JP7600176B2 - Battery management device and battery management method - Google Patents

Description

The present invention relates to a battery management device and a battery management method.

Conventionally, assembled batteries made up of multiple battery cells have been used as power sources for driving vehicles, etc. The temperature of the battery cells can become too high, for example, due to repeated rapid charging and discharging or changes in the environmental temperature. When the battery cells are in a high-temperature state, the charging and discharging efficiency can decrease. Examples of related art documents include Patent Documents 1 to 3. For example, Patent Document 1 describes how, when it is determined that a battery cell is in a high-temperature state, a Peltier element is controlled to absorb heat from the battery cell, and a cooling fan is started to lower the temperature of the battery cell.

Japanese Patent Application Publication No. 8-148189 JP 2015-119605 A International Publication No. 2013-105152

However, according to the inventor's research, there is room for improvement in the above technology when considering the lifespan of battery cells. Therefore, the main objective of the present invention is to provide a battery management device and a battery management method that can extend the lifespan of battery cells.

The present invention provides a battery management device including a temperature measurement unit that measures the temperature of a battery cell, an electrical characteristic measurement unit that measures the electrical characteristics of the battery cell, a Peltier element that is thermally connected to the battery cell, a heat transfer member that is thermally connected to the Peltier element, and a control unit that controls the temperature measurement unit, the electrical characteristic measurement unit, and the Peltier element. The control unit includes a first determination unit that determines whether the temperature of the battery cell measured by the temperature measurement unit is equal to or higher than a predetermined lower limit temperature, a second determination unit that determines whether the state of charge (SOC) of the battery cell obtained from the electrical characteristics measured by the electrical characteristic measurement unit is equal to or higher than a predetermined lower limit SOC, and a cell temperature control unit that drives the Peltier element to send heat from the battery cell to the heat transfer member when both the first determination unit and the second determination unit determine yes.

The battery management device is configured to determine whether or not to cool the battery cells based on the temperature and SOC of the battery cells. According to the inventor's research, if a battery cell is kept in a high temperature and high SOC state for a long time, its life performance will rapidly deteriorate. Therefore, by determining the need for cooling taking into account not only the temperature of the battery cells but also the SOC, the life of the battery cells can be accurately extended. In addition, by using a Peltier element, the battery cells can be cooled quickly, and weight and space can be saved.

In a preferred embodiment of the battery management device disclosed herein, the cell temperature control unit is configured not to drive the Peltier element when the result of the determination by at least one of the first determination unit and the second determination unit is negative. According to the inventor's study, when the temperature of the battery cell is low or the SOC of the battery cell is low, the deterioration of the life performance is relatively small. By not driving the Peltier element in such a case, the energy required to drive the Peltier element can be reduced.

In a preferred embodiment of the battery management device disclosed herein, the battery cells are multiple, and each of the multiple battery cells is provided with the electrical characteristic measuring unit and the Peltier element. In an assembled battery, a decrease in the performance of one battery cell can significantly affect the overall battery characteristics. Therefore, applying the technology disclosed herein is particularly effective.

In one preferred embodiment of the battery management device disclosed herein, the lower limit temperature is set in the range of 40±5°C. In another preferred embodiment of the battery management device disclosed herein, the lower limit SOC is set in the range of 40±5%. This allows the life performance of the battery cells to be improved to a higher level.

The present invention also provides a battery management method using a battery management device including a temperature measurement unit for measuring the temperature of a battery cell, an electrical characteristic measurement unit for measuring the electrical characteristics of the battery cell, a Peltier element thermally connected to the battery cell, a heat transfer member thermally connected to the Peltier element, and a control unit for controlling the temperature measurement unit, the electrical characteristic measurement unit, and the Peltier element. The method includes a first determination step for determining whether the temperature of the battery cell measured by the temperature measurement unit is equal to or higher than a predetermined lower limit temperature, a second determination step for determining whether the state of charge (SOC) calculated based on the electrical characteristics measured by the electrical characteristic measurement unit is equal to or higher than a predetermined lower limit SOC, and a cell temperature control step for controlling the Peltier element to drive and send heat from the battery cell to the heat transfer member when the results of both the first and second determination steps are positive, and not driving the Peltier element when the results of at least one of the first and second determination steps are negative. This effectively extends the life of the battery cells.

FIG. 1 is a schematic side view of a battery management device according to one embodiment. FIG. 2 is a functional block diagram of the control device. FIG. 3 is a flow chart illustrating an example of a temperature control process. FIG. 4 is a view corresponding to FIG. 1 and showing the flow of airflow during cooling according to one embodiment.

Below, preferred embodiments of the technology disclosed herein will be described with reference to the drawings. Note that matters other than those specifically mentioned in this specification that are necessary for implementing the present invention can be understood as design matters for a person skilled in the art based on the prior art in the relevant field. The present invention can be implemented based on the contents disclosed in this specification and common technical knowledge in the relevant field.

[Battery management device]
FIG. 1 is a schematic side view of a battery management device 10 according to an embodiment. In the following description, the symbols L, R, U, and D in the drawings represent left, right, top, and bottom, and the symbols X and Y in the drawings represent the arrangement direction and up-down direction of the battery cells 20, respectively. However, these directions are merely for the convenience of explanation and do not limit the installation form of the battery management device 10 or the battery cells 20 in any way. In addition, each figure is a schematic diagram and does not necessarily faithfully reflect an actual implementation. In the following, the same symbols are used for members and parts that perform the same function, and duplicated descriptions are omitted or simplified as appropriate.

The battery management device 10 is a device that manages the temperature of one or more battery cells 20. The battery cells 20 are housed inside a housing 22. The battery cells 20 are secondary batteries, for example lithium ion batteries. In this specification, the term "secondary battery" refers to any power storage device that can be repeatedly charged and discharged, and is a concept that encompasses so-called storage batteries (chemical batteries) such as lithium ion secondary batteries and nickel-metal hydride batteries, and capacitors (physical batteries) such as electric double layer capacitors.

The battery cell 20 is configured by housing an electrode body and an electrolyte (not shown) inside an exterior body. The configuration of the battery cell 20 may be the same as that of the conventional battery cell, and is not limited in any way. The exterior body is made of a metal material with good thermal conductivity, such as aluminum, an aluminum alloy, or stainless steel. Here, the battery cell 20 has a flat outer shape and a rectangular parallelepiped shape (square shape) with a bottom. The battery cell 20 has a flat bottom surface 20b, side surfaces 20s extending from the bottom surface 20b, and a positive electrode terminal and a negative electrode terminal (not shown). However, the shape of the battery cell 20 is not limited to a square shape, and may be any shape, such as a cylinder or a bag shape. The bottom surface 20b faces the first heat transfer plate 30 described later.

Here, there are multiple battery cells 20. The multiple battery cells 20 are arranged along the arrangement direction X so that the wide side surfaces 20s face each other. The multiple battery cells 20 are electrically connected to each other to form a battery pack. Here, the multiple battery cells 20 are connected in series via a metal bus bar. However, in other embodiments, the multiple battery cells 20 may be connected in parallel.

The battery management device 10 of this embodiment includes a plurality of first heat transfer plates 30, a plurality of Peltier elements 40 (see also FIG. 2), a second heat transfer plate 50, a plurality of temperature measurement units 62 (see also FIG. 2), a plurality of voltage measurement units 64 (see FIG. 2), a control device 70 (see FIG. 2), and a blower 80 (see also FIG. 2). In this embodiment, the second heat transfer plate 50 is an example of a heat transfer member connected to the Peltier elements, the temperature measurement unit 62 is an example of a temperature measurement unit that measures the temperature of the battery cell, and the voltage measurement unit 64 is an example of an electrical characteristic measurement unit that measures the electrical characteristics of the battery cell.

The first heat transfer plates 30 each have one surface (upper surface in FIG. 1) in contact with the bottom surface 20b of the battery cells 20 (specifically, the exterior body of the battery cells 20). The opposite surface (lower surface in FIG. 1) of the first heat transfer plates 30 to the surface in contact with the battery cells 20 contacts the Peltier element 40 described below. The first heat transfer plate 30 is in the form of a sheet having approximately the same size as the bottom surface 20b of the battery cells 20. The first heat transfer plate 30 is made of a material with excellent thermal conductivity, such as aluminum foil. However, the material of the first heat transfer plate 30 is not particularly limited. Furthermore, the first heat transfer plate 30 is not essential and may be omitted in other embodiments.

One surface (upper surface in FIG. 1) of each of the multiple Peltier elements 40 is in contact with each of the multiple first heat transfer plates 30, and the other surface (lower surface in FIG. 1) is in contact with a second heat transfer plate 50 described below. Here, the Peltier elements 40 are thermally connected to the battery cells 20 via the first heat transfer plate 30. However, the Peltier elements 40 may also be thermally connected to each battery cell 20 directly without the first heat transfer plate 30. In this specification, the term "thermally connected" means that heat can be conducted between the two, and is a term that does not ask whether an intermediate object such as the first heat transfer plate 30 is present between the two.

The Peltier elements 40 each include a control circuit 41 having a power supply 41a. The control circuits 41 are electrically connected to the control device 70 (see FIG. 2) and configured to control each of the Peltier elements 40. The power supply 41a is capable of switching the direction of voltage application, and is configured to selectively pass a current in a first direction or a current in a second direction opposite to the first direction through the Peltier elements 40. The direction of voltage application from the power supply 41a is controlled by a cell temperature control unit 76, which will be described later.

The Peltier element 40 is a semiconductor element that can transfer heat from one end to the other end by passing an electric current through it. The direction of heat transfer by the Peltier element 40 can be changed by changing the direction of the electric current. The amount of heat transferred per unit time by the Peltier element 40 is generally not linear, but changes according to the electric current. Note that one Peltier element 40 here means a group of Peltier elements 40 that are controlled in a synchronous manner, and is a term that does not ask whether they are physically separated.

The Peltier element 40 may be any conventionally known Peltier element, and is not particularly limited. The Peltier element 40 has, for example, a plurality of P-type and N-type semiconductors. When a current flows from one of the P-type and N-type semiconductors to the other, the first heat transfer plate 30 absorbs heat. This allows heat to be transferred from the first heat transfer plate 30 to the second heat transfer plate 50, thereby cooling the battery cell 20.

The second heat transfer plate 50 is thermally connected to the other surface (the lower surface in FIG. 1) of the multiple Peltier elements 40. The second heat transfer plate 50 thermally connects the multiple battery cells 20 via the multiple Peltier elements 40. The number of second heat transfer plates 50 is one here. The second heat transfer plate 50 is a flat member having approximately the same area as the entire bottom surface 20b of the multiple battery cells 20. The second heat transfer plate 50 is made of a material with excellent thermal conductivity, such as aluminum or an aluminum alloy. However, the material of the second heat transfer plate 50 is not particularly limited. The second heat transfer plate 50 plays the role of a heat sink. For this reason, the second heat transfer plate 50 may have, for example, a radiator structure or heat sink fins that efficiently release heat.

The plurality of temperature measurement units 62 are for measuring the temperatures of the plurality of battery cells 20, respectively. The temperature measurement units 62 are attached to, for example, metal members such as electrode terminals and bus bars (not shown), or to the side surfaces 20s of the battery cells 20. The configuration of the temperature measurement units 62 is not particularly limited. The temperature measurement units 62 are composed of, for example, resistance temperature detectors (thermistors) or thermocouples. The temperature measurement units 62 are electrically connected to the control device 70. The number of temperature measurement units 62 here is the same as the number of battery cells 20. However, the temperature measurement unit 62 may be attached to one of the plurality of battery cells 20 and arranged to measure a representative value (representative temperature) of the plurality of battery cells 20. In addition, the temperature of some or all of the battery cells 20 may be an estimated value estimated from the temperatures (e.g., representative temperatures) of the other battery cells 20 or other indicators.

The multiple voltage measurement units 64 are for measuring the voltages (terminal voltages) of the multiple battery cells 20. The voltage measurement units 64 are attached to metal members such as electrode terminals and bus bars (not shown). The configuration of the voltage measurement units 64 is not particularly limited. The voltage measurement units 64 are composed of, for example, electronic components (e.g., voltage detection wires) and electronic devices having a conventionally known voltage measurement function. Note that, although the voltage is measured as an electrical characteristic of the battery cells 20 here, other electrical characteristics may be measured. For example, in other embodiments, a current measurement unit may be provided instead of the voltage measurement units 64. The voltage measurement units 64 are electrically connected to the control device 70. The number of voltage measurement units 64 here is the same as the number of battery cells 20.

The blower 80 is a device that blows air into the second heat transfer plate 50 or the inside of the housing 22. The blower 80 is a cooling fan that takes in gas (air) from the intake port 22a of the housing 22 by rotating, for example, and expels the gas from the exhaust port 22b. The blower 80 is electrically connected to the control device 70, and may be configured to be driven simultaneously when the Peltier element 40 described below is driven. However, the blower 80 is not essential, and may be omitted in other embodiments. The inside of the housing 22 is typically maintained at a temperature below a predetermined value (for example, below 40°C) by a constant temperature maintaining device (not shown) electrically connected to the control device 70.

The control device 70 includes a BMU (Battery Monitoring Unit). FIG. 2 is a functional block diagram of the control device 70. The control device 70 includes a temperature acquisition unit 71, a first determination unit 72, a voltage acquisition unit 73, an SOC calculation unit 74, a second determination unit 75, and a cell temperature control unit 76.

The temperature acquisition unit 71 is configured to control the plurality of temperature measurement units 62 to measure the temperature T of the battery cell 20 and acquire the measured temperature T. The first determination unit 72 is configured to determine whether the temperature T acquired by the temperature acquisition unit 71 is equal to or higher than a predetermined temperature (lower limit temperature). The voltage acquisition unit 73 is configured to control the plurality of voltage measurement units 64 to measure the voltage of the battery cell 20 and acquire each of the measured voltages. The SOC calculation unit 74 stores in advance a "voltage-SOC chart" in which the voltage and the state of charge (SOC) are associated. The SOC calculation unit 74 is configured to calculate the SOC of the battery cell 20 by comparing the voltage acquired by the voltage acquisition unit 73 with the "voltage-SOC chart". The second determination unit 75 is configured to determine whether the SOC calculated by the SOC calculation unit 74 is equal to or higher than a predetermined SOC (lower limit SOC).

The cell temperature control unit 76 is configured to drive the control circuit 41 based on the judgment results of the first judgment unit 72 and the second judgment unit 75. In detail, when the first judgment unit 72 judges that the temperature of the battery cell 20 is higher than the predetermined lower limit temperature and the second judgment unit 75 judges that the SOC is higher than the predetermined lower limit SOC, the cell temperature control unit 76 drives the Peltier element 40 connected to the corresponding battery cell 20 to send heat from the battery cell 20 toward the second heat transfer plate 50. This cools the battery cell 20, and the temperature of the battery cell 20 becomes lower than the lower limit temperature, which is the high temperature threshold. On the other hand, when the first judgment unit 72 judges that the temperature is equal to or lower than the predetermined lower limit temperature and when the second judgment unit 75 judges that the temperature is equal to or lower than the predetermined lower limit SOC, the cell temperature control unit 76 does not drive the Peltier element 40 connected to the corresponding battery cell 20. This improves efficiency.

The configuration of the control device 70 is not particularly limited, but may include, for example, a microcomputer. The microcomputer may include, for example, an interface (I/F) that receives data from an external device, a central processing unit (CPU) that executes program instructions, a read only memory (ROM) that stores the program executed by the CPU, a random access memory (RAM) used as a working area for expanding the program, and a storage device such as a memory that stores the program and various data.

The battery management device 10 can be used for various purposes, but for example, it can be suitably mounted on vehicles such as passenger cars and trucks together with a battery pack including a plurality of battery cells 20. The type of vehicle is not particularly limited, but may be, for example, an electric vehicle (BEV; Battery Electric Vehicle) powered only by a motor operated by power supplied from the battery cells 20, or a hybrid vehicle (HEV; Hybrid Electric Vehicle) equipped with an internal combustion engine and a motor operated by power supplied from the battery cells 20. The hybrid vehicle may also be a plug-in hybrid electric vehicle (PHEV; Plug-in Hybrid Electric Vehicle) in which the battery cells 20 can be charged by an external power source.

[Battery management method]
3 is a flowchart of the temperature control of the battery management device 10. Note that, in the following, the temperature control of one battery cell 20 among the multiple battery cells 20 will be mainly described, but similar control is performed for each of the other battery cells 20. In addition, in the following temperature control, "YES" is synonymous with "yes" and "NO" is synonymous with "no."

There are no particular limitations on the timing of this temperature control, and it may be performed periodically at a specified interval, or at any time. In addition, if the battery management device 10 is mounted on a vehicle, for example, this temperature control may be started when the user starts the vehicle's power source, and may be ended when the user brakes the vehicle's power source. Alternatively, this temperature control may be performed periodically or at any time while the user leaves the vehicle's power source braked.

In the temperature control of this embodiment, first, in step S1, the temperature acquisition unit 71 acquires the temperature T of the battery cell 20 from the temperature measurement unit 62. Next, in step S2, the first judgment unit 72 judges whether the temperature of the battery cell 20 is equal to or higher than a predetermined lower limit temperature. The lower limit temperature is pre-stored in the control device 70. The lower limit temperature is typically equal to or higher than the temperature inside the housing 22 maintained by the constant temperature controller. Although not particularly limited, from the viewpoint of improving the life of the battery cell 20, the lower limit temperature is preferably about 60° C. or less, preferably 50° C. or less, and more preferably 40° C. or less. Also, from the viewpoint of efficiency, the lower limit temperature is preferably about 35° C. or more. The lower limit temperature is particularly preferably 40±5° C., and is set to 40° C. in this embodiment. In this embodiment, step S2 is an example of a first judgment step.

If the temperature of the battery cell 20 is below the lower limit temperature (the result of step S2 is NO), the Peltier element 40 is not driven and the control ends as in step S3.

On the other hand, if the temperature of the battery cell 20 is equal to or higher than the lower limit temperature (if the result of step S2 is YES), in step S4, the voltage acquisition unit 73 acquires the voltage of the battery cell 20 from the voltage measurement unit 64. Next, in step S5, the SOC calculation unit 74 calculates the SOC of the battery cell 20 from a pre-stored voltage-SOC chart based on the voltage acquired from the voltage measurement unit 64. However, if a current measurement unit is provided instead of the voltage measurement unit 64, the SOC may be calculated from the integrated value of the current measured by the current measurement unit.

In the next step S6, the second judgment unit 75 judges whether the SOC of the battery cell 20 is equal to or higher than a predetermined lower limit SOC. The lower limit SOC is pre-stored in the control device 70. Although not particularly limited, from the viewpoint of improving the life of the battery cell 20, the lower limit SOC is preferably approximately 60% or less, preferably 50% or less, and more preferably 40% or less. Also, from the viewpoint of efficiency, the lower limit SOC is preferably approximately 30% or more, for example 35% or more. The lower limit SOC is particularly preferably 40±5%, and is set to 40% here. In this embodiment, step S6 is an example of a second judgment process.

If the SOC of the battery cell 20 is less than the lower limit SOC (the result of step S6 is NO), the Peltier element 40 is not driven and the control ends as in step S7, unlike the conventional technology described in, for example, Patent Document 1.

On the other hand, if the SOC of the battery cell 20 is equal to or higher than the lower limit SOC (the result of step S6 is YES), in step S8, the Peltier element 40 is driven to transfer heat from the battery cell 20 to the second heat transfer plate 50. This cools the battery cell 20. The Peltier element 40 may be configured to drive the Peltier element 40 until the temperature measured by the temperature measurement unit 62 becomes less than the lower limit temperature, for example, or may be configured to drive the Peltier element 40 for a predetermined fixed time. In this embodiment, step S8 is an example of a cell temperature control process.

In this embodiment, the blower 80 is further driven in step S8. FIG. 4 is a diagram corresponding to FIG. 1 showing the flow of air during cooling. Note that FIG. 4 omits illustrations other than the battery cells 20, the housing 22, and the blower 80. As shown in FIG. 4, the air taken in from the air intake 22a of the housing 22 by the blower 80 is heated by the high-temperature battery cells 20 and the second heat transfer plate 50. This creates an airflow as shown by the arrows in FIG. 4. As a result, the heat trapped inside the housing 22 is dissipated, and the battery cells 20 are efficiently cooled.

According to the battery management device 10 described above, even if there is a variation in temperature or SOC among the multiple battery cells 20, the Peltier element 40 of each battery cell 20 can be driven individually. In other words, it is possible to selectively and efficiently cool battery cells 20 for which the results of steps S2 and S6 are both judged to be positive, i.e., battery cells 20 that are in a high temperature and high SOC state and require cooling. In addition, since the Peltier element 40 is not driven in battery cells 20 that are in a low temperature and/or low SOC state and do not require cooling, energy waste can be reduced. Therefore, the life of the battery cells 20 or the battery pack can be efficiently extended.

The above describes an embodiment of the present invention, but the above embodiment is merely an example. The present invention can be embodied in various other forms. The present invention can be embodied based on the contents disclosed in this specification and the technical common sense in the relevant field. The technology described in the claims includes various modifications and variations of the above-exemplified embodiment.

For example, in the embodiment of FIG. 3 described above, step S2 is performed following step S1. However, this is not limited to this. In a modified example, the control device 70 may further have an abnormality determination unit configured to determine whether or not the temperature T acquired by the temperature acquisition unit 71 is equal to or higher than a predetermined abnormal temperature (upper limit temperature). The abnormal temperature is stored in advance in the control device 70. The abnormal temperature is a temperature at which some abnormality is thought to have occurred in the battery cell 20, such as an internal short circuit. Although not particularly limited, the abnormal temperature may be, for example, 70°C or higher, 80°C or higher, or 90°C or higher. In this case, in the temperature control of FIG. 3, between steps S1 and S2, step S1A may be interposed in which the abnormality determination unit determines whether or not the temperature of the battery cell 20 is equal to or higher than the abnormal temperature (upper limit temperature). Then, if the temperature of the battery cell 20 is lower than the abnormal temperature (upper limit temperature), step S2 is executed, whereas if the temperature of the battery cell 20 is equal to or higher than the abnormal temperature, the Peltier elements 40 of all the battery cells 20 may be driven to cool all the battery cells 20 at once.

For example, in the embodiment of FIG. 3 described above, if the judgment result of step S2 or step S6 is NO (in other words, if the judgment result of at least one of the first judgment unit 72 and the second judgment unit 75 is NO), the Peltier element 40 is not driven. However, this is not limited to this. In a modified example, the Peltier element 40 of the battery cell 20 judged as NO in step S2 or step S6 may be driven. In this case, in step S8 (cell temperature control unit 76), the Peltier element 40 may be driven to transfer heat between the multiple battery cells 20 via the second heat transfer plate 50 and equalize the temperatures of the multiple battery cells 20. Specifically, the heat transfer direction of multiple Peltier elements is controlled, and for battery cells 20 for which a YES decision is made in step S6, the Peltier element 40 is driven to transfer heat from the battery cell 20 toward the second heat transfer plate 50, as in the above embodiment, while for battery cells 20 for which a NO decision is made in step S2 or step S6, the Peltier element 40 may be driven to transfer heat from the second heat transfer plate 50 toward the battery cell 20.

As described above, specific aspects of the technology disclosed herein include those described in the following sections.
Item 1: A battery management device comprising: a temperature measurement unit that measures a temperature of a battery cell; an electrical characteristic measurement unit that measures electrical characteristics of the battery cell; a Peltier element thermally connected to the battery cell; a heat transfer member thermally connected to the Peltier element; and a control unit that controls the temperature measurement unit, the electrical characteristic measurement unit, and the Peltier element, wherein the control unit comprises: a first determination unit that determines whether the temperature of the battery cell measured by the temperature measurement unit is equal to or higher than a predetermined lower limit temperature; a second determination unit that determines whether a state of charge (SOC) of the battery cell obtained from the electrical characteristics measured by the electrical characteristic measurement unit is equal to or higher than a predetermined lower limit SOC; and a cell temperature control unit that controls the Peltier element to send heat from the battery cell to the heat transfer member when both of the determination results of the first determination unit and the second determination unit are positive.
Item 2: The battery management device according to item 1, wherein the cell temperature control unit is configured not to drive the Peltier element when the judgment result of at least one of the first judgment unit and the second judgment unit is negative.
Item 3: The battery management device according to item 1 or 2, wherein the battery cells are multiple, and the electrical characteristic measuring unit and the Peltier element are provided in each of the multiple battery cells.
Item 4: The battery management device according to any one of items 1 to 3, wherein the lower limit temperature is set in the range of 40±5° C.
Item 5: The battery management device according to any one of items 1 to 4, wherein the lower limit SOC is set in a range of 40±5%.

REFERENCE SIGNS LIST 10 Battery management device 20 Battery cell 30 First heat transfer plate 40 Peltier element 50 Second heat transfer plate 62 Temperature measurement unit 64 Voltage measurement unit 70 Control device 71 Temperature acquisition unit 72 First determination unit 73 Voltage acquisition unit 75 Second determination unit 76 Cell temperature control unit

Claims (5)

A plurality of temperature measuring units each measuring a temperature of a plurality of battery cells;
A plurality of electrical characteristic measuring units each measuring an electrical characteristic of a plurality of the battery cells;
A plurality of Peltier elements thermally connected to the plurality of battery cells, respectively ;
A heat transfer member thermally connected to the plurality of Peltier elements;
A control unit that controls the temperature measurement units, the electrical characteristic measurement units, and the Peltier elements;
Equipped with
The control unit is
an abnormality determination unit that determines whether the temperature of the battery cell measured by the temperature measurement unit is equal to or higher than a predetermined upper limit temperature;
a control unit that drives all of the Peltier elements and controls them to transfer heat from all of the battery cells to the heat transfer member when a result of the determination by the abnormality determination unit is positive;
a first determination unit that determines whether or not the temperature of the battery cell measured by the temperature measurement unit is equal to or higher than a predetermined lower limit temperature when a determination result of the abnormality determination unit is negative ;
a second determination unit that determines whether a state of charge (SOC) of the battery cell obtained from the electrical characteristics measured by the electrical characteristic measurement unit is equal to or higher than a predetermined lower limit SOC;
a cell temperature control unit that drives the Peltier element and controls the Peltier element to transfer heat from the battery cell to the heat transfer member when the first determination unit and the second determination unit both determine "yes."
A battery management device comprising: The cell temperature control unit is configured not to drive the Peltier element when at least one of the first determination unit and the second determination unit determines that the Peltier element is not activated.
The battery management device according to claim 1 . The lower limit temperature is set in the range of 40±5° C.
The battery management device according to claim 1 or 2. The lower limit SOC is set in the range of 40±5%.
The battery management device according to claim 1 or 2. A plurality of temperature measuring units each measuring a temperature of a plurality of battery cells;
A plurality of electrical characteristic measuring units each measuring an electrical characteristic of a plurality of the battery cells;
A plurality of Peltier elements thermally connected to the plurality of battery cells, respectively ;
A heat transfer member thermally connected to the plurality of Peltier elements;
A control unit that controls the temperature measurement units, the electrical characteristic measurement units, and the Peltier elements;
A battery management method using a battery management device comprising:
an abnormality determination step of determining whether or not the temperature of the battery cell measured by the temperature measurement unit is equal to or higher than a predetermined upper limit temperature;
a step of controlling, when a result of the determination step of the abnormality determination step is positive, to drive all of the Peltier elements so as to transfer heat from all of the battery cells to the heat transfer member;
a first determination step of determining whether or not the temperature of the battery cell measured by the temperature measurement unit is equal to or higher than a predetermined lower limit temperature when the determination result of the abnormality determination step is negative ;
a second determination step of determining whether a state of charge (SOC) calculated based on the electrical characteristics measured by the electrical characteristics measurement unit is equal to or greater than a predetermined lower limit SOC;
a cell temperature control process configured to drive the Peltier element and control it to transfer heat from the battery cell to the heat transfer member when the determination results of the first determination process and the second determination process are both positive, and not drive the Peltier element when the determination results of at least one of the first determination process and the second determination process are negative;
A battery management method comprising:

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