Battery sulfation: what it is and why timing matters.
Sulfation is associated with lead-acid battery chemistry. It is often discussed as a cause of reduced performance, but not all sulfation is equally reversible.
What happens
Lead-acid operation naturally involves lead sulfate. Problems arise when sulfate crystallization becomes persistent, particularly when a battery spends extended periods inadequately charged.
Soft vs hard sulfation
Early/reversible sulfation is sometimes described as “soft” sulfation. Long-standing crystal growth can become “hard” or permanent sulfation and is substantially more difficult to reverse. That is why blanket promises to revive any sulfated battery deserve skepticism.
Prevention is stronger than rescue
Correct charging and avoiding prolonged undercharged storage are important parts of lead-acid battery care. Follow the battery/charger manufacturer's requirements rather than applying a generic charging recipe.