The electrolyte is prepared by mixing a specialized sulfuric acid with distilled water in a specific ratio, typically having a density of 1.24–1.30 g/cm³. Its specific gravity ranges from 12.75 to 12.85 g/cm³ when sulfuric acid is combined with pure water. If water is consumed during battery operation, simply add distilled water and recharge the battery.

For example, the electrolyte in a lead‑acid battery is prepared by mixing 80% sulfuric acid with distilled water in a specific ratio, typically resulting in a density of 1.24–1.30 g/cm³ and a specific gravity of 12.75–12.85 g/cm³. Some lead‑acid batteries—such as those used in motorcycles—require the electrolyte to be replenished manually; therefore, extreme caution is essential during refilling, and care must be taken to prevent contact with eyes or ingestion.

If the battery loses water during use, simply top it up with distilled water and recharge.

Electrolyte is not merely a shorthand for electrolyte solution; rather, it encompasses a broader range, including both aqueous solutions of electrolytes and electrolytes in the molten state.