Work machine battery warm-up control device

Abstract

To suppress battery over-discharge in a configuration in which the battery can be warmed up using power thereof.SOLUTION: A work machine battery warm-up control device (40) includes: battery 41; a heater 43 capable of warming up the battery 41 using power of the battery 41; and a battery state detection unit 65. A controller 70 determines whether or not the battery 41 can be warmed up using the power of the battery 41, on the basis of a charge state of the battery 41 detected by the battery state detection unit 65 (S4). When determining that the battery 41 cannot be warmed up using the power of the battery 41, the controller 70 does not allow the heater 43 to warm up the battery 41 using the power of the battery 41 (S11).SELECTED DRAWING: Figure 3

Description

[Technical Field]

[0001] The present invention relates to a work machine battery warm-up control device that controls the warm-up of a battery. [Background technology]

[0002] For example, Patent Document 1 describes a technology for controlling the warm-up of a battery (called a power storage device in the document) based on the outside air temperature. The document also describes warming up the battery using the battery's power (e.g., claim 2 of the document). [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Japanese Patent Application Laid-Open No. 2016-160843 Summary of the Invention [Problem to be solved by the invention]

[0004] However, when the battery is warmed up using the battery's power, depending on the state of charge of the battery, the battery may be over-discharged, which may cause the battery to deteriorate.

[0005] SUMMARY OF THE INVENTION Accordingly, an object of the present invention is to provide a work machine battery warm-up control device that can suppress over-discharge of the battery in a configuration that allows the battery to be warmed up using the battery's power. [Means for solving the problem]

[0006] The work machine battery warm-up control device includes a battery, a heater, a battery state detection unit, and a controller. The battery outputs electric power for operating a work machine. The heater is capable of warming up the battery using the electric power of the battery. The battery state detection unit detects the temperature and state of charge of the battery. The controller determines whether or not the battery can be warmed up using the electric power of the battery based on the state of charge of the battery detected by the battery state detection unit. If the controller determines that the battery cannot be warmed up using the electric power of the battery, it does not cause the heater to warm up the battery using the electric power of the battery. [Effects of the Invention]

[0007] The above-described work machine battery warm-up control device can suppress over-discharge of the battery in a configuration in which the battery can be warmed up using the battery's power. [Brief explanation of the drawings]

[0008] [Figure 1] FIG. 1 is a side view of the work machine 10. [Figure 2] FIG. 2 is a block diagram of the electrical circuit 40 shown in FIG. [Figure 3] 3 is a flowchart of the processing of the controller 70 shown in FIG. 2. [Figure 4] 4 is a map for calculating the available output power Pp shown in step S3 of FIG. 3. [Figure 5] 4 is a map for calculating the available output energy Ep shown in step S3 of FIG. 3. [Figure 6] 3 is a flowchart of processing etc. in a second embodiment of the controller 70 shown in FIG. 2. DETAILED DESCRIPTION OF THE INVENTION

[0009] (First embodiment) A work machine 10 equipped with an electric circuit 40 (work machine battery warm-up control device) of a first embodiment will be described with reference to FIGS. 1 to 5.

[0010] As shown in FIG. 1, the work machine 10 is a machine that performs work. The work machine 10 may be a construction machine that performs construction work, or a loading and unloading machine that performs loading and unloading work. The work machine 10 may be, for example, a shovel or a crane. The work machine 10 may be a bulldozer or a wheel loader. The work machine 10 is powered by electricity output from a battery 41 (see FIG. 2). The power source of the work machine 10 includes at least the battery 41, and may also include a power source other than the battery 41 (for example, an engine (motor)). The work machine 10 is, for example, a battery-powered shovel. The following description will mainly focus on the case where the work machine 10 is a shovel. The work machine 10 comprises a machine main body 10a, an attachment 15, a hydraulic circuit 20 shown in FIG. 2, and an electric circuit 40.

[0011] As shown in FIG. 1, the machine body 10a is the main body of the work machine 10. The machine body 10a includes a lower body 11 and an upper rotating body 13. The lower body 11 supports the upper rotating body 13 so that it can rotate. The lower body 11 may be a lower running body that can run on a running surface (such as the ground). If the lower body 11 is runnable, the lower body 11 may be equipped with crawlers or wheels. The upper rotating body 13 is mounted on the lower body 11 so that it can rotate.

[0012] The attachment 15 is the part that performs work. The attachment 15 is attached to the machine body 10a (more specifically, to the upper rotating body 13). For example, the attachment 15 includes a boom 15a, an arm 15b, and a tip attachment 15c. The boom 15a is rotatably attached to the upper rotating body 13 (capable of rotating in the front-to-back and up-down directions). The arm 15b is rotatably attached to the boom 15a (capable of rotating in the front-to-back and up-down directions). The tip attachment 15c is provided at the tip of the attachment 15. The tip attachment 15c is rotatably attached to the arm 15b (capable of rotating in the front-to-back and up-down directions). The tip attachment 15c may be a bucket that can be used to scoop up work objects and perform excavation, etc. The tip attachment 15c may be equipped with a device for clamping the work object (grapple, nibbler, rotating fork, etc.), a device for crushing the work object (breaker, etc.), or a magnet for attracting metal work objects.

[0013] As shown in Fig. 2, the hydraulic circuit 20 is a circuit for operating the hydraulic actuator 30. In Fig. 2, the hydraulic actuator 30 is described as "hydraulic ACT." The hydraulic circuit 20 includes a hydraulic pump 21 and the hydraulic actuator 30.

[0014] The hydraulic pump 21 draws hydraulic oil from a tank. The hydraulic pump 21 supplies hydraulic oil to the hydraulic actuator 30. The hydraulic pump 21 is driven (rotationally driven) by an electric motor 57. Only one hydraulic pump 21 may be provided, or multiple hydraulic pumps 21 may be provided.

[0015] The hydraulic actuator 30 is a device that moves the work machine 10 (see FIG. 1). The hydraulic actuator 30 is hydraulically driven by hydraulic oil supplied from the hydraulic pump 21. The hydraulic actuator 30 may be equipped with a hydraulic motor for rotational drive, or may be equipped with a hydraulic cylinder (telescopic cylinder) for telescopic drive. As shown in FIG. 1, the hydraulic actuator 30 is equipped with a travel motor 31, a swing motor 33, a boom cylinder 35a, an arm cylinder 35b, and a tip attachment cylinder 35c. The travel motor 31 drives the lower body 11 to travel. The travel motor 31 is a hydraulic motor (as is the swing motor 33). The swing motor 33 drives the upper swing body 13 to swing relative to the lower body 11. The boom cylinder 35a drives (raise and lower) the boom 15a relative to the upper swing body 13. The boom cylinder 35a is a hydraulic cylinder (as are the arm cylinder 35b and the tip attachment cylinder 35c). The arm cylinder 35b rotates the arm 15b relative to the boom 15a. The tip attachment cylinder 35c rotates the tip attachment 15c relative to the arm 15b. If the tip attachment 15c itself is drivable, for example, as a device for clamping an object, a hydraulic actuator 30 may be provided to drive the tip attachment 15c.

[0016] The electric circuit 40 (work machine battery warm-up control device) is a circuit for powering the work machine 10. The electric circuit 40 is mounted on the machine main body 10a (specifically, the upper rotating body 13). As shown in FIG. 2, the electric circuit 40 includes a battery 41, a heater 43, an electric motor inverter 51, a high-voltage DC unit 53, an AC unit 55, and an electric motor 57. The electric circuit 40 also includes a power supply device 61, an auxiliary machine 63, a battery state detection unit 65, and a controller 70.

[0017] The battery 41 outputs electric power for powering the work machine 10. The battery 41 is the power source for the work machine 10 (see FIG. 1). The battery 41 is a secondary battery, and may be, for example, a lead-acid battery or a lithium-ion battery.

[0018] The heater 43 is a device that warms up (heats or heats) the battery 41. The heater 43 is powered by electricity. The heater 43 can be powered by the power of the battery 41 (power supplied from the battery 41). The heater 43 can be powered by power supplied from the power supply device 61. The heater 43 may directly heat the battery 41. The heater 43 may indirectly heat the battery 41. For example, the heater 43 may heat the battery 41 by heating the cooling fluid (such as coolant) of the battery 41. The heater 43 may include an electric heating wire or a heat pump.

[0019] The motor inverter 51 is a device (motor drive device) that drives the motor 57. The motor inverter 51 is configured to be able to receive power from the battery 41. The motor inverter 51 converts the power received from the battery 41 and supplies the converted power to the motor 57. More specifically, the motor inverter 51 converts a direct current input from the high-voltage DC unit 53 into an alternating current. The motor inverter 51 outputs the alternating current to the motor 57 via the AC unit 55.

[0020] High voltage DC section 53 (high voltage DC section) is a section through which direct current (DC) flows. High voltage DC section 53 is a section configured so that electric power can be supplied from battery 41 to motor inverter 51.

[0021] The AC section 55 is a section between the motor inverter 51 and the motor 57, through which an alternating current (AC) flows.

[0022] The electric motor 57 is configured to be able to receive power from the battery 41. The electric motor 57 is driven by the power output by the battery 41. The electric motor 57 is driven by the electric motor inverter 51. The electric motor 57 is used to drive the work machine 10 (see FIG. 1). Specifically, the electric motor 57 drives the hydraulic pump 21. When the hydraulic pump 21 is driven, the hydraulic pump 21 discharges hydraulic oil, which is supplied to the hydraulic actuator 30, which moves the hydraulic actuator 30, thereby moving the work machine 10. Note that an electric motor 57 that moves something other than the hydraulic pump 21 may also be provided. For example, the electric motor 57 may move the work machine 10 without going through the hydraulic circuit 20. Specifically, the electric motor 57 may be the swing motor 33 that rotates the upper swing body 13 relative to the lower body 11 shown in FIG. 1. Only one electric motor 57 may be provided, or multiple electric motors 57 may be provided as shown in FIG. 2.

[0023] The power supply device 61 is capable of supplying power to the heater 43. The power supply device 61 is connectable to the high-voltage DC unit 53. The power supply device 61 is a device different from the battery 41 (the battery 41 is not included in the power supply device 61). The power supply device 61 is connectable to a power source (external power source) external to the work machine 10 (for example, an AC power source). The power supply device 61 may be a charging device (charger) for charging the battery 41 (supplying power to the battery 41). For example, the power supply device 61 may be an on-board charger (OBC). Note that the power supply device 61 may be a device that is capable of supplying power to the heater 43 but is not used to charge the battery 41.

[0024] The accessory 63 can be operated using power from the battery 41. The accessory 63 is a device different from the heater 43 (main engine), and is not related to (more specifically, not directly related to) warming up the battery 41. For example, the accessory 63 is a device different from the electric motor 57. Specifically, the accessory 63 may include an air conditioner (air conditioner) in the cab of the work machine 10, and may include, for example, a compressor for the air conditioner. The accessory 63 may include a cooling fan (for example, a fan that cools the electric motor 57).

[0025] The battery state detection unit 65 detects the state of the battery 41. The battery state detection unit 65 detects the temperature of the battery 41. The battery state detection unit 65 detects the state of charge (remaining charge, SOC: State of Charge) of the battery 41. The battery state detection unit 65 may calculate the state of charge based on the voltage of the battery 41 (calculation is included in detection), may calculate the state of charge based on the current of the battery 41, or may calculate the state of charge based on the voltage and current of the battery 41. For example, the battery state detection unit 65 is a battery management system (BMU) mounted on the battery 41.

[0026] The controller 70 is a computer that inputs and outputs signals, performs calculations (processing), stores information, etc. The functions of the controller 70 are realized by executing a program stored in a storage unit of the controller 70 in a calculation unit of the controller 70. The controller 70 and other devices may be connected by wireless communication or by wired communication. For example, information is input to the controller 70 from a battery state detection unit 65. The controller 70 outputs information to a notification device 80. The functions of the controller 70 include an outputtable parameter calculation means 71, a warm-up control means 73, and an auxiliary device control means 75.

[0027] The output capacity parameter calculation means 71 calculates (determines) the output capacity parameters. The output capacity parameters may include the power (output capacity power Pp (described later)) that the battery 41 can output (can be used, utilized), or may include the energy (output capacity energy Ep (described later)) that the battery 41 can output. The output capacity parameter calculation means 71 calculates the output capacity parameters based on the state of the battery 41 detected by the battery state detection unit 65 (details will be described later).

[0028] The warm-up control means 73 controls the warm-up of the battery 41. The warm-up control means 73 controls the heater 43. For example, the warm-up control means 73 may control the on / off operation of the heater 43, or may control the degree (level, strength) of warm-up by the heater 43. The warm-up control means 73 controls the warm-up of the battery 41 based on the state of the battery 41 detected by the battery state detection unit 65 (details will be described later).

[0029] The accessory control means 75 controls the operation of the accessory 63. For example, the accessory control means 75 may control the on / off of the operation of the accessory 63, or may control the degree of operation of the accessory 63 (details will be described later).

[0030] The notification device 80 is a device (output device) that outputs information. The notification device 80 is capable of outputting a notification to the worker. The notification device 80 outputs information based on a signal output from the controller 70. The notification device 80 may output light (such as a display) or sound (such as audio). If the notification device 80 outputs light, the notification device 80 may be equipped with a display device (monitor). The notification device 80 may be a display device. The notification device 80 may be provided in the driver's cab of the work machine 10 (see FIG. 1), or may be provided in a remote control device for remotely operating the work machine 10. The notification device 80 may be a status output device (such as a status display device or status display means) (specifically, a cluster gauge, etc.) that outputs (for example, displays) the status of equipment on the work machine 10. The notification device 80 may be provided in a tablet, a smartphone, or a personal computer.

[0031] (Activated) Work machine 10 (see FIG. 1) is configured to operate as follows.

[0032] As described above, the electric motor 57 is driven to rotate by the electric power output by the battery 41. The driving of the electric motor 57 is controlled by the controller 70. The electric motor 57 drives the hydraulic pump 21. The hydraulic pump 21 draws hydraulic oil from a tank, discharges the hydraulic oil, and supplies the hydraulic oil to the hydraulic actuator 30. A control valve (not shown) controls the flow rate and direction of the hydraulic oil supplied from the hydraulic pump 21 to the hydraulic actuator 30. The hydraulic actuator 30 moves (drives) when hydraulic oil is supplied from the hydraulic pump 21. The working machine 10 (see FIG. 1) moves when the hydraulic actuator 30 moves.

[0033] (Warm-up control) When the battery 41 is at a low temperature (for example, 10°C or below), the amount of power that the battery 41 can charge and discharge is lower than when the battery 41 is at room temperature (for example, above 10°C). Furthermore, if the battery 41 is charged or discharged at a low temperature, the battery 41 may deteriorate. Therefore, the controller 70 performs warm-up control and causes the heater 43 to warm up the battery 41. Specifically, the controller 70 controls the heater 43 so that the battery 41 reaches an appropriate temperature (for example, 30°C to 40°C).

[0034] The heater 43 is configured to be able to warm up the battery 41 using power supplied from the battery 41. Warming up the battery 41 using power from the battery 41 is also referred to as "battery-power battery warm-up." However, there are cases where battery-power battery warm-up is impossible (or difficult (the same applies to "impossible" below)). For example, when the battery 41 is at a low temperature, the power that the battery 41 can output is low compared to the power required to warm up the battery 41, and battery-power battery warm-up may be impossible. Also, for example, when the battery 41 is at a low temperature and the remaining charge is low (low SOC), the energy stored in the battery 41 may be insufficient compared to the energy required to warm up the battery 41, and battery-power battery warm-up may be impossible. In a situation where battery-power battery warm-up is impossible, even if the battery 41 supplies power to the heater 43, the battery 41 cannot be sufficiently warmed up (the temperature of the battery 41 does not rise sufficiently), and further, there is a risk that the battery 41 may be over-discharged. If the battery 41 is over-discharged, there is a risk that the battery 41 may deteriorate.

[0035] Therefore, the controller 70 performs warm-up control. Specifically, the controller 70 determines whether or not battery warm-up is possible based on the state of the battery 41 (described later) detected by the battery state detection unit 65. If the controller 70 determines that battery warm-up is possible, it causes the heater 43 to warm up the battery 41 (step S5 in FIG. 3 described later). On the other hand, if the controller 70 determines that battery warm-up is not possible, it does not cause the heater 43 to warm up the battery 41 (step S11 in FIG. 3 described later). This prevents the battery 41 from becoming over-discharged, and thus prevents deterioration of the battery 41 due to the battery 41 becoming over-discharged.

[0036] There are various settings possible for the timing at which the controller 70 performs warm-up control. For example, the controller 70 may perform warm-up control when the work machine 10 (see FIG. 1) is started, or may perform warm-up control after the work machine 10 has been started (for example, while it is on standby).

[0037] (Details of warm-up control) The warm-up control by the controller 70 will be described in detail with reference to the flowchart shown in Fig. 3. Unless otherwise specified, the following description will be given in the order of the processes. Note that the order of the processes can be changed in various ways. Each step shown in Fig. 3 will be described with reference to Fig. 3, and each component of the electric circuit 40 shown in Fig. 2 will be described with reference to Fig. 2.

[0038] In step S1 (see FIG. 3), the controller 70 acquires the state of the battery 41. The controller 70 acquires the temperature of the battery 41 detected by the battery state detection unit 65. The controller 70 acquires the state of charge of the battery 41 detected by the battery state detection unit 65. The controller 70 may acquire one or both of the voltage and current of the battery 41 detected by the battery state detection unit 65, and calculate the state of charge of the battery 41 (calculation is included in acquisition).

[0039] In step S2 (see FIG. 3), the controller 70 (e.g., warm-up control means 73) determines whether or not warm-up of the battery 41 is necessary based on the temperature of the battery 41. For example, a threshold value for the temperature of the battery 41 (temperature threshold value) is set in the controller 70. The controller 70 determines whether or not the temperature of the battery 41 is equal to or higher than the temperature threshold value. The temperature threshold value may be a constant value set in advance (before step S2) in the controller 70. The controller 70 may change the temperature threshold value depending on the state of charge of the battery 41.

[0040] If the temperature of the battery 41 is lower than the temperature threshold, the controller 70 determines that the battery 41 needs to be warmed up (YES in step S2). In this case, the controller 70 advances the processing flow to step S3.

[0041] If the temperature of the battery 41 is equal to or higher than the temperature threshold, the controller 70 determines that warming up of the battery 41 is not necessary (NO in step S2). In this case, the controller 70 does not cause the heater 43 to warm up the battery 41. In this case, the controller 70 may end the current process (the flow proceeds to "RETURN") and start the next process (the flow may return to "START"). Note that the controller 70 may end the current process and end the warm-up control (the flow does not have to return to "START").

[0042] In step S3 (see FIG. 3), the controller 70 (for example, the output parameter calculation means 71) calculates the output parameters. Specifically, the controller 70 calculates one or both of the output power Pp and the output energy Ep.

[0043] The available output power Pp is the power (maximum battery power, available battery power) that the battery 41 can output in the state (current state, detected state) of the battery 41 detected by the battery state detection unit 65. The controller 70 calculates the available output power Pp based on the temperature and state of charge of the battery 41 detected by the battery state detection unit 65.

[0044] A specific example of calculation of the available output power Pp is as follows. As shown in FIG. 4, a relationship (e.g., a map) between the temperature of the battery 41, the state of charge (e.g., in %), and the available output power Pp (e.g., in watts) is set in advance (before step S3) in the controller 70. In the map shown in FIG. 4, the relationship between the temperature of the battery 41 and the available output power Pp is as follows. Even if the state of charge of the battery 41 is the same, the higher the temperature of the battery 41, the larger the available output power Pp. T1 to T9 shown in FIG. 4 represent the temperatures of the battery 41. The temperatures are higher in the order of T1, T2, . . . T8, and T9. Note that T1 is a temperature at which the battery 41 cannot output power (e.g., −30° C.). Furthermore, T9 is, for example, 50° C. In the map shown in FIG. 4, the relationship between the state of charge of the battery 41 and the available output power Pp is, for example, as follows. Here, it is assumed that the temperature of the battery 41 is a certain temperature (e.g., T2) excluding T1. At this time, between a certain remaining charge SOC1 (e.g., 20%) and a predetermined remaining charge SOC2 (e.g., 30%) that is greater than the remaining charge SOC1, the available output power Pp increases as the remaining charge increases. Furthermore, above the predetermined remaining charge SOC2, the available output power Pp is constant. Note that the relationship shown in FIG. 4 is an example. Furthermore, the controller 70 does not have to calculate the available output power Pp based on a map. For example, the controller 70 may calculate the available output power Pp using a formula for calculating the available output power Pp from the temperature and state of charge of the battery 41.

[0045] 2 is the energy that the battery 41 can output in the state of the battery 41 detected by the battery state detection unit 65. The controller 70 calculates the output energy Ep based on the state of charge of the battery 41 detected by the battery state detection unit 65. Note that the controller 70 may further calculate the output energy Ep based on the temperature of the battery 41 detected by the battery state detection unit 65.

[0046] A specific example of calculation of the available output energy Ep is as follows. As shown in FIG. 5, a relationship (e.g., a map) between the state of charge of the battery 41 and the available output energy Ep (unit: kJ, for example) is set in advance (before step S3) in the controller 70. The relationship between the state of charge and the available output energy Ep in the map shown in FIG. 5 is as follows: As the remaining charge increases, the available output energy Ep increases. For example, the available output energy Ep is proportional to the remaining charge. Note that the relationship shown in FIG. 5 is just an example. Furthermore, the controller 70 does not have to calculate the available output energy Ep based on a map. For example, the controller 70 may calculate the available output energy Ep from the state of charge of the battery 41 using a formula for calculating the available output energy Ep.

[0047] In step S4 (see FIG. 3), the controller 70 (e.g., warm-up control means 73) shown in FIG. 2 determines whether or not battery warm-up is possible based on the state of the battery 41 detected by the battery state detection unit 65. The controller 70 determines whether or not battery warm-up is possible based on at least the state of charge of the battery 41. The controller 70 may also determine whether or not battery warm-up is possible based on the temperature and state of charge of the battery 41. Specifically, the controller 70 makes this determination based on one or both of the available output power Pp and the available output energy Ep.

[0048] (Determination based on available output power Pp) The controller 70 may determine whether or not the battery warm-up is possible by determining whether or not the permissible output power Pp exceeds the first power threshold P1.

[0049] The first power threshold P1 (required power for battery warm-up) is determined based on the power required for battery warm-up (referred to as required power for warm-up). The first power threshold P1 is a value equal to or greater than the required power for warm-up. The first power threshold P1 may be the value of the required power for warm-up, or may be a value greater than the required power for warm-up.

[0050] The first power threshold P1 is set in the controller 70. The first power threshold P1 may be a constant value set in advance (before step S4) in the controller 70. The controller 70 may change the first power threshold P1 according to the temperature of the battery 41. Specifically, because the power required for warm-up increases as the temperature of the battery 41 decreases, the controller 70 may set the first power threshold P1 to a larger value as the temperature of the battery 41 decreases. The controller 70 may set the first power threshold P1 to a larger value continuously or in stages as the temperature of the battery 41 decreases. The controller 70 may set the first power threshold P1 to a smaller value as the temperature of the battery 41 increases.

[0051] The first power threshold P1 is preferably set to a value (a value greater than the power required for warm-up) that allows the work machine 10 (see FIG. 1) to operate after the battery 41 has been warmed up. More specifically, when battery warm-up is performed, the remaining charge of the battery 41 decreases. If the work machine 10 operates on the power of the battery 41 when the remaining charge of the battery 41 is low, the remaining charge of the battery 41 may decrease further, and the battery 41 may become over-discharged. This may result in the work machine 10 being unable to operate, or it may become necessary to impose operational restrictions (such as speed restrictions) on the work machine 10. Therefore, the first power threshold P1 is preferably set so that the work machine 10 can operate even when the remaining charge of the battery 41 has decreased after battery warm-up. The first power threshold P1 is preferably set so that operational restrictions on the work machine 10 are not necessary even when the remaining charge of the battery 41 has decreased after battery warm-up.

[0052] (Example of judgment based on available output power Pp) When the available output power Pp is equal to or less than the first power threshold P1, the controller 70 determines that battery warm-up is not possible (NO in step S4). When the available output power Pp exceeds the first power threshold P1, the controller 70 may determine that battery warm-up is possible (described later).

[0053] (Determination based on outputtable energy Ep) The controller 70 may determine whether or not the battery warm-up is possible using the battery power by determining whether or not the outputtable energy Ep exceeds the first energy threshold E1.

[0054] The first energy threshold E1 (required battery warm-up energy) is determined based on the energy required for battery warm-up (required warm-up energy). The first energy threshold E1 is a value equal to or greater than the required warm-up energy. The first energy threshold E1 may be the required warm-up energy or may be a value greater than the required warm-up energy.

[0055] The first energy threshold E1 is set in the controller 70. The first energy threshold E1 may be a constant value set in advance (before step S4) in the controller 70. The controller 70 may change the first energy threshold E1 in accordance with the temperature of the battery 41. Specifically, since the energy required for warm-up increases as the temperature of the battery 41 decreases, the controller 70 may set the first energy to a larger value as the temperature of the battery 41 decreases (a further specific example is similar to the first power threshold P1). The first energy threshold E1 is preferably set to a value (a value larger than the energy required for warm-up) that allows the work machine 10 to operate after the battery 41 has been warmed up (a specific example is similar to the first power threshold P1).

[0056] (Example of judgment based on outputtable energy Ep) The controller 70 determines that battery warm-up is not possible when the available output energy Ep is equal to or less than the first energy threshold E1 (NO in step S4). The controller 70 may determine that battery warm-up is possible when the available output energy Ep exceeds the first energy threshold E1 (described later).

[0057] (Example of judgment based on available output power Pp and available output energy Ep) A specific example of the case where the controller 70 determines whether or not battery warm-up is possible based on both the available output power Pp and the available output energy Ep is as follows: The controller 70 determines that battery warm-up is possible when the available output power Pp exceeds the first power threshold P1 and the available output energy Ep exceeds the first energy threshold E1 (YES in step S4). In this case, the controller 70 causes the heater 43 to warm up the battery (step S5) and ends the current process.

[0058] If the available output power Pp is equal to or less than the first power threshold P1, the controller 70 determines that battery warm-up is not possible (NO in step S4). Also, if the available output energy Ep is equal to or less than the first energy threshold E1, the controller 70 determines that battery warm-up is not possible (NO in step S4). If the controller 70 determines that battery warm-up is not possible (NO in step S4), the controller 70 advances the processing flow to step S11.

[0059] In step S11 (see FIG. 3), the controller 70 (warm-up control means 73) stops the battery power battery warm-up. The controller 70 does not cause the heater 43 to warm up the battery 41. If the battery power battery warm-up is already in progress, the controller 70 causes the heater 43 to stop the battery power battery warm-up. If the battery power battery warm-up is not in progress, the controller 70 does not cause the heater 43 to start the battery power battery warm-up (maintains the stopped state). By not performing the battery power battery warm-up, over-discharge of the battery 41 is suppressed.

[0060] In step S12 (see FIG. 3 ), if the controller 70 (e.g., warm-up control means 73) determines that battery warm-up is not possible (NO in step S4), it causes the notification device 80 to issue a notification. The controller 70 causes the notification device 80 to notify that the power supply device 61 should be placed in a power-on state (power supply connection request). The “power-on state” of the power supply device 61 refers to a state in which the power supply device 61 is able to supply power to the electric circuit 40. The “power-on state” of the power supply device 61 refers to a state in which, for example, power from an external power source is able to be supplied to the electric circuit 40 via the power supply device 61. The “power-on state” of the power supply device 61 is specifically a state in which the power supply device 61 is able to supply power to the high-voltage DC unit 53. The “power-on state” of the power supply device 61 is a state in which the power supply device 61 is able to supply power to the heater 43. If the power supply device 61 is a charging device for charging the battery 41, the controller 70 may cause the notification device 80 to notify that the charging device should be turned on (charging request, charging connection request). The controller 70 may also cause the notification device 80 to issue a notification other than that the power supply device 61 should be turned on. For example, the controller 70 may cause the notification device 80 to notify that the battery 41 needs to be warmed up. The notification device 80 may issue a notification by display, or may issue a notification by text (such as "Please connect the charger"), a figure, a symbol, or the like. The notification device 80 may also issue a notification by sound (such as a voice or a buzzer).

[0061] In step S13 (see FIG. 3), the controller 70 (e.g., warm-up control means 73) determines whether the power supply device 61 is in a conducting state (e.g., whether it is connected to an external power source). For example, the controller 70 may determine whether the voltage of the high-voltage DC unit 53 has reached a predetermined voltage. If the power supply device 61 is not in a conducting state (NO in step S13), the controller 70 causes the notification device 80 to continue notifying (the flow returns to step S12). If the power supply device 61 is in a conducting state (YES in step S13), the controller 70 causes the processing flow to proceed to step S14.

[0062] In step S14 (see FIG. 3), the controller 70 (warm-up control means 73) causes the heater 43 to warm up the battery 41. For example, the controller 70 controls the heater 43 to operate using power supplied from the power supply device 61 to warm up the battery 41. Therefore, even in a state where battery warm-up using battery power is not possible, the battery 41 can be warmed up.

[0063] The battery 41 may be warmed up using the power of the power supply device 61 and charged using the power of the power supply device 61 (charging device) at the same time. The controller 70 may control the heater 43 to warm up the battery 41 using the power of the power supply device 61 and, at the same time, control the charging of the battery 41 using the power of the power supply device 61 (charging device). For example, the controller 70 may control the battery 41 to be charged using the power of the power supply device 61 when the temperature of the battery 41 is equal to or higher than a chargeable temperature. The above-mentioned "chargeable temperature" is a temperature at which deterioration of the battery 41 can be suppressed and at which the battery 41 can be charged. Note that the warming up and charging of the battery 41 using the power of the power supply device 61 do not have to be performed simultaneously, and may be performed at different times.

[0064] After it is determined that battery warm-up is not possible (after NO in step S4), warm-up of battery 41 may be completed using only the power of power supply device 61 (NO in step S2). Also, as described above, after it is determined that battery warm-up is not possible (after NO in step S4), one or both of charging and warm-up of battery 41 are performed (step S14). Then, the state of battery 41 may change, and battery warm-up may become possible (YES in step S4). In this case, battery warm-up may be started (step S5).

[0065] (Second embodiment) With reference to Figure 6 and other figures, differences between the electric circuit 40 of the second embodiment (see Figure 2) and the first embodiment will be described. Note that a description of commonalities with the first embodiment will be omitted. Below, details of the warm-up control by the electric circuit 40 (controller 70) of the second embodiment will be described mainly with reference to the flowchart shown in Figure 6.

[0066] If the auxiliary device 63 operates when the battery 41 needs to be warmed up (at low temperatures) (YES in step S2) as shown in FIG. 2, the power of the battery 41 is consumed by the auxiliary device 63. This increases the possibility that the battery 41 will be over-discharged. Therefore, it is preferable to prevent the battery 41 from being over-discharged by limiting the operation of the auxiliary device 63 when the battery 41 needs to be warmed up (step S211 in FIG. 6).

[0067] In step S204 (see FIG. 6), the controller 70 (e.g., the auxiliary control means 75) determines whether or not "auxiliary operation battery warm-up" is possible. The "auxiliary operation battery warm-up" refers to battery power battery warm-up being performed while the auxiliary equipment 63 is operating (more specifically, operating without restriction) using the power of the battery 41. The controller 70 determines whether or not auxiliary operation battery warm-up is possible based on at least the state of charge of the battery 41. The controller 70 may also determine whether or not auxiliary operation battery warm-up is possible based on the temperature and state of charge of the battery 41. Specifically, the controller 70 makes this determination based on one or both of the available output power Pp and the available output energy Ep.

[0068] (Determination based on available output power Pp) The controller 70 may determine whether or not the auxiliary operation battery warm-up is possible by determining whether or not the permissible output power Pp exceeds the second power threshold P2.

[0069] The second power threshold P2 (required power for warming up the battery for operating the accessories) is determined based on the power required to warm up the battery for operating the accessories (referred to as the required power for warming up the battery for operating the accessories). The second power threshold P2 is a value equal to or greater than the required power for warming up the battery for operating the accessories. The second power threshold P2 may be the value of the required power for warming up the battery for operating the accessories, or may be a value greater than the required power for warming up the battery for operating the accessories.

[0070] The second power threshold P2 is set in the controller 70. The second power threshold P2 may be a constant value set in advance (before step S204) in the controller 70. In this case, the second power threshold P2 is a value greater than the first power threshold P1. The controller 70 may change the second power threshold P2 in accordance with the temperature of the battery 41 (a specific example is similar to that of the first power threshold P1). The second power threshold P2 is preferably set to a value that allows the work machine 10 to operate after the battery 41 has warmed up (a value greater than the power required to warm up the accessories) (a specific example is similar to that of the first power threshold P1).

[0071] (Example of judgment based on available output power Pp) If the available output power Pp is equal to or less than the second power threshold P2, the controller 70 determines that the auxiliary operation battery warm-up is not possible (NO in step S204). If the available output power Pp exceeds the second power threshold P2, the controller 70 may determine that the auxiliary operation battery warm-up is possible (described later).

[0072] (Determination based on outputtable energy Ep) The controller 70 may determine whether or not the auxiliary operation battery warm-up is possible by determining whether or not the available output energy Ep exceeds the second energy threshold E2.

[0073] The second energy threshold E2 (required energy for warming up the battery for operating the auxiliary devices) is determined based on the energy required to warm up the battery for operating the auxiliary devices (referred to as the required energy for warming up the battery for operating the auxiliary devices). The second energy threshold E2 is a value equal to or greater than the required energy for warming up the battery for operating the auxiliary devices. The second energy threshold E2 may be the value of the required energy for warming up the battery for operating the auxiliary devices, or may be a value greater than the required energy for warming up the battery for operating the auxiliary devices.

[0074] The second energy threshold E2 is set in the controller 70. The second energy threshold E2 may be a constant value set in advance (before step S204) in the controller 70. In this case, the second energy threshold E2 is a value greater than the first energy threshold E1. The controller 70 may change the second energy threshold E2 in accordance with the temperature of the battery 41 (a specific example is similar to that of the first energy threshold E1). The second energy threshold E2 is preferably set to a value that allows the work machine 10 to operate after the battery 41 has warmed up (a value greater than the energy required to warm up the accessories) (a specific example is similar to that of the first power threshold P1).

[0075] (Example of judgment based on outputtable energy Ep) When the available output energy Ep is equal to or less than the second energy threshold E2, the controller 70 determines that the auxiliary operation battery warm-up is not possible (NO in step S204). When the available output energy Ep exceeds the second energy threshold E2, the controller 70 may determine that the auxiliary operation battery warm-up is possible (described later).

[0076] (Example of judgment based on available output power Pp and available output energy Ep) A specific example of the case where the controller 70 determines whether or not the auxiliary operation battery warm-up is possible based on both the available output power Pp and the available output energy Ep is as follows: The controller 70 determines that the auxiliary operation battery warm-up is possible when the available output power Pp exceeds the second power threshold P2 and the available output energy Ep exceeds the second energy threshold E2 (YES in step S204). In this case, the controller 70 causes the process flow to proceed to step S205.

[0077] If the available output power Pp is equal to or less than the second power threshold P2, the controller 70 determines that the auxiliary operation battery warm-up is not possible (NO in step S204). Also, if the available output energy Ep is equal to or less than the second energy threshold E2, the controller 70 determines that the auxiliary operation battery warm-up is not possible (NO in step S204). If the controller 70 determines that the auxiliary operation battery warm-up is not possible (NO in step S204), the controller 70 advances the process flow to step S211.

[0078] In step S205 (see FIG. 6), if the controller 70 (e.g., the auxiliary control means 75) determines that auxiliary operation battery warm-up is possible (YES in step S204), it permits operation of the auxiliary 63. In this case, the controller 70 does not restrict operation of the auxiliary 63 (see step S210 for details of "restriction"). Then, the controller 70 causes the process flow to proceed to step S4.

[0079] In step S211 (see FIG. 6 ), if the controller 70 (e.g., the auxiliary control means 75) determines that auxiliary operation battery warm-up is not possible (NO in step S204), it limits the operation of the auxiliary 63. This limits power consumption of the battery 41 due to the operation of the auxiliary 63. This makes it possible to prevent over-discharge of the battery 41 due to auxiliary operation battery warm-up. Furthermore, since the operation of the auxiliary 63 is limited, it is possible to prevent a decrease in the warm-up efficiency of the battery 41. More specifically, if the operation of the auxiliary 63 is limited during battery power battery warm-up, the power that can be supplied from the battery 41 to the heater 43 increases. This prevents a decrease in the warm-up efficiency of the battery 41. Furthermore, when the battery 41 is warmed up using power from the power supply device 61, the operation of the auxiliary 63 may be limited. In this case, limiting the operation of the auxiliary 63 increases the power that can be supplied from the power supply device 61 to the heater 43. This prevents a decrease in the warm-up efficiency of the battery 41.

[0080] The controller 70 may limit the operation of the accessories 63, for example, as follows. The controller 70 may limit the operation speed of the accessories 63. Specifically, the controller 70 may limit the operation speed of the accessories 63 to a requested speed or less, to a predetermined speed (speed limit) or less, or may slow down the speed. The controller 70 may stop the accessories 63 (prohibit operation of the accessories 63). If there are multiple accessories 63, the controller 70 may limit the operation of some of the multiple accessories 63, or may limit the operation of all of the accessories 63. For example, if there are multiple accessories 63, the controller 70 may stop all of the accessories 63. The controller 70 may change the content of the restriction on the operation of the accessories 63 (such as the level of restriction) depending on the conditions. For example, the controller 70 may change the content of the restriction on the operation of the accessories 63 depending on the state (e.g., temperature, state of charge) of the battery 41 detected by the battery state detection unit 65.

[0081] In step S212 (see FIG. 6 ), if the controller 70 (e.g., the auxiliary control means 75) determines that warming up of the auxiliary operating battery is not possible (NO in step S204), it causes the notification device 80 to issue a notification. The controller 70 causes the notification device 80 to notify that operation of the auxiliary 63 is being restricted. This allows an operator who receives (e.g., sees) the notification to understand that operation of the auxiliary 63 is being restricted. For example, the operator can understand that the auxiliary 63 is not malfunctioning, but that operation of the auxiliary 63 is being restricted due to control by the controller 70. The controller 70 may cause the notification device 80 to notify that operation of the auxiliary 63 is being restricted in order to prioritize warming up of the battery 41. Then, the controller 70 causes the process flow to proceed to step S4.

[0082] (Effects of the first invention) The effects of the electric circuit 40 (work machine battery warm-up control device) shown in Figure 2 are as follows. The electric circuit 40 includes a battery 41, a heater 43, a battery state detection unit 65, and a controller 70. The battery 41 outputs power to operate the work machine 10. The heater 43 is capable of warming up the battery 41 using the power of the battery 41. The battery state detection unit 65 detects the temperature and charge state of the battery 41.

[0083] [Configuration 1] The controller 70 determines whether or not warming up the battery 41 using the electric power of the battery 41 (battery-powered battery warm-up) is possible based on the state of charge of the battery 41 detected by the battery state detection unit 65 (step S4 in FIG. 3). If the controller 70 determines that battery-powered battery warm-up is not possible (NO in step S4 in FIG. 3), it does not cause the heater 43 to perform battery-powered battery warm-up (step S11 in FIG. 3).

[0084] In the above [Configuration 1], when the controller 70 determines that battery warm-up is not possible based on the state of charge of the battery 41, it does not cause the heater 43 to perform battery warm-up (step S11 in FIG. 3). This prevents the problem of the battery 41 discharging for battery warm-up even when the state of the battery 41 is such that it is determined that battery warm-up is not possible. Therefore, in a configuration in which warm-up of the battery 41 is possible using the electric power of the battery 41, it is possible to prevent over-discharge of the battery 41. This prevents deterioration of the battery 41 due to over-discharge of the battery 41.

[0085] (Effects of the second invention) [Configuration 2] The controller 70 calculates the available output power Pp (step S3 in FIG. 3). The available output power Pp is the power that the battery 41 can output at the temperature and state of charge of the battery 41 detected by the battery state detection unit 65. A first power threshold P1 is set in the controller 70. The first power threshold P1 is determined based on the power required for battery warm-up. The controller 70 determines whether the available output power Pp exceeds the first power threshold P1, thereby determining whether battery warm-up is possible (step S4 in FIG. 3).

[0086] The above [Configuration 2] makes it possible to determine whether the power that the battery 41 can output at the temperature and charge state of the battery 41 detected by the battery state detection unit 65 exceeds the power required to warm up the battery 41 (whether the power is sufficient). This makes it possible to prevent the problem of the power that the battery 41 can output being insufficient for the power required to warm up the battery 41, resulting in insufficient warm-up of the battery 41. It also makes it possible to prevent the problem of the power of the battery 41 being consumed without the battery 41 being sufficiently warmed up, resulting in over-discharge of the battery 41.

[0087] (Effect of the third invention) [Configuration 3] The controller 70 calculates the available output energy Ep (step S3 in FIG. 3). The available output energy Ep is the energy that the battery 41 can output when the battery 41 is in a state of charge detected by the battery state detection unit 65. A first energy threshold E1 is set in the controller 70. The first energy threshold E1 is determined based on the battery power and the energy required for battery warm-up. The controller 70 determines whether the available output energy Ep exceeds the first energy threshold E1, thereby determining whether battery power and battery warm-up are possible (step S4 in FIG. 3).

[0088] The above [Configuration 3] makes it possible to determine whether the energy that the battery 41 can output in the state of charge of the battery 41 detected by the battery state detection unit 65 exceeds the energy required to warm up the battery 41 (whether the energy is sufficient). This makes it possible to prevent a problem in which the energy that the battery 41 can output is insufficient for the energy required to warm up the battery 41, resulting in insufficient warm-up of the battery 41. It also makes it possible to prevent a problem in which the energy of the battery 41 is consumed without the battery 41 being sufficiently warmed up, resulting in over-discharge of the battery 41.

[0089] (Effect of the fourth invention) The electric circuit 40 includes a notification device 80 and a power supply device 61. The notification device 80 is capable of outputting a notification. The power supply device 61 is capable of supplying power to the heater 43 and is different from the battery 41.

[0090] [Configuration 4] If the controller 70 determines that battery warm-up is not possible using battery power (NO in step S4 of FIG. 3), it notifies the notification device 80 that the power supply device 61 should be energized (step S12 of FIG. 3).

[0091] With the above [Configuration 4], the worker who receives the notification from the notification device 80 can understand that the power supply device 61 should be energized. As a result, the following effect may be obtained. When the power supply device 61 is energized, the heater 43 can operate using the power supplied from the power supply device 61 and warm up the battery 41. Therefore, even if the state of the battery 41 is such that it is determined that battery warm-up is not possible, the heater 43 can warm up the battery 41 using the power supplied from the power supply device 61.

[0092] (Effect of the fifth invention) [Configuration 5] The power supply device 61 is a charging device for charging the battery 41.

[0093] The above [Configuration 5] allows the device (power supply device 61) to be used both as a device that can supply power to the heater 43 even when it is determined that battery warm-up is not possible using battery power, and as a device that charges the battery 41.

[0094] (Effect of the sixth aspect of the invention) The electric circuit 40 includes an auxiliary device 63. The auxiliary device 63 is a device different from the heater 43 and can be operated by the power of the battery 41.

[0095] [Configuration 6] The controller 70 determines whether or not auxiliary operation battery warm-up is possible based on the state of charge of the battery 41 detected by the battery state detection unit 65 (step S204 in FIG. 6). Auxiliary operation battery warm-up means that battery power battery warm-up is performed while the auxiliary equipment 63 is operating using power from the battery 41. If the controller 70 determines that auxiliary operation battery warm-up is not possible (NO in step S204 in FIG. 6), it limits the operation of the auxiliary equipment 63 (step S211 in FIG. 6).

[0096] According to the above [Configuration 6], when the operation of the auxiliary device 63 is restricted, the consumption of power from the battery 41 by the auxiliary device 63 is suppressed. Therefore, the problem of the battery 41 discharging to operate the auxiliary device 63 even when the battery 41 is in a state where it is determined that battery warm-up with the auxiliary device 63 is not possible is suppressed. Therefore, over-discharge of the battery 41 can be suppressed. Therefore, deterioration of the battery 41 due to over-discharge of the battery 41 can be suppressed. Furthermore, when the operation of the auxiliary device 63 is restricted, more power (power of the battery 41 or power of the power supply device 61) can be supplied to the heater 43. Therefore, a decrease in the warm-up efficiency of the battery 41 due to the operation of the auxiliary device 63 can be suppressed.

[0097] (Effect of the seventh invention) [Configuration 7] The controller 70 calculates the available output power Pp (step S3 in FIG. 6). The available output power Pp is the power that the battery 41 can output at the temperature and state of charge of the battery 41 detected by the battery state detection unit 65. A second power threshold P2 is set in the controller 70. The second power threshold P2 is determined based on the power required to warm up the battery with the accessories operating. The controller 70 determines whether the available output power Pp exceeds the second power threshold P2, thereby determining whether the battery with the accessories operating can be warmed up (step S204 in FIG. 6).

[0098] The above [Configuration 7] makes it possible to determine whether the power that the battery 41 can output at the temperature and charge state of the battery 41 detected by the battery state detection unit 65 exceeds the power required to warm up the battery with the accessories operating (whether the power is sufficient). This makes it possible to prevent the problem of the power that the battery 41 can output being insufficient for the power required to warm up the battery with the accessories operating, resulting in insufficient warm-up of the battery 41. It also makes it possible to prevent the problem of the battery 41 being over-discharged due to power consumption without the battery 41 being sufficiently warmed up.

[0099] (Effect of the eighth invention) [Configuration 8] The controller 70 calculates the available output energy Ep (step S3 in FIG. 6). The available output energy Ep is the energy that the battery 41 can output when the battery 41 is in a state of charge detected by the battery state detection unit 65. A second energy threshold E2 is set in the controller 70. The second energy threshold E2 is determined based on the energy required to warm up the battery with the accessories operating. The controller 70 determines whether the available output energy Ep exceeds the second energy threshold E2, thereby determining whether the battery with the accessories operating can be warmed up (step S204 in FIG. 6).

[0100] The above [Configuration 8] makes it possible to determine whether the energy that the battery 41 can output in the state of charge of the battery 41 detected by the battery state detection unit 65 exceeds the energy required to warm up the battery with the accessories operating (whether the energy is sufficient). This makes it possible to prevent a problem in which the energy that the battery 41 can output is insufficient for the energy required to warm up the battery with the accessories operating, and the battery 41 is not sufficiently warmed up. It also makes it possible to prevent a problem in which the energy of the battery 41 is consumed without the battery 41 being sufficiently warmed up, resulting in the battery 41 being over-discharged.

[0101] (Effect of the ninth invention) [Configuration 9] The electric circuit 40 includes a notification device 80 that can output a notification. When the controller 70 determines that warming up the battery with the auxiliary equipment 63 in operation is not possible (NO in step S204 of FIG. 6), the controller 70 causes the notification device 80 to notify that operation of the auxiliary equipment 63 is restricted (step S212 of FIG. 6).

[0102] By the above [Configuration 9], the worker who receives the notification from the notification device 80 can understand that the operation of the auxiliary device 63 is restricted. As a result, for example, the worker can understand that the auxiliary device 63 is not malfunctioning.

[0103] (Other variations) The above-described embodiments (including modified examples within the embodiments (the same applies hereinafter)) may be modified in various ways. For example, the number of components in the above-described embodiments may be changed, or some of the components may not be provided. For example, the connections between the components shown in FIG. 2 may be changed. For example, the inclusion relationships between the components may be changed in various ways. For example, a component described as a lower-level component included in a higher-level component may not be included in this higher-level component, but may be included in another component. For example, what is described as multiple different components may be combined into a single component. For example, what is described as a single element may be provided as multiple different elements. For example, the order of the steps in the flowcharts shown in FIGS. 3 and 6 may be changed, some steps may not be performed, or steps in different flowcharts may be combined. For example, various information (such as values) may be set in advance in the controller 70, or may be set by being read into the controller 70 from an external storage device of the controller 70. The various information may be set directly by manual operation by an operator, or may be set in the controller 70 based on information set by manual operation by the operator. The various pieces of information may be set in the controller 70 based on information detected by a sensor (e.g., the battery state detection unit 65, etc.). For example, the various pieces of information may not be changeable, may be changeable by manual operation, or may be automatically changed by the controller 70 in response to certain conditions. For example, the controller 70 may perform substantially the same processing (calculation, determination, etc.) as the processing of the above-described embodiment. For example, the mathematical formulas, processing procedures, information used in the processing, etc. may be changed in various ways. Specifically, the controller 70 may perform processing using information that can be converted into the various pieces of information used in the above-described embodiment. The processing performed by the controller 70 may be combined in various ways. For example, each component may have only a part of its characteristics (function, arrangement, shape, operation, etc.).

[0104] A program (e.g., a battery warm-up control program) may be set that causes the controller 70 (computer) shown in FIG. 2 to execute processing to perform each operation of the work machine 10 (e.g., the electric circuit 40) shown in FIG. 1. A method (e.g., a battery warm-up control method) for performing each of the above operations may be performed. Each of the above operations may be considered a "step" in the program and method. For example, calculation of an outputtable parameter (one example of an operation) may be considered an "outputtable parameter calculation step." [Explanation of symbols]

[0105] 10. Work Machinery 40 Electrical circuit (work machine battery warm-up control device) 41 Battery 43 Heater 61 Power supply 63 Auxiliary Machine 65 Battery status detector 70 Controller 80 Notification device E1 First energy threshold E2 Second energy threshold Ep Outputtable Energy P1 First power threshold P2 Second power threshold Pp Output power

Claims

1. a battery that outputs power to operate the work machine; a heater capable of warming up the battery using the power of the battery; a battery state detection unit that detects the temperature and charge state of the battery; A controller; Equipped with the controller determines whether or not the battery can be warmed up using the electric power of the battery based on the state of charge of the battery detected by the battery state detection unit; When the controller determines that the battery cannot be warmed up using the electric power of the battery, the controller does not cause the heater to warm up the battery using the electric power of the battery. Work machine battery warm-up control device.

2. 2. The working machine battery warm-up control device according to claim 1, the controller calculates an available output power that is an output power that the battery can output at the temperature and state of charge of the battery detected by the battery state detection unit; a first power threshold determined based on power required to warm up the battery using power from the battery is set in the controller; the controller determines whether the available output power exceeds the first power threshold, thereby determining whether the battery can be warmed up using the power of the battery; Work machine battery warm-up control device.

3. 2. The working machine battery warm-up control device according to claim 1, the controller calculates an outputtable energy that is energy that can be output by the battery in a state of charge of the battery detected by the battery state detection unit; a first energy threshold determined based on energy required to warm up the battery using the power of the battery is set in the controller; the controller determines whether the available output energy exceeds the first energy threshold, thereby determining whether the battery can be warmed up using the electric power of the battery; Work machine battery warm-up control device.

4. A working machine battery warm-up control device according to any one of claims 1 to 3, a notification device capable of outputting a notification; a power supply device capable of supplying power to the heater and different from the battery; Equipped with When the controller determines that the battery cannot be warmed up using the power of the battery, the controller causes the notification device to notify that the power supply device should be placed in a power-on state. Work machine battery warm-up control device.

5. The working machine battery warm-up control device according to claim 4, the power supply device is a charging device for charging the battery; Work machine battery warm-up control device.

6. 2. The working machine battery warm-up control device according to claim 1, an auxiliary device that is different from the heater and can be operated by power from the battery; the controller determines whether or not auxiliary operation battery warm-up is possible, i.e., warming up the battery using the electric power of the battery while the auxiliary equipment is operating using the electric power of the battery, based on the state of charge of the battery detected by the battery state detection unit; When the controller determines that the auxiliary operation battery cannot be warmed up, the controller limits the operation of the auxiliary. Work machine battery warm-up control device.

7. 7. A work machine battery warm-up control device according to claim 6, the controller calculates an available output power that is an output power that the battery can output at the temperature and state of charge of the battery detected by the battery state detection unit; a second power threshold determined based on power required to warm up the auxiliary device operating battery is set in the controller; the controller determines whether the auxiliary operation battery can be warmed up by determining whether the available output power exceeds the second power threshold. Work machine battery warm-up control device.

8. 7. A work machine battery warm-up control device according to claim 6, the controller calculates an outputtable energy that is energy that can be output by the battery in a state of charge of the battery detected by the battery state detection unit; a second energy threshold determined based on energy required to warm up the auxiliary device operating battery is set in the controller; the controller determines whether the available output energy exceeds the second energy threshold, thereby determining whether the auxiliary operation battery can be warmed up. Work machine battery warm-up control device.

9. A work machine battery warm-up control device according to any one of claims 6 to 8, A notification device capable of outputting a notification is provided, When the controller determines that the auxiliary operation battery cannot be warmed up, the controller notifies the notification device that operation of the auxiliary is being restricted. Work machine battery warm-up control device.

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