Electric power shovel

Abstract

A battery-powered excavator (1) as an electric working machine has a secondary battery (201), a battery management unit (202) that manages the secondary battery (201), and a controller (300) that controls ordinary charging or diagnostic charging for the secondary battery (201). The controller (300) has a diagnostic charging recommendation judging section (301) that judges whether or not to recommend diagnostic charging based on a work history of the secondary battery output from the battery management unit (202), and a diagnostic charging implementation judging section (302) that, in the case of judging to make the recommendation, judges whether or not to implement diagnostic charging based on a state of the secondary battery output from the battery management unit (202), a charging estimation time required for diagnostic charging, and a site work plan constituted by a work start time.

Description

Technical Field

[0001] This invention relates to electric work machinery equipped with a secondary battery.

[0002] This application claims priority based on Japanese Patent Application No. 2020-128003, filed on July 29, 2020, the contents of which are incorporated herein by reference. Background Technology

[0003] In recent years, measures have been underway to electrify the power sources mounted on construction machinery and other work equipment. Electrification of the power source is achieved by using an energy storage device to store electricity, which powers the electric motor mounted on the work equipment. Besides secondary batteries such as lithium-ion batteries, lead-acid batteries, NAS batteries, and redox flow batteries, other energy storage devices include capacitors such as dual-capacitor capacitors and lithium-ion capacitors, but particular attention is being paid to secondary batteries.

[0004] A battery management unit for managing secondary batteries mounted on electric work machinery (battery excavators, plug-in hybrid excavators, etc.) can calculate the full charge capacity of the secondary battery, calculate the remaining working time and remaining driving range, and diagnose the state of health (SOH) of the secondary battery. Furthermore, as a method for calculating the full charge capacity of the secondary battery, for example, as described in Patent Document 1, the open circuit voltage (OCV) is estimated from the voltage change after charging during at least two pauses, and the state of charge (SOC) calculated from the estimated OCV and the amount of charge are used for calculation.

[0005] Existing technical documents

[0006] Patent documents

[0007] Patent Document 1: Japanese Patent Application Publication No. 2013-070534 Summary of the Invention

[0008] However, in the electric working machine described in Patent Document 1, although the calculation error of the full charge capacity or the degradation degree of the secondary battery capacity, i.e. SOHQ, can be reduced by setting a rest time, the total charging time is increased due to setting the rest time, which may hinder the work plan depending on the application on site.

[0009] The purpose of this invention is to provide an electric work machine that can prevent disruption to work plans.

[0010] The electric work machinery of the present invention has a secondary battery, characterized in that it comprises: a battery management unit for managing the secondary battery; and a controller for controlling the secondary battery to perform normal charging without a pause time or diagnostic charging with a pause time during charging, the controller comprising: a diagnostic charging recommendation judgment unit that determines whether to recommend diagnostic charging based on the working history of the secondary battery output from the battery management unit; and a diagnostic charging implementation judgment unit that, when it is determined that diagnostic charging is recommended, determines whether to implement diagnostic charging based on the state of the secondary battery output from the battery management unit, the estimated charging time required for diagnostic charging, and the on-site work plan consisting of the work start time.

[0011] In the electric work machine of the present invention, the controller includes: a diagnostic charging recommendation judgment unit, which determines whether diagnostic charging is recommended based on the working history of the secondary battery output from the battery management unit; and a diagnostic charging implementation judgment unit, which, when diagnostic charging is recommended, determines whether to implement diagnostic charging based on the state of the secondary battery output from the battery management unit, the estimated charging time required for diagnostic charging, and the on-site work plan consisting of the work start time. Therefore, diagnostic charging with a pause time is only implemented when diagnostic charging is recommended, thereby reducing the number of diagnostic charging sessions with long total charging times. Furthermore, considering the on-site work plan, diagnostic charging is limited to being implemented only when the total charging time for diagnostic charging can be ensured, thereby reducing the risk of affecting the on-site work plan. As a result, it is possible to prevent disruption to the work plan of the electric work machine.

[0012] Invention Effects

[0013] According to the present invention, it is possible to prevent work schedules from being disrupted by electric work machinery. Attached Figure Description

[0014] Figure 1 This is a perspective view showing the appearance of the battery excavator according to the first embodiment.

[0015] Figure 2 This is a configuration diagram of the battery system of the battery excavator according to the first embodiment.

[0016] Figure 3 This is a functional block diagram representing the controllers installed within the vehicle control unit.

[0017] Figure 4 This is a flowchart illustrating the charging control of a secondary battery.

[0018] Figure 5This is a graph illustrating an example of the changes in battery voltage during diagnostic charging and the time variation of the charging pause signal.

[0019] Figure 6 This is a block diagram representing the full charge capacity and SOHQ calculations in the battery management unit.

[0020] Figure 7 This is a table showing the relationship between open-loop voltage OCV and charge rate SOC.

[0021] Figure 8 This is the table for setting the rest time.

[0022] Figure 9 This is an explanatory diagram of ΔSOHQ.

[0023] Figure 10 This is a flowchart illustrating the diagnostic process of charging.

[0024] Figure 11 This is another flowchart representing the diagnostic charging process for making judgments.

[0025] Figure 12 This is a diagram showing the configuration of the battery system of the battery excavator according to the second embodiment.

[0026] Figure 13 This is a functional block diagram showing the controller installed in the vehicle control unit of the second embodiment.

[0027] Figure 14 This is a flowchart illustrating the charging control of the secondary battery in the second embodiment.

[0028] Figure 15 This is an example diagram illustrating the display screen and selection process of a monitoring display device. Detailed Implementation

[0029] Hereinafter, embodiments of the electric work machinery of the present invention will be described with reference to the accompanying drawings. In the description of the drawings, the same reference numerals are used for the same elements, and repeated descriptions are omitted. In addition, in the following description, a battery-powered hydraulic excavator (hereinafter referred to as a battery excavator) is used as an example of electric work machinery, but the present invention is not limited to battery excavators, and can also be applied to electric work machinery such as plug-in hybrid excavators.

[0030] [First Implementation]

[0031] Figure 1 This is a perspective view showing the appearance of the battery-powered excavator according to the first embodiment. Figure 1As shown, the battery-powered excavator 1 includes: a multi-joint working device 104 having a boom 101, a stick 102, and a bucket 103; and a body 107 having an upper rotating body 105 and a lower traveling body 106. The boom 101 is rotatably supported on the upper rotating body 105 and is driven by a boom hydraulic cylinder (hydraulic cylinder) 108. The stick 102 is rotatably supported on the boom 101 and is driven by a stick hydraulic cylinder (hydraulic cylinder) 109. The bucket 103 is rotatably supported on the stick 102 and is driven by a bucket hydraulic cylinder (hydraulic cylinder) 110.

[0032] The upper rotating body 105 is driven by a rotary motor (electric motor), and the lower traveling body 106 is driven by left and right traveling motors (hydraulic motors) 111. The boom hydraulic cylinder 108, stick hydraulic cylinder 109, bucket hydraulic cylinder 110, and traveling motor 111 are driven by hydraulic oil discharged from the hydraulic pump.

[0033] Figure 2 This is a configuration diagram of the battery system of the battery excavator according to the first embodiment. The battery system 200 is mounted on the battery excavator 1 and includes: a secondary battery 201; a battery management unit (BMU) 202 for monitoring the state of the secondary battery 201; a current meter 203 for detecting the current flowing in the secondary battery 201; a communication line 204 connecting the secondary battery 201 and the BMU 202; a charger 205 for charging the secondary battery 201; a motor 206 that generates power using electricity from the secondary battery 201; an inverter 207 that converts DC power from the secondary battery 201 into AC power and controls the motor 206; and a vehicle control unit (VCU) that controls the charger 205 and the inverter 207 based on information such as the state of the secondary battery 201 output from the BMU 202. Unit: VCU) 208; communication line 209 connecting battery management unit 202 and vehicle control unit 208; communication line 210 connecting charger 205 and vehicle control unit 208; and communication line 211 connecting inverter 207 and vehicle control unit 208.

[0034] The secondary battery 201 is, for example, an assembly of battery modules consisting of multiple individual cells, i.e., a battery pack. A battery module connects multiple individual cells in series and houses them in a casing. The battery modules are further connected in series or parallel to form a component of the battery pack. In this embodiment, a lithium-ion battery with high input / output and energy density is used for the secondary battery. Figure 2The secondary battery 201 shown is constructed by connecting battery modules in series, but it can also be configured in series and parallel. Furthermore, in this case, a battery management unit 202 and a current meter 203 are provided for each series connection. The secondary battery 201 is configured to monitor the voltage of each battery and periodically send voltage values ​​to the battery management unit 202 via communication line 204.

[0035] The battery management unit 202, as a hardware component, includes an arithmetic processing unit (e.g., CPU) for executing various control programs and a storage unit (e.g., ROM, RAM) for storing various data, represented by the control programs. For example, the battery management unit 202 stores and manages the operating history of the secondary battery 201. The operating history of the secondary battery 201 includes information such as its charging history, discharging history, current time, and temperature.

[0036] Furthermore, the battery management unit 202 calculates the full-charge capacity of the secondary battery 201 based on the voltage of each battery obtained from the secondary battery 201 and the current obtained via the ammeter 203. The calculation method for the full-charge capacity will be described later. Additionally, based on the calculated full-charge capacity of the secondary battery, the battery management unit 202 calculates the overall charge rate (SOC) and degradation degree (SOH) of the secondary battery 201, as well as the SOC and SOH of each battery module and individual battery. Moreover, the battery management unit 202 can calculate the degradation degree of the secondary battery capacity, i.e., SOHQ. The degradation degree of the secondary battery capacity, i.e., SOHQ, is calculated, for example, based on Equation 1 below, and the charge rate (SOC) is calculated, for example, based on Equation 2 below.

[0037] SOHQ(%)=100×Current Full Charge Capacity (Ah) / Initial Full Charge Capacity (Ah) (Equation 1)

[0038] SOC (%) = 100 - 100 × Discharge amount since full charge (Ah) / Current full charge capacity (Ah) (Equation 2)

[0039] In addition, the battery management unit 202 stores the battery voltage OCV[V] under no-load conditions as specification information of the secondary battery 201. The value of OCV varies depending on the state of charge (i.e., charge rate SOC) of the secondary battery, so the battery management unit 202 in this embodiment stores the relationship between SOC and OCV in tabular form. Furthermore, as a method for calculating SOC, in addition to Equation 2, there is also a method that uses the obtained battery voltage or estimated OCV value and the relationship table between SOC and OCV.

[0040] As the ammeter 203, for example, an ammeter utilizing a shunt resistor or an ammeter utilizing a Hall element can be used. The current value detected by the ammeter 203 is output to the battery management unit 202. As the communication line 204, LIN (Local Interconnect Network) and CAN (Controller Area Network) can be used.

[0041] Charger 205 is used to charge secondary battery 201 and is connected to secondary battery 201. Charger 205 can be mounted on battery excavator 1 or installed independently outside battery excavator 1. Charger 205 can perform charging methods such as CCCV charging (Constant-Current Constant-Voltage) and pulse charging. CCCV charging involves charging in a constant current mode from the start of charging, and then charging in a constant voltage mode after reaching the target voltage. Pulse charging, on the other hand, involves inputting a pulse current at predetermined intervals (e.g., a few seconds) to charge until the target voltage is reached.

[0042] In this embodiment, the charger 205 is configured to start or stop charging of the secondary battery 201 based on a signal output from the vehicle control unit 208, and automatically stop charging when the secondary battery 201 is fully charged. Furthermore, as a replacement for the charging stop signal, it has the following configuration: a relay is connected to an existing charger, and its switching is controlled. The communication line 210 for control from the vehicle control unit 208 can utilize CAN, or it can utilize two voltage lines indicating the ON / OFF state of the switch (one for sending a signal from the charger 205 to the vehicle control unit 208 indicating that charging has started based on the charger 205 (charging start signal), and one for sending a charging stop signal from the vehicle control unit 208 to the charger 205, for a total of two lines).

[0043] Motor 206 is a rotary motor used for rotating drive, such as the upper rotating body 105 described above.

[0044] Figure 3 This is a functional block diagram representing the controllers installed within the vehicle control unit. For example... Figure 3 As shown, the vehicle control unit 208 includes a controller 300. The controller 300 performs diagnostic charging recommendation and implementation decisions based on information from the battery management unit 202, and controls the charging of the secondary battery 201 based on the decision results. The controller 300 includes a diagnostic charging recommendation decision unit 301, a diagnostic charging implementation decision unit 302, and a charger control unit 303.

[0045] The diagnostic charging recommendation judgment unit 301 determines whether to recommend diagnostic charging based on information from the battery management unit 202. Specifically, the diagnostic charging recommendation judgment unit 301 determines whether to recommend diagnostic charging based on the operating history of the secondary battery 201 output from the battery management unit 202. Furthermore, the diagnostic charging recommendation judgment unit 301 outputs the judgment result to the diagnostic charging implementation judgment unit 302 and the charger control unit 303, respectively.

[0046] The diagnostic charging implementation determination unit 302 determines whether to perform diagnostic charging based on the status of the secondary battery 201 output from the battery management unit 202, the estimated charging time required for diagnostic charging, and the start time of the next operation, i.e., the on-site operation plan. Furthermore, the diagnostic charging implementation determination unit 302 outputs the result of this determination to the charger control unit 303.

[0047] The charger control unit 303 controls the charging mode of the secondary battery 201 via the charger 205. The charging mode of the secondary battery 201 includes at least normal charging and diagnostic charging. Normal charging is a charging mode without any special restrictions, specifically, it does not include a pause time during charging. On the other hand, diagnostic charging refers to a charging mode that includes a pause time during charging. In this embodiment, diagnostic charging is preferably a charging mode with a preset pause time before and after charging, and more preferably, based on the preset pause time before and after charging, the ΔSOC obtained from charging is at least a predetermined value. In this way, calculation errors such as the full charge capacity of the secondary battery 201 and SOHQ can be suppressed. Furthermore, ΔSOC is the change in SOC before and after charging.

[0048] Next, based on Figure 4 This will explain the charging control for the secondary battery 201. Figure 4 The control process shown is initiated by entering a state that starts the charging operation of the battery excavator 1, for example, by connecting the current cable.

[0049] First, in step S110, the diagnostic charging recommendation judgment unit 301 determines whether diagnostic charging is recommended based on the operating history of the secondary battery 201 output from the battery management unit 202. The operating history of the secondary battery 201 includes, for example, charging history, discharging history, current time, and temperature. The specific judgment method will be described later. If diagnostic charging is recommended, the control process proceeds to step S120.

[0050] In step S120, the diagnostic charging implementation determination unit 302 determines whether to implement diagnostic charging based on the state of the secondary battery 201 output from the battery management unit 202, the estimated charging time required for diagnostic charging, and the operation start time, i.e., the on-site operation plan. The specific determination method will be described later. The state of the secondary battery 201 can include its charging state and temperature state. If it is determined that diagnostic charging should be implemented, the control process proceeds to step S130.

[0051] In step S130, the charger control unit 303 creates a diagnostic charging model based on information such as the status of the secondary battery 201 output from the battery management unit 202, and controls the diagnostic charging of the secondary battery 201 via the charger 205 using the created charging model.

[0052] On the other hand, if it is determined in step S110 that diagnostic charging is not recommended, or in step S120 that diagnostic charging is not to be performed, the control process proceeds to step S140. In step S140, the charger control unit 303 determines the charging current based on information such as the state of the secondary battery 201 output from the battery management unit 202, and controls the normal charging of the secondary battery 201 via the charger 205.

[0053] Here, based on Figure 5 Detailed description of the diagnostic charging. Figure 5 This is a graph illustrating an example of the changes in battery voltage during diagnostic charging and the time variation of the charging pause signal.

[0054] like Figure 5 As shown, in the diagnostic charging process, preset rest periods are provided before and after charging. Specifically, after the discharge time of the secondary battery 201 (in other words, the working time of the battery excavator 1) t501 and before charging the secondary battery 201, a fixed post-work rest period t502 is provided. After the post-work rest period t502, the secondary battery 201 is charged for a charging time t503. After the charging time t503, a fixed post-charging rest period t504 is also provided. In contrast, in normal charging, rest periods such as the post-work rest period t502 and the post-charging rest period t504 are not provided as in diagnostic charging.

[0055] Figure 5 The example shown illustrates setting the charging time t503 once, but there is no limit to the number of times the charging time can be set. For example, a preparatory charging time can be set after the rest time t502 after work. The actual charging (i.e., charging time t503) is then performed after this preparatory charging time.

[0056] Next, the calculation of the full charge capacity of the secondary battery and the SOHQ implemented based on the battery management unit 202 will be explained.

[0057] During diagnostic charging, the battery management unit 202 calculates the full charge capacity and SOHQ of the secondary battery 201 based on operational history data such as the charging current. Similarly, during normal charging, the battery management unit 202 calculates the full charge capacity and SOHQ of the secondary battery 201 based on operational history data such as the charging current. Furthermore, during diagnostic charging, the battery management unit 202 treats the full charge capacity and SOHQ calculated based on the diagnostic charging operational history as the current state value of the secondary battery 201. The diagnostic charging operational history includes, in addition to the charging current of the secondary battery 201 during diagnostic charging, charging history, discharging history, current time, and temperature. Conversely, during normal charging, the battery management unit 202 treats the full charge capacity and SOHQ calculated based on the normal charging operational history as reference values. The normal charging operational history includes, in addition to the charging current of the secondary battery 201 during normal charging, charging history, discharging history, current time, and temperature.

[0058] Figure 6 This is a block diagram representing the full charge capacity and SOHQ calculations in the battery management unit 202. (Example) Figure 6 As shown, the battery management unit 202 includes a charge amount calculation unit 601, a ΔSOC calculation unit 602, a battery capacity calculation unit 603, and a SOHQ calculation unit 604. The charge amount calculation unit 601 uses the current I obtained through the ammeter 203 to calculate the charge amount ΔQ based on Equation 3, and outputs the calculation result to the battery capacity calculation unit 603.

[0059] The amount of charge ΔQ(Ah) = ∫Idt (Equation 3)

[0060] The ΔSOC calculation unit 602 calculates the SOC change ΔSOC before and after charging, and outputs the calculation result to the battery capacity calculation unit 603. The battery capacity calculation unit 603 uses the charging charge ΔQ and the SOC change ΔSOC to calculate the current full-charge capacity Q (refer to Equation 4). Figure 6 (Q1).

[0061] The current full charge capacity Q (Ah) = Charge amount ΔQ × 100 / Change in SOC ΔSOC (Equation 4)

[0062] The SOHQ computing unit 604 uses the current full-charge capacity Q (refer to...). Figure 6 SOHQ is calculated based on Equation 1 above, where Q1) and the initial full charge capacity Q0 are used.

[0063] Here, use Figure 7 The table below illustrates how to calculate the change in SOC, ΔSOC, before and after charging.

[0064] Figure 7 This is a table showing the relationship between the open-loop voltage (OCV) and the state of charge (SOC). This table is, for example, stored in the storage section of the battery management unit 202. First, the battery management unit 202 estimates the OCV (OCV1) at the end of the rest period t502 after operation based on the operating history of the secondary battery 201 (the estimation method will be described later). From the estimated OCV1, it uses... Figure 7 A table is used to predict the SOC (SOC1) before charging. For example, with an estimated OCV1 of 3.2V, SOC1 is 20%.

[0065] Next, the battery management unit 202 estimates the OCV (OCV2) at the end of the post-charging rest time t504 based on the operating history of the secondary battery 201, and uses the estimated OCV2. Figure 7 The table predicts the SOC (SOC2) after charging. Then, the battery management unit 202 calculates ΔSOC by obtaining the difference between SOC1 and SOC2 before and after charging.

[0066] Furthermore, as an example of a method for estimating OCV, the method using a battery equivalent circuit model can be cited. OCV is calculated, for example, based on Equation 5. In Equation 5, R0 represents the internal resistance, V... P1 Indicating the voltage drop due to polarization, CCV stands for Closed Circuit Voltage. (V) P1 The voltage deviation from OCV, caused by the electrochemical reaction of the secondary battery, is represented by a temporary delay formula, such as Equation 6. Rp1 represents the polarization resistance, t represents the elapsed time, and τ represents the polarization time constant. In Equation 6, the temporary delay parameter can be one or more. Furthermore, the battery management unit 202 calculates OCV using parameter tables of R0, Rp1, and τ prepared in advance through battery characteristic evaluation, operational history data such as current, and Equation 7 derived from Equations 5 to 6.

[0067] OCV(V)=CCV-I×R0-V P1 (Equation 5)

[0068] V P1 (V) = I×R P1 ×{1-exp((﹣t) / τ)} (Equation 6)

[0069] OCV(V)=CCV-I×R0-I×R P1 ×{1-exp((﹣t) / τ)}(Equation 7)

[0070] The above describes the calculation method of OCV before and after charging for ΔSOC, but the voltage values ​​at the end of the working rest time t502 and the end of the charging rest time t504 can also be used instead of OCV.

[0071] Furthermore, during diagnostic charging, the set values ​​for the rest time t502 after operation and the rest time t504 after charging are preferably sufficient for the OCV to be calculated using Formula 7 with high precision, or for the OCV to converge due to sufficient mitigation of polarization inside the secondary battery 201 before and after charging. Preferably, these values ​​are prepared in advance in tabular form and stored in the storage section of the battery management unit 202.

[0072] Furthermore, considering that the rest time t502 after operation and the rest time t504 after charging will vary depending on temperature or SOC, therefore, for example, it is possible to... Figure 8 Set it up as shown in the table. Figure 8 The table represents the set value of the rest time within the specified temperature range and SOC range, but it can also be a table that only represents the temperature range or only represents the SOC range. Figure 8 The set value for the rest time can be determined through prior experiments or based on the polarization time constant τ in Equation 6. The polarization time constant τ is related to the time until the polarization inside the secondary battery 201 is mitigated. If the time of polarization time constant τ has elapsed, 67% of the polarization voltage is reduced; if the time of polarization time constant τ has elapsed, 99.5% of the polarization voltage is reduced.

[0073] Furthermore, during normal charging, while there are no long rest periods like those used for diagnostic charging, short rest periods can be set for both post-work and post-charging rest periods. The rest period for normal charging is a preset value that will not interfere with the operation of the battery-powered excavator 1, for example, 1 minute.

[0074] In addition, in diagnostic charging, the ΔSOC obtained based on the charging is a specified value k. ΔSOC The above are the characteristics. The full charge capacity Q is calculated based on Equation 4 using the amount of charge and ΔSOC. If ΔSOC is small, the errors in the calculation of the amount of charge and ΔSOC, which depend on the detection accuracy of the ammeter 203, the detection accuracy of the voltmeter, and the accuracy of the SOC calculation, will have a greater impact, increasing the error in both the full charge capacity Q and SOHQ. Therefore, a larger ΔSOC is desirable. The specified value k... ΔSOCIt is predetermined based on the target accuracy of the full charge capacity Q and SOHQ, as well as the assumed accuracy of the charging charge and ΔSOC calculations. For example, simply ignoring the error in the charging charge and setting the error in the ΔSOC calculation as x%, the error of the full charge capacity Q and SOHQ is expressed by Equation 8. If the target accuracy of the full charge capacity Q and SOHQ is 5%, and x is 2%, then the ΔSOC that satisfies this is the specified value k. ΔSOC It is 38%.

[0075] (ΔQ / ΔSOC-(ΔQ / (ΔSOC-x))) / (ΔQ / ΔSOC)×100=-x / (ΔSOC-x)×100 (Equation 8)

[0076] Next, detailed explanation Figure 4 The diagnostic method in step S110 uses the recommended charging method.

[0077] As described above, in step S110, the diagnostic charging recommendation judgment unit 301 determines whether to recommend diagnostic charging based on the operating history of the secondary battery 201 output from the battery management unit 202. More specifically, the diagnostic charging recommendation judgment unit 301 determines whether the current full charge capacity Q and SOHQ deviate from the calculated values ​​of the full charge capacity and SOHQ obtained from the previous diagnostic charging based on the operating history of the secondary battery 201 output from the battery management unit 202. If the determination is that there is a deviation, the diagnostic charging recommendation judgment unit 301 recommends diagnostic charging; if the determination is that there is no deviation, it does not recommend diagnostic charging. A specific example of its judgment method is shown below.

[0078] [Recommended judgment method 1]

[0079] In Recommendation Method 1, the diagnostic charging recommendation determination unit 301 extracts the start date of use of the battery excavator 1, the date of the last diagnostic charging, and the current time from the working history of the secondary battery 201 output from the battery management unit 202. Based on this extracted information, it determines whether to recommend diagnostic charging. Since the secondary battery 201 deteriorates over time or through charging and discharging, deterioration will progress if it is used for a fixed period or longer, resulting in a decrease in State of Health (SOHQ). In this case, the diagnostic charging recommendation determination unit 301 determines that diagnostic charging is recommended.

[0080] As shown in Equation 9, immediately after the start of use of the battery excavator 1, it is used in a state where diagnostic charging is not implemented, at the current time t C Starting with the use of battery-powered excavators 1 S After the specified time k t Under the above circumstances, it is determined that diagnostic charging is recommended. Furthermore, after performing diagnostic charging more than once, using Equation 10, at the current time t...C From the date of implementation of the previous diagnostic charging D After the specified time k t In the above cases, it is determined that charging for diagnostic purposes is recommended.

[0081] t C -t S ≥k t (Equation 9)

[0082] t C -t D ≥k t (Equation 10)

[0083] The specified time k t This is a predetermined timeframe based on the degradation progression of the secondary battery 201, such as one month, three months, six months, or more. Additionally, the predetermined time k... t It can be a fixed value or vary based on the total working time of the battery-powered excavator 1. Although it also depends on the usage method of the secondary battery 201, battery degradation is significant at the beginning of use, and the rate of degradation gradually decreases. Therefore, for example, within the first year of use, a specified time k can be set. t Set to two weeks or one month, and after one year of use, the specified time k will be... t Set it to three months or six months.

[0084] [Recommended Judgment Method 2]

[0085] In recommendation method 2, the diagnostic charging recommendation judgment unit 301 determines whether to recommend diagnostic charging based on the SOHQ calculation value (or initial value if diagnostic charging was not performed) output from the battery management unit 202 during the previous diagnostic charging and the SOHQ change ΔSOHQ. The SOHQ change ΔSOHQ is calculated using the degradation prediction function of the secondary battery 201 from the current-based operating history.

[0086] Secondary batteries degrade over time or through charging and discharging, and the rate of degradation depends on environmental factors such as temperature, current, and state of charge (SOC). Therefore, the degradation degree (SOHQ) of a secondary battery is represented, for example, by a degradation prediction function f(T,I,SOC,t) based on temperature T, current I, SOC, and time t, and is usually constructed based on the results of prior tests.

[0087] Figure 9 The diagram illustrates ΔSOHQ. It compares the calculated value SOHQ0 from the previous diagnostic charging with the current value calculated using the degradation prediction function f(T,I,SOC,t) based on the work history since the previous diagnostic charging. Figure 9The difference between the estimated values ​​of SOHQ (t0 + Δt) is denoted as ΔSOHQ. In this recommended judgment method, ΔSOHQ is the threshold k. Q1 When the above values ​​are met, it is judged as a sign of deterioration, i.e., a decrease in SOHQ, and a diagnostic charging is recommended. Threshold k Q1 It is any predetermined value, which can be 1%, 2%, or more.

[0088] [Recommended judgment method 3]

[0089] In the recommended judgment method 3, the diagnostic charging recommendation judgment unit 301 determines whether to recommend diagnostic charging based on the SOHQ calculation value output from the battery management unit 202 during the previous diagnostic charging (or the initial value if diagnostic charging was not performed) and the result of analyzing the SOHQ change from the SOHQ calculation value during normal charging (reference value).

[0090] As shown in Equation 11, when the latest N points of the SOHQ calculated value (reference value) are averaged, SOHQ... R,A(N) The difference between the calculated SOHQ value (SOHQ0) and the value obtained during the previous diagnostic charging is called the threshold k. Q2 When the above values ​​are met, it is considered a sign of deterioration, i.e., a decrease in SOHQ. In this case, it is recommended to use a diagnostic charger.

[0091] SOHQ R,A(N) -SOHQ0≥k Q2 (Equation 11)

[0092] During normal charging, the pause time required for polarization mitigation is insufficient, resulting in significant errors and deviations in the calculated SOHQ value (reference value) during normal charging. Therefore, to analyze the SOHQ changes since the last diagnostic charging, the average of the most recent N points is taken. The number of N points used for averaging is an arbitrary value predetermined, for example, determined by the calculation errors of the SOHQ values ​​during diagnostic charging and the SOHQ values ​​(reference value) during normal charging. If the error in the SOHQ calculation during diagnostic charging is 5%, and the error during normal charging is 20%–25%, then considering that the error of the average value with respect to the sample size N depends on √N, it is desirable that the number of N points be 25 or more.

[0093] Additionally, outliers can be removed when calculating the average. Methods for identifying outliers include the Smirnov-Grubbs test or using quartile ranges. Considering the above, for example, if N is set to 30 points, and assuming a charging frequency of 3 times / day and 5 working days / week, then 30 normal charging cycles would equivalent to two weeks' worth of data. Threshold k Q2 It is any predetermined value, which can be 1%, 2%, or more.

[0094] [Recommended judgment method 4]

[0095] In the recommended judgment method 4, the diagnostic charging recommendation judgment unit 301 determines whether to recommend diagnostic charging based on the difference between the working SOC range calculated from the full charge capacity or SOHQ calculation value of the secondary battery during the previous diagnostic charging output from the battery management unit 202 (or the initial value of the degradation degree of the full charge capacity or secondary battery capacity if diagnostic charging is not performed) and the charging SOC range calculated from the working history of normal charging.

[0096] Specifically, Equation 12 will be used to illustrate this. The ΔSOC in Equation 12... D It is based on the change in SOC caused by the operation of the battery excavator 1 (discharge of the secondary battery 201) after the start-up of the battery excavator 1 or the completion of the previous charge, and the amount of discharge charge ∫I caused by the operation. D dt, and the calculated value Q0 of the secondary battery's full charge capacity during the previous diagnostic charging. ΔSOC R,C ΔSOC is calculated using the full charge capacity of the secondary battery during normal charging or the SOHQ calculation process.

[0097] In ΔSOCD and ΔSOC R,C The average value of the differences between the N points is the threshold k. Q3 In the following cases, it is determined that the SOC is operating within a larger range than the SOC operating range calculated based on the full charge capacity of the secondary battery during the previous diagnostic charge, i.e., the SOC has deteriorated compared to the previous diagnostic charge, and the SOHQ has decreased, and a diagnostic charge is recommended.

[0098] (ΔSOC D -ΔSOC R，C ) A(N) =(∫I D dt / Q0-ΔSOC R，C ) A(N) ≤k Q3 (Equation 12)

[0099] As shown in recommended method 3, the error and deviation in ΔSOC calculation during normal charging are also significant. Therefore, the average of the latest N points is taken. The number N used for averaging is an arbitrary value predetermined; considering the calculation error during normal charging, it is set to 30 points, for example. Threshold k Q3 It is any predetermined value, which can be -1% or -2% or a value smaller than that.

[0100] Next, the diagnostic method for charging in step S120 will be explained in detail.

[0101] As described above, in step S120, the diagnostic charging implementation determination unit 302 determines whether to implement diagnostic charging based on the state of the secondary battery 201 output from the battery management unit 202, the estimated charging time required for diagnostic charging, and the operation start time, i.e., the on-site operation plan. Here, the diagnostic charging implementation determination unit 302 determines to implement diagnostic charging only if all relationships in Equations 13 and 14 are satisfied. Therefore, for example, if the relationship in Equation 13 is satisfied but the relationship in Equation 14 is not satisfied, or if the relationship in Equation 13 is not satisfied but the relationship in Equation 14 is satisfied, it is determined that diagnostic charging will not be implemented.

[0102] Specifically, as described above, the ΔSOC obtained from the charging process in diagnostic applications is a specified value k. ΔSOC The above are the features. Therefore, the diagnostic charging implementation judgment unit 302 calculates the preset charging SOC setting value (maximum) as shown in Equation 13. C,Max The difference ΔSOC between the current SOC (before charging) output from the battery management unit 202 and the current SOC (as output before charging). C And determine the calculated difference ΔSOC C Is it the specified value k? ΔSOC above.

[0103] ΔSOC C =SOC C,Max -SOC Cur ≥k ΔSOC (Equation 13)

[0104] Next, the diagnostic charging implementation judgment unit 302 calculates the remaining rechargeable time based on the operation start time, i.e., the field operation plan (i.e., the start time of secondary battery use) pre-registered from the vehicle control unit 208. ava And the estimated charging time (time) required for diagnostic charging calculated by the battery management unit 202. Charge,D The remaining rechargeable time is determined as shown in Equation 14. ava Is this the estimated charging time required for diagnostic purposes? Charge,D above.

[0105] time ava ≥time Charge,D (Equation 14)

[0106] Remaining charging time ava This is calculated by the battery management unit 202 from the difference between the current time and the start time of the next operation (from the current time to the next use start time of the secondary battery 201). The estimated charging time required for diagnostic charging is [time]. Charge,DThis can be referred to as the total charging time, as shown in Equation 15, which is the charging time (t503)time. Charge Rest time after work (t502) R,before Rest time after charging (t504) R,after The total value.

[0107] time Charge,D =time Charge +time R,before +time R,after (Equation 15)

[0108] Charging time Charge For example, it is calculated from the charging time using the CCCV charging method. The CCCV charging method, as described above, starts charging in constant current mode and then switches to constant voltage mode once the target SOC voltage is reached. Charging time Charge It can be easily calculated using Equation 16.

[0109] time Charge =time Charge,CC +time Charge,CV =ΔQc / I C +time Charge,CV =(SOC) C,Max -SOC Cur ) / 100×Q0 / I C +time Charge,CV (Equation 16)

[0110] As shown in Equation 16, the charging time is... Charge It is through the amount of charge required for charging, ΔQc, from the charging current I. C CC charging time of operation Charge,CC and CV charging time Charge,CV The summation operation. CV charging time. Charge，CV Therefore, it can be fully charged until the SOC setting (maximum) is reached. C,Max This is a value predetermined based on battery performance, for a specific purpose. It can be a fixed value such as one hour, or a value calculated using a function or map based on the state of the secondary battery 201, which depends on factors such as cell temperature, SOC, and SOH. (Time is the rest time after work.) R,before , pause time after charging R,after This is based on the state of the secondary battery 201, which is determined by the cell temperature and SOC. Figure 8 The rest time was calculated using the map shown.

[0111] The detailed processing of the diagnostic charging implementation judgment in step S120 is, for example, as follows: Figure 10 The flowchart is shown. First, in step S121, the ΔSOC calculation unit 602 of the battery management unit 202 obtains the current secondary battery charging state SOC output from the battery management unit 202 as described above, and uses Equation 13 based on the preset charging SOC setting value (maximum) SOC. C,Max ΔSOC is calculated using the obtained SOC. C .

[0112] In step S122, which follows step S121, the diagnostic charging implementation judgment unit 302 obtains the ΔSOC calculated by the ΔSOC calculation unit 602. C Determine the obtained ΔSOC C Is it the specified value k? ΔSOC The above. In the case of ΔSOC... C The specified value k ΔSOC In the above cases, the control process proceeds to step S123. In step S123, the remaining rechargeable time (time) is calculated. ava And the estimated charging time required for diagnostic charging. Charge,D In step S124, which follows step S123, the diagnostic charging implementation judgment unit 302 judges the calculated time. ava Is it time? Charge,D That's all. (Regarding the judgment as time) ava For time Charge,D In the above cases, the diagnostic charging implementation determination unit 302 ultimately determines that diagnostic charging can be implemented (in other words, diagnostic charging is implemented) (see step S125).

[0113] On the other hand, in step S122, it is determined that ΔSOC C Less than the specified value k ΔSOC In the case of, or when determined to be time in step S124 ava Less than time Charge,D In the event that the diagnostic charging implementation determination unit 302 ultimately determines that the diagnostic charging cannot be implemented (in other words, the diagnostic charging is not implemented) (see step S126).

[0114] In step S124 above, because the temperature of the individual cells in the secondary battery is low, the estimated charging time required for diagnostic charging is time. Charge,D The increased length allows for increased cell temperature even when diagnostic charging is not possible, through mechanical preheating. In this case, it becomes... Figure 10 Mechanical preheating was added to the control process. Figure 11 Control processing (refer to) Figure 11 ).

[0115] Figure 11 Steps S121 to S125 shown are Figure 10 Similarly, therefore, repeated explanations are omitted, and only the different steps (i.e., the steps involving mechanical preheating) will be described below. Specifically, in step S124, the time is determined. ava Less than time Charge,D In the case where mechanical preheating is required, the control process proceeds to step S210 to determine whether mechanical preheating should be performed. Here, the following process is performed: it is determined whether the temperature rise of the individual cells within a specified range achieved by mechanical preheating can reduce the estimated charging time required for diagnostic charging. Charge,D With remaining charging time ava The relationship between them satisfies Equation 14; the calculation is based on the target value (target temperature) T of the unit temperature obtained from mechanical preheating. D ; and determine whether mechanical preheating can be implemented using energy surplus based on SOC, etc. Target temperature T D The estimated charging time required for diagnostic charging (time) Charge,D and remaining charging time ava The temperature that satisfies Equation 14.

[0116] If it is determined in step S210 that mechanical preheating can be implemented, the control process proceeds to step S220. In step S220, the target temperature T for mechanical preheating operation is set. D In step S230, which follows step S220, the diagnostic charging implementation judgment unit 302 determines the cell temperature T. C Is it greater than the target temperature T? D The temperature T of the monomer was determined to be... C greater than the target temperature T D In this case, the control process proceeds to step S125 above and determines that diagnostic charging can be performed.

[0117] On the other hand, in step S230, the monomer temperature T is determined. C For the target temperature T D In the following cases, the control process proceeds to step S240 to perform mechanical preheating operation. This mechanical preheating operation occurs at a unit temperature T. C Reach the target temperature T D This process is repeated. Furthermore, if it is determined in step S210 that mechanical preheating cannot be performed, the control process proceeds to step S126 above, where it is determined that diagnostic charging cannot be performed.

[0118] This embodiment describes a method for calculating the secondary battery capacity and the capacity degradation degree SOHQ based on operational history data such as voltage, temperature, and current obtained from diagnostic charging. However, it is also possible to calculate the battery DC resistance (mΩ) and resistance degradation degree SOHR (%) based on this data. For example, the battery DC resistance can be calculated from the voltage change after a specified time when a fixed current load is applied at a specified SOC after the voltage has stabilized.

[0119] The State of Charge (SOC) is defined as the SOC after the rest period following operation, and is calculated from the voltage change after a specified time when the charging load is applied during the charging time of the secondary battery. Equation 17 shows an example of the calculation formula.

[0120] DCR Charge,5 =ΔV Charge,5 / I Charge (Equation 17)

[0121] In Equation 17, the voltage change ΔV is calculated based on the voltage change 5 seconds after the start of charging. Charge,5 and charging load I Charge To calculate the charging DC resistance (at the 5th second) DCR Charge,5 SOHR is calculated by setting the initial battery DC resistance at the start of charging SOC to 100% and using it as a proportion of the current battery DC resistance (resistance degradation). Since DC resistance depends on cell temperature and SOC, the initial battery DC resistance is calculated based on a pre-built battery DC resistance map (initial) with parameters of pre-created cell temperature and SOC, and the obtained current cell temperature and SOC.

[0122] In the battery excavator 1 of this embodiment, the controller 300 includes: a diagnostic charging recommendation judgment unit 301 that determines whether diagnostic charging is recommended based on the working history of the secondary battery 201 output from the battery management unit 202; and a diagnostic charging implementation judgment unit 302 that determines whether to implement diagnostic charging when diagnostic charging is recommended, based on the state of the secondary battery output from the battery management unit 202, the estimated charging time required for diagnostic charging, and the on-site work plan consisting of the start time of the next operation. Therefore, diagnostic charging with a pause time is only implemented when diagnostic charging is recommended, thereby reducing the number of diagnostic charging operations with long total charging times. Furthermore, considering the on-site work plan, diagnostic charging is limited to being implemented when the total charging time for diagnostic charging can be ensured, thereby reducing the risk of affecting the on-site work plan. As a result, the work plan of the battery excavator 1 can be prevented from being hindered, and the work efficiency of the battery excavator 1 can be improved.

[0123] Furthermore, the battery management unit 202 calculates the charge rate SOC before and after charging based on the working history of the secondary battery 201, and calculates the full charge capacity Q or the degradation degree SOHQ of the secondary battery based on the calculated charge rate SOC before and after charging and the charge amount ΔQ of the secondary battery 201. Therefore, it can calculate the full charge capacity or SOHQ with high accuracy.

[0124] [Second Implementation]

[0125] Next, the second embodiment of the battery-powered excavator will be described. In the first embodiment, automatic execution... Figure 4 In contrast to the control processing shown, in the second embodiment, the final decision on whether to perform diagnostic charging or normal charging is made by the operator (operator, maintenance service personnel, etc.), even when it is determined that diagnostic charging should be performed. In this case, the final decision on whether to perform diagnostic charging or normal charging is made, for example, by setting up a charging mode selection screen on the monitoring display device and allowing the operator to select it.

[0126] Figure 12 This is a diagram illustrating the battery system configuration of the battery excavator according to the second embodiment. (See diagram for example.) Figure 12 As shown, the battery system of this embodiment also has a monitoring display device 212, which is different from the battery system of the first embodiment.

[0127] The monitoring display device 212 displays the charging mode selection screen and other information generated by the vehicle control unit 208. The charging mode selection screen generated by the vehicle control unit 208 is generated based on the judgment results of the diagnostic charging recommendation judgment unit 301, the judgment results of the diagnostic charging implementation judgment unit 302, and the calculation results of the battery management unit 202.

[0128] Figure 13 This is a functional block diagram showing the controller installed in the vehicle control unit of the second embodiment. Compared with the controller 300 of the first embodiment, the controller 300A of this embodiment also has a charging end time calculation unit 304, a monitoring display production unit 305, and a selection content determination unit 306.

[0129] Figure 14 This is a flowchart illustrating the charging control of the secondary battery in the second embodiment. Figure 14 The control process shown is initiated by entering a state that starts the charging operation of the battery excavator 1, for example, by connecting the current cable.

[0130] In step S310, the diagnostic charging recommendation judgment unit 301 determines whether to recommend diagnostic charging based on the operating history of the secondary battery 201 output from the battery management unit 202. The specific judgment method is the same as that described in the first embodiment above. Furthermore, if it is determined that diagnostic charging is recommended, the control process proceeds to step S320.

[0131] In step S320, the diagnostic charging implementation determination unit 302 determines whether to implement diagnostic charging based on the state of the secondary battery 201 output from the battery management unit 202, the estimated charging time required for diagnostic charging, and the on-site work plan consisting of the work start time. The specific determination method is the same as that described in the first embodiment above. If it is determined that diagnostic charging can be implemented, the control process proceeds to step S330.

[0132] In step S330, the charging time is calculated. Here, the battery management unit 202 calculates the estimated charging time required for normal charging and diagnostic charging based on Equations 15 and 16 above.

[0133] In step S340, following step S330, a charging mode selection screen is monitored and displayed. Here, charging mode selection refers to choosing either "normal charging" or "diagnostic charging." Specifically, firstly, the charging end time calculation unit 304 calculates the charging end time for normal charging and diagnostic charging respectively, based on the current time and the estimated charging time required for normal charging and diagnostic charging calculated by the battery management unit 202. Next, the monitoring display production unit 305 creates a display screen showing the charging end times for normal charging and diagnostic charging calculated by the charging end time calculation unit 304, and displays it on the monitoring display device 212.

[0134] In step S350, following step S340, a charging mode selection is performed. Here, the operator or maintenance technician selects the charging mode displayed on the monitoring display device 212. The operator selects "1. Diagnostic Charging" (see reference...) displayed on the monitoring display device 212. Figure 15 In the case of [missing information], the content selection unit 306 determines the selected content and sends a command to the charger control unit 303. Thus, diagnostic charging is performed (see step S360).

[0135] On the other hand, if it is determined in step S310 that diagnostic charging is not recommended, or in step S320 that diagnostic charging is not performed, or in step S340 the operator selects "2. Normal charging" (refer to...) Figure 15In the case of selection, the content determination unit 306 determines the selected content and sends a command to the charger control unit 303. Normal charging then begins (see step S370).

[0136] Figure 15 This is an example diagram illustrating the display screen and selection process of a monitoring display device. For example... Figure 15 As shown, firstly, the display screen (selection screen) 2121 of the monitoring display device 212 displays, for example, "Recommended period for implementation of diagnostic charging." This draws the operator's attention. Based on this, the charging mode "1. Diagnostic charging" or "2. Normal charging" is displayed for the operator to choose from. In "1. Diagnostic charging", in addition to indicating the recommendation, the estimated charging time required is also indicated.

[0137] When the operator selects "1. Diagnostic Charging", the monitoring display device 212 changes to the diagnostic charging implementation confirmation screen 2122. At this time, the diagnostic charging implementation confirmation screen 2122 displays the charging end time for the diagnostic charging, allowing the operator to choose whether to start charging based on the work plan. If charging start (i.e., yes) is selected, diagnostic charging is performed, and the display screen of the monitoring display device 212 changes to the diagnostic charging implementation screen 2123.

[0138] On the other hand, if the operator selects "2. Normal charging" through the selection screen 2121, or selects not to start charging (i.e., no) through the diagnostic charging implementation confirmation screen 2122, normal charging will be performed, and the display screen of the monitoring display device 212 will change to the normal charging implementation screen 2124.

[0139] The battery excavator according to this embodiment not only achieves the same effects as the first embodiment, but also improves the ability to respond to on-site conditions, etc., because it is configured such that even if it is determined that diagnostic charging is to be performed, the operator can make a final decision on whether to perform diagnostic charging or normal charging.

[0140] Furthermore, this embodiment illustrates a situation where the operator makes the final decision on whether to perform diagnostic charging or normal charging, even when it is determined that diagnostic charging should be performed. However, it is also possible that, even when it is determined that diagnostic charging should be performed, if the operator wants to diagnose the state of the secondary battery 201, etc., instructions can be issued to the battery management unit 202 and the vehicle control unit 208 by an external computer or other means, either through on-site operation or remote operation, to arbitrarily perform diagnostic charging.

[0141] The embodiments of the present invention have been described in detail above. The present invention is not limited to the above embodiments, and various design changes can be made without departing from the spirit of the present invention described in the technical solution.

[0142] Explanation of reference numerals in the attached figures

[0143] 1. Battery-powered excavator (electric work machinery)

[0144] 201 secondary battery

[0145] 202 Battery Management Unit

[0146] 203 Ammeter

[0147] Communication lines 204, 209, 210, and 211

[0148] 205 charger

[0149] 206 motor

[0150] 207 Inverter

[0151] 208 vehicle control unit

[0152] 212 Monitoring Display Device

[0153] 300, 300A controller

[0154] 301 Diagnostic Charging Recommendation Judgment Unit

[0155] 302 Diagnostic Charging Implementation Judgment Unit

[0156] 303 Charger Control Section

[0157] 304 Charging End Time Calculation Unit

[0158] 305 Monitoring Display Production Department

[0159] 306 Content Judgment Department

[0160] 601 Charge Calculation Unit

[0161] 602ΔSOC Computing Unit

[0162] 603 Battery Capacity Calculation Unit

[0163] 604SOHQ arithmetic unit.

Claims

1. An electric work machine, comprising a secondary battery, characterized in that, have: A battery management unit that manages the secondary battery; and The controller for the secondary battery is used for both normal charging without a pause time and diagnostic charging with a pause time. The controller has: The diagnostic charging recommendation judgment unit determines whether to recommend diagnostic charging based on the operating history of the secondary battery output from the battery management unit; and The diagnostic charging implementation judgment unit determines whether to perform diagnostic charging based on the status of the secondary battery output from the battery management unit, the estimated charging time required for diagnostic charging, and the on-site work plan consisting of the work start time; and The charger control unit controls the charging of the secondary battery. The diagnostic charging recommendation judgment unit determines that it recommends diagnostic charging if it determines that the current full charge capacity and the degree of degradation of the secondary battery deviate from the calculated values ​​of the full charge capacity and the degree of degradation of the secondary battery obtained from the previous diagnostic charging. Conversely, it determines that it does not recommend diagnostic charging if it determines that the current full charge capacity and the degree of degradation of the secondary battery do not deviate from the calculated values ​​of the full charge capacity and the degree of degradation of the secondary battery obtained from the previous diagnostic charging. If the diagnostic charging recommendation determination unit determines that diagnostic charging is not recommended, the charger control unit performs normal charging. When the diagnostic charging recommendation determination unit determines that diagnostic charging is recommended, and the diagnostic charging implementation determination unit determines that diagnostic charging is to be implemented, the charger control unit executes the diagnostic charging. When the diagnostic charging recommendation determination unit determines that diagnostic charging is recommended, and the diagnostic charging implementation determination unit determines that diagnostic charging is not to be implemented, the charger control unit performs the normal charging.

2. The electric operating machinery according to claim 1, characterized in that, The diagnostic charging method features a charging mode with preset rest periods before and after charging. The pause time for the diagnostic charging is set based on the polarization time constant of the secondary battery, which depends on temperature and charging rate.

3. The electric operating machinery according to claim 1 or 2, characterized in that, The battery management unit calculates the charging rate before and after charging based on the working history of the secondary battery during diagnostic charging or normal charging, and calculates the full charge capacity or the degradation degree of the secondary battery capacity based on the calculated charging rate before and after charging and the charging charge of the secondary battery.

4. The electric operating machinery according to any one of claims 1 to 3, characterized in that, The diagnostic charging recommendation judgment unit determines that a diagnostic charge is recommended when the difference between the current time and the start date of use of the secondary battery, or the difference between the current time and the implementation date of the previous diagnostic charge, is more than a predetermined time.

5. The electric operating machinery according to any one of claims 1 to 3, characterized in that, The diagnostic charging recommendation judgment unit determines that a diagnostic charge should be recommended when the difference between the initial value of the secondary battery capacity degradation degree or the degradation degree of the secondary battery capacity calculated during the previous diagnostic charge and the current degradation degree of the secondary battery capacity calculated using a degradation prediction function based on the working history since the previous diagnostic charge is above a predetermined threshold.

6. The electric operating machinery according to any one of claims 1 to 3, characterized in that, When the difference between the average value of the latest point of the secondary battery capacity degradation during normal charging and the initial value of the secondary battery capacity degradation or the secondary battery capacity degradation during the previous diagnostic charging is greater than or equal to a predetermined threshold, the diagnostic charging recommendation judgment unit determines that a diagnostic charging is recommended.

7. The electric operating machinery according to any one of claims 1 to 3, characterized in that, The diagnostic charging recommendation judgment unit determines that a diagnostic charge is recommended when the difference between the working charging rate range calculated based on the initial value of the secondary battery's full charge capacity or the degree of degradation of the secondary battery's capacity and the secondary battery's full charge capacity or the degree of degradation of the secondary battery's capacity during the previous diagnostic charge, and the charging rate range calculated based on the working history of the secondary battery during normal charging, is below a predetermined threshold.

8. The electric operating machinery according to any one of claims 1 to 7, characterized in that, The diagnostic charging implementation judgment unit determines to implement diagnostic charging when the remaining charging time calculated based on the current time and the on-site work plan is greater than or equal to the estimated charging time required for diagnostic charging, and the change in charging rate before and after diagnostic charging is greater than or equal to a predetermined value.

9. The electric operating machinery according to claim 8, characterized in that, If the remaining rechargeable time is less than the estimated charging time required for diagnostic charging, and the temperature of the secondary battery is made greater than the set target temperature through mechanical preheating operation, the diagnostic charging implementation judgment unit determines that diagnostic charging should be implemented.

10. The electric operating machinery according to any one of claims 1 to 9, characterized in that, It also has a monitoring and display device that displays the judgment results of the diagnostic charging recommendation judgment unit and the judgment results of the diagnostic charging implementation judgment unit, and displays a screen for selecting between normal charging and diagnostic charging.

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