1998 Honda Prelude Owner's Manual - Page 190

Battery If the terminals are severely corroded, clean them with baking soda and water. Then use a wrench to loosen and remove the cables from the terminals. Always disconnect the negative ( -) cable first and reconnect it last. Clean the battery terminals with a terminal cleaning tool or wire brush. Reconnect and tighten the cables, then coat the terminals with grease. Check the battery terminals for corrosion (a white or yellowish powder). To remove it, cover the terminals with a solution of baking soda and water. It will bubble up and turn brown. When this stops, wash it off with plain water. Dry off the battery with a cloth or paper towel. Coat the terminals with grease to help prevent future corrosion. If you need to connect the battery to a charger, disconnect both cables to prevent damage to the vehicle's electrical system. The battery gives off explosive hydrogen gas during normal operation. A spark or flame can cause the battery to explode with enough force to kill or seriously hurt you. Wear protective clothing and a face shield, or have a skilled mechanic do the battery maintenance. CONTINUED Maintenance