The problem of sulfation in forklift lead-acid batteries: Causes and Repair

Time：2025-07-16 15:49:53

Browse：613

This article will delve into the causes and repair methods of sulfation in forklift lead-acid batteries and answer related questions.

During the operation of forklifts, the performance of lead-acid batteries directly affects the working efficiency and service life of forklifts. Sulfation is one of the common faults of lead-acid batteries in forklifts. It can lead to a significant reduction in battery capacity and deterioration of charging and discharging performance, causing great trouble to the normal operation of forklifts. This article will delve into the causes and repair methods of sulfation in forklift lead-acid batteries and answer related questions.
1. The Concept of sulfation of Lead-acid Batteries for Forklifts
Sulfation of forklift lead-acid batteries refers to the formation of lead sulfate crystals that are difficult to dissolve on the battery plates due to a series of chemical changes. During normal charging and discharging processes, lead sulfate is also produced on the plates. However, these lead sulfate are fine crystals that can redissolve during charging and participate in chemical reactions. The lead sulfate crystals produced by sulfidation are large and hard. They adhere to the surface of the plates, hindering the chemical reactions inside the battery, leading to a decrease in battery capacity, poor charging and discharging performance, and in severe cases, even battery scrapping.
2. Causes of Sulfation in Forklift Lead-Acid Batteries
(1) Factors related to charging
1. Long-term undercharging: During the daily use of forklifts, if the charging time is insufficient, the battery cannot be fully charged, and the lead sulfate on the plates cannot be completely converted into active substances. Over time, unconverted lead sulfate will gradually crystallize, forming sulfidation. For instance, some forklift operators, in order to save time, often stop charging the battery before it is fully charged. If they operate in this way for a long time, it is easy to cause sulfation.
2. Excessively high or low charging voltage: Excessively high charging voltage can cause intense chemical reactions inside the battery, accelerating the corrosion of the plates and the crystallization of lead sulfate. If the charging voltage is too low, the lead sulfate on the plates cannot be fully decomposed, which will also lead to sulfation.
(2) Discharge-related factors
Failure to charge in time after discharge: After the forklift has completed its operation, if the battery is discharged and not charged in time, the lead sulfate on the plates will gradually crystallize during the static process, forming sulfidation. For instance, if a forklift is not promptly connected to a charger for charging after a day's work and is left unused overnight, the risk of sulfation may increase.
2. Over-discharge: When the forklift battery is discharged below the terminal voltage, a large amount of lead sulfate will form on the plates. This lead sulfate is difficult to fully recover during charging and is prone to sulfation. Some operators do not pay attention to the battery power when using forklifts and do not stop using them until the battery is completely drained. This kind of excessive discharge behavior is very harmful to the battery.
(3) Electrolyte factors
1. Excessively high electrolyte concentration: If the electrolyte concentration is too high, it will cause an excessive number of sulfate ions inside the battery. During the discharge process, these ions tend to combine with lead on the plates, forming coarse lead sulfate crystals and triggering sulfation. Moreover, a high concentration of electrolyte will also accelerate the corrosion of the plates.
2. Low electrolyte level: When the electrolyte level is lower than the upper edge of the plates, the plates will be exposed to the air. After contact with the air, oxidation reactions are prone to occur, and it will also lead to an increase in the concentration of the electrolyte, thereby causing sulfidation. This situation may occur in daily use if the electrolyte level is not checked regularly and distilled water is not replenished in time.
(4) Idle factors
If a battery is left idle for a long time and not fully charged before being idle, the lead sulfate on the plates will gradually crystallize, forming sulfation. Many enterprises do not pay attention to the maintenance of batteries when forklifts are idle, thereby increasing the probability of sulfation.
3. Repair Methods for Sulfation of Lead-Acid Batteries in Forklifts
(1) Pulse repair method
The pulse repair method utilizes high-frequency pulse current to shatter and decompose the lead sulfide sulfate crystals on the battery plates, thereby converting them back into active substances. The specific operation is to connect the pulse repair instrument to the battery, set the parameters according to the instrument manual, and carry out the repair for a certain period of time. This method is simple to operate and has a good repair effect, and is suitable for moderately sulfated batteries.
(2) Water replenishment repair method
When the electrolyte level is too low, causing sulfation, the water replenishment repair method can be adopted. First, open the battery cover plate and check the liquid level of each single cell. Then, add distilled water to the cells with a low liquid level to bring the liquid level to the specified height. After replenishing, let it stand for a while before charging. It should be noted that tap water or electrolyte should not be replenished to avoid affecting the battery performance.
(3) Balanced charging repair method
The balanced charging repair method involves charging the battery with a small current for a long time to fully decompose the lead sulfate on the plates. The specific steps are as follows: First, charge the battery normally, then disconnect the charger, let it stand for 1 to 2 hours, and then reconnect the charger. Charge it with a small current (usually 1/20 of the battery's rated capacity) until the battery voltage and electrolyte density stabilize. This method is applicable to batteries with mild sulfation.
4. Frequently Asked Questions
(1) How to prevent sulfation of forklift lead-acid batteries?
To prevent sulfation of forklift lead-acid batteries, it is necessary to start from daily use and maintenance. First of all, it is necessary to ensure that the battery is fully charged to avoid long-term undercharging and failure to charge in time after discharging. Secondly, it is necessary to control the charging voltage well to avoid it being too high or too low. Furthermore, it is necessary to regularly check the electrolyte level and concentration, replenish distilled water in a timely manner, and keep the electrolyte concentration within the specified range. Finally, when the forklift is idle for a long time, the battery should be fully charged first and regular supplementary charging should be carried out.
(2) Are there any differences in the repair methods for different degrees of vulcanization?
Yes, different degrees of vulcanization require different repair methods. For batteries with mild sulfation, the equalization charging repair method can be adopted. For moderately sulfated batteries, the pulse repair method is a relatively effective approach. For severely sulfated batteries, since the lead sulfate crystals on the plates are already very hard, the repair is rather difficult and may require the replacement of the plates or the battery.
5. Summary
Sulfation of forklift lead-acid batteries is an important factor affecting battery performance and service life. Its causes are mainly related to charging, discharging, electrolyte and idleness, etc. By adopting appropriate repair methods such as pulse repair, water replenishment repair and balanced charging repair, the performance of the battery can be restored to a certain extent. At the same time, doing a good job in daily prevention can effectively reduce the occurrence of sulfation, extend the service life of the battery, and ensure the normal operation of the forklift.

Statement: The articles on this site are written by the GSGT team or reprinted from other media or compiled by AI.No reproduction without permission.For copyright or other issues, please contact:gsgtpower@163.com.

News

The problem of sulfation in forklift lead-acid batteries: Causes and Repair

24V/VCF6A lead-acid battery NICHIYU FBR9 forward forklift battery factory direct supply

24-7PBS/560M Forklift Battery for Hyster E40XN 48V 560Ah Excellent in Both Price and Quality

24V/4HPzS620 Lead-Acid Battery for ForkLifts and Hyster N30XMR3 Special Battery for ForkLifts

24-6PZS480 48V480Ah Lead-Acid Battery The Best Partner for CLARK EPX20S Series ForkLifts