Quick Answer
Sulfation in flooded lead-acid batteries is characterized by swelling, increased internal pressure, and a decrease in battery capacity. The battery may also produce a hissing sound when charging, and sulfation typically occurs after prolonged periods of inactivity or deep discharge. A sulfated battery can be identified by its reduced performance and lifespan.
Recognizing the Symptoms of Sulfation
Sulfation occurs when lead sulfate builds up on the plates of a lead-acid battery, reducing its ability to hold a charge. One of the first signs of sulfation is a decrease in battery capacity, which can be measured using a hydrometer or a multimeter. A sulfated battery may take longer to charge and hold less charge overall, resulting in a decrease in overall system performance.
Diagnosing Sulfation with the “Bubble Test”
The “bubble test” is a simple method for diagnosing sulfation. To perform the bubble test, charge the battery and then disconnect the charger. Allow the battery to rest for a few minutes, then reconnect the charger. If bubbles form on the surface of the electrolyte, it’s a sign that the battery is sulfated. The number of bubbles can indicate the severity of the sulfation. For example, a few small bubbles may indicate minor sulfation, while a large number of bubbles or a loud gurgling sound indicates severe sulfation.
Preventing and Treating Sulfation
Preventing sulfation is easier than treating it. Regular maintenance, such as keeping the battery terminals clean and charging the battery regularly, can help prevent sulfation. If a battery is already sulfated, treatment involves deep discharging the battery (to around 10.5V) and then recharging it to 14.4V. This process can help break up the lead sulfate crystals and restore the battery’s capacity. However, this method may not completely eliminate sulfation and may need to be repeated multiple times. Replacing the battery is often the most effective solution if it has become severely sulfated.
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