What is sulfation of a lead-acid battery?
If a lead-acid battery remains in a state of deep discharge for a long time, it will suffer a sulfation process. Some of the sulfuric acid will combine with the lead from the plates to form lead sulfate. If the battery is not topped up periodically with distilled water, part of the plates will remain exposed to the air and the process will be acelerated. The lead sulfate covers the plates in such a way that the electrolyte cannot penetrate them. This means an irreversible loss of battery capacity that even with the addition of water, cannot be recovered.
