How high should the electrolyte level be in a properly serviced lead-acid battery?

• A. At the bottom of the cell
• B. Up to the level of the indicator in the cell
• C. Just above the separator
• D. At the top of the cell

Answer: (B)

In a properly serviced lead-acid battery, the electrolyte should be brought up to the indicator in each cell. That indicator marks the maximum safe level, ensuring the plates remain submerged for proper chemical reaction without risking overflow. If the level drops below the indicator, the plates can become exposed, leading to sulfation and loss of capacity. If it’s kept too high, charging can push electrolyte out through vents, causing water loss and potential corrosion. Always check when the battery is at rest and cool, and use distilled water to bring the level up to the indicator.