1997 Ford Expedition Owner's Manual - Page 176
1997 Ford Expedition Manual
Page 176 highlights
Maintenance and care Batteries contain sulfuric acid which burns skin, eyes, and clothing. Servicing your battery A low-maintenance replacement battery has removable vent caps for checking the electrolyte level and adding water. Check the electrolyte level every 24 months or 40,000 km (24,000 miles) in average temperatures below 32°C (90°F). Keep the electrolyte level in each cell up to the level indicator. Do not overfill. If the level gets low, refill the battery with distilled water. If the battery needs water quite often, have the charging system checked for a possible malfunction. Your vehicle is equipped with a battery saver feature designed to prevent your battery from accidental wear down due to doors left ajar. For information on this system, refer to the Controls and features chapter. 177