Negative pressure and positive pressure combined acid adding process suitable for medium-high density 12V lead-acid storage battery

Abstract

The invention relates to the technical field of manufacturing of lead-acid storage batteries, and particularly discloses a negative-positive pressure combined acid adding process suitable for medium-and-large-density 12V lead-acid storage batteries, which comprises the following steps: carrying out first-stage, second-stage and third-stage stage treatment on a storage battery to be subjected to acid adding according to the thickness of a polar plate, and then setting an acid adding process flow. Finally, acid adding process parameters are automatically adjusted according to the acid adding requirements of the pole plates with the first-level thickness, the second-level thickness and the third-level thickness, negative-pressure and positive-pressure combined acid adding operation is carried out according to the adjusted acid adding process parameters, and the flow of the negative-pressure and positive-pressure combined acid adding operation comprises an acid adding stage, a vacuumizing stage and a positive-pressure treatment stage. By establishing the corresponding relation between the pole plate thickness and the process parameters, the acid adding effect can be remarkably improved, and the formation time is shortened; during negative pressure and positive pressure combined acid adding operation, uniform distribution of acid liquor in the storage battery and discharge of bubbles are facilitated through positive pressure treatment, and the acid adding quality of the storage battery is improved.

Description

Technical Field

[0001] The invention belongs to the technical field of lead-acid battery manufacturing, and in particular relates to a negative-positive pressure combined acid-adding process suitable for medium- and large-density 12V lead-acid batteries. Background Art

[0002] Lead-acid batteries are usually divided into three categories according to their capacity: small-density, medium-density and large-density. Among them, batteries with a capacity of 25Ah (inclusive) and above to 200Ah (inclusive) are called medium-density lead-acid batteries, while batteries with a capacity of more than 200Ah are called large-density lead-acid batteries. Medium-density and large-density lead-acid batteries are a type of battery with relatively large capacity among sealed lead-acid batteries.

[0003] At present, due to the characteristics of large plate thickness and high density of active materials, medium and large density lead-acid batteries usually adopt negative pressure acid addition to carry out acid addition operations. The negative pressure acid addition system usually includes several acid storage containers, battery conveying carriers and vacuum chambers and other key components. When adding acid, several assembled battery components are placed on the battery conveying carrier with the acid addition holes facing upwards and at equal intervals along a straight line. Then, the drainage port of the acid storage container is plugged into the acid addition hole of the battery one by one to ensure that the sealing between the drainage port and the acid addition hole is good to prevent electrolyte leakage. Then, the electrolyte is added to the container through the filling port of the acid storage container. A certain amount of electrolyte is injected into the device. During the addition process, it is necessary to ensure that the density and temperature of the electrolyte meet the process requirements; then the battery carrier containing the battery assembly is sent into the vacuum chamber, and the vacuum chamber is closed, and then the vacuum switch is turned on to start the vacuum operation. During the vacuum process, the pressure changes in the vacuum chamber must be closely monitored to ensure that a stable negative pressure state is formed in the battery assembly. When the battery assembly is in a negative pressure state, the vent switch of the vacuum chamber is turned on. Due to the pressure difference between the inside and outside of the battery assembly, the acid in the acid storage container is quickly sucked into it by the negative pressure in the battery assembly, completing the acid addition operation.

[0004] However, the above-mentioned traditional negative pressure acid addition method is single, and it is difficult for the electrolytic solution to fully penetrate into the thick plate, and bubbles are easily retained inside the plate, thereby affecting the utilization rate of the active material and making the acid addition effect unsatisfactory. Therefore, we need to propose a negative and positive pressure combined acid addition process suitable for medium and large density 12V lead-acid batteries to solve the above-mentioned problems, so that by establishing a corresponding relationship between the plate thickness and the process parameters, the acid addition effect can be significantly improved and the formation time can be shortened. Summary of the Invention

[0005] The purpose of the present invention is to provide a negative-positive pressure combined acid-adding process suitable for medium and large density 12V lead-acid batteries. By establishing a corresponding relationship between the plate thickness and the process parameters, the acid-adding effect is significantly improved and the formation time is shortened to solve the problems raised in the above-mentioned background technology.

[0006] To achieve the above object, the present invention adopts the following technical solutions:

[0007] A negative-positive pressure combined acid-adding process for medium- and large-density 12V lead-acid batteries comprises the following steps:

[0008] S1. The battery to be acid-added is graded into primary, secondary and tertiary levels according to the thickness of the plate, wherein the thickness of the primary plate is 2.3-2.5 mm, the thickness of the secondary plate is 2.6-2.8 mm, and the thickness of the tertiary plate is 2.9 mm or above;

[0009] S2. Set the acid addition process parameters. The acid addition process parameters are: acid addition section time ≧15 seconds, quantitative section time ≧10 seconds, lower acid section time ≧20 seconds, the negative pressure of the first vacuum section is ≦-85kPa, the vacuum time is 15-22 seconds, the acid injection section time ≧15 seconds, the negative pressure of the second vacuum section is ≦-85kPa, the vacuum time is 15-22 seconds, the positive pressure of the positive pressure treatment section is 25kPa-35kPa, and the positive pressure time is 15-22 seconds;

[0010] S3. Automatically adjust the acid adding process parameters according to the acid adding requirements of the primary, secondary and tertiary thickness plates, and perform negative and positive pressure combined acid adding operations according to the adjusted acid adding process parameters. The process of the negative and positive pressure combined acid adding operation includes an acid adding stage, a vacuuming stage and a positive pressure treatment stage.

[0011] Preferably, in step S1, the process of thickness grading of the electrode plate is as follows:

[0012] S11, using a laser rangefinder to measure the thickness of the plates in the lead-acid batteries to be acidified, and recording the thickness value of the plates in each lead-acid battery to be acidified;

[0013] S12. Classify the lead-acid batteries to be charged with acid according to the first, second and third level classification standards.

[0014] Preferably, in step S3, the acid adding process parameters of the primary plate are: acid adding section time ≧17 seconds, quantitative section time ≧12 seconds, lower acid section time ≧22 seconds, the negative pressure of the first vacuum section is ≦-85kPa, the vacuuming time is 15 seconds, the acid injection section time ≧15 seconds, the negative pressure of the second vacuum section is ≦-85kPa, the vacuuming time is 15 seconds, the positive pressure of the positive pressure treatment section is 25kPa, and the positive pressure time is 17 seconds.

[0015] Preferably, the acid adding process parameters of the secondary electrode plate are: acid adding section time ≧17 seconds, quantitative section time ≧12 seconds, acid lowering section time ≧22 seconds, the negative pressure of the first vacuum section is ≦-85kPa, the vacuuming time is 18 seconds, the acid injection section time ≧15 seconds, the negative pressure of the second vacuum section is ≦-85kPa, the vacuuming time is 18 seconds, the positive pressure of the positive pressure treatment section is 30kPa, and the positive pressure time is 19 seconds.

[0016] Preferably, the acid adding process parameters of the tertiary electrode plate are: the acid adding section time ≧17 seconds, the quantitative section time ≧12 seconds, the acid lowering section time ≧22 seconds, the negative pressure of the first vacuum section is ≦-85kPa, the vacuuming time is 20 seconds, the acid injection section time ≧15 seconds, the negative pressure of the second vacuum section is ≦-85kPa, the vacuuming time is 20 seconds, the positive pressure of the positive pressure treatment section is 35kPa, and the positive pressure time is 21 seconds.

[0017] Preferably, in step S3, the acid addition stage includes the following process:

[0018] S31. Open the acid solution valve and control the acid solution to flow into the acid adding container at a steady rate, ensuring that the acid addition time is not less than 15 seconds to ensure that the acid solution fully enters the acid adding container;

[0019] S32. When the preset acid volume is reached, close the acid valve and keep the metering time at least 10 seconds to ensure accurate measurement.

[0020] S33. Slowly flow the acid in the acid adding container into the battery through the pipe. The acid addition time should be no less than 20 seconds to prevent the acid from splashing or impacting the inside of the battery.

[0021] Preferably, the process of the vacuuming stage is as follows:

[0022] S34, placing the battery in a vacuum container and connecting a vacuum pump;

[0023] S35. Start the vacuum pump to perform the first vacuuming, control the negative pressure to no more than -85 kPa, and control the vacuuming time to be 15-22 seconds to remove air and moisture inside the battery;

[0024] S36. After the first vacuuming, inject acid into the battery again for at least 15 seconds to ensure that the acid is evenly distributed;

[0025] S37, repeat the step of S35 to perform vacuuming for the second time to ensure that the inside of the battery is vacuumed again.

[0026] Preferably, in step S34, the vacuum pump's pumping rate is set to ≧60m 3 / h, the gas source fluctuation is ±1kPa, the time control accuracy is 0.1 second, and the vacuum pump is equipped with a pressure sensor with an accuracy of 0.1kPa.

[0027] Preferably, the process of the positive pressure treatment stage is as follows:

[0028] S38. After the second vacuuming is completed, compressed air is filled into the vacuum container, and the positive pressure is controlled between 25 kPa and 35 kPa, and the positive pressure time is controlled within 15-22 seconds;

[0029] S39. Immediately seal the battery cover after the positive pressure treatment is completed to ensure a tight seal.

[0030] Preferably, the negative-positive pressure combined acid addition process can shorten the battery formation time by 15-25%, reduce energy consumption by 15-20%, improve capacity consistency by 15-20%, improve internal resistance consistency by 12-15%, and increase the matching rate by 18-22%.

[0031] The negative-positive pressure combined acid-adding process for medium- and large-density 12V lead-acid batteries proposed in the present invention has the following advantages over the prior art:

[0032] 1. The present invention first performs primary, secondary and tertiary grading treatment on the batteries to be acid-added according to the thickness of the electrode plates, then sets an acid-adding process flow, and finally automatically adjusts the acid-adding process parameters according to the acid-adding requirements of the primary, secondary and tertiary thickness electrode plates, and performs negative and positive pressure combined acid-adding operations according to the adjusted acid-adding process parameters. The process of the negative and positive pressure combined acid-adding operation includes an acid-adding stage, a vacuuming stage and a positive pressure treatment stage. By establishing a corresponding relationship between the electrode plate thickness and the process parameters, the acid-adding effect can be significantly improved and the formation time can be shortened.

[0033] 2. In the negative and positive pressure combined acid adding operation, the positive pressure treatment helps to evenly distribute the acid solution inside the battery and discharge bubbles, thereby improving the acid adding quality of the battery. BRIEF DESCRIPTION OF THE DRAWINGS

[0034] Figure 1 It is a flowchart of the present invention;

[0035] Figure 2 It is a flow chart of the acid addition stage of the present invention;

[0036] Figure 3 It is a flow chart of the vacuuming stage of the present invention;

[0037] Figure 4 It is a flow chart of the positive pressure treatment stage of the present invention. DETAILED DESCRIPTION

[0038] The following will be combined with the drawings in the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. Obviously, the embodiments described are only part of the embodiments of the present invention, not all of the embodiments. The specific embodiments described herein are only used to explain the present invention and are not used to limit the present invention. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without making creative work are within the scope of protection of the present invention.

[0039] Example 1

[0040] The present invention provides Figure 1-4 The negative and positive pressure combined acid addition process for medium and large density 12V lead-acid batteries shown includes the following steps:

[0041] S1. The battery to be acid-added is graded into primary, secondary and tertiary levels according to the thickness of the plate, wherein the thickness of the primary plate is 2.3-2.5 mm, the thickness of the secondary plate is 2.6-2.8 mm, and the thickness of the tertiary plate is 2.9 mm or above;

[0042] The process of thickness grading of the plate is as follows:

[0043] S11, using a laser rangefinder to measure the thickness of the plates in the lead-acid batteries to be acidified, and recording the thickness value of the plates in each lead-acid battery to be acidified;

[0044] S12. Classify the lead-acid batteries to be charged with acid according to the first, second and third level classification standards.

[0045] S2. Set the acid addition process parameters. The acid addition process parameters are: acid addition section time ≧15 seconds, quantitative section time ≧10 seconds, lower acid section time ≧20 seconds, the negative pressure of the first vacuum section is ≦-85kPa, the vacuum time is 15-22 seconds, the acid injection section time ≧15 seconds, the negative pressure of the second vacuum section is ≦-85kPa, the vacuum time is 15-22 seconds, the positive pressure of the positive pressure treatment section is 25kPa-35kPa, and the positive pressure time is 15-22 seconds;

[0046] S3, automatically adjusting the acid adding process parameters according to the acid adding requirements of the primary, secondary and tertiary thickness plates, and performing negative and positive pressure combined acid adding operations according to the adjusted acid adding process parameters, wherein the process of the negative and positive pressure combined acid adding operation includes an acid adding stage, a vacuuming stage and a positive pressure treatment stage;

[0047] The acid adding process parameters for the primary plate are: acid application section time ≧17 seconds, quantitative section time ≧12 seconds, acid removal section time ≧22 seconds, the negative pressure of the first vacuum section is ≦-85kPa, the vacuum time is 15 seconds, the acid injection section time ≧15 seconds, the negative pressure of the second vacuum section is ≦-85kPa, the vacuum time is 15 seconds, the positive pressure of the positive pressure treatment section is 25kPa, and the positive pressure time is 17 seconds.

[0048] The acid adding process parameters for the secondary plate are: acid application section time ≧17 seconds, quantitative section time ≧12 seconds, acid removal section time ≧22 seconds, the negative pressure of the first vacuum section is ≦-85kPa, the vacuum time is 18 seconds, the acid injection section time ≧15 seconds, the negative pressure of the second vacuum section is ≦-85kPa, the vacuum time is 18 seconds, the positive pressure of the positive pressure treatment section is 30kPa, and the positive pressure time is 19 seconds.

[0049] The acid adding process parameters for the tertiary plate are: acid application section time ≧17 seconds, quantitative section time ≧12 seconds, acid removal section time ≧22 seconds, the negative pressure of the first vacuum section is ≦-85kPa, the vacuum time is 20 seconds, the acid injection section time ≧15 seconds, the negative pressure of the second vacuum section is ≦-85kPa, the vacuum time is 20 seconds, the positive pressure of the positive pressure treatment section is 35kPa, and the positive pressure time is 21 seconds.

[0050] The acid addition stage includes the following processes:

[0051] S31. Open the acid solution valve and control the acid solution to flow into the acid adding container at a steady rate, ensuring that the acid addition time is not less than 15 seconds to ensure that the acid solution fully enters the acid adding container;

[0052] S32. When the preset acid volume is reached, close the acid valve and keep the metering time at least 10 seconds to ensure accurate measurement.

[0053] S33. Slowly flow the acid in the acid adding container into the battery through the pipe. The acid addition time should be no less than 20 seconds to prevent the acid from splashing or impacting the inside of the battery.

[0054] The process of vacuuming is as follows:

[0055] S34, placing the battery in a vacuum container, connecting a vacuum pump, and setting the vacuum pump's pumping rate to ≥ 60m 3 / h, the gas source fluctuation is ±1kPa, the time control accuracy is 0.1 second, and the vacuum pump is equipped with a pressure sensor with an accuracy of 0.1kPa, which is convenient for the vacuum pump to stably control the pressure in the vacuum container and ensure that the battery can be acidified evenly;

[0056] S35. Start the vacuum pump to perform the first vacuuming, control the negative pressure to no more than -85 kPa, and control the vacuuming time to be 15-22 seconds to remove air and moisture inside the battery;

[0057] S36. After the first vacuuming, inject acid into the battery again for at least 15 seconds to ensure that the acid is evenly distributed;

[0058] S37, repeat the step of S35 to perform vacuuming for the second time to ensure that the inside of the battery is vacuumed again.

[0059] The process of the positive pressure treatment stage is as follows:

[0060] S38. After the second vacuuming is completed, compressed air is filled into the vacuum container, and the positive pressure is controlled to be between 25 kPa and 35 kPa, and the positive pressure time is controlled to be 15 to 22 seconds. The positive pressure treatment helps to evenly distribute the acid inside the battery and discharge bubbles;

[0061] S39. Immediately seal the battery cover after the positive pressure treatment is completed to ensure a tight seal to avoid leakage of the battery and ensure that the battery can work normally.

[0062] This negative and positive pressure combined acid addition process can shorten the battery formation time by 15-25%, reduce energy consumption by 15-20%, improve capacity consistency by 15-20%, improve internal resistance consistency by 12-15%, and increase the matching rate by 18-22%.

[0063] The battery to be acid-added is first graded into primary, secondary and tertiary levels according to the thickness of the plate, and then the acid-adding process flow is set. Finally, the acid-adding process parameters are automatically adjusted according to the acid-adding requirements of the primary, secondary and tertiary thickness plates, and negative and positive pressure combined acid-adding operations are performed according to the adjusted acid-adding process parameters. Among them, the process of the negative and positive pressure combined acid-adding operation includes an acid-adding stage, a vacuuming stage and a positive pressure treatment stage. By establishing a corresponding relationship between the plate thickness and the process parameters, the acid-adding effect can be significantly improved and the formation time can be shortened.

[0064] Example 2

[0065] The similarities are not repeated here. The difference from Example 1 is that the acid adding process parameters of the primary plate are: the acid adding section time is 20 seconds, the quantitative section time is 15 seconds, the lower acid section time is 25 seconds, the negative pressure of the first vacuum section is -95 kPa, the vacuuming time is 15 seconds, the acid injection section time is 17 seconds, the negative pressure of the second vacuum section is -95 kPa, the vacuuming time is 15 seconds, the positive pressure of the positive pressure treatment section is 25 kPa, and the positive pressure time is 17 seconds.

[0066] The acid adding process parameters for the secondary plate are: acid application section time 20 seconds, quantitative section time 15 seconds, acid removal section time 25 seconds, the negative pressure of the first vacuum section is -95kPa, the vacuum time is 18 seconds, the acid injection section time is 17 seconds, the negative pressure of the second vacuum section is -95kPa, the vacuum time is 18 seconds, the positive pressure of the positive pressure treatment section is 30kPa, and the positive pressure time is 19 seconds.

[0067] The acid adding process parameters for the tertiary plate are: acid application time 20 seconds, quantitative time 15 seconds, acid removal time 25 seconds, the negative pressure of the first vacuum section is -95kPa, the vacuum time is 20 seconds, the acid injection section time is 17 seconds, the negative pressure of the second vacuum section is -95kPa, the vacuum time is 20 seconds, the positive pressure of the positive pressure treatment section is 35kPa, and the positive pressure time is 21 seconds.

[0068] Example 3

[0069] The similarities are not repeated here. The difference from Example 1 is that the acid adding process parameters of the primary plate are: the upper acid section time is 25 seconds, the quantitative section time is 18 seconds, the lower acid section time is 28 seconds, the negative pressure of the first vacuum section is -100 kPa, the vacuum time is 15 seconds, the acid injection section time is 20 seconds, the negative pressure of the second vacuum section is -100 kPa, the vacuum time is 15 seconds, the positive pressure of the positive pressure treatment section is 25 kPa, and the positive pressure time is 17 seconds.

[0070] The acid adding process parameters for the secondary plate are: acid application time 25 seconds, quantitative section time 18 seconds, acid removal section time 28 seconds, the negative pressure of the first vacuum section is -100kPa, the vacuum time is 18 seconds, the acid injection section time is 20 seconds, the negative pressure of the second vacuum section is -100kPa, the vacuum time is 18 seconds, the positive pressure of the positive pressure treatment section is 30kPa, and the positive pressure time is 19 seconds.

[0071] The acid adding process parameters for the tertiary plate are: acid adding section time 25 seconds, quantitative section time 18 seconds, acid removing section time 28 seconds, the negative pressure of the first vacuum section is -100kPa, the vacuum time is 20 seconds, the acid injection section time is 20 seconds, the negative pressure of the second vacuum section is -100kPa, the vacuum time is 20 seconds, the positive pressure of the positive pressure treatment section is 35kPa, and the positive pressure time is 21 seconds.

[0072] Example 4

[0073] According to the methods provided in Example 1, Example 2, and Example 3 and the existing acid addition method provided in the background technology, the medium and large density 12V lead-acid batteries were acidified, and then the performance of the lead-acid batteries after acid addition was tested to confirm the acid addition effect of the batteries. The performance test results are as follows:

[0074]

[0075]

[0076] According to the test results in the above table, it can be concluded that the acid addition method provided by the present invention can shorten the battery formation time by 15-25%, reduce energy consumption by 15-20%, improve capacity consistency by 15-20%, improve internal resistance consistency by 12-15%, and increase the battery packing rate by 18-22%.

[0077] Finally, it should be noted that the above is only a preferred embodiment of the present invention and is not intended to limit the present invention. Although the present invention has been described in detail with reference to the aforementioned embodiments, those skilled in the art can still modify the technical solutions described in the aforementioned embodiments or make equivalent substitutions for some of the technical features therein. Any modifications, equivalent substitutions, improvements, etc. made within the spirit and principles of the present invention should be included in the scope of protection of the present invention.

Claims

1. A negative and positive pressure combined acid addition process suitable for medium and large density 12V lead-acid batteries, characterized by: The steps include: S1. The battery to be acid-added is graded into primary, secondary and tertiary levels according to the thickness of the plate, wherein the thickness of the primary plate is 2.3-2.5 mm, the thickness of the secondary plate is 2.6-2.8 mm, and the thickness of the tertiary plate is 2.9 mm or above; S2. Set the acid addition process parameters. The acid addition process parameters are: acid addition section time ≧15 seconds, quantitative section time ≧10 seconds, lower acid section time ≧20 seconds, the negative pressure of the first vacuum section is ≦-85kPa, the vacuum time is 15-22 seconds, the acid injection section time ≧15 seconds, the negative pressure of the second vacuum section is ≦-85kPa, the vacuum time is 15-22 seconds, the positive pressure of the positive pressure treatment section is 25kPa-35kPa, and the positive pressure time is 15-22 seconds; S3. Automatically adjust the acid adding process parameters according to the acid adding requirements of the primary, secondary and tertiary thickness plates, and perform negative and positive pressure combined acid adding operations according to the adjusted acid adding process parameters. The process of the negative and positive pressure combined acid adding operation includes an acid adding stage, a vacuuming stage and a positive pressure treatment stage.

2. The negative-positive pressure combined acid-adding process for medium- and large-density 12V lead-acid batteries according to claim 1, characterized in that: In step S1, the process of thickness grading of the electrode plate is as follows: S11, using a laser rangefinder to measure the thickness of the plates in the lead-acid batteries to be acidified, and recording the thickness value of the plates in each lead-acid battery to be acidified; S12. Classify the lead-acid batteries to be charged with acid according to the first, second and third level classification standards.

3. The negative-positive pressure combined acid-adding process for medium- and large-density 12V lead-acid batteries according to claim 1, characterized in that: In step S3, the acid adding process parameters of the primary plate are: acid application time ≧17 seconds, quantitative section time ≧12 seconds, acid application time ≧22 seconds, the negative pressure of the first vacuum section is ≦-85kPa, the vacuum time is 15 seconds, the acid injection section time ≧15 seconds, the negative pressure of the second vacuum section is ≦-85kPa, the vacuum time is 15 seconds, the positive pressure of the positive pressure treatment section is 25kPa, and the positive pressure time is 17 seconds.

4. The negative-positive pressure combined acid-adding process for medium- and large-density 12V lead-acid batteries according to claim 3, characterized in that: The acid adding process parameters for the secondary plate are: acid application section time ≧17 seconds, quantitative section time ≧12 seconds, acid removal section time ≧22 seconds, the negative pressure of the first vacuum section is ≦-85kPa, the vacuum time is 18 seconds, the acid injection section time ≧15 seconds, the negative pressure of the second vacuum section is ≦-85kPa, the vacuum time is 18 seconds, the positive pressure of the positive pressure treatment section is 30kPa, and the positive pressure time is 19 seconds.

5. The negative and positive pressure combined acid addition process for medium and large density 12V lead-acid batteries according to claim 4, characterized in that: The acid adding process parameters for the tertiary plate are: acid application section time ≧17 seconds, quantitative section time ≧12 seconds, acid removal section time ≧22 seconds, the negative pressure of the first vacuum section is ≦-85kPa, the vacuum time is 20 seconds, the acid injection section time ≧15 seconds, the negative pressure of the second vacuum section is ≦-85kPa, the vacuum time is 20 seconds, the positive pressure of the positive pressure treatment section is 35kPa, and the positive pressure time is 21 seconds.

6. The negative-positive pressure combined acid-adding process for medium-large density 12V lead-acid batteries according to claim 5, characterized in that: In step S3, the acid addition stage includes the following process: S31. Open the acid solution valve and control the acid solution to flow into the acid adding container at a steady rate, ensuring that the acid addition time is not less than 15 seconds to ensure that the acid solution fully enters the acid adding container; S32. When the preset acid volume is reached, close the acid valve and keep the metering time at least 10 seconds to ensure accurate measurement. S33. Slowly flow the acid in the acid adding container into the battery through the pipe. The acid addition time should be no less than 20 seconds to prevent the acid from splashing or impacting the inside of the battery.

7. A negative-positive pressure combined acid-adding process for medium-large density 12V lead-acid batteries according to claim 6, characterized in that: The process of vacuuming is as follows: S34, placing the battery in a vacuum container and connecting a vacuum pump; S35. Start the vacuum pump to perform the first vacuuming, control the negative pressure to no more than -85 kPa, and control the vacuuming time to be 15-22 seconds to remove air and moisture inside the battery; S36. After the first vacuuming, inject acid into the battery again for at least 15 seconds to ensure that the acid is evenly distributed; S37, repeat the step of S35 to perform vacuuming for the second time to ensure that the inside of the battery is vacuumed again.

8. The negative-positive pressure combined acid-adding process for medium- and large-density 12V lead-acid batteries according to claim 7, characterized in that: In step S34, the vacuum pump's pumping rate is set to ≥60m 3 / h, the gas source fluctuation is ±1kPa, the time control accuracy is 0.1 second, and the vacuum pump is equipped with a pressure sensor with an accuracy of 0.1kPa.

9. A negative-positive pressure combined acid-adding process for medium-large density 12V lead-acid batteries according to claim 8, characterized in that: The process of the positive pressure treatment stage is as follows: S38. After the second vacuuming is completed, compressed air is filled into the vacuum container, and the positive pressure is controlled between 25 kPa and 35 kPa, and the positive pressure time is controlled within 15-22 seconds; S39. Immediately seal the battery cover after the positive pressure treatment is completed to ensure a tight seal.

10. A negative and positive pressure combined acid addition process for medium and large density 12V lead-acid batteries according to claim 9, characterized in that: This negative and positive pressure combined acid addition process can shorten the battery formation time by 15-25%, reduce energy consumption by 15-20%, improve capacity consistency by 15-20%, improve internal resistance consistency by 12-15%, and increase the matching rate by 18-22%.

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