Battery management device and battery device

Abstract

A battery management device includes a range setting unit (1) and a measurement unit (3; 103). The range setting unit (1) is configured to set a defined measurement range that limits a range in which a voltage of each of a plurality of batteries (7) of a vehicle is measured. The measurement unit (3; 103) is configured to measure the voltage of each of the plurality of batteries within the defined measurement range.

Description

Technical Field

[0001] This disclosure relates to battery management devices and battery devices. Background Technology

[0002] As disclosed in JP 2010-141957 A, the battery device performs an equalization process on each battery block in order to quickly reduce voltage variations among multiple batteries. Summary of the Invention

[0003] In devices used to manage battery status, it is important to perform battery equalization, estimate the battery's state of charge (SOC), and estimate the battery's state of decay (SOH) with high accuracy. Therefore, it is necessary to improve the accuracy of battery voltage measurement.

[0004] To address the aforementioned problems, one object of this disclosure is to provide a battery management device and a battery device that can improve the accuracy of voltage measurement.

[0005] According to one aspect of this disclosure, a battery management device includes a range setting unit and a measurement unit. The range setting unit sets a defined measurement range that limits the range for measuring the voltage of each of a plurality of batteries in a vehicle. The measurement unit measures the voltage of each of the plurality of batteries within the defined measurement range.

[0006] According to another aspect of this disclosure, a battery device includes a plurality of batteries for a vehicle, a range setting unit, and a measuring unit. The range setting unit sets a defined measurement range that limits the range for measuring the voltage of each of the plurality of batteries in the vehicle. The measuring unit measures the voltage of each of the plurality of batteries within the defined measurement range.

[0007] Depending on the configuration, the range setting unit can set a defined voltage measurement range from the entire voltage range of the battery. Because this configuration allows for setting an appropriate voltage measurement range, the accuracy of voltage measurement can be improved. Attached Figure Description

[0008] The above and other objects, features, and advantages of the present invention will become more apparent from the following detailed description with reference to the accompanying drawings. In the drawings:

[0009] Figure 1 This is a configuration diagram of the battery unit;

[0010] Figure 2 This is a configuration diagram of the monitoring IC;

[0011] Figure 3 It is a characteristic graph showing the relationship between OCV and SOC of a battery cell;

[0012] Figure 4 This is a flowchart showing the battery management according to the first embodiment;

[0013] Figure 5 This is a flowchart showing the battery management according to the second embodiment;

[0014] Figure 6 It is a characteristic plot showing the operations related to SOH estimation;

[0015] Figure 7 This is a flowchart showing battery management according to the third embodiment;

[0016] Figure 8 This is a flowchart showing battery management according to the fourth embodiment;

[0017] Figure 9 This is a configuration diagram of the monitoring IC according to the fifth embodiment;

[0018] Figure 10 It is a timing diagram showing the voltage detection.

[0019] Figure 11 It displays the timing diagram of voltage detection; and

[0020] Figure 12 This is a flowchart showing the process of obtaining target settings. Detailed Implementation

[0021] Embodiments for carrying out this disclosure will now be described with reference to the accompanying drawings. In each embodiment, constituent elements corresponding to those marked with reference numerals or numbers in the foregoing embodiments may be represented by the same reference numerals or numbers to omit redundant descriptions. When only a portion of a configuration is described in one embodiment, another preceding embodiment may be applied to other portions of the configuration. Not only can portions explicitly described in one embodiment be combined, but portions not explicitly described in various embodiments may also be combined if no particular obstacle arises in combining portions of various embodiments.

[0022] (First Embodiment)

[0023] Reference Figures 1 to 4The first embodiment is described. The battery management device can be applied to the management of secondary batteries installed in vehicles such as hybrid vehicles, electric vehicles, or fuel cell vehicles. Vehicles include passenger cars, buses, construction vehicles, agricultural machinery vehicles, etc. Secondary batteries include lithium-ion secondary batteries, nickel-metal hydride secondary batteries, organic radical batteries, etc.

[0024] Figure 1 The configuration of the battery device 200 and the external device for charging the combined battery 5 is shown. The battery device 200 includes the combined battery 5 and the battery management device 100.

[0025] The battery management device 100 includes a control device 10 associated with the battery pack 5. External devices include a charging facility (CF) 12 and a charging terminal (CT) 11. A charge-discharge circuit (CDC) 8 installed in the vehicle is capable of exchanging power between the battery pack 5 and the charging terminal 11.

[0026] A battery management device 100 is installed in the aforementioned vehicle. The battery management device 100 functions as a management device for monitoring and controlling the charging and discharging of the combined battery 5, which includes a secondary battery, in the aforementioned vehicle. The combined battery 5 can be charged by an external device.

[0027] A power process is provided between the battery management device 100 and the charging device 12 to allow power to flow in one or both directions. The charging device 12 is a power supply device installed in homes, commercial establishments, etc. The charging device 12 is configured as a simple power outlet or a charging dock for charging.

[0028] The charging terminal 11 can be a portable or fixed device. The charging terminal 11 can be located in the charging equipment 12 or in a vehicle. The charging terminal 11 communicates with the vehicle using a dedicated signal line. The charging terminal 11 can also be configured as a charger. The system main relay 6 can switch between a conductive and a non-conductive state between the charging terminal 11 and the battery pack 5.

[0029] The charging device 12 includes an AC power source and a socket for outputting power supplied from the AC power source. The AC power is supplied by a small power generation facility or a wide area power grid. The socket is located outside the facility where the charging device 12 is installed and is capable of accepting a predetermined plug. The socket and plug provide a connection means for connecting the charging device 12 and the charging terminal 11.

[0030] The vehicle equipped with the battery management device 100 has an inlet. The inlet provides an input-side connector for the charging terminal 11. The inlet has a terminal group including multiple terminals for DC power and multiple terminals for data communication.

[0031] The charging terminal 11 includes a plug capable of connecting to a socket of the charging device 12. The plug is capable of conducting alternating current. The charging terminal 11 includes a connector capable of connecting to the vehicle's inlet. The connector is also referred to as a charging gun. The connector has a terminal group including multiple terminals for alternating current and multiple terminals for data communication. The connector at the vehicle inlet and the charging terminal 11 provides a connection means for connecting the charging terminal 11 and the vehicle. The charging terminal 11 includes a control device that adjusts the power supplied to the plug of the charging terminal 11 and supplies the adjusted power to the connector. The control device of the charging terminal 11 includes a switching circuit that interrupts the power supply to the connector. The control device of the charging terminal 11 may include a voltage conversion circuit.

[0032] The control device for charging terminal 11 is also a communication device that communicates with the vehicle via the connector of charging terminal 11. The control device for charging terminal 11 cooperates with the control device 10 of battery management device 100 to execute a charging process for controlling the charging of the battery pack 5. The control device for charging terminal 11 sends a signal indicating that power can be supplied from charging terminal 11 by a CPLT signal. Further, the control device for charging terminal 11 receives a signal indicating that the battery pack 5 can be discharged by a CPLT signal. The control device for charging terminal 11 interrupts the power supply from charging terminal 11 to the battery pack 5.

[0033] The battery pack 5 supplies power to the electric motor installed in the vehicle for driving. The battery pack 5 includes a large capacity and high voltage capable of being used as a power source for vehicle operation. The battery pack 5 includes multiple battery cells connected in series or parallel. Each battery cell includes multiple battery cells 7 connected in series. The battery cells 7 are powered by secondary batteries.

[0034] A charging / discharging circuit 8 is installed on the vehicle. The charging / discharging circuit 8 serves as a charging circuit that rectifies and converts the power supplied to the vehicle's inlet and supplies the power to the battery pack 5. The charging / discharging circuit 8 also serves as a discharging circuit that converts the direct current (DC) power obtained from the battery pack 5 into alternating current (AC) power and outputs the AC power to the vehicle's inlet. The charging / discharging circuit 8 can charge the battery pack 5 from the AC power supply of the charging facility 12 and can also allow power to flow in reverse from the battery pack 5 to the AC power supply. The charging / discharging circuit 8 may include an inverter circuit and a voltage converter circuit. The control device 10 of the battery management device 100 controls the charging / discharging circuit 8.

[0035] The control device 10 includes a monitoring IC (BMIC) 3, an insulating element (IE) 2, and a microcomputer (μC) 1. The monitoring IC 3 serves as a measuring unit for measuring the voltage (terminal voltage) between the anode and cathode of each battery cell 7. A monitoring IC 3 measures, for example, the voltage between the terminals of each battery cell 7 included in a battery pack.

[0036] The microcomputer 1 is insulated from each monitoring IC 3 by an insulating element 2. The microcomputer 1 acquires the voltage between the terminals measured by each monitoring IC 3 via the insulating element 2. The microcomputer 1 monitors each battery cell 7 and manages the state of the combined battery 5, such as its charge / discharge state, via each monitoring IC 3. The monitoring ICs 3 are insulated from each other by an insulating element (IE) 21. This insulation configuration ensures communication performance between the monitoring ICs 3, each with a different GND level.

[0037] Microcomputer 1 adjusts the voltage measurement range in battery cell 7 to set a limited measurement range. Microcomputer 1 sets the limited measurement range when the vehicle is in a state of low noise. Microcomputer 1 serves as a range setting unit capable of setting any limited measurement range across the entire voltage range of battery cell 7. Microcomputer 1 sets the voltage measurement range adjusted by commands transmitted to monitoring IC 3 as the limited measurement range. Monitoring IC 3 interprets the commands output from microcomputer 1 and operates within the voltage measurement range contained in those commands.

[0038] As an example, microcomputer 1 sets the limited measurement range according to the following logic: Microcomputer 1 sets a limited measurement range including a maximum value. The maximum value is the highest voltage measurement value among those measured by monitoring IC 3 for the entire voltage range in battery cell 7. Microcomputer 1 sets a limited measurement range including a minimum value. The minimum value is the lowest voltage measurement value among those measured by monitoring IC 3 for the entire voltage range in battery cell 7. Microcomputer 1 uses the maximum and minimum values ​​among the voltage measurement values ​​measured by monitoring IC 3 for the entire voltage range of the battery to set the limited measurement range.

[0039] like Figure 2 As shown, the monitoring IC3 includes a command unit (CS) 31, an analog-to-digital converter (A / D) 32, a level converter (L / S) 33, and a switching group (MUX) 34. The monitoring IC3 also includes an equalization circuit (BC) 4.

[0040] Command unit 31 includes serial I / O, non-volatile memory and digital filter, and has the function of interpreting commands from microcomputer 1.

[0041] The analog-to-digital converter 32 includes an A / D converter provided by electronic circuitry that converts analog electrical signals into digital electrical signals, and a clamping circuit that limits the input range of the A / D converter. The quantization bits of the A / D converter are a fixed value. The input range of the A / D converter is controlled by the command unit 31 through the control clamping circuit.

[0042] The switch group 34 has the function of arbitrarily selecting the voltage of each battery cell 7. The switch group 34 has the function of selecting multiple inputs and outputting them as a single signal.

[0043] Level shifter 33 serves as both a level shifter and a gain sector. Level shifter 33 includes an operational amplifier and multiple feedback circuits connected in parallel between the input and output terminals of the operational amplifier. These feedback circuits include switches and capacitors connected in series. The capacitances of the capacitors included in the multiple feedback circuits may be the same or different.

[0044] The switches of multiple feedback circuits included in the level shifter 33 are selectively controlled between a conducting state and an off state. As a result, the number of capacitors connected between the input and output terminals of the operational amplifier changes. The capacitance between the input and output terminals of the operational amplifier changes. Furthermore, the resistance between the input and output terminals of the operational amplifier changes. Consequently, the gain and offset of the level shifter 33 are controlled.

[0045] By limiting the input range of the analog-to-digital converter 32 and adjusting the gain and offset of the level converter 33, the voltage range of the analog electrical signal converted into a digital signal by the analog-to-digital converter 32 is controlled. The voltage range of the battery cell 7, also converted into a digital signal by the analog-to-digital converter 32, is thus controlled. As a result, the voltage measurement range is adjusted.

[0046] The monitoring IC3 measures the voltage of the battery cell 7 within a voltage measurement range set by the microcomputer 1. The monitoring IC3 is used as a measuring unit to measure the voltage of the battery cell 7 within a defined measurement range set by the microcomputer 1.

[0047] The battery cell 7 included in the battery pack 5 has unique characteristics regarding the relationship between its state of charge (SOC) and open circuit voltage (OCV). In this specification, the state of charge of the battery cell 7 can be described as SOC. When the battery cell 7 is supplied by a lithium-ion secondary battery, the battery cell 7 has, as an example, [details omitted]. Figure 3 The characteristic data shown. Figure 3The characteristic data shown is stored in the storage unit (ME) 22 of the control device 10. The temperature dependence of the SOC and OCV characteristic data of various secondary batteries is stored in the storage unit 22. Characteristic data based on the type and temperature of the battery cell 7 is read out by the microcomputer 1. The storage unit 22 can be built into the microcomputer 1. In the accompanying drawings, the microcomputer 1 and the storage unit 22 are shown separately for clear illustration of the components.

[0048] The microcomputer 1 is used as a SOC estimation unit to estimate the SOC of the battery cell 7 by calculating the voltage between the terminals of the battery cell 7 measured by the monitoring IC 3 and this characteristic data. The microcomputer 1 is also used as a SOC estimation unit to estimate the SOC based on voltage measurements taken over the entire voltage range of the battery cell 7.

[0049] Figure 3 The characteristic data shown illustrates the relationship between the State of Charge (SOC) and open-circuit voltage of battery cell 7. This characteristic data includes a low-variance region where the voltage variation width relative to SOC is equal to or less than a predetermined value. The characteristic data also includes a high-variance region, in which the voltage variation in each of the SOC ranges below and above the low-variance region is greater than the voltage variation in the low-variance region.

[0050] The low voltage variation region is caused by Figure 3 The range indicated by the arrow on the vertical axis. The SOC of battery cell 7, corresponding to the low variation region, corresponds to the range determined by... Figure 3 The range indicated by the arrow on the horizontal axis. The entire range of voltage between the terminals of battery cell 7 includes a low-variety region, in which the voltage variation width relative to SOC is smaller than that in the low SOC region and the high SOC region.

[0051] The microcomputer 1 serves as a range setting unit to define a measurement range based on the unique characteristics of the battery cell 7, which represent the relationship between SOC and open-circuit voltage. Preferably, the microcomputer 1 sets the voltage range encompassing a low-variance region as the defined measurement range across the entire voltage range associated with the battery cell 7. The control device 10 has the capability to measure voltage with high precision and accurately estimate the storage state of the battery cell 7 with such characteristics.

[0052] The equalization circuit 4 serves as an equalization processing unit, performing a process (equalization processing) to reduce voltage variations among the multiple battery cells 7 contained in the battery pack. The equalization circuit 4 includes a control unit and equalization circuit units. The control unit is built into the monitoring IC 3. The equalization circuit units are connected to each battery cell 7. The equalization circuit units are built into the monitoring IC 3. The equalization circuit units can also be located externally to the monitoring IC 3.

[0053] In the equalization process, for example, among the multiple battery cells 7 included in the battery pack, the battery cell 7 exhibiting a higher voltage measurement value is discharged. Simultaneously, among the battery cells 7 included in the battery pack, the battery cell 7 exhibiting a lower voltage measurement value is charged. As a result, the state of charge (SOC) of the multiple battery cells 7 included in the battery pack is equalized.

[0054] When the equalization processing conditions are met, the microcomputer 1 sends a signal to the equalization circuit 4 instructing the corresponding battery pack to perform equalization processing. When the equalization processing conditions are not met, the microcomputer 1 does not send a signal to the equalization circuit 4 instructing the corresponding battery pack to perform equalization processing. When the equalization processing conditions are not met, the microcomputer 1 may send a signal to the equalization circuit 4 to prohibit equalization processing.

[0055] The microcomputer 1 serves as a leveling determination unit, used to determine whether to perform leveling processing based on whether leveling processing conditions are met. When the difference between the maximum and minimum voltage measurements within a predetermined battery pack is less than a predetermined threshold, the microcomputer 1 determines not to perform leveling processing. When the difference between the maximum and minimum voltage measurements is greater than the predetermined threshold, the microcomputer 1 determines to perform leveling processing.

[0056] The control device in this disclosure may be referred to as an electronic control unit (ECU). The control device or control system is provided by (a) an algorithm of multiple logic in the form of if-then-else, or (b) a learning model adapted by machine learning, for example, an algorithm as a neural network.

[0057] The control device is provided by a control system including at least one computer. The control system may include multiple computers linked by data communication equipment. The computer includes at least one processor as hardware (hardware processor). The hardware processor may be provided by (i), (ii), or (iii) below.

[0058] (i) The hardware processor may be at least one processor core that executes a program stored in at least one memory. In this case, the computer has at least one memory and at least one processor core. The processor core may be provided by a central processing unit (CPU), a graphics processing unit (GPU), a RISC-CPU, etc. Memory is also called storage medium. Memory is a non-transitory and tangible storage medium that non-transitorily stores "programs and / or data" readable by the processor. Storage medium may be semiconductor memory, magnetic disk, optical disk, etc. Programs may be distributed as individual units or as storage media storing programs.

[0059] (ii) The hardware processor may be hardware logic circuitry. In this case, the computer has digital circuitry comprising multiple programmable logic units (gates). The digital circuitry may be provided by arrays of logic circuits, such as ASIC (Application-Specific Integrated Circuit), FPGA (Field-Programmable Gate Array), SoC (System-on-Chip), PGA (Programmable Gate Array), or CPLD (Complex Programmable Logic Device). The digital circuitry may include memory storing programs and / or data. The computer may be provided by analog circuitry. The computer may be provided by a combination of digital and analog circuitry.

[0060] (iii) The hardware processor can be a combination of (i) and (ii) above. (i) and (ii) are located on different chips or on a common chip. In these cases, part (iii) is also referred to as an accelerator.

[0061] Control devices, signal sources, and controlled objects provide various components. At least some of these components may be referred to as blocks, modules, or parts. Furthermore, the components included in a control system are only referred to as functional devices when intentionally chosen.

[0062] Next, we will refer to Figure 4 The flowchart describes the control related to battery management of the control device 10. In this specification, to clarify which component of the control device 10 performs the process, if necessary, the subject of the sentence explaining the process is described by the component of the control device 10 that performs the process, rather than the control device 10 itself. Additionally, in the figures, the beginning is indicated by S, and the end by E.

[0063] In S100, control device 10 is activated. In S110, control device 10 determines whether the voltage measurement conditions are met. In S110, control device 10 determines that there is no noise interference when the motor or engine that generates power to drive the vehicle stops and the battery pack 5 is not charging or discharging. For example, when the ignition switch or motor starter switch is in the off state, control device 10 determines that the motor or engine is in a stopped state.

[0064] For example, when the connectors of the vehicle's inlet and charging terminal 11 are not connected, the control device 10 determines that charging or discharging of the battery has stopped. Similarly, when the system main relay 6 is in an off state and the charging terminal 11 and the battery pack 5 are not conductive, the control device 10 determines that charging or discharging of the battery pack 5 has stopped. When the vehicle's power device is stopped and charging or discharging of the battery pack 5 has stopped, the control device 10 determines that voltage measurement conditions are met. When voltage measurement conditions are met, the control device 10 determines that the noise is acceptable.

[0065] When it is determined in S110 that the voltage measurement conditions are not met, the control device 10 terminates. Figure 4 The flowchart is as follows. When it is determined in S110 that the voltage measurement conditions are met, the control device 10 proceeds to S120. In S120, the control device 10 determines whether a fault exists in the circuit of the battery management device 100. The control device 10 functions as a fault determination unit for determining whether a fault exists in the circuit of the battery management device 100. When a fault is determined in the circuit in S120, the control device 10 terminates. Figure 4 The flowchart does not perform the process of setting a limited measurement range.

[0066] When it is determined in S120 that there is no fault in the circuit, the control device 10 proceeds to S130. In S130, the control device 10 determines whether the voltage value (cell voltage) of each battery cell 7 can be estimated. When an approximate value of the current voltage is known, the control device 10 determines in S130 that the voltage value is estimated. For example, when the voltage value is stored in the storage unit 22, the control device 10 determines in S130 that the voltage value is estimated.

[0067] If it is determined in S130 that the voltage value is estimated, the control device 10 proceeds to S140. If it is determined in S130 that the voltage value is not estimated, the control device 10 proceeds to S150.

[0068] When the voltage value of each battery cell 7 is estimated, the microcomputer 1 outputs a command as a limit command to the monitoring IC 3 in S140 for detecting the voltage of the battery cell 7 within a defined range. The command unit 31 controls the analog-to-digital converter 32 and the level converter 33 based on the limit command to control the input range, gain, and offset. As a result, a defined measurement range for the battery cell 7 is set.

[0069] When processing proceeds from S140 to S160, the monitoring IC3 of the control device 10 measures the voltage of the battery cell 7 within the limited measurement range set in S150, and outputs the measured voltage value to the microcomputer 1. The microcomputer 1 acquires the voltage measured within the limited measurement range and stores the voltage in the storage unit 22. The control device 10 then proceeds to S180.

[0070] When it is determined that the voltage value of each battery cell 7 is not to be estimated, in S150, the microcomputer 1 outputs a command for detecting the voltage of the battery cell 7 over the entire range as an unrestricted command to the monitoring IC 3. The command unit 31 controls the analog-to-digital converter 32 and the level converter 33 based on the unrestricted command to control the input range, gain, and offset. As a result, the measurement range of the battery cell 7 is set over the entire range.

[0071] When an unrestricted command is received, in S170, monitoring IC3 measures the voltage of battery cell 7 across the entire range and outputs the measured voltage value to microcomputer 1. Microcomputer 1 acquires the measured voltage across the entire range and stores the voltage in storage unit 22. Control device 10 proceeds to S180.

[0072] In S180, the microcomputer 1 determines whether to perform equalization processing on the battery pack. In S180, the microcomputer 1 determines whether to perform equalization processing based on whether the difference between the maximum and minimum voltage measurements associated with the multiple battery cells 7 included in the battery pack, i.e., the voltage difference, is greater than a predetermined threshold. When the voltage difference is less than the predetermined threshold, the microcomputer 1 terminates the process. Figure 4 The flowchart does not perform equalization processing. When the voltage difference is greater than a predetermined threshold, the microcomputer 1 determines that equalization processing is necessary. The microcomputer 1 controls the equalization circuit 4 to perform equalization processing in S190. When the voltage difference is less than the predetermined threshold, the microcomputer 1 determines that equalization processing is unnecessary.

[0073] The determination process in S110 can be performed as follows. In S110, when the power unit providing vehicle driving force stops, the charging or discharging of the battery pack 5 stops, or the system main relay 6 is in the off state, the microcomputer 1 determines that the noise is acceptable. In S110, when the noise is determined to be acceptable, the microcomputer 1 determines the noise level and whether the noise level is acceptable. When the microcomputer 1 determines that the noise level is acceptable, the microcomputer 1 proceeds to S120. When the noise level is acceptable under the condition that the noise is acceptable, the microcomputer 1 can determine that the voltage measurement conditions are met. When the SN ratio, which is the ratio of signal to noise, is equal to or greater than a specified value, the control device 10 determines that the noise is acceptable. When the SN ratio is equal to or less than the specified value, the noise has a greater impact on the signal used for voltage detection, and a greater impact on the voltage detection error. The noise source is, for example, an on-board load or an external device such as a power unit connected to the battery pack 5.

[0074] The operational advantages arising from the battery management device 100 according to the first embodiment will now be described. The battery management device 100 includes a range setting unit and a measurement unit, wherein the range setting unit sets a limited measurement range that restricts the voltage measurement range of the battery cells 7 included in the on-board battery pack 5, and the measurement unit measures the voltage of the battery cells 7 within the limited measurement range set by the range setting unit. This configuration sets an appropriate voltage measurement range to improve the accuracy of voltage measurement. By improving the accuracy of voltage measurement, high-accuracy estimation can be achieved when using voltage measurement for SOC estimation or SOH estimation.

[0075] For example, the battery management device 100 narrows the voltage measurement range of the battery cell 7 from the entire range of 0.0V to 5.0V to a limited measurement range of 3.0V to 3.5V. Within this limited measurement range, the analog electrical signal of the battery cell 7 voltage is converted into a digital electrical signal by the analog-to-digital converter 32. As a result, the quantization error of the analog-to-digital converter 32 is reduced. In the case of the previous example, the quantization error is approximately 1 / 10. Consequently, the accuracy of voltage detection of the battery cell 7 is improved.

[0076] The monitoring IC3 adjusts the voltage measurement range according to the command output from the microcomputer 1 that sets the measurement range. With this configuration, a single control device 10 can be used to perform appropriate voltage measurements on multiple battery cells 7 with different open-circuit voltage ranges.

[0077] When the voltage value of battery cell 7 is estimated, the range setting unit of battery management device 100 sets a limited measurement range adjusted based on the estimated voltage value. When the voltage value of battery cell 7 is not estimated, the range setting unit of battery management device 100 sets a limited measurement range based on voltage measurements performed across the entire range. For example, when the voltage value of battery cell 7 is not stored, the range setting unit of battery management device 100 sets a limited measurement range based on voltage measurements performed across the entire range. With this configuration, after confirming that the open-circuit voltage of battery cell 7 has been measured, a limited measurement range is set based on the measured value. Therefore, setting an appropriate voltage measurement range improves the accuracy of voltage measurement.

[0078] The range setting unit of the battery management device 100 sets a limited measurement range using at least one of the maximum and minimum values ​​of the voltage measurement values ​​measured over the entire voltage range. This configuration sets the voltage measurement range to a limited range that reflects the voltage value under the current condition. This configuration improves the accuracy of voltage measurement.

[0079] When the noise level is within an acceptable range, the range setting unit sets a defined measurement range. The measurement unit measures the voltage of the battery cell 7 within this defined measurement range. In this configuration, the voltage is measured within the defined measurement range set when the noise level is acceptable under conditions of minimal noise influence. Therefore, the battery management device 100 can perform voltage measurement by separating noise and signal, further contributing to improved voltage measurement accuracy.

[0080] When the power unit providing driving force to the vehicle stops and the charging or discharging of the battery pack 5 stops, the range setting unit sets a limited measurement range. The measurement unit measures the voltage of the battery cell 7 within this limited measurement range. With this configuration, since the voltage is measured within the limited measurement range set under conditions of minimal noise influence, voltage measurement is performed with noise and signal separation. Therefore, the battery management device 100 further contributes to improving the accuracy of voltage measurement.

[0081] The battery management device 100 includes an equalization determination unit that determines whether to perform equalization processing to reduce voltage variations among multiple battery cells 7 included in a predetermined battery pack among multiple battery packs. The equalization determination unit determines whether to perform equalization processing based on voltage measurements of the battery cells 7 measured within a defined measurement range. Using this configuration, the determination of whether to perform equalization processing can be made with high precision based on high-precision voltage measurements measured within a defined measurement range.

[0082] The battery management device 100 includes a SOC estimation unit that estimates the SOC based on characteristic data indicating the relationship between open-circuit voltage and state of charge, and voltage measurements of the battery cell 7 measured within a defined measurement range. Using this configuration, SOC estimation can be performed with high accuracy by estimating based on highly accurate voltage measurements measured within a defined measurement range.

[0083] (Second Embodiment)

[0084] Reference Figure 5 and 6 The second embodiment will be described. Reference will be made to... Figure 5 and Figure 6 The control of battery management in the second embodiment is described. Configurations, actions, and effects not specifically described in the second embodiment are the same as in the first embodiment; only the differences from the first embodiment are described below.

[0085] The control of battery management in the second embodiment differs from that in the first embodiment only in the SOC estimation process, the determination process related to SOH estimation, and the execution process. Figure 5 In S200 to S270 of the flowchart shown, the execution is performed with Figure 4 The same process is shown in S100 to S170.

[0086] like Figure 5 As shown, after performing voltage measurement in S260 or S270, the control device 10 performs the process of estimating SOC in S280, as described above. The microcomputer 1 estimates SOC by calculating SOC using the measured voltage value and characteristic data.

[0087] In S290, the microcomputer 1 determines whether the conditions for estimating the state of harm (SOH) representing the degree of degradation of the battery cell 7 are met (SOH estimation conditions). For example, at the time point for voltage measurement used for SOC estimation, if a predetermined time has elapsed since the ignition switch and motor starter switch were turned off, the microcomputer 1 determines that the SOH estimation conditions are met. In this case, since battery polarization is mitigated, the microcomputer 1 allows SOH estimation.

[0088] When microcomputer 1 determines in S290 that the SOH estimation condition is not met, it terminates. Figure 5 The flowchart is shown without estimating SOH. When microcomputer 1 determines in S290 that the SOH estimation condition is met, microcomputer 1 estimates SOH in S300 and terminates. Figure 5 The flowchart is shown. Microcomputer 1 is used as the SOH estimation unit for estimating SOH.

[0089] The microcomputer 1 can estimate SOH by calculating SOH (%) using the following mathematical formula (1).

[0090] (Formula 1)

[0091]

[0092] Right now:

[0093]

[0094] Figure 6 Characteristic data related to battery cell 7 and calculations used to obtain the SOH estimate are shown. For example... Figure 6 As shown, SOC1 and SOC2 are estimates of the SOC, calculated using high-precision voltage measurements taken within a defined measurement range set by the microcomputer 1. The integral value of I is calculated by integrating the current values ​​from SOC1 to SOC2. The initial full charge capacity is the full charge capacity at the time of manufacturing the battery cell 7; in other words, the full charge capacity before degradation begins.

[0095] The battery management device 100 can perform the determination process in S290 using the following method: When the measurement error of the voltage measuring device is less than the reference value, the microcomputer 1 can determine that the SOH estimation condition is met. When the voltage measuring device and the current measuring device are operating normally, the microcomputer 1 can determine that the SOH estimation condition is met.

[0096] (Third Embodiment)

[0097] Reference Figure 7 The third embodiment will be described. Reference will be made to... Figure 7 The control of battery management in the third embodiment is described. Configurations, actions, and effects not specifically described in the third embodiment are the same as in the first embodiment; only the differences from the first embodiment are described below.

[0098] The difference between the battery management-related control in the third embodiment and the control in the first embodiment is at least that a portion of S110 is subdivided into S112, S114, and S116. Figure 7 In the flowchart, with Figure 4 The steps shown are the same and are assigned the same step number.

[0099] like Figure 7 As shown, in S112, microcomputer 1 determines whether there is a noise effect. When microcomputer 1 determines that there is no noise effect, microcomputer 1 proceeds to S120. When microcomputer 1 determines that there is a noise effect, microcomputer 1 executes the determination process in S114.

[0100] In S114, the control device 10 determines whether the battery pack 5 is currently being charged from an external device or is about to be charged from an external device. The external device is, for example, a charging facility 12. The external device includes a device that outputs AC power supplied by a small power generation facility or a wide area power grid. The external device also includes a storage device that outputs DC power, a battery, etc.

[0101] When the microcomputer 1 determines in S114 that charging has not been performed or is not ready to be performed, the control device 10 terminates. Figure 7 The flowchart is as follows. When the microcomputer 1 determines in S114 that charging is in progress or preparing to charge, the control device 10 executes a process to stop charging or a process to stop charging preparation in S116. After stopping charging in S116, the control device 10 executes the processes described in S120 and beyond. Based on the processes in S114 and S116, by stopping charging when the battery pack 5 is charging or preparing to charge, the impact of noise can be reduced. Therefore, a limited measurement range capable of performing highly accurate voltage measurements is set.

[0102] The third embodiment has the following effects. When the battery pack 5 is being charged from an external power source, the range setting unit sets a limited measurement range, and the measurement unit measures the battery voltage within the limited measurement range, while charging is temporarily stopped. Based on this control, a battery management device 100 capable of high-precision voltage measurement can be obtained even when the battery pack 5 is being charged from an external device.

[0103] (Fourth Embodiment)

[0104] Reference Figure 8 The fourth embodiment will be described. Reference will be made to... Figure 8 The battery management-related controls of the fourth embodiment are described below. Configurations, actions, and effects not specifically described in the fourth embodiment are the same as in the first embodiment; only the differences from the first embodiment are described below.

[0105] The control of battery management according to the fourth embodiment differs from that of the first embodiment in that the fourth embodiment includes processes S162, S164, and S166. Figure 8 In the flowchart, for and Figure 4 The same steps shown are assigned the same step number.

[0106] like Figure 8As shown, after measuring the voltage within the defined measurement range in S160, the control device 10 performs a determination process in S162. In S162, the microcomputer 1 of the control device 10 acts as an equalization determination unit, which determines a correction value for the determination threshold used in the determination in S180 based on the width of the defined measurement range. When the width of the defined measurement range is greater than the predetermined range width stored in the storage unit 22, the microcomputer 1 determines the threshold correction to be large. When the width of the defined measurement range is less than the predetermined range width, the microcomputer 1 determines the threshold correction to be small.

[0107] When the width of the defined measurement range is greater than the predetermined range width, microcomputer 1 proceeds to S164. Microcomputer 1 executes a process that determines the determination threshold, which was corrected in S164, to be larger. In S180, microcomputer 1 determines whether to perform equalization processing based on whether the voltage difference is greater than the corrected determination threshold. When the determination threshold mentioned in S164 is corrected to be larger, equalization processing is tended not to be performed compared to before correction.

[0108] When the width of the defined measurement range is less than the predetermined range width, microcomputer 1 proceeds to S166. In S166, microcomputer 1 performs a determination process to determine if the threshold has been corrected to a smaller value. In S180, microcomputer 1 determines whether to perform equalization processing based on whether the voltage difference is greater than the corrected threshold. When it is determined in S166 that the threshold has been corrected to a smaller value, equalization processing may be performed compared to before the correction.

[0109] The microcomputer 1 can set a determination threshold based on the width of a defined measurement range using the following method: The microcomputer 1 multiplies the width of the defined measurement range by a coefficient, and when the width of the defined measurement range calculated in this way is smaller, the determination threshold is corrected to be smaller. When the width of the defined measurement range calculated in this way becomes larger, the microcomputer 1 corrects the determination threshold. When the difference between the maximum voltage measurement value and the minimum voltage measurement value measured in the predetermined battery pack is less than the determination threshold, the microcomputer 1 determines not to perform equalization processing. When the difference between the maximum voltage measurement value and the minimum voltage measurement value is greater than the determination threshold, the microcomputer 1 determines to perform equalization processing.

[0110] The fourth embodiment has the following effects. The microcomputer 1 sets a threshold value based on the width of a defined measurement range. According to this control, the necessity of high-precision equalization processing is determined by using the threshold value set based on the width of the defined measurement range. As a result, highly accurate equalization processing is performed.

[0111] When the width of the defined measurement range is greater than the predetermined range width, the microcomputer 1 determines that the threshold correction is large. When the width of the defined measurement range is less than the predetermined range width, the microcomputer 1 determines that the threshold correction is small. When the difference between the maximum voltage measurement value and the minimum voltage measurement value measured in a predetermined battery pack among multiple battery packs is less than a determined threshold, the microcomputer 1 determines not to perform equalization processing. When the difference between the maximum voltage measurement value and the minimum voltage measurement value is greater than the determined threshold, the microcomputer 1 determines to perform equalization processing.

[0112] According to this control, the necessity of equalization processing is determined based on high-precision voltage measurements taken within a defined measurement range, enabling the execution of high-precision equalization processing. Furthermore, the necessity of high-precision equalization processing is determined by using a threshold corrected according to the width of the defined measurement range. As a result, high-accuracy equalization processing is performed.

[0113] (Fifth Embodiment)

[0114] Reference Figure 9 The fifth embodiment is described. Figure 9 This is a configuration diagram of monitoring IC 103. The configurations, actions, and effects not specifically described in the fifth embodiment are the same as in the first embodiment; only the differences from the first embodiment are described below.

[0115] The monitoring IC 103 of the fifth embodiment includes a command unit 31, a plurality of analog-to-digital converters 32, a plurality of level converters 33, and a switch group 34. The monitoring IC 103 also includes an equalization circuit 4. The analog-to-digital converters 32 and the level converters 33 are configured to correspond to each other.

[0116] The monitoring IC 103 sets multiple different defined measurement ranges by providing a configuration of multiple analog-to-digital converters 32 for a switch group 34. The monitoring IC 103 serves as a measurement unit for measuring the voltage of the battery cell 7 within multiple defined measurement ranges. Each analog-to-digital converter 32 can be configured to have the function of setting a predetermined defined measurement range. In this case, multiple analog-to-digital converters 32 and multiple level converters 33 corresponding to a battery group are configured to set different predetermined defined measurement ranges.

[0117] The range setting unit of the fifth embodiment sets multiple different defined measurement ranges. With this configuration, appropriate voltage measurements are performed on multiple battery cells 7.

[0118] Furthermore, the monitoring IC 103 includes multiple level shifters 33 and multiple analog-to-digital converters 32 for a switch group 34. Therefore, the voltage of multiple battery cells 7 can be measured quickly.

[0119] When the switch group 34 selects the voltage of the multiple battery cells 7 one by one, the voltage measurement range of each of the multiple battery cells 7 can be set by the analog-to-digital converter 32 and the level converter 33. This configuration is applicable to all embodiments and variations.

[0120] Furthermore, when the switch group 34 selects the voltage of the plurality of battery cells 7 included in the battery pack, the analog-to-digital converter 32 and the level converter 33 can set a common voltage measurement range for at least a portion of the plurality of battery cells 7. In such a configuration, the common voltage measurement range can be set as a defined measurement range based on at least one of the maximum and minimum values ​​measured by the selected battery cell 7. Such a configuration is applicable to all embodiments and variations.

[0121] (Sixth Embodiment)

[0122] The sixth embodiment will refer to Figures 10 to 12 Describe it.

[0123] In the first embodiment, an example is shown where the microcomputer 1 sets the voltage measurement range of the battery cell 7 when the vehicle's power unit is stopped. An example is also shown where the microcomputer 1 sets the voltage measurement range of the battery cell 7 when the vehicle's ignition switch is in the off state.

[0124] On the other hand, in this embodiment, when the vehicle's ignition switch is on, the microcomputer 1 sets the voltage measurement range of the battery cell 7. The microcomputer 1 performs the setting of the voltage measurement range and voltage detection as a cyclic task.

[0125] First, refer to Figure 10 Describe the voltage detection of battery cell 7 in detail. Figure 10 The voltage change of battery cell 7 over time is shown. The vertical axis represents arbitrary units. The horizontal axis represents time. Arbitrary units are represented by au. Time is represented by T.

[0126] Battery cell 7 has internal resistance. Therefore, based on the voltage drop due to the internal resistance and the current flowing through battery cell 7, there exists a difference between the open-circuit voltage of battery cell 7 at its state of charge (SOC) and the closed-circuit voltage detected by monitoring IC3. The voltage and closed-circuit voltage detected by monitoring IC3 of battery cell 7 will be reconciled below.

[0127] Besides closed-circuit voltage Figure 10 The diagram illustrates the driving state of the battery management device 100, the actual current flowing through the battery pack 5, and the closed-circuit voltage of a single battery cell 7. The driving state of the battery management device 100 is described as DS. For simplicity, it is assumed that the closed-circuit voltage of the battery cell 7 shown in the diagram behaves the same as the closed-circuit voltage of the battery pack 5. To illustrate the behavior, the diagram shows a significant change in the closed-circuit voltage of the battery cell 7 over a short period of time.

[0128] At time 0, the vehicle's ignition switch is off. The battery management device 100 is in a non-driven state. No battery information, such as closed-circuit voltage, is stored in the storage unit 22. The system main relay 6, which controls the conductivity between the battery pack 5 and various vehicle-mounted devices, is off. Therefore, virtually no current flows through the battery pack 5. The closed-circuit voltage of the battery cell 7 is a value in the low-variation region.

[0129] Even when no current flows through battery cell 7, the state of charge (SOC) of battery cell 7 will decrease due to self-discharge. Therefore, in the initial state at time 0, the closing voltage of battery cell 7 tends to decrease slightly.

[0130] At time t0, the vehicle's ignition switch changes from the off state to the on state. The battery management device 100 changes from a non-drive state to a drive state. The system main relay 6 changes from an off state to a conducting state. As a result, power begins to be supplied from the battery pack 5 to various vehicle devices. Actual current begins to flow in the battery pack 5. The rate of decrease in the state of charge (SOC) of battery cell 7 increases. With this configuration, the rate of decrease in the closing voltage of battery cell 7 also increases.

[0131] At time t1, the microcomputer 1 acquires the closed voltage of battery cell 7. At this time, the storage unit 22 does not store battery information, therefore, the microcomputer 1 sets the voltage measurement range at time t1 to the entire range. That is, the microcomputer 1 sets the voltage measurement range to 0.0V to 5.0V.

[0132] At time t2, microcomputer 1 again acquires the closed-circuit voltage of battery cell 7. At this time, microcomputer 1 determines the center value of the defined measurement range at time t2 based on the closed-circuit voltage of battery cell 7 acquired at time t1. Furthermore, microcomputer 1 determines the range width α of the defined measurement range.

[0133] Voltage measurement range is from Figure 10 The width of the arrows at both ends of the solid line shown indicates the range width α. The difference between the center value and the upper or lower limit of the measurement range is set as the range width α. The range width α is a value greater than the detection error of the closed-circuit voltage. The range width α is less than... Figure 6The value shown is half the difference between OCV1 and OCV2. The difference between the center value and the upper limit value and the difference between the center value and the lower limit value can be the same or different. In this embodiment, the range width α is set to a fixed value. The range width α is stored in the storage unit 22. Therefore, the defined measurement range is determined essentially based on the closed-circuit voltage. The microcomputer 1 sets the defined measurement range based on the range width α and the acquired closed-circuit voltage. For example, the microcomputer 1 sets the defined measurement range at time t2 to 2.8V to 3.2V. The microcomputer 1 acquires the closed-circuit voltage detected by the monitoring IC3 within the defined measurement range at time t2.

[0134] Strictly speaking, because the battery management device 100 performs calculations, the time at which the defined measurement range is determined at time t2 is not the same as the time at which the closed-circuit voltage is acquired. The determination time precedes the acquisition time. However, the difference between these two times is small. Therefore, these two times are considered the same and described.

[0135] Microcomputer 1 acquires the closed-circuit voltage during an acquisition cycle. This acquisition cycle is a predetermined time interval during which the SOC of battery cell 7 will not suddenly change unless the state of charge or discharge of battery cell 7 changes abruptly due to fast charging or similar reasons. The acquisition cycle is a time interval during which the expected change in the closed-circuit voltage of battery cell 7 does not exceed a range width α. When the acquisition cycle has elapsed from time t1, time becomes t2.

[0136] When the acquisition cycle has elapsed from time t2, time becomes t3. At time t3, microcomputer 1 determines a defined measurement range based on the closed-circuit voltage at time t2. For example, microcomputer 1 sets the defined measurement range at time t3 to 2.6V to 3.0V. Microcomputer 1 acquires the closed-circuit voltage of battery cell 7 detected by monitoring IC 3 within the defined measurement range.

[0137] When time t3 changes to time tc1, the vehicle's driving state changes. The actual current decreases. This configuration also reduces the rate of decrease in closed-circuit voltage.

[0138] When the acquisition cycle has elapsed from time t3, time becomes t4. At time t4, microcomputer 1 determines a defined measurement range based on the closed-circuit voltage at time t3. For example, microcomputer 1 sets the detection range at time t4 to 2.4V to 2.8V. Microcomputer 1 acquires the closed-circuit voltage of battery cell 7 detected by monitoring IC 3 within the defined measurement range.

[0139] From time t4 to time tc2, the charging device 12 is connected to the vehicle via the charging terminal 11. The battery pack 5 is rapidly charged by the charging device 12. As a result, the actual current increases sharply. The microcomputer 1 obtains this information from the charging device 12. At this time, the microcomputer 1 sets the voltage measurement range to the entire range.

[0140] When the acquisition cycle has elapsed from time t4, time becomes t5. At time t5, microcomputer 1 acquires the closed-circuit voltage of battery cell 7 detected by monitoring IC 3 over the entire range. Due to variations in the voltage measurement range, such as... Figure 10 As shown, even if the cyclic closing voltage suddenly rises from time tc2, the cyclic closing voltage detected at time t5 is still within the voltage measurement range.

[0141] When time t5 changes to time tc3, the output voltage of the battery pack 5 reaches the target voltage. Upon detecting this, the microcomputer 1 terminates the fast charging by the charging device 12. The microcomputer 1 then instructs the charging device 12 to perform a full charge.

[0142] Fast charging and full charging provide different amounts of current. Fast charging uses a larger supply current than full charging.

[0143] There is a voltage drop difference between the closed-circuit voltage and the open-circuit voltage. Therefore, for example, even if the maximum output voltage of battery pack 5 is detected as the closed-circuit voltage, the open-circuit voltage will not reach the maximum output voltage. The state of charge (SOC) of battery pack 5 has not yet reached its full charge capacity.

[0144] The target voltage is based on the maximum output voltage of the battery pack 5. When the microcomputer 1 determines that the output voltage of the battery pack 5 has reached the target voltage, the microcomputer 1 causes the charging device 12 to fully charge the battery. During full charging, while providing charging power to the battery pack 5, the output voltage of the battery pack 5 is maintained at the target voltage so that the SOC of the battery pack 5 is close to the full charging capacity while avoiding overcharging. The target voltage and the maximum output voltage are pre-stored in the storage unit 22.

[0145] When the acquisition cycle has elapsed from time t5, time becomes t6. At time t6, microcomputer 1 acquires the closed-circuit voltage of battery cell 7 detected by monitoring IC 3 over the entire range. At this time, the output voltage of the expected battery pack 5 has reached the target voltage. Therefore, the closed-circuit voltage can be detected within the voltage measurement range based on this target voltage.

[0146] (Seventh Embodiment)

[0147] Reference Figure 11 The seventh embodiment is described.

[0148] In the sixth embodiment, as referenced Figure 10 As described, when switching from a non-drive state to a drive state, the microcomputer 1 acquires the closed-circuit voltage detected by the monitoring IC 3 over the entire range.

[0149] On the other hand, in this embodiment, when switching from a non-driving state to a driving state, the microcomputer 1 acquires the closed-circuit voltage detected by the monitoring IC 3 within the available range of the battery cell 7. In this configuration, the detection accuracy of the closed-circuit voltage can be improved even when the battery management device 100 switches from a non-driving state to a driving state.

[0150] For example, in Figure 11 At time t0, the battery management device 100 changes from a non-driven state to a driven state. The system main relay 6 changes from an open state to a conductive state. Current begins to flow in the battery pack 5. The rate of decrease in the state of charge (SOC) and closed-circuit voltage of the battery cell 7 increases.

[0151] From time t0 to time t1, microprocessor 1 is based on Figure 6 The characteristic data of SOC and OCV shown define the measurement range. For example, the microcomputer 1 sets the usable range of battery cell 7 to... Figure 6 The distance between SOC1 and SOC2 is shown. Then, microcomputer 1 sets a defined measurement range based on OCV1 and OCV2, which correspond to SOC1 and SOC2 respectively. For example... Figure 11 As shown, the microcomputer 1 sets the lower limit of the measurement range as CCV1 and the upper limit as CCV2.

[0152] Figure 6 The characteristic data shown depends on temperature. There is a voltage drop difference between the open-circuit voltage and the closed-circuit voltage. Therefore, microcomputer 1 can consider not only… Figure 6 The characteristic data shown also takes into account the temperature, current, and degree of degradation of battery cell 7 at time t1 to set the limited measurement range.

[0153] To clarify the difference from the entire range described in other embodiments, this embodiment describes the microcomputer 1 setting the voltage measurement range at time t1 to the limited measurement range as described above. However, the battery cell 7 is used within the usable range. Therefore, the detected closing voltage is expected to be within the usable range. Thus, the usable range can be set to the entire range. Such a setting can also be applied to other embodiments and variations.

[0154] (Eighth Embodiment)

[0155] Reference Figure 12 The eighth embodiment is described.

[0156] In the above embodiments, regardless of the execution of the equalization process, the microcomputer 1 acquires the closed-circuit voltage of each of the plurality of battery cells 7. On the other hand, in this embodiment, after performing the equalization process, the microcomputer 1 acquires a portion of the closed-circuit voltage of the plurality of battery cells 7.

[0157] During the equalization process, the State of Charge (SOC) of each of the multiple battery cells 7 is equalized. Therefore, it is desirable that the closed-circuit voltages of the multiple battery cells 7 are identical. Thus, after the equalization process, the monitoring IC3 detects the closed-circuit voltage of a portion of the multiple battery cells 7. The microcomputer 1 acquires the closed-circuit voltage detected by the monitoring IC3. This configuration simplifies the arithmetic processing of the monitoring IC3 and the microcomputer 1.

[0158] The monitoring IC3 can detect the closed-circuit voltage of all battery cells 7. The microcomputer 1 can then acquire a portion of the multiple closed-circuit voltages detected by the monitoring IC3. This configuration simplifies the arithmetic processing of the microcomputer 1.

[0159] However, after a certain amount of time has elapsed since the self-equilibrium process began, the state of charge (SOC) of the multiple battery cells 7 changes. The closing voltage of each of the multiple battery cells 7 becomes unequal.

[0160] Therefore, microcomputer 1 executes... Figure 12 The target setting process is shown. Microcomputer 1 executes this target setting process as a recurring task. Microcomputer 1, along with, for example... Figure 4 and Figure 10 The other battery management functions shown perform this target setting process in parallel.

[0161] In S310, the microcomputer 1 determines whether the equalization counter held by the microcomputer 1 is less than the expected change value stored in the storage unit 22. When the microcomputer 1 determines that the equalization counter is less than the expected change value, the microcomputer 1 proceeds to S320. When the microcomputer 1 determines that the equalization counter is equal to or greater than the expected change value, the microcomputer 1 proceeds to S330.

[0162] When the equalization process is performed, the value of the equalization counter is reset to zero. After the equalization process is performed, the expected change value is determined based on the time of inconsistency in the expected closing voltage of multiple battery cells 7.

[0163] In step S320, microcomputer 1 increments the equalization counter. Then, microcomputer 1 proceeds to step S340.

[0164] When the process reaches step S340, the microcomputer 1 sets only the portion of the multiple battery cells 7 that has undergone equalization processing as the target for obtaining the closed-circuit voltage (voltage measurement target). For example, the microcomputer 1 sets one battery cell 7 from the multiple battery cells 7 in a battery pack as the target for obtaining the closed-circuit voltage. For example, the microcomputer 1 sets one battery cell 7 from all the battery cells 7 in a battery pack as the target for obtaining the closed-circuit voltage. Then, the microcomputer 1 terminates the target setting process.

[0165] When it is determined in S310 that the equalization counter is equal to or greater than the expected change value and the process proceeds to S330, the microcomputer 1 sets all of the multiple battery cells 7 as the target for acquiring the closed-circuit voltage. Then, the microcomputer 1 terminates the target acquisition setting process.

[0166] After performing the equalization process, the microcomputer 1 repeatedly executes S310, S320, and S340. During this period, only the portion of the closed-circuit voltage that has undergone equalization processing in the multiple battery cells 7 is set as the acquisition target.

[0167] Then, when the equalization counter reaches the expected change value, the microcomputer 1 repeats S330. Afterwards, all closed voltages of the multiple battery cells 7 are set to the acquisition target until the equalization process is executed again.

[0168] (Other embodiments)

[0169] The disclosure in this specification is not limited to the embodiments shown. This disclosure includes embodiments and variations thereof as illustrated by those skilled in the art. For example, this disclosure is not limited to the combinations of components and elements shown in the embodiments, and various modifications and implementations are possible. This disclosure can be implemented in various combinations. This disclosure may have additional portions that can be added to the embodiments. This disclosure includes omissions of portions and elements of the embodiments. This disclosure includes substitutions or combinations of components and elements between one embodiment and another. The scope of the disclosed technology is not limited to the description of the embodiments. It should be understood that the scope of the disclosed technology is defined by the claims and includes the meaning equivalent to the claims and all modifications within the scope of the claims.

[0170] (Other modifications)

[0171] The battery management device 100 is not limited to providing a monitoring IC 3 configuration for each battery pack. The battery management device 100 may have a monitoring IC 3 for combining batteries 5 and a microcomputer 1. The battery management device 100 may include a microcomputer 1 for each battery pack.

Claims

1. A battery management device, comprising: A range setting unit (1) is configured to set a limited measurement range, said limited measurement range restricting the range of voltage for measuring each of the plurality of batteries (7) of the vehicle, and Measurement unit (3; 103), configured to measure the voltage of each of the plurality of batteries within the defined measurement range, wherein, When estimating the voltage value of each of the plurality of batteries, the range setting unit sets a defined measurement range adjusted based on the voltage value of each of the plurality of batteries, and When the voltage value of each of the plurality of batteries is not estimated, the range setting unit sets the limited measurement range based on the measured voltage of each of the plurality of batteries over the entire range.

2. The battery management device according to claim 1, wherein The measuring unit limits the defined measuring range by adjusting the range of the measuring voltage in response to a command output from the range setting unit.

3. The battery management device according to claim 1, wherein... The range setting unit sets the defined measurement range by using at least one of the maximum and minimum values ​​of the measured voltage of each of the plurality of batteries measured over the entire range.

4. The battery management device according to claim 1 or 2, wherein The range setting unit sets multiple different measurement ranges.

5. The battery management device according to claim 1 or 2, wherein When the noise level is acceptable under acceptable conditions, the range setting unit sets the defined measurement range and the measurement unit measures the voltage within the defined measurement range.

6. The battery management device according to claim 5, wherein When the power unit providing driving force to the vehicle stops and the charging or discharging of each of the plurality of batteries stops, the range setting unit sets the defined measurement range and the measuring unit measures the voltage within the defined measurement range.

7. The battery management device according to claim 1 or 2, wherein When the plurality of batteries are charged from an external power source (12), the range setting unit sets the defined measurement range and the measurement unit measures the voltage within the defined measurement range while charging is temporarily stopped.

8. The battery management device according to claim 1 or 2, further comprising: A balancing determination unit (1) is configured to determine whether to perform a balancing process to reduce voltage variations on a predetermined battery pack comprising at least a portion of the plurality of batteries, wherein... The equalization determination unit determines whether to perform equalization processing based on the measured voltage of each of the plurality of batteries measured within the defined measurement range.

9. The battery management device according to claim 8, wherein When equalization processing is performed on the batteries included in the predetermined battery pack, the equalization determination unit selects a portion of the batteries included in the predetermined battery pack as the target for voltage measurement.

10. The battery management device according to claim 1 or 2, further comprising: The SOC estimation unit (1) is configured to estimate the state of charge based on characteristic data representing the relationship between the open-circuit voltage and the state of charge of each of the plurality of batteries and the measured values ​​of the voltage of each of the plurality of batteries measured within the defined measurement range.

11. The battery management device according to claim 10, further comprising: SOH estimation unit (1) is configured to use the estimated state of charge to estimate the state of health (SOH) representing the degree of degradation of each of the plurality of cells.

12. A battery device, comprising: Multiple batteries for the vehicle (7); A range setting unit (1) is configured to set a limited measurement range, the limited measurement range restricting the range for measuring the voltage of each of the plurality of batteries; and Measurement unit (3; 103), configured to measure the voltage of each of the plurality of batteries within the defined measurement range, wherein, When estimating the voltage value of each of the plurality of batteries, the range setting unit sets a defined measurement range adjusted based on the voltage value of each of the plurality of batteries, and When the voltage value of each of the plurality of batteries is not estimated, the range setting unit sets the limited measurement range based on the measured voltage of each of the plurality of batteries over the entire range.

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