Method and equipment for monitoring height of pole of valve regulated lead-acid storage battery

Abstract

The invention discloses a method and equipment for monitoring the height of a pole of a valve-regulated lead-acid storage battery, and relates to the field of lead-acid storage battery monitoring, 1 mm interval scales are carved on a shell of the pole, numbers are marked every 5 mm, and green, yellow and red are sequentially coated, and correspond to the normal range of 0-12 mm, the normal range of 12-20 mm and the abnormal range of more than or equal to 20 mm. The pole is in sliding fit with the sheath through the sealing rubber ring, and the exposed color area and the scales indicate the state in real time after rising. Green continues to run, yellow strengthens monitoring, red is replaced immediately, and tools are not needed. Scales can be etched or printed by laser, an initial value is recorded during on-site installation, annual charge-discharge test retest is carried out, a rising trend is tracked, and faults are predicted. Compared with one-by-one ruler measurement, the device is simple in structure, visual in reading, one-time in implementation and lifelong in use, and operation and maintenance efficiency and system safety are remarkably improved.

Description

Technical Field

[0001] This invention relates to the field of lead-acid battery monitoring, specifically to a method and device for monitoring the height of valve-regulated lead-acid battery terminals. Background Technology

[0002] The statements in this section are provided only as background information in connection with this disclosure and may not constitute prior art.

[0003] Valve-regulated lead-acid batteries are widely used in power plants, substations and other places because of their stable performance and safety. They are called maintenance-free batteries because they do not require the addition of acid or water during use. However, during long-term operation, valve-regulated lead-acid batteries may generate irreversible lead sulfate inside due to plate sulfation, plate corrosion, thermal runaway, water loss, and improper maintenance. After long-term accumulation, the plate volume gradually increases. Since the bottom of the plate is supported by the bracket, it can only grow upward or to the periphery.

[0004] Therefore, valve-regulated lead-acid batteries are manufactured with this factor in mind. The terminals and sheaths are designed to slide, and a certain amount of upward space is provided for the terminals. While ensuring a tight seal to prevent electrolyte leakage, the valve-regulated lead-acid battery terminals can slide upwards through the sealing rubber ring, resulting in a higher terminal height. This increased terminal height is permissible within a certain range. As long as the battery's internal resistance, voltage, capacity, and other indicators are normal, and there are no leaks, gas leaks, or damage, it can be used normally.

[0005] However, based on actual operation of valve-regulated lead-acid batteries, after approximately 10 years of operation, some individual batteries in the entire battery pack will exhibit an increase in the height of their positive and negative terminals, especially the positive terminal. When the terminal height increases excessively, the cover around the battery terminals may bulge, crack, or break, leading to a decrease in battery capacity and even short circuits in the positive and negative busbars. Therefore, when valve-regulated lead-acid batteries have been used for an extended period, the terminal height must be monitored regularly. Generally, the terminal height of new valve-regulated lead-acid batteries is 8 to 15 mm at the factory, with an allowable increase of no more than 20 mm. Different brands of valve-regulated lead-acid batteries may have different height requirements. Because the positive and negative terminals of valve-regulated lead-acid batteries are not marked with graduations at the factory, the terminals are usually the same color, and there are many batteries in the whole group, the current approach is to first visually judge whether the battery terminals are too high, and then use a ruler to measure and record the height of the terminals. The height of the valve-regulated lead-acid battery terminals will be measured and tracked regularly.

[0006] Currently, using a ruler to measure the height of valve-regulated lead-acid (VRA) battery terminals has many drawbacks. Due to the large number of VRA batteries installed, each terminal must be manually measured one by one with a ruler, which is not only time-consuming and labor-intensive but also drastically increases the workload of operators, resulting in extremely low efficiency. Furthermore, the accuracy of this method is difficult to guarantee. The ruler itself has limited precision, and the reading errors inherent in manual operation lead to inaccurate measurement results. Moreover, when judging terminal height visually, factors such as distraction and fatigue can easily cause individuals to overlook abnormally high terminals. If these elevated terminals are not detected in time, leakage problems may occur during subsequent use of the VRA batteries, or the battery capacity may decrease, or even short circuits may occur in the positive and negative busbars, severely impacting the stable operation of the entire power system and causing unpredictable safety hazards and economic losses. Summary of the Invention

[0007] The purpose of this invention is to address the problems existing in the prior art by providing a method and device for monitoring the height of valve-regulated lead-acid battery terminals. This method involves marking scales and values ​​on the battery terminal casing and using three different colors to distinguish between normal, caution, and abnormal terminal height states, thereby achieving the purpose of monitoring the height of valve-regulated lead-acid battery terminals.

[0008] The technical solution of the present invention is as follows: A method for monitoring the terminal height of a valve-regulated lead-acid battery includes: A scale is set on the outer casing of the terminal of the valve-regulated lead-acid battery, and the smallest unit of the scale is 1 mm; A scale value is set on the outer shell of the pole at 5 mm intervals; Based on the actual allowable height range of the terminals in valve-regulated lead-acid batteries, the terminal casing is divided into: Normal range, corresponding to the first color; Note the area; it corresponds to the second color. The abnormal range corresponds to the third color. When the pole slides upward due to changes in its internal volume, the inspection personnel determine the pole's height status and read the corresponding scale value by observing the exposed color and scale value.

[0009] Furthermore, the normal range is 0–12 mm, the attention range is 12–20 mm, and the abnormal range is 20 mm and above.

[0010] The first color is green, the second color is yellow, and the third color is red.

[0011] Furthermore, the scale and scale values ​​are formed on the electrode housing by etching or printing.

[0012] Furthermore, it also includes: recording the initial terminal height value after the battery is installed, and recording the terminal height value again during annual charge-discharge tests or maintenance to track the terminal height increase trend.

[0013] Furthermore, when the terminal height enters the warning range, strengthen battery status monitoring; when it enters the abnormal range, replace the battery in a timely manner.

[0014] This invention also proposes a valve-regulated lead-acid battery terminal height monitoring device for implementing the above-mentioned valve-regulated lead-acid battery terminal height monitoring method, comprising: Terminals, sheaths, and battery casing; The outer shell of the pole post is provided with scales, scale values, and three color areas; The sheath is installed inside the battery casing and sleeved over the terminals. A sliding seal is achieved between the sheath and the terminals through a sealing rubber ring. The terminals can slide up and down relative to the sheath, while the sheath remains fixed relative to the battery casing. When the pole slides upwards, the exposed scale, scale values, and color areas are used to indicate the pole's height status.

[0015] Furthermore, the starting point of the scale on the outer shell of the terminal post is flush with the upper edge of the battery sheath, and the initial terminal post height is set to 0 mm.

[0016] Furthermore, the three color zones are continuously arranged along the pole axis, corresponding to the normal, warning, and abnormal height ranges, respectively.

[0017] Furthermore, the sealing rubber allows the terminal post to slide upwards while preventing leakage of battery electrolyte.

[0018] Compared with existing technologies, the advantages of this invention are: A method for monitoring the height of valve-regulated lead-acid battery terminals includes: setting a scale on the outer casing of the valve-regulated lead-acid battery terminals, with the smallest unit of the scale being 1 mm; setting a scale value on the outer casing of the terminals at 5 mm intervals; dividing the outer casing of the terminals into three categories based on the actual allowable terminal height range of the valve-regulated lead-acid battery: normal range (corresponding to a first color); warning range (corresponding to a second color); and abnormal range (corresponding to a third color); when the terminal slides upward due to internal volume changes, the inspection personnel determine the terminal height status and read the corresponding scale value by using the exposed color and scale value. This invention achieves accurate monitoring of terminal height by setting a scale and values ​​on the outer casing of the valve-regulated lead-acid battery terminals. Specifically, by setting three colors on the outer casing of the valve-regulated lead-acid battery terminals, the three terminal height statuses of normal, warning, and abnormal can be accurately identified, facilitating later maintenance. Attached Figure Description

[0019] Figure 1 This is a schematic diagram of a valve-regulated lead-acid battery terminal height monitoring method. Detailed Implementation

[0020] It should be noted that relational terms such as "first" and "second" are used merely to distinguish one entity or operation from another, and do not necessarily require or imply any such actual relationship or order between these entities or operations. Furthermore, the terms "comprising," "including," or any other variations thereof are intended to cover non-exclusive inclusion, such that a process, method, article, or apparatus that comprises a list of elements includes not only those elements but also other elements not expressly listed, or elements inherent to such a process, method, article, or apparatus. Without further limitations, an element defined by the phrase "comprising one..." does not exclude the presence of other identical elements in the process, method, article, or apparatus that includes said element.

[0021] The features and performance of the present invention will be further described in detail below with reference to embodiments.

[0022] Example 1 Valve-regulated lead-acid (VRLA) batteries, with their advantages of stable performance, safety, reliability, and maintenance-free operation, have been widely used in power plants and substations. However, during long-term operation, factors such as plate sulfation, plate corrosion, thermal runaway, water loss, or improper maintenance can lead to the formation of irreversible lead sulfate crystals inside the plates, causing the plates to gradually expand. Because the bottom of the plates is restricted by the bracket, the expansion can only extend upwards or outwards, ultimately resulting in the elevation of the terminal post.

[0023] To address this type of expansion, existing VRLA batteries are designed with sliding terminals and sheaths, allowing for some upward movement. A sealing rubber ring ensures no electrolyte leakage while allowing the terminals to slide upwards. As long as the terminal height remains within the specified range and the battery's internal resistance, voltage, capacity, and other performance indicators are normal, with no leakage or damage, the battery can continue to operate.

[0024] Practical experience shows that after about 10 years of operation, some individual batteries in the battery bank will exhibit a significant increase in the height of their positive and negative terminals, with the positive terminal being particularly prominent. When the terminal height exceeds the limit, the battery cover may bulge, crack, or even break, leading to a decrease in capacity or a short circuit in the busbar. Therefore, it is necessary to monitor the terminal height regularly. Current standards require that the factory-installed terminal height is typically 8–15 mm, and the maximum allowable increase during operation generally does not exceed 20 mm, although this varies between different brands.

[0025] Since VRLA batteries have no markings on the positive and negative terminals and the casings are uniformly colored, and the number of batteries in a group is large, the current method is to visually inspect each battery and then measure them one by one with a ruler. This method has the following shortcomings: (1) It requires manual operation for each battery, which is time-consuming, labor-intensive, and inefficient; (2) The ruler has limited accuracy, and manual reading is prone to errors; (3) Visual inspection is affected by attention and fatigue, and it is easy to miss abnormally high terminals; (4) Failure to detect terminals exceeding the limit in time will lead to leakage, capacity reduction, or busbar short circuit, thereby endangering the safety of the power system and causing economic losses.

[0026] Therefore, this embodiment addresses the above-mentioned problems by proposing a method for monitoring the height of valve-regulated lead-acid battery terminals. By marking scales and scale values ​​on the battery terminal casing and using three different colors to distinguish between normal, warning, and abnormal terminal height states, the method achieves the purpose of monitoring the height of valve-regulated lead-acid battery terminals.

[0027] Please see Figure 1 A method for monitoring the terminal height of a valve-regulated lead-acid battery, comprising: A scale is set on the outer casing of the terminal of the valve-regulated lead-acid battery, and the smallest unit of the scale is 1 mm; A scale value is set on the outer shell of the terminal post at 5 mm intervals; for example, 0 mm, 5 mm, 10 mm, 15 mm, 20 mm, 25 mm, 30 mm, etc. The specific maximum scale value is based on the allowable increase value of the terminal post of the valve-regulated lead-acid battery. Based on the actual allowable height range of the terminals in valve-regulated lead-acid batteries, the terminal casing is divided into: Normal range, corresponding to the first color; Note the area; it corresponds to the second color. The abnormal range corresponds to the third color. When the pole slides upward due to changes in its internal volume, the inspection personnel determine the pole's height status and read the corresponding scale value by observing the exposed color and scale value.

[0028] Example 2 Example 2 is a description of Example 1; please refer to [link / reference]. Figure 1 A method for monitoring the terminal height of a valve-regulated lead-acid battery, comprising: A scale is set on the outer casing of the terminal of the valve-regulated lead-acid battery, and the smallest unit of the scale is 1 mm; A scale value is set on the outer shell of the terminal post at 5 mm intervals; for example, 0 mm, 5 mm, 10 mm, 15 mm, 20 mm, 25 mm, 30 mm, etc. The specific maximum scale value is based on the allowable increase value of the terminal post of the valve-regulated lead-acid battery. Based on the actual allowable height range of the terminals in valve-regulated lead-acid batteries, the terminal casing is divided into: Normal range, corresponding to the first color; Note the area; it corresponds to the second color. The abnormal range corresponds to the third color. When the pole slides upward due to changes in its internal volume, the inspection personnel determine the pole's height status and read the corresponding scale value by observing the exposed color and scale value.

[0029] In this embodiment, specifically, the normal range is 0–12 mm, the attention range is 12–20 mm, and the abnormal range is 20 mm and above.

[0030] In this embodiment, specifically, the first color is green, the second color is yellow, and the third color is red.

[0031] In this embodiment, the outer shell of the pole is divided as follows: Set the first color: Based on the actual allowable normal height increase of the valve-regulated lead-acid battery, for example, if the normal range of the terminal height increase is 0 to 12 mm, set the color of the plastic casing of the terminal within this range as the first color, such as green or other normal indicator colors.

[0032] Set a second color: Based on the actual allowable increase in terminal height for valve-regulated lead-acid batteries, for example, if the increase in terminal height is 12 to 20 mm, set the color of the plastic casing of the terminal within this range as a second color, such as yellow, as a warning color.

[0033] Set a third color: Based on the actual allowable abnormal height increase of the valve-regulated lead-acid battery, for example, if the abnormal height increase range of the terminal is 20mm or more, set the plastic color of the terminal casing within this range as a third color, such as red or other warning color.

[0034] In this embodiment, it should be noted that the height of the terminal post of the valve-regulated lead-acid battery is set to 0mm when it is manufactured, that is, the battery sheath is flush with the 0mm mark. The manufacturing standard is uniform, which makes it easy to track the trend of changes in the terminal post height later.

[0035] When the valve-regulated lead-acid battery terminals begin to rise, they slide upwards through the sealing rubber on the sheath, and the first colored part on the terminal begins to appear. Inspectors can identify the normal terminal height and read the precise scale value by observing the first color.

[0036] When the terminals of a valve-regulated lead-acid battery rise further beyond the normal range, the terminals slide upwards through the sealing rubber on the sheath, and a second color appears on the terminals. Inspectors can use this second color to identify the terminal height as a critical condition and read the precise scale value. The scale value should be recorded, and the terminal height should be tracked regularly. Battery height and status monitoring should be strengthened.

[0037] When the terminals of a valve-regulated lead-acid battery rise further beyond the abnormal range, the terminals slide upwards through the sealing rubber on the sheath, and a third color portion begins to appear on the terminals. Inspectors can identify the abnormal terminal height by the appearance of this third color and read the precise scale value. At this point, maintenance personnel should replace the battery promptly.

[0038] Example 3 Example 3 is a description of Example 2; please refer to [link / reference]. Figure 1 A method for monitoring the terminal height of a valve-regulated lead-acid battery, comprising: A scale is set on the outer casing of the terminal of the valve-regulated lead-acid battery, and the smallest unit of the scale is 1 mm; A scale value is set on the outer shell of the terminal post at 5 mm intervals; for example, 0 mm, 5 mm, 10 mm, 15 mm, 20 mm, 25 mm, 30 mm, etc. The specific maximum scale value is based on the allowable increase value of the terminal post of the valve-regulated lead-acid battery. Based on the actual allowable height range of the terminals in valve-regulated lead-acid batteries, the terminal casing is divided into: Normal range, corresponding to the first color; Note the area; it corresponds to the second color. The abnormal range corresponds to the third color. When the pole slides upward due to changes in its internal volume, the inspection personnel determine the pole's height status and read the corresponding scale value by observing the exposed color and scale value.

[0039] In this embodiment, specifically, the normal range is 0–12 mm, the attention range is 12–20 mm, and the abnormal range is 20 mm and above.

[0040] In this embodiment, specifically, the first color is green, the second color is yellow, and the third color is red.

[0041] In this embodiment, the outer shell of the pole is divided as follows: Set the first color: Based on the actual allowable normal height increase of the valve-regulated lead-acid battery, for example, if the normal range of the terminal height increase is 0 to 12 mm, set the color of the plastic casing of the terminal within this range as the first color, such as green or other normal indicator colors.

[0042] Set a second color: Based on the actual allowable increase in terminal height for valve-regulated lead-acid batteries, for example, if the increase in terminal height is 12 to 20 mm, set the color of the plastic casing of the terminal within this range as a second color, such as yellow, as a warning color.

[0043] Set a third color: Based on the actual allowable abnormal height increase of the valve-regulated lead-acid battery, for example, if the abnormal height increase range of the terminal is 20mm or more, set the plastic color of the terminal casing within this range as a third color, such as red or other warning color.

[0044] In this embodiment, it should be noted that the height of the terminal post of the valve-regulated lead-acid battery is set to 0mm when it is manufactured, that is, the battery sheath is flush with the 0mm mark. The manufacturing standard is uniform, which makes it easy to track the trend of changes in the terminal post height later.

[0045] When the valve-regulated lead-acid battery terminals begin to rise, they slide upwards through the sealing rubber on the sheath, and the first colored part on the terminal begins to appear. Inspectors can identify the normal terminal height and read the precise scale value by observing the first color.

[0046] When the terminals of a valve-regulated lead-acid battery rise further beyond the normal range, the terminals slide upwards through the sealing rubber on the sheath, and a second color appears on the terminals. Inspectors can use this second color to identify the terminal height as a critical condition and read the precise scale value. The scale value should be recorded, and the terminal height should be tracked regularly. Battery height and status monitoring should be strengthened.

[0047] When the terminals of a valve-regulated lead-acid battery rise further beyond the abnormal range, the terminals slide upwards through the sealing rubber on the sheath, and a third color portion begins to appear on the terminals. Inspectors can identify the abnormal terminal height by the appearance of this third color and read the precise scale value. At this point, maintenance personnel should replace the battery promptly.

[0048] In this embodiment, after the valve-regulated lead-acid battery is installed on site, the height of the terminals is recorded. During the annual battery charge-discharge test or maintenance, the height of the positive and negative terminals is recorded to track the annual trend of battery terminal height increase, promptly identify batteries with abnormal terminal height increase rates, facilitate long-term analysis of battery operating status by maintenance personnel, predict potential fault risks, and ensure stable operation of the power system.

[0049] In this embodiment, it should be noted that when the height of the terminal post enters the attention range, the battery status monitoring should be strengthened; when it enters the abnormal range, the battery should be replaced in a timely manner.

[0050] Example 4 Example 4 is a description of Example 1; please refer to [link / reference]. Figure 1 A method for monitoring the terminal height of a valve-regulated lead-acid battery, comprising: A scale is set on the outer casing of the terminal of the valve-regulated lead-acid battery, and the smallest unit of the scale is 1 mm; A scale value is set on the outer shell of the terminal post at 5 mm intervals; for example, 0 mm, 5 mm, 10 mm, 15 mm, 20 mm, 25 mm, 30 mm, etc. The specific maximum scale value is based on the allowable increase value of the terminal post of the valve-regulated lead-acid battery. Based on the actual allowable height range of the terminals in valve-regulated lead-acid batteries, the terminal casing is divided into: Normal range, corresponding to the first color; Note the area; it corresponds to the second color. The abnormal range corresponds to the third color. When the pole slides upward due to changes in its internal volume, the inspection personnel determine the pole's height status and read the corresponding scale value by observing the exposed color and scale value.

[0051] In this embodiment, specifically, the scale and scale values ​​are formed on the electrode shell by etching or printing.

[0052] Example 5 Example 5 is a description of Example 1; please refer to [link / reference]. Figure 1 Furthermore, a valve-regulated lead-acid battery terminal height monitoring device is proposed, used in the valve-regulated lead-acid battery terminal height monitoring method described in Example 1, comprising: Terminals, sheaths, and battery casing; The outer shell of the pole post is provided with scales, scale values, and three color areas; The sheath is installed inside the battery casing and sleeved over the terminals. A sliding seal is achieved between the sheath and the terminals through a sealing rubber ring. The terminals can slide up and down relative to the sheath, while the sheath remains fixed relative to the battery casing. When the pole slides upwards, the exposed scale, scale values, and color areas are used to indicate the pole's height status.

[0053] In this embodiment, specifically, the starting point of the scale on the outer shell of the terminal post is flush with the upper edge of the battery sheath, and the initial terminal post height is set to 0 mm.

[0054] In this embodiment, specifically, the three color regions are arranged continuously along the pole axis, corresponding to the normal, warning, and abnormal height ranges, respectively.

[0055] In this embodiment, specifically, the sealing rubber allows the terminal post to slide upwards while preventing leakage of battery electrolyte.

[0056] The specific implementation method of the valve-regulated lead-acid battery terminal height monitoring device proposed in this embodiment is as follows: During the operation of a valve-regulated lead-acid battery, when the terminals shift upwards due to internal chemical reactions or other factors, the sealing rubber maintains tight contact with the terminals to ensure a tight seal and prevent battery leakage. The terminals slide upwards through the sheath. The sheath guides and protects the sliding of the terminals, ensuring a stable sliding path.

[0057] As the battery terminal slides upwards through the sealing rubber, markings, values, and colors appear on it, allowing maintenance personnel to accurately read and track changes in terminal height. These markings, values, and colors alert maintenance personnel to timely inspection and maintenance of the battery.

[0058] The embodiments described above merely illustrate specific implementation methods of this application, and while the descriptions are detailed and specific, they should not be construed as limiting the scope of protection of this application. It should be noted that those skilled in the art can make various modifications and improvements without departing from the concept of the technical solution of this application, and these modifications and improvements all fall within the scope of protection of this application.

[0059] This background section is provided to generally present the context of the invention. The work of the currently named inventors, the work to the extent described in this background section, and aspects of this section that did not constitute prior art at the time of application are neither expressly nor impliedly acknowledged as prior art to the invention.

Claims

1. A method for monitoring the height of the terminals of a valve-regulated lead-acid battery, characterized in that, include: A scale is set on the outer casing of the terminal of the valve-regulated lead-acid battery, and the smallest unit of the scale is 1 mm; A scale value is set on the outer shell of the pole at 5 mm intervals; Based on the actual allowable height range of the terminals in valve-regulated lead-acid batteries, the terminal casing is divided into: Normal range, corresponding to the first color; Note the area; it corresponds to the second color. The abnormal range corresponds to the third color. When the pole slides upward due to changes in its internal volume, the inspection personnel determine the pole's height status and read the corresponding scale value by observing the exposed color and scale value.

2. The method for monitoring the terminal height of a valve-regulated lead-acid battery according to claim 1, characterized in that, The normal range is 0–12 mm, the attention range is 12–20 mm, and the abnormal range is 20 mm and above.

3. A method for monitoring the terminal height of a valve-regulated lead-acid battery according to claim 1 or 2, characterized in that, The first color is green, the second color is yellow, and the third color is red.

4. The method for monitoring the terminal height of a valve-regulated lead-acid battery according to claim 1, characterized in that, The scale and scale values ​​are formed on the electrode shell by etching or printing.

5. The method for monitoring the terminal height of a valve-regulated lead-acid battery according to claim 1, characterized in that, Also includes: Record the initial terminal height value after battery installation, and record the terminal height value again during annual charge-discharge tests or maintenance to track the terminal height increase trend.

6. A method for monitoring the terminal height of a valve-regulated lead-acid battery according to claim 1 or 5, characterized in that, When the terminal height enters the warning range, strengthen battery status monitoring; when it enters the abnormal range, replace the battery in a timely manner.

7. A valve-regulated lead-acid battery terminal height monitoring device, used to implement the valve-regulated lead-acid battery terminal height monitoring method according to any one of claims 1-6, characterized in that, include: Terminals, sheaths, and battery casing; The outer shell of the pole post is provided with scales, scale values, and three color areas; The sheath is installed inside the battery casing and sleeved over the terminals. A sliding seal is achieved between the sheath and the terminals through a sealing rubber ring. The terminals can slide up and down relative to the sheath, while the sheath remains fixed relative to the battery casing. When the pole slides upwards, the exposed scale, scale values, and color areas are used to indicate the pole's height status.

8. The valve-regulated lead-acid battery terminal height monitoring device according to claim 7, characterized in that, The starting point of the scale on the outer shell of the terminal post is flush with the upper edge of the battery sheath, and the initial height of the terminal post is set to 0 mm.

9. A valve-regulated lead-acid battery terminal height monitoring device according to claim 7 or 8, characterized in that, The three color zones are arranged continuously along the pole axis, corresponding to the normal, warning, and abnormal height ranges, respectively.

10. A valve-regulated lead-acid battery terminal height monitoring device according to claim 7, characterized in that, The sealing rubber allows the terminal post to slide upwards while preventing leakage of battery electrolyte.

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