1. What is a lead-acid battery (Pb-A)?
Lead-acid battery, the electrode is mainly made of lead, and the electrolyte is a kind of storage battery of sulfuric acid solution.
The representative symbol of lead-acid battery is Pb-A or LA, where: Pb is the code for lead in the periodic table, L is the prefix of the English name of lead, A is the prefix of the English name of acid, Acid, the above two The spelling all represent lead-acid batteries.
There are many varieties of L-A batteries, such as horizontal plate, roll-pole cylindrical, etc.
Although emerging battery industries such as lithium batteries have developed rapidly in recent years, lead-acid batteries are still the most mature technology in the world due to their simple manufacturing process, abundant raw material sources, and high quality-price ratio. The largest and longest-lasting power supply on the market.
In the field of lead-acid battery manufacturing in my country, with the advancement of the development concept of Industry 4.0 and the goal of Made in China 2025, the lead-acid battery industry has gradually accelerated the pace of transformation from traditional manufacturing mode to intelligent manufacturing mode. Casting machines with multiple pots, large tonnage lead powder machines, vacuum and paste high-speed coating and assembly casting and welding automatic production lines are widely used. Under the same production capacity, energy consumption is reduced and more environmentally friendly. At the same time, labor is saved and products are improved. Consistency and stability of equipment performance. At the same time, the innovative application of digital and networked management systems has also made the battery manufacturing process more efficient, automated, intelligent and clean.
2. What is a colloidal lead-acid battery?
The electrolyte is colloidal. The so-called colloidal electrolyte is prepared by a special process with a gel agent and a sulfuric acid solution in proportion. It is a milky white gel.
The colloidal electrolyte is more scientific, it is not easy to cause the vulcanization of the pole plate, and the shell will not leak when the shell is broken. Low internal resistance, low self-discharge rate, less than 3% self-discharge per month, good capacity recovery performance: after discharging to close to OV, short-circuit the positive and negative electrodes for 24h, then recharge to the termination voltage, and then repeat the discharge, short circuit After 5 times of discharge, the discharge termination voltage reaches 10.5V. After that, the battery capacity is still greater than 90% of the rated capacity.
Under normal circumstances, the lifespan can reach 500 times. The voltage ratio of the gel battery cell is 0.5~1V lower than the modern sealed type, and the applicable temperature is 10℃~40℃, which is relatively low temperature resistant.
3. What standard is used for lead-acid batteries?
Battery standards are divided into three levels: national standards, industry standards, and enterprise standards. At present, the vehicle battery implements the industry standard numbered JB/T 10262-2001.
4. How are the lead-acid batteries for electric vehicles named?
The name of the lead-acid battery for vehicles is called 6-DZM-X, where X is the suffix, and X can be 8, 10, 12, representing the capacity of the battery. 6DZM represents 6 groups of single-cell batteries combined into a 12V voltage valve-regulated sealed maintenance-free battery for electric vehicles. If it is a gel battery, its marking method is 6-DJM-X.
5. What is the capacity labeling method of lead-acid batteries for electric vehicles?
It should be based on C2, that is, discharge at a current of 0.5C2. When the voltage reaches the discharge termination voltage of the battery, the product of the discharge time and the current should be equal to or close to the rated capacity value. For example, a 12V, 12Ah battery is discharged with a current of 5A, and when the discharge termination voltage reaches 10.5V, the time cannot be less than 140 minutes; similarly, a 12V, 10Ah battery is discharged with a current of 5A until the voltage reaches the termination voltage of 10.5V, the time is not less than 140min. The time cannot be less than 120min.
Its error is 0.1Ah
In fact, the industry standard stipulates that the time for a 10Ah battery to discharge with a current of 5A to the termination voltage shall not be less than 120min. The actual product achieved by the enterprise is 130~137min.
6. What is the overcharge capability of lead-acid batteries?
Industry standards stipulate that lead-acid batteries are continuously charged for 48 hours at a current of 1.2A, and the actual capacity shall not be lower than 95% of the rated capacity.
7. What is the overdischarge capacity of lead-acid batteries?
The industry standard stipulates that the discharge current of lead-acid battery is 12A±1.2A, and it is continuously discharged for 2.0h in a constant impedance mode, and the actual capacity shall not be lower than 75%
8. What are the low temperature storage characteristics of lead-acid batteries?
Industry standards stipulate that lead-acid batteries should be stored for 10 hours under the environmental conditions of -10℃±0.1℃, and the actual capacity should not be lower than 70%.
9. How to evaluate the life of lead-acid batteries?
With a deep discharge of 75% of the capacity, the life should not be less than 350 times.
10. What are the advantages and disadvantages of lead-acid batteries?
(1) Advantages
Super high quality and price ratio: the price of lead-acid batteries is 1/4~1/6 of the price of other types of batteries. The one-time investment is relatively low, and most users can afford it.
(2) Disadvantages
Large weight, large volume, low energy-to-mass ratio, squeamish, and strict requirements for charging and discharging.
11. Why do lead-acid batteries need to be stored for a period of time before they can be packaged and shipped?
The storage performance of the battery is an important parameter to measure the stability of the comprehensive performance of the battery. After the battery is stored for a certain period of time, the capacity and internal resistance of the battery are allowed to change to a certain extent. After a period of storage, the electrochemical properties of the internal components can be stabilized, and the self-discharge performance of the battery can be known to ensure the quality of the battery.
12. What is the relationship between the discharge rate and use of lead-acid batteries?
Motors with the same power have different rated voltages, and the speed of power consumption is absolutely different. For example: the same 180W motor, when the rated voltage is 24V, the current is 7.5A; and when the rated voltage is 36V, the current is only 5A, they use the same capacity battery pack, the combination is 36V, and the 5A current discharges, the electrochemical reaction is slow , and the combination is 24V, discharge with 7.5A current, the electrochemical reaction will be relatively intense, it is better to discharge calmly with 5A.
It is economical to discharge the battery at a current below 0.5C.
What is 0.5C? C: indicates the capacity of the battery, and C2 indicates the actual capacity measured on the battery when discharged at a rate of 2 hours. That is to say, when the capacity is rated as C2, half of the capacity (0.5C2) should be released per hour to meet the capacity regulations. If it exceeds 0.5C2, its capacity will be discounted. And it's bad for battery life.
Now, a battery with a capacity of 12Ah marked with a 2-hour discharge rate should be marked as C2=12Ah, so 0.5C2=0.5×12=6A. Therefore, a 12Ah battery is discharged at 0.5C, which is a current of 6A.
When the battery works for a long time, the output working current should not be greater than the rated capacity of the battery Cx /X, X is the hour rate under the rated value of the battery, which is the principle of selection. If X is 2, the discharge rate should be 2 hours; if X is 3, the use time should be considered as 3 hours.
13. What are the current labelling methods for the capacity of lead-acid batteries?
At present, the capacity of lead-acid batteries is indicated by the following methods, such as C20, C10, C5, and C2, which represent the actual capacity obtained when discharging at a discharge rate of 20h, 10h, 5h, and 2h, respectively.
If it is the capacity at a 20h discharge rate, the label should be a battery with C20, C20=10Ah, which refers to the capacity value obtained by discharging at a current of C20/20 for 20h. Converted to C5, that is to discharge at 4 times the current specified by C20, the capacity is only about 7Ah. Electric bicycles are generally discharged with high current within 1~2h, and lead-acid batteries are discharged within 1~2h (C1~C2). , which is close to 10 times the specified current, then the actual electric energy it can supply is only 50% to 54% of the C20 discharge capacity.
The battery capacity is marked as C2, that is, the capacity marked at the rate of 2h discharge. If it is not C2, it should be calculated to obtain the correct discharge time and capacity. If the capacity indicated by the 5h discharge rate (C5) is 100%, if it is changed to discharge within 3h, the actual capacity is only 88%; after discharge within 2h, only 78%; after discharge within 1h, only 5h of discharge is left. 65% of the capacity. The indicated capacity is assumed to be 10Ah. So now, only 8.8Ah of actual power can be obtained by discharging for 3h; if it is discharged for 1h, only 6.5Ah can be obtained, and the discharge rate can be reduced at will. The discharge current > 0.5C2 not only reduces the capacity than the marked, but also affects the life of the battery. There is also a certain impact.
Similarly, for a battery with a marked (rated) capacity of C3, the discharge current is C3/3, that is, ≈ 0.333C3. If it is C5, the discharge current should be 0.2C5, and so on.
14. What are the characteristics of secondary lead-acid batteries?
Common characteristics of secondary batteries: the negative electrode generates gas during charging, which surrounds the negative electrode, so that electrons cannot reach the negative electrode for electrochemical reaction, which not only affects the charging efficiency, but also causes the plate to heat up, the electrolyte evaporates, and the concentration changes. The lead-acid battery electrolyte will evaporate and thicken, which will promote the vulcanization of the plate, reduce the charging efficiency, reduce the capacity, and finally cause the battery to be scrapped.
All batteries should not be over-discharged. Over-discharge is at the expense of shortening the life. The discharge should not be lower than the discharge termination voltage.
15. Why should lead-acid batteries be fully discharged once a month?
If the lead-acid battery is in a state of incomplete discharge for a long time, it should be given a chance to fully discharge once a month to maintain the activity of the battery plate material. Full discharge can run for a long distance until the controller under-voltage protection, automatic cut-off.
16. What are the unfavorable factors for lead-acid batteries?
There are many factors that are unfavorable to the battery, mainly in the charging and discharging stage.
1. The "second super" discharge stage is mainly due to the excessive discharge current, that is, the discharge exceeds the allowable current value for a long time; the second problem of discharge is overdischarge, that is, the discharge exceeds the allowable discharge of the battery, which is called "second super", which is very harmful to the battery life. .
2. "Two overs" and "two debts" charging stage include "two overs" and "two debts".
(1) "Two passes": one is overcharging; the other is that the lead-acid battery is not used for too long, and the power is replenished from time to time.
(2) "Two owes": one is that the lead-acid battery is undercharged, the battery is often not fully charged, and the plates cannot be restored in time after vulcanization, which is extremely taboo for lead-acid batteries; the other is that the cells in the battery pack are not fully charged. The under-balance between the batteries causes the gap between the discharge level and the charge level of the individual cells in a group of batteries to become larger and larger, and the under-charged ones are more under-charged, and the over-discharged ones are more over-discharged. Affect the life of the entire battery pack, but also increase their economic expenses.
"Two overs" and "two owes" are the great enemies of batteries and should not be underestimated. However, "two overs" and "two debts" are caused by people themselves, and the problems are more complicated. There are many reasons, ranging from model selection, use and maintenance, rationality of matching controllers and chargers, and timely detection of battery failure reasons. Detection, etc., they are linked to each other.
17. What is the reason for the temperature rise of the new lead-acid battery after adding the electrolyte?
After the new battery is added to the electrolyte, the temperature rise is related to the internal factors of the new battery. The temperature of the dry-charged battery increases after adding liquid, but the temperature of the battery is not very obvious. This is because the dry-charged electrode plate has undergone anti-oxidation treatment, and the battery is in a fully charged state. , Without anti-oxidation treatment, the negative plate is in a half-charged state, and a considerable part of the material is in the reaction of lead oxide and dilute sulfuric acid to generate a lot of heat, so the temperature is very high. In summer, the temperature sometimes reaches more than 50 ℃, so it is necessary to pay attention to artificial cooling when charging.
18. How to maintain the consistency of the battery pack?
Although lead-acid batteries have been strictly controlled and selected when they leave the factory, after a certain period of use, the unevenness will appear and gradually become larger, and the charger does not have the option and identification. The charging limit and how to balance the battery capacity must be done by people. In the middle and late use of the battery pack, the user regularly and irregularly measures the open circuit voltage of each battery. For batteries with a lower voltage, supplementary charging is required to make their voltage and capacity consistent with other batteries, and try to reduce the gap between them.
19. Can lead-acid batteries be supplemented with distilled water?
Valve-regulated sealed maintenance-free lead-acid battery is different from other batteries. In fact, it cannot be completely maintenance-free, but can only reduce the maintenance workload, with less electrolyte evaporation and no leakage. Since the charger has not yet reached the fully ideal level, a small amount of evaporation of water is still unavoidable. For users who have a little knowledge of batteries, and the capacity has dropped significantly, you can consider adding water appropriately to restore the electrolyte to the original concentration or appropriately lower than the original concentration, which is more beneficial to the plate.
20. What are the main components of lead-acid battery electrolyte?
It is a mixture of sulfuric acid and distilled (or deionized) water.
21. What kinds of common lead-acid battery tanks (shells) are there?
Common battery cells include hard rubber and polypropylene for automobiles, motorcycles, and traction battery cells, ABS sealed battery cells, and a small amount of polystyrene battery cells.
22. What are the common lead-acid battery separators?
Common battery separators include rubber separators, PP separators, PE separators, PVC separators and AGM separators.
23. What are the alloys commonly used in the manufacture of lead-acid batteries?
The alloys used in the manufacture of lead-acid batteries mainly include lead-antimony alloys, lead-low antimony alloys, lead-antimony-cadmium alloys and lead-calcium alloys.
24. What are the charging methods for lead-acid batteries?
There are mainly constant current charging, constant voltage charging, constant current voltage limiting charging, equalizing charging, floating charging and pulse fast charging.
25. What is the relationship between the electrolyte density of the lead battery and the open circuit voltage?
Open circuit voltage = 0.85 + electrolyte density (empirical formula)
26. What does the plate capacity of lead-acid batteries depend on?
It mainly depends on the amount of active material in the positive and negative plates.
27. What are the main components of the active material of the positive and negative plates of the lead battery?
The main component of the active material of the positive plate is lead dioxide, and the main component of the active material of the negative plate is lead sponge.
28. Why does the lead-acid battery have a pungent smell when charging?
During the charging process of the battery, the mixed substances such as sulfuric acid vapor, water vapor, hydrogen and oxygen generated inside the battery escape and diffuse into the air, which will make people feel a pungent odor.
29. What is lead-acid battery floating charging and equalizing charging?
Float Charge: A battery that supplies power to the circuit when the normal power supply is interrupted. Its terminals are always connected to the constant voltage power supply to maintain the battery in a state of near full charge.
Equalization Charge: A continuous charge to ensure that all cells in a battery pack are fully charged.
30. What are the reasons for the sulfation of lead-acid battery raw plates?
The reasons for the sulfation of the plates are as follows:
1) The initial charge of the battery is insufficient or the initial charge is interrupted for a long time;
2) The battery is not charged enough for a long time;
3) Failure to charge in time after discharge;
4) Frequent overcharge or low current deep discharge;
5) If the density of the electrolyte is too high or the temperature is too high, lead sulfate will be deeply formed and difficult to recover;
6) The battery has been put on hold for a long time, and it is not used for a long time without regular charging;
7) The electrolyte is impure and the self-discharge is large;
8) The local action of internal short circuit or the leakage of water on the battery surface;
9) The electrolyte level inside the battery is low, so that the exposed part of the plate is sulfated.
31. What are the requirements for the storage of lead-acid batteries?
The ventilation facilities are required to be good and dry (air conditioners are best), and the ambient temperature should be kept at about 25 °C; the ground bearing capacity should be strong; after 3 months of storage, supplementary electricity should be used.
32. What is the difference between colloidal lead-acid batteries and automotive lead-acid batteries?
The difference between colloidal lead-acid batteries and automotive sealed lead-acid batteries is that the inner plates, separators, and colloidal electrolytes of colloidal batteries are packed more tightly, and there is almost no spare space in the single battery box; in addition, colloidal batteries have an optimal job point, glue
The end-of-charge voltage limit of a single cell of the bulk battery is between 2.32 and 2.35V. The charge-discharge acceptance capacity, lifespan, and the ability of deep discharge of the electrolyte can be exerted. If the end-of-charge voltage exceeds this value, the shell of the gel battery is prone to bulge or even rupture. .
The gel battery is a liquid-rich battery with large heat capacity and good heat dissipation. Generally, thermal runaway will not occur. However, if the charging voltage exceeds 2.4V, the critical voltage is reached, the water is rapidly decomposed, the battery heats up rapidly, and the added substances in the electrolyte expand rapidly. , causing the battery case to swell and rupture. The higher the voltage, the faster the action, and the faster the water loss, expansion and damage. Gel batteries are easy to be undercharged in winter, and are easy to damage and reduce battery life in summer.
33. What is three-stage charging of lead-acid batteries?
The charging method of lead-acid batteries should be divided into three stages, namely: constant current charging - constant voltage charging - trickle charging.
Constant current charging stage: charge to 13.4V with a current of 1.7A.
Constant voltage charging stage: 14.7V (single battery), charging time 3h, cut-off current 0.35A
Trickle charging stage: 13.9V (single-cell battery), when the charging current is less than 100mA, it is considered sufficient.
34. Why should the lead-acid battery be charged by the three-stage charging method?
At the beginning of charging, the battery has a strong acceptance ability. This feature can be used to charge the battery with a large current, so that the battery can quickly get enough power to save time and power. When the charge reaches a certain level, in order to prevent the voltage from exceeding the limit, it should be automatically transferred to And limited to a constant voltage value, limit the voltage to continue to rise, to prevent the voltage from exceeding the end of the charge, so that the battery plate is damaged.
However, after charging in this way, due to the inhomogeneity of the material of the battery plates, some materials are still not completely reduced. If these materials are in a vulcanized state for a long time, they may become permanent lead sulfate and can no longer be reduced. The capacity of the battery will be damaged and gradually decrease.
Therefore, at the end of the charging, a trickle charge should be carried out to make a small part of the sulfide hidden in the deep inside reduce as much as possible, so that the charging level of the plates in one battery can be uniform inside and outside, and the plates of several batteries can also be charged. Try to be as uniform as possible.
