Batteries – How much do you know about the model naming and electrolyte preparation technology of lead batteries?
2022 Apr 20 By admin 0 comment
  1. Model designation of lead-acid battery

1.1. Traditional nomenclature of lead-acid battery models

The model designation of lead-acid battery is often composed of three characters. The first part uses numbers to indicate the number of single cells in series. If it is a single cell, this part is often not marked; The second part uses 1-3 letters to indicate the purpose, type and material of lead-acid battery in turn; the third part uses numbers to indicate the rated capacity of battery. The marking method of its model is as follows.

1) Standard marking method of lead-acid battery model

For example, the model marked on the surface of a lead-acid battery is “3-qb-35”, in which “3” refers to that it is composed of three single batteries in series; the letter “Q” is the first letter of Chinese Pinyin of “start”, indicating that the lead-acid battery is used for starting; the letter “B” is the first letter of Chinese Pinyin of “thin”, indicating that the battery is thin: “35” indicates that the rated capacity of the battery is 35A · H.

For another example, 3-mg-20 battery is a tubular (g, positive plate is glass filament tube) lead battery for motorcycle (m), which is composed of three single batteries in series with a capacity of 20a · H

For another example, 6-qa-50 battery is a dry charged (a) lead battery for starting (q). It is composed of six single batteries in series with a capacity of 50a · h. The “a” takes the second letter of the Chinese pinyin “Gan”.

2) Brief notation of lead-acid battery model

Some lead-acid batteries are marked with abbreviations.

For example, 6-q-60 battery is a lead-acid battery used for startup (q), which is composed of six single batteries in series, with a rated capacity of 60A · H. The marking of battery type is omitted.

As another example, model 3-m-12 refers to the lead-acid battery for motorcycle (m), which is composed of three single batteries in series, with a rated capacity of 12a · H. The type marking of the battery is omitted.

For another example, model 2-x-30 is a lead-acid battery for small (x) telephone exchange, which is composed of two single batteries in series, with a rated capacity of 30a · H

To sum up, in the traditional naming method of lead-acid battery models, the second part usually has some letters with specified meanings in addition to the above letters.

1.2. New naming method of lead-acid battery model

The lead-acid battery was first developed and produced as a large open type battery, which formed a traditional naming method and is still in use.

Later, a small sealed battery with high performance was developed and produced, and new regulations were made on the model naming of this kind of battery. Only the second part of the traditional naming method is adjusted. Q represents lead-acid battery, M represents sealing structure, f represents square and Y represents circle.

It should also be pointed out that some manufacturers of lead-acid batteries do not follow the above two typical naming methods, but use their own regulations to name the models of lead-acid batteries.

New lead-acid battery
New lead-acid battery
  1. Electrolyte preparation technology of lead-acid battery

Generally, the new lead-acid battery needs to be filled with electrolyte, the electrolyte should be replaced when repairing the battery, the electrolyte should be supplemented regularly in the use of the battery, and the density of the battery electrolyte should be adjusted at different seasons. It can be seen that it is necessary to understand the nature and preparation method of the electrolyte in the battery.

2.1 . Properties and requirements of electrolyte

2.1.1. Properties of electrolyte

The electrolyte used in lead-acid battery is dilute sulfuric acid solution, which is a liquid prepared by concentrated sulfuric acid and distilled water in a certain proportion. From the outside, it is as clear and transparent as pure water, but it has sour taste and mild corrosiveness.

2.1.2. Electrolyte purity

Lead-acid batteries have high requirements for the quality of electrolyte, which is prepared with pure sulfuric acid and distilled water. If industrial sulfuric acid is used, it will be brought into the battery because it contains impurities such as iron and copper, which will cause self discharge and premature damage of electrode plate. If water containing impurities is used, the battery will also be damaged.

2.1.3 electrolyte density

The density of electrolyte has a great influence on the performance and service life of battery. If a higher density is adopted, the electromotive force will increase, and the freezing of electrolyte can be avoided in a certain range. When the density of the electrolyte is too high, the corrosion of the battery separator will be accelerated. According to the test, the density is 1.29g/cm ³ The replacement density of electrolyte is 1.25g/cm ³~ 1.26g/cm ³ The battery life will be reduced by 40% when the electrolyte is.

2.2 steps and precautions for preparing electrolyte

2.2.1. General steps for preparing electrolyte

(1) Determine the quantity of sulfuric acid and water according to the required density. The ratio of water to sulfuric acid will be different with the density of electrolyte. This ratio can be expressed by mass or volume. Expressed in volume, it is more convenient to use.

According to the quantity of electrolyte to be prepared and the proportion in the table, the dosage of sulfuric acid and water can be basically determined.

(2) Pour the required amount of distilled water into the container, then slowly pour sulfuric acid into the distilled water, and continuously stir with a glass rod to make it mix evenly and dissipate heat quickly.

(3) Adjust the electrolyte density. The density of electrolyte will change with temperature. When the temperature increases, the density decreases, and when the temperature decreases, the density increases. Generally speaking, the density usually refers to 20 ℃. If the electrolyte temperature is not 20 ℃ when measuring density, it shall be converted to the value at 20 ℃. Because the density decreases by 0.0007g/cm for each degree of temperature rise ³; On the contrary, the density increases by 0.0007g/cm when the temperature decreases by one degree ³, Therefore, the conversion method can be carried out according to the following formula: d0 = DS + (T-20) x0 0007

Where: D is the density of electrolyte at 20 ℃, D is the actual measured density of electrolyte, and the unit is g / cm ³; T is the actual temperature when measuring the electrolyte, in ° C.

When the electrolyte density does not meet the specified value, a small amount of distilled water or sulfuric acid can be added for adjustment.

2.2.2 precautions when preparing electrolyte

When preparing dilute sulfuric acid electrolyte, the following operating procedures must be strictly observed.

(1) Workers should wear protective glasses and rubber gloves.

(2) When preparing electrolyte, acid and temperature resistant containers such as glass, ceramic, plastic or lead shall be used, and other metal containers shall not be used to avoid mixing metal impurities in the electrolyte. The size of the container shall be determined according to the amount of electrolyte prepared, and the volume of the container shall be selected by preparing the required amount of electrolyte at one time.

(3) When preparing electrolyte, first pour distilled water into the cleaned container, then slowly inject concentrated sulfuric acid into the water, and constantly stir with an acid resistant rod to fully mix the acid and water and dissipate heat in time. When preparing dilute sulfuric acid solution, never pour distilled water into concentrated sulfuric acid, otherwise the solution will splash due to violent chemical reaction and hurt people and objects. It even causes explosion accidents due to the generation of a large amount of heat.

If the temperature rise of the solution is found to increase during the mixing process, the work shall be suspended and cooling measures shall be taken. After cooling down to about 40 ℃, continue to mix to ensure safety.

(4) Before preparing electrolyte, the workplace shall prepare 5% baking soda solution and put it on site. When sulfuric acid splashes on the skin or clothes, wash it immediately with baking soda solution or 10% ammonia solution, and then rinse it with clean water. After the deployment and application of electrolyte, clean the appliance with baking soda solution and clean water in time.

(5) The temperature of the newly prepared electrolyte is high, sometimes up to about 80 ℃. It must not be injected into the battery immediately, otherwise the electrode plate will be damaged. It must be cooled to room temperature before injection.

(6) Whether the electrolyte preparation density is accurate and whether the quality is pure has a great impact on the service life of the battery. Generally, it should be prepared according to the instructions of the battery or with reference to the data in table 6-19.

(7) The density of electrolyte injected into the new battery for the first time shall be 0.02g/cm lower than the rated value in the manual ³, Generally, the density of starting electrolyte injected into the battery shall be 1.26g/cm after normal and sufficient charging ³~ 1.29g/cm ³; After discharge, the density shall be 1.10g/cm ³~ 1.16g/cm ³. 2。

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