Before doing any service to a battery, keep in mind that the storage battery in your car produces gases that can explode if a spark or flame ignites them. Also keep in mind that the fluid inside the battery is acidic; it can eat away paint, metal and skin. Wear heavy chemically resistant rubber gloves and eye protection when working near a battery. A full face shield is better than goggles because it protects your facial skin. Even if your collector car was manufactured before sealed batteries became standard equipment, you can use a sealed battery in it today. However, if you want the car to appear authentic under the hood, you may have purchased an old-fashioned-looking “tar-top” battery with removable filler caps. These are sold at many flea markets and through hobby publication ads.
This is a companion discussion topic for the original entry at https://www.hagerty.com/articles-videos/Articles/2007/05/02/Spring-Battery-Check-Up