Nothing disrupts productivity like a dead battery. Whether it's your TV remote failing at a critical moment or your fire alarm chirping at 3 a.m., battery failures are frustrating. But when that dead battery was meant to power a forklift for an entire workday, the consequences are far more serious. One of the primary culprits behind lead acid batteries failing to hold a charge is battery sulfation.
What Is a Sulfated Battery?
A lead acid battery contains multiple cells, each featuring lead anodes and cathodes immersed in an electrolyte solution of sulfuric acid and water. During electricity generation, the sulfuric acid breaks down into sulfate and hydrogen atoms. The sulfate naturally bonds with lead on either the anode or cathode, creating lead sulfate. When properly recharged, this process reverses, separating sulfate from the lead and returning it to the electrolyte solution.
However, problems arise when batteries are consistently undercharged. Some hardened lead sulfate remains attached to the lead plates. Once this buildup begins, it compounds with each charge cycle, resulting in a sulfated battery.
Recognizing the Signs of Battery Sulfation
While you can't visually inspect sulfation without opening the battery (which isn't recommended), several performance issues indicate potential sulfation:
- Decreased runtime
- Inability to maintain a charge
- Extended charging times (sulfation increases internal resistance)
- Difficulty starting your forklift
- Low battery voltage
- Poor cold storage performance (cold storage conditions already reduce a battery’s capacity; when combined with sulfation, the performance can be further compromised).
- Visible corrosion
- Bulging or swollen battery case (indicating severe sulfation requiring replacement)
What Does sul Mean on a Battery Charger?
Many modern battery chargers can identify sulfation through specific error codes, often labeled as "SUL." Common status indicators include:
- F01—Battery voltage is less than 10
- F02—Charger unable to desulfate
- F03—Battery cannot reach full charge
- F04—Reversed connection
- F05—Unable to maintain charge/decreased efficiency
Can Sulfated Batteries Be Recharged?
The answer is nuanced. If there's no external damage like corrosion or case swelling, charging remains possible, but there's no guarantee the charge will fully take or last. Also, it is important to use caution. Charging a sulfated battery can generate excessive heat, potentially causing further damage or creating workplace hazards.
How to Desulfate Battery Corrosion
Not all sulfation damage can be reversed. "Hard" sulfation is permanent, requiring battery replacement. However, when the sulfation is “soft,” there are techniques that could help salvage the battery.
Using a long, slow charging cycle with low current can actually dissolve those stubborn lead sulfate crystals and bring your battery back to life. This method works by slowly breaking down the hardened sulfates so they can mix back into the electrolyte solution where they belong.
Another technique is equalization charging, which basically means giving your battery a controlled overcharge at a slightly higher voltage than normal. This extended charging process helps break down and dissolve the lead sulfate crystals, allowing the battery to recover its capacity and performance. It is essential to follow the manufacturer’s guidelines and recommendations to prevent overcharging and potential damage.
There are also specialized desulfation devices that employ high-frequency pulses and chemical additives to dissolve or reduce the sulfation buildup on the battery plates. The high-frequency pulses break down lead sulfate crystals, and the chemical additives help dissolve them.
It is also possible to physically remove lead sulfate by physically shaking or vibrating a battery to dislodge the lead sulfate crystals from the plates. This technique should only be performed by a professional because inexperienced, vigorous shaking can damage the delicate battery plates.
How to Prevent Battery Sulfation
The only way to prevent battery sulfation is through a routine battery maintenance schedule that ensures the batteries are regularly charged, properly watered and they avoid deep discharges. You should follow the manufacturer guidelines to ensure proper charging procedures because maintaining optimal charge levels helps prevent sulfation from occurring.
Also, avoid exposing lead acid batteries to extreme temperatures. High temperatures can accelerate sulfation. So, store your batteries in a cool, dry environment when they are not in use.
Professional Forklift Maintenance Solutions
For industrial applications, professional preventive maintenance programs offer significant benefits. Regular scheduled service addresses potential battery issues before they become costly problems, protecting both your equipment investment and workplace safety.
Consider a comprehensive fleet performance analysis to ensure you're using optimal batteries for your specific applications, maximizing uptime and operational efficiency.
For all your industrial battery maintenance and repair needs, Concentric can help keep your equipment running at peak performance.