Battery maintenance system, battery maintenance method and replenishment device

Abstract

A battery maintenance system includes: a supply path for supplying liquid to a battery; a first on / off valve disposed on the supply path; and a second on / off valve disposed on the supply path downstream of the first on / off valve in the direction of liquid supply.

Description

Technical Field

[0001] This disclosure relates to battery maintenance systems, battery maintenance methods, and supplementary devices. Background Technology

[0002] Japanese Patent Application Publication No. 2021-165057 discloses an automatic battery fluid replenishment device for adding battery fluid to a battery. This automatic battery fluid replenishment device performs the following control: when the battery is filled to full capacity twice consecutively, a correction is performed to ensure that the amount of fluid lost due to charging after filling to full capacity matches the amount of fluid replenished during the actual filling time (i.e., the actual filling time). The fluid replenishment process ends after performing corrections when the battery is full and when it is not full. Summary of the Invention

[0003] [The technical problem the invention aims to solve] The purpose of this disclosure is to improve the maintainability of batteries.

[0004] [Solutions for solving technical problems] The battery maintenance system of the first aspect of this disclosure includes: a supply line for supplying liquid to a battery; a first on / off valve disposed on the supply line; and a second on / off valve disposed on the supply line downstream of the first on / off valve in the direction of liquid supply.

[0005] In the battery maintenance system of the first aspect, liquid is supplied to the battery via a supply path by opening both the first and second on / off valves. Here, in this battery maintenance system, even if the second on / off valve malfunctions while liquid is being supplied to the battery, the supply of liquid to the battery can be stopped by closing the first on / off valve, which is located upstream of the second on / off valve in the liquid supply direction. This prevents excessive liquid supply to the battery. By suppressing excessive liquid supply to the battery in this way, the increased maintenance frequency due to liquid overflow is prevented, and the maintainability of the battery is improved.

[0006] The battery maintenance system of the second aspect of this disclosure is in the first aspect of the battery maintenance system, wherein the first on / off valve is an electrically driven valve, and the battery maintenance system further includes a control unit that controls the actuation of the first on / off valve.

[0007] In the second aspect of the battery maintenance system, the drive (opening and closing action) of the first opening and closing valve is controlled by the control unit. Therefore, in the above-mentioned battery maintenance system, the operator's workload can be reduced compared to the case where the operator manually operates the first opening and closing valve.

[0008] The battery maintenance system of the third aspect of this disclosure is a battery maintenance system of the second aspect, wherein the battery maintenance system further includes a charging cable that connects a charger to the battery, and the control unit controls the start and stop of charging the battery.

[0009] In the third aspect of the battery maintenance system, a control unit controls the charger to start and stop charging the battery. Therefore, in the above-described battery maintenance system, compared to the situation where an operator performs the charging operation, which includes starting and stopping charging the battery, the workload of the operator can be reduced.

[0010] In the battery maintenance system of the fourth aspect of this disclosure, compared with the battery maintenance system of the third aspect, the control unit simultaneously charges the battery and supplies the liquid.

[0011] In the fourth aspect of the battery maintenance system, the control unit performs battery charging and fluid supply simultaneously. Therefore, in the above-described battery maintenance system, compared to performing battery charging and fluid supply separately, the time spent on charging the battery and supplying fluid can be shortened.

[0012] The fifth aspect of the battery maintenance system disclosed herein, in the third aspect of the battery maintenance system, wherein the control unit supplies the liquid after or before charging the battery.

[0013] In the fifth aspect of the battery maintenance system, a control unit supplies liquid to the battery either after charging or before charging. Depending on factors such as the battery's condition and type, it is sometimes preferable to supply liquid to the battery after charging or before charging. Therefore, in the aforementioned battery maintenance system, supplying liquid to the battery after charging or before charging, depending on the battery's condition, can extend the battery's lifespan.

[0014] In the battery maintenance system of the sixth aspect of this disclosure, in any of the second to fifth aspects of the battery maintenance system, the control unit determines the amount of liquid to be supplied to the battery based on the battery's charge and discharge history, and opens the first on / off valve until the determined amount of liquid is supplied to the battery.

[0015] In the battery maintenance system of the sixth aspect, the control unit determines the amount of liquid to be supplied to the battery based on the battery's charge and discharge history. Furthermore, the control unit keeps the first on / off valve open until the determined supply amount is supplied to the battery. Therefore, in the above-described battery maintenance system, compared to the case where a fixed amount of liquid is not always supplied to the battery based on its charge and discharge history, it is possible to efficiently supply any insufficient liquid to the battery.

[0016] The battery maintenance system of the seventh aspect of this disclosure, in the battery maintenance system of the sixth aspect, wherein the battery is composed of a plurality of battery cells, and the second on / off valve is in an open state when the liquid level of the storage liquid stored in at least one of the battery cells is less than a first threshold, and in a closed state when the liquid level of the storage liquid stored in at least one of the battery cells is above the first threshold.

[0017] In the battery maintenance system of the seventh aspect, when supplying liquid to the battery, the second on / off valve is open until the liquid level in at least one battery cell reaches a first threshold. Furthermore, if the liquid level exceeds the first threshold, the second on / off valve closes, stopping the supply of liquid to the battery. Here, in the aforementioned battery maintenance system, by setting the liquid level that can suppress excessive supply of liquid to the battery to the first threshold, it is possible to further suppress the increase in maintenance frequency due to liquid overflow.

[0018] The battery maintenance system of the eighth aspect of this disclosure, in the battery maintenance system of the seventh aspect, further includes a liquid level sensor for detecting the liquid level of the stored liquid. When the height of the liquid level detected by the liquid level sensor is greater than or equal to a second threshold, the control unit closes the first on / off valve, wherein the second threshold is greater than the first threshold.

[0019] In the battery maintenance system of the eighth aspect, when the liquid level detected by the liquid level sensor is above a second threshold, the control unit closes the first on / off valve, where the second threshold is greater than the first threshold. Here, in the aforementioned battery maintenance system, when the upper limit for suppressing liquid overflow from the battery cell is set to the second threshold, for example, even if the second on / off valve malfunctions, if the liquid level is above the second threshold, the control unit will close the first on / off valve, thus effectively suppressing liquid overflow caused by excessive liquid supply to the battery.

[0020] The battery maintenance system of the ninth aspect of this disclosure, in the battery maintenance system of the seventh aspect, further includes a liquid level sensor for detecting the liquid level of the stored liquid. The control unit maintains the first on / off valve in an open state when the height of the liquid level detected by the liquid level sensor is less than a third threshold, wherein the third threshold is less than the first threshold.

[0021] In the battery maintenance system of the ninth aspect, when the liquid level detected by the liquid level sensor is less than a third threshold, the control unit maintains the first on / off valve in an open state, wherein the third threshold is less than the first threshold. Here, in the aforementioned battery maintenance system, when the lower limit for preventing the battery cell from drying out is set to the third threshold, if the liquid supply is insufficient and the liquid level does not reach the third threshold, the control unit maintains the first on / off valve in an open state, thus preventing the battery cell from drying out.

[0022] In the battery maintenance system of the ninth aspect of this disclosure, the control unit maintains the first on / off valve in an open state when the height of the liquid level detected by the liquid level sensor is below a fourth threshold, wherein the fourth threshold is set between the first threshold and the third threshold.

[0023] In the battery maintenance system of the tenth aspect, when the liquid level detected by the liquid level sensor is below a fourth threshold, the control unit maintains the first on / off valve in an open state, wherein the fourth threshold is set between the first threshold and the third threshold. Here, in the aforementioned battery maintenance system, when the optimal value of the liquid level in the battery cell is set to the fourth threshold, the control unit maintains the first on / off valve in an open state until the liquid supply reaches the fourth threshold. Therefore, it can suppress liquid overflow caused by excessive liquid supply to the battery, while simultaneously ensuring liquid supply until the optimal value is reached.

[0024] The eleventh aspect of the battery maintenance system of this disclosure, in the sixth aspect of the battery maintenance system, the battery is composed of multiple battery cells, the supply path branches into multiple branches midway to supply the liquid to each of the battery cells, the first on / off valve is disposed upstream of the branch portion of the supply path in the supply direction, and the second on / off valve is disposed in the multiple branch passages respectively, the multiple branch passages constituting the downstream portion of the supply path in the supply direction compared to the branch portion.

[0025] In the eleventh aspect of the battery maintenance system, the supply path branches into multiple branch paths. Therefore, the amount of liquid supplied to each battery cell varies due to the distance between the branch paths. However, by installing second on / off valves on each of the multiple branch paths, if the liquid supplied to any one battery cell becomes excessive, the second on / off valve corresponding to the battery cell with excessive supply is closed, thereby stopping the liquid supply to that battery cell. In this battery maintenance system, compared to the case where the second on / off valve is installed upstream of the branch portion of the supply path in the supply direction, excessive liquid supply to each battery cell constituting the battery can be suppressed.

[0026] In the battery maintenance system of the eleventh aspect of this disclosure, each of the second on / off valves is in an open state when the level of the storage liquid stored in each of the battery cells is less than a first threshold, and in a closed state when the level of the storage liquid stored in each of the battery cells is above the first threshold.

[0027] In the battery maintenance system of the twelfth aspect, when liquid is supplied to the battery, if the liquid level in each battery cell is less than a first threshold, the second on / off valve corresponding to each battery cell is opened. Furthermore, if the liquid level in each battery cell is above the first threshold, the second on / off valve corresponding to each battery cell is closed, stopping the supply of liquid to each battery cell. Here, in the aforementioned battery maintenance system, by setting the liquid level that can suppress excessive supply of liquid to the battery to the first threshold, it is possible to further suppress the increase in maintenance frequency due to liquid overflow.

[0028] The battery maintenance system of the thirteenth aspect of this disclosure is in the battery maintenance system of the twelfth aspect, the battery maintenance system further comprising a liquid level sensor for detecting the liquid level of the storage liquid, the liquid level sensor being disposed in two or more of the battery cells, the control unit causing the first on / off valve to be closed when the height of the liquid level detected by at least one of the liquid level sensors is greater than or equal to a second threshold, the second threshold being greater than the first threshold.

[0029] In the battery maintenance system of the thirteenth aspect, a liquid level sensor is provided in each of two or more battery cells. When the liquid level detected by at least one liquid level sensor is above a second threshold, the control unit closes the first on / off valve, where the second threshold is greater than the first threshold. In this battery maintenance system, when the upper limit for suppressing liquid overflow from the battery cell is set to the second threshold, for example, even if the second on / off valve malfunctions, if the liquid level is above the second threshold, the control unit will close the first on / off valve, thus effectively suppressing liquid overflow caused by excessive liquid supply to the battery.

[0030] The battery maintenance system of the fourteenth aspect of this disclosure is in the battery maintenance system of the thirteenth aspect, wherein the plurality of battery cells are arranged side by side in a metal storage box, and the liquid level sensors are respectively disposed in the first battery cell with the most contact surfaces with the storage box and the second battery cell with the fewest contact surfaces with the storage box.

[0031] In the battery maintenance system of aspect fourteen, liquid level sensors are respectively installed in the first battery cell and the second battery cell. Here, compared to the second battery cell, which has the fewest contact surfaces with the metal storage box and the first battery cell, which has the most contact surfaces with the storage box, it is difficult for the second battery cell to dissipate heat through the storage box, or it may be unable to dissipate heat at all, thus easily becoming overheated. Therefore, the liquid level in the second battery cell decreases faster than in the first battery cell. Therefore, by installing liquid level sensors in the second battery cell, where the liquid level decreases faster, and in the first battery cell, where the liquid level decreases slower, liquid supply can be adjusted according to the degree of liquid level decrease in the second battery cell, and liquid supply can be stopped according to the degree of liquid overflow in the first battery cell.

[0032] The battery maintenance system of the fifteenth aspect of this disclosure, in the battery maintenance system of the fourteenth aspect, wherein the control unit opens the first on / off valve when the height of the liquid level detected by the liquid level sensor provided in the second battery cell is less than a third threshold, wherein the third threshold is less than the first threshold; and closes the first on / off valve when the height of the liquid level detected by the liquid level sensor provided in the first battery cell is greater than or equal to a second threshold, wherein the second threshold is greater than the first threshold.

[0033] In the battery maintenance system of the fifteenth aspect, when the liquid level detected by the liquid level sensor of the second battery cell, where the stored liquid decreases rapidly, is less than a third threshold, the control unit opens the first on / off valve, where the third threshold is less than the first threshold. Here, in the aforementioned battery maintenance system, when the lower limit for preventing the liquid in the battery cell from drying out is set to the third threshold, if the liquid supply is insufficient and the liquid level does not reach the third threshold, the control unit maintains the first on / off valve open, thus preventing the second battery cell from drying out.

[0034] Furthermore, in the aforementioned battery maintenance system, when the liquid level detected by the liquid level sensor in the first battery cell, where the storage liquid decreases slowly, is above a second threshold, the control unit closes the first on / off valve, where the second threshold is greater than the first threshold. Here, in the aforementioned battery maintenance system, when the upper limit for suppressing liquid overflow from the battery cell is set to the second threshold, for example, even if the second on / off valve malfunctions, if the liquid level is above the second threshold, the control unit will close the first on / off valve, thus effectively suppressing liquid overflow (e.g., liquid overflow from the first battery cell) caused by excessive liquid supply to the battery.

[0035] In the battery maintenance system of the sixteenth aspect of this disclosure, in either the seventh or twelfth aspect, the second on / off valve comprises: a float that floats in the liquid; and a valve body that moves in conjunction with the float and, when the height of the liquid level is above a first threshold, contacts a valve seat to close the internal flow path.

[0036] In the battery maintenance system of the sixteenth aspect, when the liquid level is above a first threshold, the valve body, which moves in conjunction with the float, contacts the valve seat to close the internal flow path. In this way, compared to the case where the second on / off valve uses an electrically driven valve body, the increase in control costs associated with the second on / off valve can be suppressed.

[0037] The battery maintenance system of the seventeenth aspect of this disclosure, in the battery maintenance system of the seventh or twelfth aspect, further includes a catalyst unit that reduces the gas generated by electrolysis of the storage liquid back into the liquid.

[0038] In the battery maintenance system of aspect seventeen, the gas generated by the electrolysis of the storage liquid is reduced back to liquid by the catalyst section. Therefore, in the above-described battery maintenance system, compared with the case without a catalyst section, the rate of storage liquid loss can be slowed down.

[0039] The battery maintenance system of the eighteenth aspect of this disclosure is in the battery maintenance system of the seventeenth aspect, wherein the catalyst section is connected to the second on / off valve.

[0040] In the battery maintenance system of the eighteenth aspect, the catalyst section is connected to the second on / off valve, thus simplifying the structure of the battery cell compared to the case where the catalyst section is located at a different location from the second on / off valve in the battery cell.

[0041] In the battery maintenance system of the nineteenth aspect of this disclosure, in the battery maintenance system of the eleventh aspect, the branch portion of the supply path is detachably connected to the first on / off valve via a connector mechanism.

[0042] In the battery maintenance system of aspect nineteen, the branch of the supply path is detachably connected to the first on / off valve via a connector mechanism. Here, in the aforementioned battery maintenance system, compared to the case where the connector mechanism is located downstream of the branch in the supply direction, there are fewer parts for connecting and disconnecting the connection, making it easier to connect the supply path. That is, it reduces the workload of the operator.

[0043] The battery maintenance method of the twentieth aspect of this disclosure combines charging the battery with supplying fluid.

[0044] In the battery maintenance method of aspect 20, charging the battery and supplying liquid to the battery are performed simultaneously, thus reducing the time spent on charging and supplying liquid compared to charging and supplying liquid separately. This improves the maintainability of the battery.

[0045] The battery maintenance method of the twenty-first aspect of this disclosure, in the battery maintenance method of the twenty-tenth aspect, involves supplying the liquid from the start of charging the battery until the end of charging.

[0046] In the battery maintenance method of aspect twenty-one, liquid is supplied from the start of charging the battery until the end of charging. That is, in the above-described battery maintenance method, liquid can be supplied to the battery from the start of charging until the end of charging, thus further shortening the time spent on charging the battery and supplying liquid. Therefore, the maintainability of the battery is further improved.

[0047] The battery maintenance method of the twenty-second aspect of this disclosure, in the battery maintenance method of the twenty-first aspect, terminates the supply of liquid before the voltage of the battery reaches a predetermined voltage.

[0048] In the battery maintenance method of aspect 22, for example, when the predetermined voltage is set to be lower than the voltage at which gassing occurs, the liquid supply is stopped before the battery voltage reaches the predetermined voltage, thereby suppressing the liquid supply from being affected by gassing.

[0049] The supplementary device of the 23rd aspect of this disclosure includes: a supply path for supplying liquid to a battery; a first on / off valve disposed on the supply path; and a second on / off valve disposed on the supply path downstream of the first on / off valve in the direction of liquid supply.

[0050] In the supplementary device of aspect twenty-three, liquid is supplied to the battery via a supply path by opening both the first and second on / off valves. Here, in the supplementary device, even if the second on / off valve malfunctions while supplying liquid to the battery, the supply of liquid to the battery can be stopped by closing the first on / off valve, which is located upstream of the second on / off valve in the liquid supply direction. This prevents excessive liquid supply to the battery. In this way, by preventing excessive liquid supply to the battery, the increased maintenance frequency due to liquid overflow is suppressed, and the maintainability of the battery is improved.

[0051] The supplementary device of the 24th aspect of this disclosure, in the supplementary device of the 23rd aspect, wherein the first opening and closing valve is an electrically driven valve, and the supplementary device further includes a control unit for controlling the actuation of the first opening and closing valve.

[0052] In the supplementary device of aspect twenty-four, the drive (opening and closing action) of the first opening and closing valve is controlled by the control unit. Therefore, in the above-mentioned supplementary device, the operator's workload can be reduced compared to the case where the operator manually operates the first opening and closing valve.

[0053] The supplementary apparatus of the 25th aspect of this disclosure, in the supplementary apparatus of the 24th aspect, further comprises: a charger; and a charging cable connecting the charger and the battery, wherein the control unit controls the start and stop of charging the battery.

[0054] In the supplementary device of aspect twenty-five, the start and stop of charging the battery are controlled by a control unit. Therefore, in the above-mentioned supplementary device, the workload of the operator, which includes starting and stopping charging the battery, can be reduced compared to the case where the charging operation is performed by an operator.

[0055] The supplementary device of the 26th aspect of this disclosure, in any of the supplementary devices of the 23rd to 25th aspects, further includes a storage section disposed on the supply line upstream of the first on / off valve in the direction of liquid supply, the storage section being used to store the liquid.

[0056] In the supplementary device of the twenty-sixth aspect, since it has a storage section for storing liquid, maintenance time can be shortened, for example, by storing the liquid that has undergone predetermined treatment in the storage section in advance.

[0057] [Invention Effects] According to this disclosure, the maintainability of the battery can be improved. Attached Figure Description

[0058] Figure 1 This is a schematic diagram showing the structure of a battery maintenance system according to one embodiment of the present disclosure.

[0059] Figure 2 This is a block diagram illustrating the structure of the control system of a battery maintenance system according to one embodiment of the present disclosure.

[0060] Figure 3 This is a schematic top view of a battery that uses a battery maintenance system according to an embodiment of the present disclosure for liquid supply.

[0061] Figure 4 This is a cross-sectional view showing the structure of a first battery cell, a second on / off valve, and a first liquid level sensor used in a battery maintenance system according to an embodiment of the present disclosure.

[0062] Figure 5This is a cross-sectional view showing the structure of the second battery cell, the second on / off valve, and the second liquid level sensor used in a battery maintenance system according to one embodiment of the present disclosure.

[0063] Figure 6 This is a flowchart illustrating the process of supplying liquid to a battery using a battery maintenance system according to one embodiment of the present disclosure.

[0064] Figure 7 This is a diagram showing the timing of charging the battery and supplying liquid.

[0065] Figure 8 This is a cross-sectional view showing the structure when the return pipeline is connected to a first battery cell and a second on / off valve used in a battery maintenance system according to an embodiment of this disclosure.

[0066] Figure 9 This is a diagram illustrating the schematic structure of a battery maintenance system according to other embodiments of the present disclosure.

[0067] Figure 10 This is a schematic top view of a modified battery.

[0068] Figure 11 This is a schematic top view of a battery that uses a battery maintenance system according to other embodiments of the present disclosure for liquid supply.

[0069] Figure 12 This is a diagram illustrating the schematic structure of a battery maintenance system according to other embodiments of the present disclosure.

[0070] Figure 13 This is a diagram of a forklift, which is an example of a mobile body equipped with the battery disclosed herein. Detailed Implementation

[0071] Hereinafter, an embodiment of the present disclosure will be described with reference to the accompanying drawings. Furthermore, in each drawing, the same reference numerals are used for the same or equivalent constituent elements and parts. Additionally, for ease of explanation, the scale of the drawings is exaggerated and sometimes differs from the actual scale.

[0072] like Figure 1 As shown, the battery maintenance system 10 of this embodiment (hereinafter, appropriately referred to as "system 10") is a system that has the function of supplying liquid (hereinafter, appropriately referred to as "liquid supply") to the battery 110. Furthermore, in the accompanying drawings, the liquid supplied to the battery 110 is indicated by the reference numeral FL. Additionally, in the accompanying drawings, the storage liquid stored in the battery cell 112 is indicated by the reference numeral RL.

[0073] First, before describing system 10, the battery 110 that supplies liquid FL through system 10 will be described.

[0074] like Figure 3 As shown, battery 110 is a lead-acid battery composed of multiple battery cells 112. The multiple battery cells 112 are arranged side-by-side in a metal storage box 114. Specifically, the storage box 114 is a rectangular box, and the multiple battery cells 112 are arranged in a matrix on the bottom surface of the storage box 114. In this embodiment, as an example, the multiple battery cells 112 are arranged in a 4x4 matrix on the bottom surface of the storage box 114. Furthermore, the outermost battery cells 112 are supported in posture by contacting the sidewall 114a of the storage box 114. In this way, the side-by-side arrangement of the multiple battery cells 112 is maintained by the sidewall 114a of the storage box 114.

[0075] In this embodiment, the battery cell 112 has a voltage of 2V when fully charged, for example. Multiple battery cells 112 can be connected in series, but they can also be connected in parallel.

[0076] Furthermore, the battery cell with the most contact surfaces with the storage box 114 among the multiple battery cells 112 is designated as the first battery cell 112a, and the battery cell with the fewest contact surfaces with the storage box 114 is designated as the second battery cell 112b. In this embodiment, the battery cell 112 located on the outer periphery and at the corner is the first battery cell 112a. The first battery cell 112a contacts three surfaces of the storage box 114: two sides and the bottom surface. The battery cell 112 located on the inner side among the multiple battery cells 112 is the second battery cell 112b. The second battery cell 112b contacts the bottom surface of the storage box 114 but not the side wall 114a. Therefore, the second battery cell 112b contacts only one side of the storage box 114.

[0077] In addition, Figure 1 In the diagram, the first battery unit 112a and the second battery unit 112b are adjacent, but this is only for illustrative purposes and does not represent the actual battery unit configuration. Furthermore, the terminals of the adjacent first battery unit 112a and second battery unit 112b are connected, but this connection is also for illustrative purposes and does not represent the actual terminal connections between battery units.

[0078] Next, we will explain System 10.

[0079] like Figure 1 As shown, system 10 includes a supply path 20, a first on / off valve 30, and a second on / off valve 40. Furthermore, system 10 in this embodiment, as an example, includes a liquid level sensor 50 and a control unit 60.

[0080] Supply path 20 is a flow path for supplying liquid FL to battery 110. Furthermore, in this embodiment, as an example, the liquid FL supplied to battery 110 is purified water, and the storage liquid RL stored in battery cell 112 of battery 110 is battery fluid. However, this disclosure is not limited to this structure. For example, liquid FL may be water containing impurities compared to purified water (for example, tap water), or it may be battery fluid. Battery fluid may include dilute sulfuric acid (sulfuric acid + water). For example, the specific gravity of dilute sulfuric acid is 1.1 to 1.3 at a temperature of 20°C. Additives such as inorganic salts and organic salts may also be included in the battery fluid. When liquid FL is dilute sulfuric acid, it may be set to the same concentration (specific gravity) as the storage liquid RL, or it may be set to a different concentration (specific gravity).

[0081] Additionally, as an example, in this embodiment, the supply path 20 supplies liquid FL from the storage section 14 to the battery 110. The storage section 14 is a container for storing liquid FL and is located upstream of the first on / off valve 30 in the liquid FL supply direction. Furthermore, the liquid FL supply direction (hereinafter appropriately referred to as the "liquid supply direction") is... Figure 1 The direction indicated by the middle arrow SD. In this embodiment, the upstream end of the supply line 20 is connected to the storage unit 14, but this disclosure is not limited to this structure. For example, the upstream end of the supply line 20 may also be connected to a water pipe.

[0082] In addition, as an example, the supply path 20 of this embodiment branches into multiple paths midway to supply liquid FL to each battery cell 112. Specifically, the supply path 20 branches into multiple branch paths 22 midway, forming multiple branch paths 22 that are downstream of the branch portion in the liquid supply direction to supply liquid FL to each battery cell 112.

[0083] A first on / off valve 30 is provided on the supply path 20. This first on / off valve 30 is an electrically driven valve, that is, a valve that is driven by electricity to open and close. As an example, the first on / off valve 30 is a solenoid valve, but it is not limited to this. In addition, as an example, the first on / off valve 30 in this embodiment is provided upstream of the branch portion of the supply path 20 in the liquid supply direction.

[0084] The second on / off valve 40 is located downstream of the first on / off valve 30 in the liquid supply direction on the supply path 20. Alternatively, as an example, in this embodiment, the second on / off valve 40 is provided in multiple branch paths 22.

[0085] Each of the second on / off valves 40 is in the open state when the height of the liquid level LS (hereinafter appropriately referred to as "liquid level height") of the storage liquid RL stored in the corresponding battery cell 112 is less than the first threshold T1, and in the closed state when the liquid level height is greater than or equal to the first threshold T1. Furthermore, the height of the liquid level LS of the storage liquid RL referred to here is the height from the bottom surface of the battery cell 112.

[0086] Furthermore, as an example, the second on / off valve 40 of this embodiment includes a float 42 floating in the storage liquid RL and a valve body 44. The valve body 44 moves in conjunction with the float 42, and when the liquid level of the storage liquid RL is above a first threshold, it contacts the valve seat 45 to close the internal flow path 48. Specifically, as... Figure 4 As shown, the second on / off valve 40 includes a housing 46. The interior of the housing 46 forms part of the supply passage 20 (branch passage 22). A guide hole 47 is provided in the housing 46 for guiding the shaft member 43 extending from the float 42. Through this guide hole 47, the float 42 can move up and down as the liquid level LS rises and falls. In addition, a valve body 44 is provided on the side of the shaft member 43 opposite to the float 42. Thus, with the float 42 and valve body 44 provided in the shaft member 43, the valve body 44 moves in the vertical direction in conjunction with the up and down movement of the float 42. Furthermore, the valve body 44 closes the internal flow path 48, which forms part of the supply passage 20 (branch passage 22), by being pushed up to a predetermined height within the housing 46 by the shaft member 43 and contacting the valve seat 45. That is, as the liquid level LS rises, the float 42 rises, thereby pushing the valve body 44 up via the shaft member 43, closing the internal flow path 48 of the housing 46, and stopping the supply of liquid FL to the battery unit 112. Here, the height of the liquid level LS that closes the internal flow path 48 by contacting the valve body 44 with the valve seat 45 is a first threshold T1. Furthermore, even if the liquid level LS exceeds the first threshold T1, the contact state between the valve body 44 and the valve seat 45 remains unchanged, thus maintaining the closed state of the internal flow path 48. Alternatively, a first threshold T1 can be set for each battery cell 112 for the second on / off valve 40.

[0087] The liquid level sensor 50 has the function of detecting the liquid level LS of the stored liquid RL. The liquid level sensor 50 can also be provided in two or more battery cells 112. As an example, in this embodiment, the liquid level sensor 50 is provided in at least one first battery cell 112a and at least one second battery cell 112b. Furthermore, as... Figure 4 As shown, the liquid level sensor 50 disposed on the first battery cell 112a shall hereby be appropriately referred to as the first liquid level sensor 50a. Additionally, as... Figure 5As shown, the liquid level sensor 50 installed in the second battery cell 112b will hereafter be appropriately referred to as the second liquid level sensor 50b. The detection results of each liquid level LS detected by each liquid level sensor 50 are sent to the control unit 60.

[0088] As an example, the liquid level sensor 50 in this embodiment is a sensor that is in a conductive state when the liquid level detection section 51 is immersed in the storage liquid RL, and in a non-conductive state when the liquid level detection section 51 is not immersed in the storage liquid RL, thereby detecting the liquid level LS in the battery cell 112. Furthermore, the liquid level sensor 50 can adjust the position of the liquid level detection section 51 in the vertical direction relative to the battery cell 112, thereby adjusting the vertical position (liquid level height) of the detected liquid level LS. For example, by providing multiple liquid level sensors 50 in one battery cell 112, and making the vertical positions of each liquid level detection section 51 different, it is possible to obtain a detailed understanding of the vertical position of the liquid level LS relative to the battery cell 112.

[0089] In addition, such as Figure 4 As shown, the liquid level detection unit 51a of the first liquid level sensor 50a is positioned at a location capable of detecting a liquid level in the first battery cell 112a that is a second threshold T2, where the second threshold is greater than (higher than) the first threshold T1. In this embodiment, as an example, the second threshold T2 is set as an upper limit value for suppressing liquid overflow from the first battery cell 112a. Furthermore, Figure 4 The double-dotted line in the figure represents the third threshold T3 in the second battery cell 112b.

[0090] In addition, such as Figure 5 As shown, the liquid level detection unit 51b of the second liquid level sensor 50b is positioned to detect a liquid level in the second battery cell 112b that is at a third threshold T3, where the third threshold is less than (lower than) the first threshold T1. In this embodiment, as an example, the third threshold T3 is set as a lower limit value for suppressing liquid drying in the second battery cell 112b. Furthermore, Figure 5 The double-dotted line shown represents the second threshold T2 of the first battery cell 112a.

[0091] Here, the first battery cell 112a, which has the most contact surfaces with the metal storage box 114, easily dissipates heat through the storage box. The second battery cell 112b, which has the fewest contact surfaces with the storage box 114, does not contact the storage box 114 compared to the first battery cell 112a, and therefore dissipates less heat through the storage box 114. Consequently, the second battery cell 112b is more prone to high temperatures than the first battery cell 112a, and the storage liquid RL decreases more rapidly. In this way, in the second battery cell 112b, where the storage liquid RL decreases the fastest, the liquid level detection part 51b of the second liquid level sensor 50b is positioned at a position capable of detecting the lower limit value, i.e., the third threshold T3, for suppressing the drying of the liquid in the second battery cell 112b. Thus, when the liquid level is above the third threshold T3, it can be known that the amount of storage liquid RL in the battery cell 112, where the second liquid level sensor 50b is not installed, is approximately above the lower limit value. Furthermore, in the first battery cell 112a, where the storage liquid RL decreases the slowest, or in other words, the storage liquid RL remains the most, thus making it prone to liquid overflow, by placing the liquid level detection part 51a of the first liquid level sensor 50a at a position that can detect the upper limit value for suppressing liquid overflow of the first battery cell 112a, namely the second threshold T2, it is possible to know that liquid is about to overflow when the liquid level is above the second threshold T2.

[0092] Furthermore, a liquid metering unit is provided between the first on / off valve 30 and the branch section of the supply path 20. The liquid metering unit has the function of measuring the pressure and flow rate of the liquid FL. As an example, the liquid metering unit in this embodiment consists of a pressure gauge 31 and a flow meter 32. Specifically, a pressure gauge 31 and a flow meter 32 are respectively provided between the first on / off valve 30 and the branch section of the supply path 20. The pressure gauge 31 sends the pressure of the liquid FL flowing in the supply path 20 to the control unit 60. The flow meter 32 sends the flow rate of the liquid FL flowing in the supply path 20 to the control unit 60.

[0093] In this embodiment, pressure gauge 31 and flow meter 32 are respectively disposed between the first on / off valve 30 and the branch portion of the supply path 20, but this disclosure is not limited to this structure. Flow meter 32 may also be disposed upstream of the first on / off valve 30 in the liquid supply direction in the supply path 20. Additionally, pressure gauge 31 may also be disposed upstream of the first on / off valve 30 in the liquid supply direction in the supply path 20. Furthermore, one of pressure gauge 31 and flow meter 32 may be disposed upstream of the first on / off valve 30 in the liquid supply direction, and the other may be disposed downstream of the first on / off valve 30 in the liquid supply direction. Furthermore, in this embodiment, liquid FL is supplied from the storage unit 14, so the flow rate flowing out of the storage unit 14 can be determined, for example, based on changes in the mass of the storage unit 14 (mass decrease) and changes in the liquid level (liquid level decrease). In this case, flow meter 32 may be omitted.

[0094] like Figure 2 As shown, the control unit 60 is configured to include, for example, a CPU (Central Processing Unit) 61, a ROM (Read Only Memory) 62, a RAM (Random Access Memory) 63, and a storage device 64.

[0095] CPU 61 is a central processing unit that executes various programs or controls different parts. Specifically, CPU 61 reads programs from ROM 62 or storage device 64 and executes programs using RAM 63 as the operating area. CPU 61 performs the control of the first on / off valve 30 and various computational processes according to the programs recorded in ROM 62 or storage device 64. Furthermore, for example, if a liquid pump is used to supply liquid FL from the storage unit 14, CPU 61 controls the liquid pump in the same manner as the first on / off valve 30.

[0096] ROM 62 stores various programs and data. RAM 63 serves as a temporary storage area for programs or data. Storage device 64 is composed of HDD (Hard Disk Drive) or SSD (Solid State Drive) and stores various programs and data, including the operating system.

[0097] The control unit 60 has the function of controlling the actuation (opening and closing action) of the first on / off valve 30. Furthermore, as an example, in this embodiment, the control unit 60 determines the amount of liquid FL supplied to the battery 110 (also called "replenishment amount") based on the charge / discharge history of the battery 110, and keeps the first on / off valve 30 open until the determined supply amount is supplied to the battery 110. Specifically, the charge / discharge history of the battery 110 is stored in the storage device 64. When supplying liquid FL to the battery 110, the control unit 60 reads the charge / discharge history of the battery 110 from the storage device 64 and determines the liquid reduction amount based on the read charge / discharge history. Furthermore, the control unit 60 controls the process in such a way that the determined liquid reduction amount is used as the liquid FL supply amount, and the first on / off valve 30 is open until the determined liquid FL supply amount is supplied to the battery 110. Furthermore, since the residual liquid level in each battery cell 112 differs before the liquid is supplied, if liquid FL is supplied to each battery cell 112 via each branch passage 22, there is a possibility that the liquid level of the storage liquid RL will be above the first threshold T1 before the entire supply amount is supplied. In this case, the second on / off valve 40 of the battery cell 112 where the liquid level of the storage liquid RL is above the first threshold T1 changes from the open state to the closed state, stopping the supply of liquid FL to the target battery cell 112. Liquid FL continues to be supplied to the other battery cells 112 except those where the second on / off valve 40 is closed.

[0098] Furthermore, in this embodiment, as an example, the liquid FL is purified water, and the storage fluid RL is battery fluid. During fluid reduction, the water (purified water component) in the battery fluid evaporates. Therefore, purified water, which is the liquid FL, is supplied to the battery fluid to replenish it.

[0099] Furthermore, as an example, in this embodiment, when the liquid level detected by the liquid level sensor 50 in any battery cell 112 is above the second threshold T2, the control unit 60 changes the first on / off valve 30 from the open state to the closed state, where the second threshold is greater than the first threshold T1. Specifically, the liquid level detection unit 51a of the first liquid level sensor 50a detects the liquid level LS of the stored liquid RL in the first battery cell 112a. If this detection signal is received, the control unit 60 controls the actuation of the first on / off valve 30 by changing it from the open state to the closed state in order to suppress liquid overflow from the first battery cell 112a.

[0100] Furthermore, as an example, in this embodiment, the control unit 60 maintains the first on / off valve 30 in an open state when the liquid level detected by the liquid level sensor 50 in any battery cell 112 is less than a third threshold T3, wherein the third threshold T3 is less than the first threshold T1. Specifically, the liquid level detection unit 51b of the second liquid level sensor 50b detects the liquid level LS of the storage liquid RL stored in the second battery cell 112b. Before receiving this detection signal, the control unit 60 controls the operation of the first on / off valve 30 to maintain the first on / off valve 30 in an open state in order to prevent the liquid in the second battery cell 112b from drying out.

[0101] In addition, as an example, the system 10 of this embodiment has the function of charging the battery 110. Specifically, the system 10 also includes a charging cable 70, which connects the charger 16 and the battery 110. The battery 110 is charged via the charging cable 70.

[0102] Furthermore, as an example, the control unit 60 of this embodiment has the function of controlling the start and stop of charging of the battery 110. Additionally, the control unit 60 can control the charging of the battery 110 and the supply of liquid FL simultaneously, or it can control the supply of liquid FL after charging the battery 110 or before charging. Moreover, from the perspective of battery 110 maintainability, it is preferable to charge the battery 110 and supply liquid FL simultaneously. Here, "charging the battery 110 and supplying liquid FL simultaneously" means that part or all of the liquid supply time overlaps with the charging time.

[0103] Alternatively, liquid FL can be supplied from the storage unit 14 to the battery 110 by positioning the storage unit 14 at a position higher than the battery 110, or an electric liquid pump (not shown) can be provided for supplying liquid FL from the storage unit 14 to the battery 110, and the control unit 60 can control the liquid pump to supply liquid FL from the storage unit 14 to the battery 110.

[0104] Furthermore, the supply path 20, the first on / off valve 30, and the second on / off valve 40 of this embodiment constitute the replenishment device 12. This replenishment device 12 may also include a storage unit 14. Additionally, the replenishment device 12 may include a control unit 60. Moreover, the replenishment device 12 may also include a charger 16 and a charging cable 70.

[0105] Next, refer to Figure 6 The process of supplying liquid to the battery 110 using the system 10 of this embodiment will be described.

[0106] First, in step S200, the control unit 60 calculates the amount of liquid FL supplied to the battery 110 based on the charge and discharge history of the battery 110. Specifically, the control unit 60 calculates the amount of liquid loss in the battery 110 based on the charge and discharge history of the battery 110, and sets this amount of liquid loss as the amount of liquid FL supplied.

[0107] Next, in step S202, in order to supply liquid FL to the battery 110 according to the calculated supply amount of liquid FL, the first on / off valve 30 is turned on. The first on / off valve 30 is turned on, thereby starting the supply of liquid FL.

[0108] Next, in step S204, the control unit 60 determines whether the pressure (liquid pressure) of the liquid FL in the supply path 20 is above or below a predetermined pressure. Specifically, the control unit 60 monitors the measurement data (hereinafter appropriately referred to as "pressure data") received from the pressure gauge 31 and determines whether the pressure of the liquid FL is above or below the predetermined pressure based on the pressure data. If the determination result is that the liquid pressure in the supply path 20 is above the predetermined pressure, the process proceeds to step S206; if the liquid pressure in the supply path 20 is below the predetermined pressure, the process proceeds to step S218.

[0109] Here, for example, if one of the second on / off valves 40 changes from the open state to the closed state, the liquid pressure in the supply path 20 drops by a predetermined value. That is, it is possible to know that the second on / off valve 40 is in the closed state by the change in liquid pressure in the supply path 20 (here, the liquid pressure drops). For example, by pre-setting the pressure drop value when the three second on / off valves 40 are in the closed state to the aforementioned predetermined pressure, it is possible to know that the three second on / off valves 40 have changed from the open state to the closed state when the liquid pressure in the supply path 20 is less than the predetermined pressure. Furthermore, step S218 is a step for changing the first on / off valve 30 from the open state to the closed state, and details will be explained below. That is, this step S204 is a determination step, used to end the liquid supply from the perspective of suppressing excessive supply of liquid FL if multiple second on / off valves 40 reach the closed state before the supply amount calculated by the control unit 60 is finished.

[0110] Next, in step S206, the control unit 60 determines whether the liquid level is less than or greater than the second threshold T2. Specifically, the control unit 60 monitors the detection data received from the first liquid level sensor 50a and determines whether the liquid level of the first battery cell 112a equipped with the first liquid level sensor 50a is less than or greater than the second threshold T2 based on the detection data. If the determination result is that the liquid level is less than the second threshold T2, the process proceeds to step S208; if the liquid level is greater than or greater than the second threshold T2, the process proceeds to step S218. That is, this step S206 is a determination step, used to, in the liquid supply process, before the supply amount calculated by the control unit 60 ends, if the liquid level of the first battery cell 112a equipped with the first liquid level sensor 50a reaches the upper limit value of liquid overflow, i.e., the second threshold T2 or greater, then, from the perspective of suppressing liquid overflow caused by excessive supply of liquid FL, the liquid supply is terminated.

[0111] Next, in step S208, the control unit 60 determines whether the calculated supply quantity is met. Specifically, the control unit 60 monitors the metering data (hereinafter, appropriately referred to as "flow data") received from the flow meter 32 and determines whether the amount of liquid FL supplied meets the calculated supply quantity based on the flow data. If the determination result is that the amount of liquid FL supplied meets the calculated supply quantity, the process proceeds to step S218; if the amount of liquid FL supplied does not meet the calculated supply quantity, the process returns (procesuses) to step S204.

[0112] Next, in step S210, the control unit 60 determines whether the liquid level is above or below the third threshold T3. Specifically, the control unit 60 monitors the detection data received from the second liquid level sensor 50b and determines whether the liquid level of the second battery cell 112b equipped with the second liquid level sensor 50b is above or below the third threshold T3 based on the detection data. If the determination result is that the liquid level is above the third threshold T3, the process proceeds to step S218; if the liquid level is below the third threshold T3, the process proceeds to step S212. That is, this step S210 is a determination step, used in liquid supply, after the supply amount calculated by the control unit 60 has been supplied, if the liquid level of the second battery cell 112b equipped with the second liquid level sensor 50b is below the lower limit of liquid drying, i.e., the third threshold T3, then, from the perspective of suppressing liquid drying in each battery cell 112, it determines whether to continue liquid supply.

[0113] Next, in step S212, the control unit 60 maintains the first on / off valve 30 in the open state. Thus, liquid continues to be supplied to each battery cell 112.

[0114] Next, in step S214, similar to step S204, the control unit 60 determines whether the liquid pressure in the supply path 20 is above or below a predetermined pressure. If the determination result is that the liquid pressure in the supply path 20 is above the predetermined pressure, the process proceeds to step S216; if the liquid pressure in the supply path 20 is below the predetermined pressure, the process proceeds to step S218. This step S214 is a determination step, used to terminate the continued liquid supply when, after the supply amount calculated by the control unit 60 has been supplied, for example, if multiple second on / off valves 40 are in the closed state, considering the need to suppress excessive supply of liquid FL.

[0115] Next, in step S216, similar to step S206, the control unit 60 determines whether the liquid level is less than or greater than the second threshold T2. If the determination result is that the liquid level is less than the second threshold T2, it returns to step S212; if the liquid level is greater than or greater than the second threshold T2, it proceeds to step S218. This step S216 is a determination step, used when, after the supply amount calculated by the control unit 60 has been supplied, if the liquid level of the first battery cell 112a equipped with the first liquid level sensor 50a reaches the upper limit of liquid overflow, i.e., the second threshold T2 or greater, then, from the perspective of suppressing liquid overflow caused by excessive supply of liquid FL, the liquid supply is terminated.

[0116] In step S218, the control unit 60 changes the first on-off valve 30 from the open state to the closed state. Specifically, the control unit 60 controls the first on-off valve 30 to change from the open state to the closed state. If the first on-off valve 30 becomes closed, the liquid supply ends.

[0117] As described above, if the system 10 of this embodiment supplies liquid to the battery 110, the maintainability of the battery 110 is improved.

[0118] Next, the maintenance method for the battery 110 of this embodiment will be described. Furthermore, in this embodiment, the system 10 described above is used as an example.

[0119] In the battery 110 maintenance method of this embodiment, charging the battery 110 and supplying liquid to the battery 110 (the aforementioned liquid supply) are performed simultaneously. Specifically, as follows... Figure 7 As shown, the control unit 60 controls the battery 110 by overlapping the time for supplying liquid to the battery 110 with the time for charging the battery 110. Here, by performing charging and liquid supply to the battery 110 simultaneously, the time spent on charging and liquid supply to the battery 110 can be shortened compared to performing charging and liquid supply separately, thus improving the maintainability of the battery 110.

[0120] Furthermore, in the battery 110 maintenance method of this embodiment, it is preferable to start supplying liquid FL from the beginning of charging the battery 110 until the end of charging. By supplying liquid to the battery 110 from the start of charging until the end of charging, the time spent charging and supplying liquid to the battery 110 can be further shortened. Therefore, the maintainability of the battery 110 is further improved.

[0121] Furthermore, in the battery 110 maintenance method of this embodiment, it is preferable to stop the liquid supply before the voltage of the battery 110 reaches a predetermined voltage t after charging of the battery 110 has begun. For example, when the predetermined voltage t is set to a voltage lower than the voltage at which gas evolution occurs, stopping the liquid supply before the voltage of the battery 110 reaches the predetermined voltage t can suppress the impact of gas evolution on the liquid supply. In addition, it is preferable to set the predetermined voltage t to, for example, 2.5V, more preferably 2.4V, and even more preferably 2.3V.

[0122] The charging current can be a constant current, ranging from 0.05C to 0.5C. Here, 1C represents the current value required to transition from a fully charged state to a fully discharged state within one hour. A current value below 0.5C reduces battery heat generation, ensuring sufficient charge. Conversely, a current value above 0.05C allows for faster charging.

[0123] In addition, the charging current can be quasi-constant voltage charging, and the inrush current value can be 0.05C~0.5C. Quasi-constant voltage charging limits the current value according to the battery voltage, thus suppressing battery heating when charging at high current values.

[0124] As described above, when the battery 110 is charged and supplied with liquid using the system 10 of this embodiment, the maintainability of the battery 110 is improved.

[0125] Next, the effects of this implementation method will be explained.

[0126] In the system 10 of this embodiment, liquid FL is supplied to the battery 110 via the supply path 20 by opening both the first on / off valve 30 and the second on / off valve 40. Here, in the system 10, even if the second on / off valve 40 malfunctions while liquid is being supplied to the battery 110, the supply of liquid to the battery 110 can be stopped by closing the first on / off valve 30, which is located upstream of the second on / off valve 40 in the liquid supply direction. This suppresses the excessive supply of liquid FL to the battery 110. In this way, by suppressing the excessive supply of liquid FL to the battery 110, the increased maintenance frequency of the battery 110 due to liquid overflow is suppressed, and the maintainability of the battery 110 is improved.

[0127] In particular, in the system 10 of this embodiment, the supply path 20 branches into multiple branch paths 22. Therefore, the amount of liquid FL supplied to each battery cell 112 varies due to the distance between each branch path 22. However, since a second on / off valve 40 is provided in each of the multiple branch paths 22, if the liquid supply to any one battery cell 112 becomes excessive, the second on / off valve 40 corresponding to the battery cell 112 that is experiencing excessive supply is closed, and the liquid supply to the battery cell 112 is stopped. In this way, in the system 10, compared to the case where the second on / off valve 40 is provided upstream of the branch portion of the supply path 20 in the liquid supply direction, it is possible to suppress the excessive supply of liquid FL to each battery cell 112 constituting the battery 110.

[0128] Furthermore, in the system 10 of this embodiment, the drive (opening and closing action) of the first opening and closing valve 30 is controlled by the control unit 60. Therefore, in the system 10, the workload of the operator can be reduced compared to the case where the operator manually performs the drive operation of the first opening and closing valve 30.

[0129] Furthermore, in the system 10 of this embodiment, the control unit 60 determines the amount of liquid FL supplied to the battery 110 based on the charge and discharge history of the battery 110. The control unit 60 keeps the first on / off valve 30 open until the determined supply amount is supplied to the battery 110. Therefore, in the system 10, compared to the case where a fixed amount of liquid FL is not always supplied to the battery 110 based on its charge and discharge history, the system 10 can efficiently supply any insufficient amount of liquid FL to the battery 110.

[0130] Furthermore, in system 10 of this embodiment, when supplying liquid to battery 110, the second on / off valve 40 is in the open state until the liquid level of the stored liquid RL stored in at least one battery cell 112 reaches a first threshold T1. If the liquid level is above the first threshold T1, the second on / off valve 40 changes from the open state to the closed state, stopping the supply of liquid to battery 110. Specifically, when supplying liquid to battery 110, if the liquid level of each battery cell 112 is less than the first threshold T1, each second on / off valve 40 corresponding to each battery cell 112 is in the open state. If the liquid level of each battery cell 112 is above the first threshold T1, each second on / off valve 40 corresponding to each battery cell 112 changes from the open state to the closed state, stopping the supply of liquid FL to each battery cell 112. Here, in system 10, by setting the liquid level that can suppress the excessive supply of liquid FL to battery 110 to the first threshold T1, it is possible to further suppress the increase in maintenance frequency due to liquid overflow.

[0131] Furthermore, in system 10 of this embodiment, such as Figure 4 As shown, when the height of the liquid level LS detected by the liquid level detection unit 51a of the first liquid level sensor 50a located in the first battery cell 112a, where the liquid level decreases relatively slowly, is above the second threshold T2, the control unit 60 closes the first on / off valve 30 from the open state. The second threshold is greater than the first threshold T1. Here, in the system 10, when the upper limit for suppressing liquid overflow from the first battery cell 112a is set to the second threshold T2, for example, even if the second on / off valve 40 malfunctions, if the liquid level is above the second threshold T2, the control unit 60 will close the first on / off valve 30. Therefore, liquid overflow (e.g., liquid overflow from the first battery cell 112a) caused by excessive supply of liquid FL to the battery 110 can be effectively suppressed.

[0132] Furthermore, in the system 10 of this embodiment, a first liquid level sensor 50a is provided in the first battery cell 112a, and a second liquid level sensor 50b is provided in the second battery cell 112b. Here, compared to the first battery cell 112a, which has the fewest contact surfaces with the metal storage box 114, the second battery cell 112b has the most contact surfaces with the storage box 114, making it difficult or impossible to dissipate heat through the storage box 114, and thus easily leading to high temperatures. Therefore, the storage liquid RL in the second battery cell 112b decreases faster than in the first battery cell 112a. Therefore, by providing the second liquid level sensor 50b in the second battery cell 112b where the storage liquid RL decreases faster, and the first liquid level sensor 50a in the first battery cell 112a where the storage liquid RL decreases slower, liquid supply can be adjusted according to the degree of decrease in the storage liquid RL of the second battery cell 112b, and liquid supply can be stopped according to the degree of overflow of the storage liquid RL of the first battery cell 112a.

[0133] Furthermore, in system 10 of this embodiment, such as Figure 5 As shown, when the height of the liquid level LS detected by the second liquid level sensor 50b of the second battery cell 112b, which is located in the storage liquid RL and decreases rapidly, is less than the third threshold T3, the control unit 60 opens the first on / off valve 30. The third threshold T3 is less than the first threshold T1. Here, in the system 10, when the lower limit for suppressing the drying of the liquid in the second battery cell 112b is set to the third threshold T3, if the supply of liquid FL is insufficient and the liquid level does not reach the third threshold T3, the control unit 60 maintains the first on / off valve 30 in the open state, thus suppressing the drying of the liquid in the second battery cell 112b.

[0134] Furthermore, in the system 10 of this embodiment, when the valve body 44, which moves in conjunction with the float 42, contacts the valve seat 45 and closes the internal flow path 48 when the liquid level is above the first threshold T1. In this way, compared to the case where the second on / off valve 40 uses an electrically driven valve body 44, the increase in control-related costs of the second on / off valve 40 can be suppressed.

[0135] Furthermore, in the system 10 of this embodiment, the control unit 60 controls the charger 16 to start and stop charging the battery 110. Therefore, in the system 10, compared to the case where an operator performs the charging operation, which includes starting and stopping charging the battery 110, the workload of the operator can be reduced.

[0136] Furthermore, in the system 10 of this embodiment, when charging the battery 110 and supplying liquid to the battery 110 are performed simultaneously by the control unit 60, the time spent charging the battery 110 and supplying liquid can be shortened compared to charging the battery 110 and supplying liquid separately.

[0137] Depending on factors such as the state and type of the battery 110, it is sometimes preferable to supply liquid to the battery 110 after charging or before charging. Therefore, in the system 10 of this embodiment, when the control unit 60 supplies liquid to the battery 110 after charging or before charging, the supply of liquid to the battery 110 after charging or before charging is determined according to the conditions of the battery 110, thereby extending the lifespan of the battery 110.

[0138] In the supplementary device 12 of this embodiment, liquid FL is supplied to the battery 110 via the supply path 20 by opening both the first on / off valve 30 and the second on / off valve 40. Here, in the supplementary device 12, even if the second on / off valve 40 malfunctions while supplying liquid to the battery 110, the supply of liquid to the battery 110 can be stopped by changing the first on / off valve 30, which is located upstream of the second on / off valve 40 in the liquid supply direction, from the open state to the closed state. This suppresses the oversupply of liquid FL to the battery 110. In this way, by suppressing the oversupply of liquid FL to the battery 110, the increased maintenance frequency due to liquid overflow is suppressed, and the maintainability of the battery 110 is improved.

[0139] Furthermore, in the supplementary device 12 of this embodiment, since a storage section 14 for storing liquid FL is provided, maintenance time can be shortened, for example, by storing liquid FL that has undergone predetermined treatment in the storage section 14 in advance.

[0140] Furthermore, the control unit 60 of this embodiment can be housed within the charger 16, installed in the battery 110, installed in a mobile body carrying the battery 110, or located in other locations. Additionally, the control unit 60 can also possess the functions of a battery management system.

[0141] Furthermore, in this embodiment, the system 10 charges or supplies liquid to the battery 110 by the user performing an operation to execute a maintenance mode set in the control unit 60. Here, the maintenance mode may include a mode that performs both charging and liquid supply to the battery 110 simultaneously, and a mode that performs only one of these operations. Additionally, in the system 10, the control unit 60 may monitor conditions such as a predetermined time elapsed since the last maintenance, the voltage of the battery 110 being less than a predetermined voltage, and the liquid level in the second battery cell 112b being less than a third threshold T3. If any one or a combination of these conditions is met, the maintenance mode is automatically executed, and the user may be notified (including via the Internet).

[0142] (Other implementation methods) Additionally, the system 10 described above may also include a catalyst unit 80, which reduces the gas generated by electrolyzing the storage liquid RL (for example, battery fluid) back to the liquid FL (for example, purified water). For example, the catalyst unit 80 may also be connected to a second on / off valve 40. Specifically, as... Figure 8 As shown, the housing 81 of the catalyst section 80 is connected to the housing 46 of the second on / off valve 40. Inside the housing 81 are a catalyst 82, a catalyst container 83 for housing the catalyst 82, and a splash guard 84. The catalyst 82 has the function of reacting hydrogen and oxygen to produce water. The catalyst 82 includes a transition metal or a transition metal oxide. Alternatively, the catalyst 82 may also contain, for example, noble metals such as Pd, Pt, and Ag, or base metals such as Fe, Co, and Mn. Here, in the system 10 equipped with the catalyst section 80, the catalyst section 80 reduces the gas generated by the electrolysis of the storage liquid RL and returns it to the liquid FL. Therefore, in the system 10, compared to the case without the catalyst section 80, the rate of decrease of the storage liquid RL can be slowed down. Furthermore, since the catalyst section 80 is connected to the second on / off valve 40, the structure of the battery unit 112 can be simplified compared to the case where the catalyst section 80 is located at a different location in the battery unit 112 than the second on / off valve 40. Furthermore, this disclosure is not limited to the above-described structure; the catalyst section 80 and the second on / off valve 40 may also be mounted on the top of the battery unit 112. In this case, since the second on / off valve 40 and the catalyst section 80 can be disassembled separately, parts replacement and maintenance are easier. Furthermore, in Figure 8 The example shown illustrates a method in which a second on / off valve 40 having a catalyst section 80 is provided in the first battery cell 112a, but it is not limited to this.

[0143] In addition, such as Figure 9As shown, the system 10 of the above embodiment may also include a connector mechanism 90 between the branch portion of the supply path 20 and the first on / off valve 30. This connector mechanism 90 is detachably connected to the supply path 20. Specifically, the connector mechanism 90 includes a male component 96 and a female component 94, which are mechanically connected by connecting the male component 96 and the female component 94. Here, the connector mechanism 90 detachably connects the branch portion of the supply path 20 to the first on / off valve 30, thus reducing the number of connection and disconnection points compared to the case where the connector mechanism 90 is located downstream of the branch portion of the supply path 20 in the liquid supply direction, making it easier to connect the supply path 20. That is, it reduces the workload of the operator. Additionally, the charging cable 70 may also have a connector mechanism 72. The connector mechanism 72 includes a male component 74 and a female component 76, which are electrically connected by connecting the male component 74 and the female component 76. Here, the battery 110 can be removed by disassembling the connector mechanism 90 and the connector mechanism 72. In this way, by using system 10, it is possible to replace battery 110 and supply water and charge new battery 110.

[0144] Furthermore, in the system 10 of the above embodiment, as an example, the battery cells 112 of the battery 110 are arranged in a matrix of 4 rows and 4 columns, but this disclosure is not limited to this. For example, it may also be arranged as follows: Figure 10 As shown, the battery cells 112 of the battery 110 are arranged in a matrix of 2 rows and 6 columns. In the same manner as in the above embodiment, the battery cell with the most contact surfaces with the storage box 124 is designated as the first battery cell 112a, and the battery cell with the fewest contact surfaces with the storage box 124 is designated as the second battery cell 112b. Furthermore, at least one first liquid level sensor 50a is provided in the first battery cell 112a, and at least one second liquid level sensor 50b is provided in the second battery cell 112b, thereby achieving the same effect as the system 10 in the above embodiment. Moreover, the n-row, m-column (n and m are positive integers) matrix arrangement of the multiple battery cells 112 can be set according to the device being used. Alternatively, the multiple battery cells 112 can also be arranged irregularly.

[0145] Furthermore, in the system 10 of the above embodiment, a first liquid level sensor 50a is provided in at least one of the first battery cells 112a, and a second liquid level sensor 50b is provided in at least one of the second battery cells 112b. In addition, as... Figure 11 As shown, the battery unit 112, whose contact surface with the storage box 114 is between the first battery unit 112a and the second battery unit 112b, can also be referred to as the third battery unit 112c. Furthermore, as... Figure 12As shown, a third liquid level sensor 50c can also be provided in the third battery cell 112c. Preferably, the third liquid level sensor 50c is set to the optimal liquid level height for each battery cell 112, i.e., the fourth threshold T4, within the range between the first threshold T1 and the third threshold T3, that is, within the range below the first threshold T1 and above the third threshold T3. In addition, the liquid level height of the fourth threshold T4 can also be the same as the first threshold T1. Furthermore, the third battery cell 112c is a battery cell 112 with intermediate properties between the first battery cell 112a, which is prone to liquid overflow, and the second battery cell 112b, which is prone to liquid drying. Therefore, when the third battery cell 112c is set to the optimal liquid level height, i.e., the fourth threshold T4, if liquid continues to be supplied after the calculated liquid has been supplied, the control unit 60 maintains the first on / off valve 30 in the open state until the liquid supply reaches the fourth threshold T4. This can suppress liquid overflow caused by excessive liquid supply to the battery 110, and at the same time, liquid supply can be maintained until the optimal value is reached.

[0146] Furthermore, in the system 10 of the above embodiment, a liquid level sensor is used to detect the liquid level LS by immersing the liquid level detection section in the liquid; however, this disclosure is not limited to this structure. For example, a non-contact liquid level sensor can also be used to detect the vertical movement of the liquid level LS in detail. In this case, non-contact liquid level sensors can be provided in all battery cells 112, or liquid level sensors can be provided in at least one of the first battery cell 112a and at least one of the second battery cell 112b.

[0147] Furthermore, in the system 10 of the above embodiment, a battery cell 112 is specified to be equipped with a first liquid level sensor 50a and a second liquid level sensor 50b, but this disclosure is not limited to this structure. For example, the first liquid level sensor 50a and the second liquid level sensor 50b may be provided in all battery cells 112. Alternatively, a third liquid level sensor 50c may be provided in all battery cells 112.

[0148] The embodiments of this disclosure have been described above with reference to the accompanying drawings. However, those skilled in the art will obviously conceive of various modifications or applications within the scope of the technical concept set forth in the claims, and these naturally also fall within the technical scope of this disclosure. For example... Figure 13 The diagram shows a forklift 200 equipped with battery 110 as an example of a moving object. Figure 13As shown, the forklift 200 is equipped with a battery 110. The forklift 200 is driven by power supplied from the battery. The battery 110 is composed of multiple battery cells 112. For example, the lead-acid battery for forklifts equipped in the forklift 200 experiences electrolyte loss due to the working conditions of the forklift. Sometimes, batteries that are repeatedly charged / discharged while connected to a load are referred to as rechargeable batteries. Rechargeable lead-acid batteries can also be lead-acid batteries whose rated capacity and depth of discharge (DOD) are, for example, within the range of 1% to 99%. In lead-acid batteries used in forklifts, if the forklift has been used to a certain extent, a state may occur where the electrolyte decreases and the remaining capacity also decreases. In such a state, the lead-acid battery can be removed from the forklift, and water can be added and recharged simultaneously by the battery maintenance system 10 of this embodiment, thus enabling the forklift to operate efficiently. The battery maintenance system 10 may also be equipped with a connector mechanism that facilitates the connection and disconnection of the charging cable and the liquid supply path for supplying fluid to the battery. A connector mechanism 72 may also be provided on the charging cable 70, and a connector mechanism 90 may be provided on the liquid supply path for supplying fluid to the battery. The battery maintenance system 10 of this embodiment is particularly effective for recycle lead-acid batteries used in mobile vehicles such as forklifts 200.

[0149] Explanation of reference numerals in the attached figures 10: Battery maintenance system; 12: Replenishment device; 14: Storage unit; 16: Charger; 20: Supply path; 22: Branch path; 30: First on / off valve; 32: Supply metering unit; 40: Second on / off valve; 42: Float; 43: Shaft assembly; 44: Valve body; 45: Valve seat; 46: Housing; 47: Guide hole; 50: Liquid level sensor; 50A: First liquid level sensor; 50B: Second liquid level sensor; 60: Control unit; 64: Storage device; 70: Charging cable; 72: Connector mechanism; 74: Anode component; 76: Cowherd component; 80: Catalyst section; 81: Shell; 82: Catalyst; 83: Catalyst container; 84: Splash guard; 90: Connector mechanism; 94: Cathode component; 96: Anode component; 110: Battery; 112: Battery cell; 112a: First battery cell; 112b: Second battery cell; 114: Storage box; 120: Battery; 124: Storage box; 200: Forklift; RL: Storage fluid; FL: Liquid; LS: Liquid level; SD: Liquid supply direction; T1: First threshold; T2: Second threshold; T3: Third threshold; T4: Fourth threshold.

Claims

1. A battery maintenance system, comprising: The supply path supplies liquid to the battery; A first on / off valve is disposed on the supply line; and A second on / off valve is disposed on the supply line downstream of the first on / off valve in the direction of liquid supply.

2. The battery maintenance system according to claim 1, wherein, The first on / off valve is an electrically driven valve. The battery maintenance system also includes a control unit that controls the actuation of the first on / off valve.

3. The battery maintenance system according to claim 2, wherein, The battery maintenance system also includes a charging cable that connects the charger to the battery. The control unit controls the start and stop of charging the battery.

4. The battery maintenance system according to claim 3, wherein, The control unit simultaneously charges the battery and supplies the liquid.

5. The battery maintenance system according to claim 3, wherein, The control unit supplies the liquid before or after charging the battery.

6. The battery maintenance system according to claim 2, wherein, The control unit determines the amount of liquid to be supplied to the battery based on the battery's charging and discharging history, and opens the first on / off valve until the determined amount of liquid is supplied to the battery.

7. The battery maintenance system according to claim 6, wherein, The battery is composed of multiple battery cells. The second on / off valve is in an open state when the liquid level of the storage liquid stored in at least one of the battery cells is less than a first threshold, and in a closed state when the liquid level of the storage liquid stored in at least one of the battery cells is above the first threshold.

8. The battery maintenance system according to claim 7, wherein, The battery maintenance system also includes a liquid level sensor for detecting the level of the stored liquid. When the height of the liquid level detected by the liquid level sensor is above a second threshold, the control unit closes the first on / off valve, where the second threshold is greater than the first threshold.

9. The battery maintenance system according to claim 7, wherein, The battery maintenance system also includes a liquid level sensor for detecting the level of the stored liquid. When the height of the liquid level detected by the liquid level sensor is less than a third threshold, the control unit maintains the first on / off valve in an open state, wherein the third threshold is less than the first threshold.

10. The battery maintenance system according to claim 9, wherein, When the height of the liquid level detected by the liquid level sensor is below a fourth threshold, the control unit maintains the first on / off valve in an open state, wherein the fourth threshold is set between the first threshold and the third threshold.

11. The battery maintenance system according to claim 6, wherein, The battery is composed of multiple battery cells. The supply path branches into multiple lines midway to supply the liquid to each of the battery cells. The first on / off valve is located upstream of the branch portion of the supply path in the supply direction. The second on / off valve is respectively disposed in multiple branch passages, and the multiple branch passages constitute the portion of the supply path that is downstream of the branch portion in the supply direction.

12. The battery maintenance system according to claim 11, wherein, Each of the second on / off valves is in an open state when the liquid level of the storage liquid in each of the battery cells is less than a first threshold, and in a closed state when the liquid level of the storage liquid in each of the battery cells is above the first threshold.

13. The battery maintenance system according to claim 12, wherein, The battery maintenance system also includes a liquid level sensor for detecting the level of the stored liquid. The liquid level sensor is disposed in two or more of the battery cells. When the height of the liquid level detected by at least one of the liquid level sensors is greater than a second threshold, the control unit closes the first on / off valve, where the second threshold is greater than the first threshold.

14. The battery maintenance system according to claim 13, wherein, The multiple battery cells are arranged side by side in a metal storage box. The liquid level sensors are respectively disposed in the first battery unit, which has the most contact surfaces with the storage box, and the second battery unit, which has the fewest contact surfaces with the storage box.

15. The battery maintenance system according to claim 14, wherein, When the control unit detects that the liquid level, as determined by the liquid level sensor located in the second battery unit, is less than a third threshold, it opens the first on / off valve. The third threshold is less than the first threshold. If the height of the liquid level detected by the liquid level sensor installed in the first battery cell is above a second threshold, the first on / off valve is closed, where the second threshold is greater than the first threshold.

16. The battery maintenance system according to claim 7 or 12, wherein, The second on / off valve includes: A float that floats in the liquid; and The valve body moves in conjunction with the float and, when the liquid level is above a first threshold, contacts the valve seat to close the internal flow path.

17. The battery maintenance system according to claim 7 or 12, wherein, The battery maintenance system also includes a catalyst unit that reduces the gas generated by electrolysis of the storage liquid back into the liquid.

18. The battery maintenance system according to claim 17, wherein, The catalyst section is connected to the second on / off valve.

19. The battery maintenance system according to claim 11, wherein, The branch portion of the supply path is detachably connected to the first on / off valve via a joint mechanism.

20. A battery maintenance method, The battery maintenance method involves charging the battery and supplying liquid simultaneously.

21. The battery maintenance method according to claim 20, wherein, During the period from the start of charging the battery to the end of charging, the liquid is supplied from the start to the end of the supply.

22. The battery maintenance method according to claim 21, wherein, The supply of liquid is stopped before the battery voltage reaches a predetermined voltage.

23. A supplementary device comprising: The supply path supplies liquid to the battery; A first on / off valve is disposed on the supply line; and A second on / off valve is disposed on the supply line downstream of the first on / off valve in the direction of liquid supply.

24. The supplementary device according to claim 23, wherein, The first on / off valve is an electrically driven valve. The supplementary device also includes a control unit for controlling the actuation of the first on / off valve.

25. The supplementary device according to claim 24, wherein, The supplementary device also includes: Charger; and A charging cable that connects the charger to the battery. The control unit controls the start and stop of charging the battery.

26. The supplementary device according to any one of claims 23 to 25, wherein, The replenishment device also includes a storage section, which is located upstream of the first on / off valve in the direction of liquid supply on the supply line, and the storage section is used to store the liquid.

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