is determined to be the open circuit voltage of the battery.
For example, the open-circuit voltage determining means may be configured to regard the voltage between the terminals when the vehicle is idling as the open-circuit voltage. Alternatively, the voltage between the terminals may be regarded as the open voltage when the state where the current between the terminals is 0 or weak continues for a predetermined time or more.

In addition to the configuration of the second aspect, the battery management apparatus for a vehicle according to the present invention (Claim 3) is characterized in that the internal resistance value calculating means includes a second predetermined current in which the inter-terminal current is larger than the predetermined current value. The internal resistance value of the battery is calculated using the open-circuit voltage determined by the inter-terminal voltage, the inter-terminal current, and the open-circuit voltage determining means when the value is equal to or greater than the value.
For example, the current detection means detects a first terminal current less than the predetermined current value when the vehicle is stopped and a second terminal current greater than the second predetermined current value when the vehicle is running, The voltage detection means detects the first terminal voltage when the first terminal current is detected and the second terminal voltage when the second terminal current is detected.

  Further, the open-circuit voltage determining means determines that the first terminal voltage is the open-circuit voltage of the battery when the first terminal current is less than a predetermined current value. The internal resistance value calculating means calculates the internal resistance value of the battery using the second terminal current, the second terminal voltage, and the open voltage.

  According to a fourth aspect of the present invention, there is provided a battery management apparatus for a vehicle according to the fourth aspect of the present invention, wherein the internal resistance value calculating means is configured so that the internal resistance value calculation means is in accordance with the following formula. It is characterized by computing.

The vehicle battery management device (Claim 5 ) of the present invention stores the internal resistance value calculated by the internal resistance value calculation means in addition to the configuration described in any one of Claims 1 to 4. Storage means, and when the internal resistance value is calculated by the internal resistance value calculation means, the storage means is within a predetermined update range set in advance from the previously stored internal resistance value. It is characterized by updating the internal resistance value.

According to the battery management apparatus for a vehicle of the present invention (Claim 1), the battery open-circuit voltage is determined in advance prior to the calculation of the internal resistance value, so that the internal resistance value of the battery can be accurately determined without using a reference map. Can be calculated. This makes it possible to determine the deterioration state of the battery and to calculate the maximum output value and maximum input value of the battery. In addition, the calculated internal resistance value can be stabilized by calculation in a state where the torque value is large.
Moreover, according to the vehicle battery management apparatus for a vehicle of the present invention (Claim 2), the influence of the voltage drop caused by the internal resistance can be reduced by measuring the voltage between the terminals when the current between the terminals is small. The open circuit voltage can be accurately determined.

Moreover, according to the battery management apparatus for a vehicle of the present invention (Claim 3), the degree of the influence of the internal resistance on the change of the inter-terminal current is accurately grasped by using the inter-terminal voltage in a state where the inter-terminal current is large. The internal resistance value can be calculated accurately.
Moreover, according to the battery management device for a vehicle of the present invention (Claim 4), the open-circuit voltage is determined in advance, so that any current between terminals and voltage during charging / discharging of the battery can be used accurately. The internal resistance value can be calculated.

Also, according to the battery management apparatus for a vehicle of the present invention (Claim 5), it is possible to it is possible to suppress the updating of the internal resistance value, keep the operation result of more accurate internal resistance .

  Hereinafter, an embodiment of the present invention will be described with reference to the drawings. 1 to 5 illustrate a vehicle battery management apparatus according to an embodiment of the present invention. FIG. 1 is a block diagram showing the overall configuration of the battery management apparatus. FIG. FIG. 3 is a flowchart showing a control procedure when determining the open circuit voltage by the battery management device, and FIG. 4 shows a control procedure when calculating the internal resistance value by the battery management device. The flowchart and FIG. 5 are graphs comparing the internal resistance value obtained by the battery management apparatus and the internal resistance value obtained by the conventional technique.

[Constitution]
The battery management apparatus of this embodiment is applied to the electric vehicle 10 shown in FIG. 1 and includes a battery 1, an ammeter (current detection means) 2, a voltmeter (voltage detection means) 3, a battery ECU 4, an inverter 5, and a motor. An ECU (torque detection means) 6 and a motor (electric motor) 7 are provided.

The battery 1 is a main power source of a motor 7 that is a drive source of the electric vehicle 10, and is configured by connecting a plurality of lithium ion battery modules in series. The electric power stored in the battery 1 is supplied to the motor 7 via the inverter 5. In the present embodiment, the open-circuit voltage of the battery 1 is V ₀ [V], and the internal resistance value is R [Ω].
In general, the open circuit voltage V ₀ and the internal resistance value R vary according to the deterioration state of the battery 1, the SOC, the load condition for the battery 1, and the like. Therefore, as will be described below, the present battery management device has a configuration for accurately grasping the open-circuit voltage V ₀ and the internal resistance value R that change from moment to moment.

First, the inverter 5 is a power control circuit having a function of converting a direct current on the battery 1 side and an alternating current on the motor 7 side. The inverter 5 is provided with a motor ECU 6.
The motor ECU 6 is an electronic control device configured by, for example, a microcomputer, and is provided as an LSI device in which a known microprocessor, ROM, RAM, and the like are integrated. The motor ECU 6 is configured to output a motor torque command value T [Nm] having a magnitude corresponding to the traveling state of the vehicle and the operation of the driver to the motor 7. Thereby, the electric power supplied to the motor 7 and the electric power regenerated from the motor 7 to the battery 1 are electronically controlled.

In the present embodiment, the motor torque command value T output from the motor ECU 6 is also input to the battery ECU 4. That is, the motor ECU 6 has a function as torque detection means for detecting the torque of the motor 7 driven by the electric power of the battery 1.
An ammeter 2 and a voltmeter 3 are interposed in the power supply line that connects the battery 1 and the inverter 5. The ammeter 2 detects the inter-terminal current I [A] of the battery 1, and the voltmeter 3 detects the inter-terminal voltage V [V] of the battery 1. The detected inter-terminal current I and inter-terminal voltage V are input to the battery ECU 4. Note that the cycles in which the ammeter 2 and the voltmeter 3 detect the inter-terminal current I and the inter-terminal voltage V are synchronized. Thereby, the inter-terminal current I and the inter-terminal voltage V at the same time can be grasped.

Battery ECU4 is an electronic control unit which is provided as an LSI device in the same manner as previously described motor ECU 6, in which computing the open-circuit voltage V ₀ and the internal resistance R of the battery 1. As shown in FIG. 1, the battery ECU 1 includes an open-circuit voltage determination unit (open-circuit voltage determination unit) 4a, an internal resistance value calculation unit (internal resistance value calculation unit) 4b, and a storage unit (storage unit) 4c. .

The open-circuit voltage determining unit 4 a determines an estimated value of the open-circuit voltage V ₀ of the battery 1 based on the inter-terminal current I and the inter-terminal voltage V detected by the ammeter 2 and the voltmeter 3. Here, the inter-terminal voltage V when the inter-terminal voltage I is less than a preset predetermined current value I _T1 and the state continues for a predetermined time or more is determined as an estimated value of the open circuit voltage V ₀ of the battery 1. To do. That is, in the state where almost no current I flows from the battery 1, the influence of the voltage drop represented by the product of the internal resistance value R of the battery 1 and the current I (that is, the voltage across the terminals detected by the voltmeter 3). Is considered to be negligible, and the inter-terminal voltage V at that time is estimated to be the open circuit voltage V ₀ . Hereinafter, the estimated value of the open circuit voltage V ₀ of the battery 1 is simply referred to as the open circuit voltage V ₀ .

In the present embodiment, the predetermined current value I _T1 is set to I _T1 = 1 [A], and the predetermined time is set to 5 [seconds]. With such a setting, the open-circuit voltage determining unit 4a is configured so that the inter-terminal voltage V when the inter-terminal current I detected after the voltage fluctuation is stabilized is less than 1 [A] mainly when the vehicle is stopped. Is determined as the open-circuit voltage V ₀ of the battery 1.
The internal resistance value calculation unit 4b calculates the internal resistance value R of the battery according to the following formula based on the inter-terminal current I, the inter-terminal voltage V, and the open-circuit voltage V ₀ determined by the open-circuit voltage determination unit 4a. .

(R: Internal resistance value, V _O : Open voltage, V: Terminal voltage, I: Terminal current)
The internal resistance value calculation unit 4b determines whether or not to calculate the internal resistance value R based on the inter-terminal current I and the motor torque command value T in the motor ECU 6. The condition for starting the calculation of the internal resistance value R in the internal resistance value calculation unit 4b is when any of the following conditions is satisfied.

[Condition 1] I> I _T2 and T> T _T
[Condition 2] I <-I _T2 and T <-T _T
(I _T2 : second predetermined current value, T _T : predetermined torque value)
Condition 1 stipulates that the current value I during discharging from the battery 1 to the motor 7 side is large, and that the motor torque command value T in the power running state of the motor 7 is also large. Condition 2 defines that the current value I during charging from the motor 7 to the battery 1 side is large, and that the motor torque command value T when the motor 7 is in the regenerative state is also large. That is, here, the internal resistance value R is calculated after confirming that the current I between the terminals is large to some extent and the motor 7 is also rotating strongly. The second predetermined current value I _T2 is set to be larger than the aforementioned predetermined current value I _T1 .

In the present embodiment, the second predetermined current value I _T2 is set to I _T2 = 40 [A], and the above condition is determined based on the inter-terminal voltage I detected when the vehicle is traveling. Yes. The predetermined torque value T _T is set to T _T = 40 [Nm].
The storage unit 4c updates and stores the internal resistance value R of the battery 1 calculated by the internal resistance value calculation unit 4b. Hereinafter, the internal resistance value R obtained as a result of the new calculation is referred to as the current value and is represented by the symbol _RC . The previous internal resistance value R originally recorded in the storage unit 4c is called the previous value, and is represented by the symbol _R0 .

First, when the difference between the previous value R ₀ and the current value R _C is not so large and is equal to or smaller than a predetermined difference (predetermined update width) R _T , the previous value R ₀ is overwritten with the current value R _C. And update. Predetermined contrast, large difference between the previous value R ₀ and the current value R _C, if it exceeds a predetermined difference R _T is the result obtained by adding a predetermined difference R _T to the immediately preceding value R _0, or from the last value R ₀ The result of subtracting the difference _RT is updated as a new internal resistance value R. That is, the new internal resistance value R is updated within the range of the upper and lower _{RT based on} the previous value R ₀ .

The internal resistance value R stored here is used for determining the deterioration state of the battery 1 and calculating the maximum output value and the minimum input value of the battery 1. For example, when the relationship between the inter-terminal current I and the inter-terminal voltage V is graphed, as shown in FIG. 2, the slope is the internal resistance value R of the battery 1, and this graph and the V axis (I = 0) The intersection point corresponds to the open circuit voltage V ₀ . If the output voltage range of the battery 1 is from V _low to V _high , the open circuit voltage V ₀ is located between V _low and V _high .

Therefore, the inter-terminal current I _{dis at} the intersection of this graph and V = V _low is the maximum current that the battery 1 can discharge at that time. Therefore, it can be seen that the maximum output value (maximum discharge power) P _out at that time is P _out = I _dis · V _low [W]. Similarly, the inter-terminal voltage I _{cha at} the intersection of this graph and V = V _high is the maximum current that can be charged to the battery 1 at that time. Therefore, the maximum input value (maximum charging power) P _in at that time is P _in = I _cha · V _high [W].

In this way, the battery ECU 1 calculates the open circuit voltage V ₀ and the internal resistance value R as needed, and calculates information regarding the input / output power at that time.

[flowchart]
A calculation procedure in the battery management apparatus will be described with reference to FIGS. 3 and 4. FIG. 3 is a flowchart for determining the open circuit voltage V ₀ of the battery 1. FIG. 4 is a flowchart for calculating and updating the internal resistance value R. Each of these flowcharts is repeatedly executed in a predetermined cycle inside the battery ECU 4.

[Flow for determining open circuit voltage]
The flow shown in FIG. 3 is mainly executed by the open-circuit voltage determination unit 4a of the battery ECU 4. In step A10, a predetermined current value I _T1 = 1 [A] set in advance is read. In subsequent step A20, the inter-terminal current I ₁ and the inter-terminal voltage V ₁ are measured using the ammeter 2 and the voltmeter 3. Is done. In step A30, it is determined whether or not the absolute value of the inter-terminal voltage I ₁ is less than the predetermined current value I _T1 for a predetermined time or more.

Here, when | I ₁ | <1 [A] for a predetermined time or more, it is considered that there is almost no influence of the voltage drop due to the internal resistance value R, and the process proceeds to Step A40, and the inter-terminal voltage V ₁ at that time is determined. Is determined as the open circuit voltage V ₀ . The timing at which the open voltage V ₀ is newly updated is mainly when the vehicle is stopped or idling.
On the other hand, if | I ₁ | ≧ 1 [A] in step A30, the voltage fluctuation is not stabilized and it is difficult to determine the exact open voltage V ₀ , so the process proceeds to step A50 and the previous open voltage V The value of ₀ is kept as it is.

[Internal resistance value update flow]
The flow shown in FIG. 4 is mainly executed by the internal resistance value calculation unit 4b. In Step B10, a preset second predetermined current value I _T2 , a predetermined torque value T _T , a preset predetermined difference _RT related to update control of the internal resistance value R, and a previous value R _{0 of the} internal resistance are read. . In the subsequent step B20, the inter-terminal current I ₂ and the inter-terminal voltage V ₂ are measured using the ammeter 2 and the voltmeter 3. The inter-terminal current I ₁ and the inter-terminal voltage V ₁ measured in the open voltage determination flow may be used here.

In the subsequent step B30, it is determined whether or not an internal resistance value calculation condition is satisfied. Specifically, it is determined whether condition 1 or condition 2 described above is satisfied. Here, when I> I _T2 [A] and T> T _T [Nm], or when I <−I _T2 [A] and T <−T _T [Nm], Proceed to step B40. On the other hand, if none of these conditions is satisfied, the process proceeds to step B50.

When the process proceeds to Step B40, the current value R _{C of the} internal resistance is calculated according to Equation 1 based on the inter-terminal current I ₂ , the inter-terminal voltage V _2, and the open-circuit voltage V ₀ determined by the open-circuit voltage determining unit 4a. Proceed to B60. On the other hand, when the process proceeds to step B50, the previous value _R0 of the internal resistance is diverted and set to the current value _RC as it is, and the process proceeds to step B60.
In the flow after step B60, a specific update width of the internal resistance value R is determined by comparing the previous value _R0 of the internal resistance with the current value _RC . First, in step B60, it is determined whether or not the difference between the previous value _R0 and the current value _RC is greater than a predetermined difference _RT . Here, if R _C −R ₀ > R _T [Ω], the process proceeds to step B80, and the previous value R ₀ predetermined difference R _T is added to update the internal resistance value R. That is, since the current value R _C calculated in step B40 has increased rapidly compared to the previous value R ₀ , the amount of change in the internal resistance value R is limited and updated only by the predetermined difference _RT. become. On the other hand, if R _C −R ₀ ≦ R _T [Ω] in step B60, the process proceeds to step B70.

The content of the determination in step B70 is to determine whether or not the current value has suddenly decreased compared to the previous value, and the difference between the previous value _R0 and the current value _RC is a negative predetermined difference -R. _It is determined whether or not it is smaller than _T. When R _C −R ₀ <−R _T , the process proceeds to Step B90, and the predetermined difference R _T is added to the previous value R ₀ to update the internal resistance value R. That is, the amount of change in the internal resistance value R is limited to the predetermined difference _RT and is updated to decrease.

Further, if R _C −R ₀ ≧ −R _T in Step B70, the change amount of the internal resistance value R is within the range of R ₀ ± _RT , so the process proceeds to Step B100, The current value _RC is updated as the internal resistance value R as it is. If the internal resistance value calculation condition is not satisfied in step B30, R _C −R ₀ = 0, so that step B100 is always executed.

[Action / Effect]
Thus, according to the battery management apparatus for a vehicle according to the embodiment of the present invention, the reference map is used by predetermining the open circuit voltage V ₀ of the battery 1 prior to the calculation of the internal resistance value R. The internal resistance value R of the battery 1 can be accurately calculated without any problem. Thereby, determination of the deterioration state of the battery 1 and the calculation of the maximum output value and the maximum input value of the battery 1 are possible.

Further, by measuring the inter-terminal voltage V ₁ detected when the inter-terminal current I ₁ is small at the time of determining the open circuit voltage V ₀ , the influence of the voltage drop caused by the internal resistance R can be reduced. Thus, the open circuit voltage V ₀ can be accurately grasped.
On the other hand, when calculating the internal resistance value R, the internal resistance value R against the fluctuation of the current between the terminals I ₁ to I ₂ is obtained by using the relatively large inter-terminal current I ₂ and the inter-terminal voltage V _2. Therefore, the internal resistance value R can be accurately calculated. Further, since the internal resistance value calculation condition includes a condition related to the motor torque command value T, the calculated internal resistance value R can be stabilized. There is no need for additional temperature correction.

Further, when the internal resistance value R is updated, the increase / decrease in the internal resistance value R in one operation is limited within the range of the update width ± _{RT with} respect to the previous value R _0, so that the internal resistance value R is changed suddenly. Therefore, the calculation result of the accurate internal resistance value R can be stored.
FIG. 5 shows a change with time of the internal resistance value R calculated by the battery management apparatus and the internal resistance value R ′ obtained by the conventional method. The conventional method here is a method of calculating the internal resistance value using the above-described equation A.

Times t ₁ and t ₂ shown in FIG. 5 are times when the state of the battery 1 has changed from the discharged state to the charged state and the sign (flow direction) of the inter-terminal current I has been reversed from positive to negative. is there. The internal resistance value R ′ indicated by the broken line has a large fluctuation, and the value is changed significantly greatly before and after the times t ₁ and t ₂ . In the electric vehicle 10 in which the state of the battery 1 frequently fluctuates, it can be seen that the calculation result of the internal resistance value R ′ obtained by the conventional method tends to be unstable, and it is difficult to accurately grasp the state of the battery 1.

On the other hand, the internal resistance value R indicated by the solid line is more stable than the internal resistance value R ′, and the continuity of the fluctuation tendency is maintained before and after the times t ₁ and t ₂ . In this battery management device, when the internal resistance value calculation condition is not satisfied, that is, when the absolute value of the inter-terminal power I or the absolute value of the motor torque command value T is small, the previous value R ₀ is held, The internal resistance value R is not updated in an unstable state such as when the direction of the rotation is reversed. Thus, according to the battery management apparatus, the state of the battery 1 can be accurately grasped with a simple configuration.

[Others]
Although one embodiment of the present invention has been described above, the present invention is not limited to such an embodiment, and various modifications can be made without departing from the spirit of the present invention.
For example, specific set values such as the predetermined current value I _T1 , the predetermined time, the second predetermined current value I _T2 , and the predetermined torque value T _T in the above-described embodiment can be changed as appropriate. The same applies to the predetermined difference _RT that is the update width of the internal resistance value R.

For example, in the above-described embodiment, the inter-terminal voltage V when the inter-terminal voltage I is less than the preset predetermined current value I _T1 and the state continues for a predetermined time or longer is used as the open-circuit voltage V _{0 of the} battery 1. As determined. The setting condition of the open circuit voltage V ₀ may be made stricter, and the open circuit voltage V ₀ may be set only when the inter-terminal voltage I is 0 for a predetermined time or more. Alternatively, it is also one idea to add other conditions such as vehicle speed and accelerator operation amount so as to set the open circuit voltage V ₀ only when the vehicle is stopped.

Further, in the above-described embodiment, when the absolute value | R _C −R ₀ | of the difference between the calculated current value R _C of the internal resistance and the previous value R ₀ is smaller than the predetermined difference R _T , Although _RC is updated as a new internal resistance value R as it is, it is also conceivable to change such an updating method. For example, when | R _C −R ₀ | is small to some extent, it may be considered that the previous value R ₀ is regarded as the internal resistance value R and is not updated. With such a configuration, it is possible to absorb a detection error in the ammeter 2 or the voltmeter 3 to suppress a sudden change in the internal resistance value R, and to stabilize the calculation result.

  In the above-described embodiment, the present invention is applied to the battery management device of the electric vehicle 10, but the vehicle travels using the driving force of the electric motor such as a hybrid electric vehicle (HEV) or a fuel cell vehicle (FCV). Any vehicle can be preferably applied.

1 is a block diagram illustrating an overall configuration of a vehicle battery management device according to an embodiment of the present invention. It is a graph which shows the VI characteristic of the battery which concerns on the battery management apparatus of the vehicle which concerns on one Embodiment of this invention. It is a flowchart which shows the control procedure at the time of the determination of the open circuit voltage by the battery management apparatus of the vehicle which concerns on one Embodiment of this invention. It is a flowchart which shows the control procedure at the time of the calculation of the internal resistance value by the battery management apparatus of the vehicle which concerns on one Embodiment of this invention. It is the graph which compared the internal resistance value obtained with the battery management apparatus of the vehicle which concerns on one Embodiment of this invention, and the internal resistance value obtained by the prior art.

Explanation of symbols

1 battery 2 ammeter (current detection means)
3 Voltmeter (voltage detection means)
4 Battery ECU
4a Open-circuit voltage determining unit (open-circuit voltage determining means)
4b Internal resistance value calculation unit (internal resistance value calculation means)
4c storage unit (storage means)
5 Inverter 6 Motor ECU (torque detection means)
7 Motor (electric motor)
10 Electric vehicles (vehicles)

Claims (5)

A battery management device mounted on a vehicle,
Current detecting means for detecting a current between terminals of the battery;
Voltage detecting means for detecting a voltage between terminals of the battery;
An open-circuit voltage determining means for determining an open-circuit voltage of the battery;
Based on the current between the terminals detected by the current detection means, the voltage between the terminals detected by the voltage detection means, and the open voltage determined by the open voltage determination means, the internal resistance value of the battery is calculated. an internal resistance value calculation means for,
Torque detecting means for detecting the torque of an electric motor driven by the electric power of the battery,
The internal resistance value calculating means calculates the internal resistance value when the absolute value of the torque detected by the torque detecting means exceeds a predetermined torque value set in advance. A vehicle battery management device. The open-circuit voltage determining means determines that the inter-terminal voltage detected by the voltage detecting means is the open-circuit voltage of the battery when the inter-terminal current is less than a predetermined current value set in advance. The battery management device for a vehicle according to claim 1. The internal resistance value calculating means is determined by the inter-terminal voltage, the inter-terminal current, and the open-circuit voltage determining means when the inter-terminal current is greater than or equal to a second predetermined current value greater than the predetermined current value. The battery management device for a vehicle according to claim 2, wherein an internal resistance value of the battery is calculated using an open-circuit voltage. 4. The vehicle battery management apparatus according to claim 1, wherein the internal resistance value calculating means calculates the internal resistance value according to an expression shown below.

Further comprising storage means for storing the internal resistance value calculated by the internal resistance value calculation means,
When the internal resistance value is calculated by the internal resistance value calculating means, the storage means updates the internal resistance value within a predetermined update range set in advance from the previously stored internal resistance value. The battery management device for a vehicle according to any one of claims 1 to 4 , wherein

Images