Before doing any service to it, 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. Headgear with a full face shield, such as sold by Eastwood, is even better than goggles because it protects your facial skin..
Your collector cars may require more battery maintenance than your modern, everyday car. It depends on the vintage of your car and whether or not you have installed a old-fashioned battery or a modern, maintenance-free type.
Even if your collector car was made 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 ads in hobby publications.
On batteries with filler caps, battery fluid levels need to be checked regularly and maintained. To inspect the fluid level, all you need to do is twist the battery cell caps counter-clockwise to remove them and look into the opening. The fluid should be level with the filler ring, which is about an inch down in the opening. If the fluid is not up to that level, add distilled water until it is.
If you discover that the fluid level in your battery drops rapidly and constantly, it can indicate three types of problems. The electrical system may be over-charging the battery, the battery case may be cracked and leaky or the battery could have suffered some kind of internal damage. The last two problems require replacement of the damaged battery.
If your battery fluid level seems OK, the next step in maintaining it is to clean the battery terminals. Remove the battery cable connectors so you can get at the terminals. To avoid making a spark, disconnect the negative cable first. Later, it should be the last cable that you reconnect.
When reconnecting the cables, you can protect against future corrosion with a light coat of petroleum jelly, light grease or a spray-on protectant available in auto supply outlets. You can also buy red and green felt rings, impregnated with protectant, that slip over the terminals.,
You can use a commercial terminal cleaner or a solution of baking soda and water to clean the battery terminals. After applying the cleaner, brush the terminals until they are nice and shiny and be careful not to get cleaner or baking soda in the battery.
Determining the batteries state of charge can be accomplished by measuring the specific gravity (density) of the fluid in each cell with a device called an hydrometer. Simple battery testers are also available in auto parts stores. An hydrometer reading of 1.275 indicates a fully charged battery. Some hydrometers have floating balls inside the tester and give you a reading based on how many balls float in a test sample of the battery fluid. If one cell gives a reading 10 percent less than other cells, it indicates high resistance in that cell and the battery needs replacement.
Carefully clean the top of the battery of dirt, corrosion and battery fluid without getting anything on your skin. Also, be sure that the vent holes in the battery filler cups aren’t clogged. If you see cell damaged cell caps or any battery warpage, the battery is no good. It has either been over-charged or over-heated. There should be no cracks in the battery case.
A battery should never be installed loosely in a car. Some type of battery hold-down system is a must. A loose battery can cause acid spills or it can short out and cause a fire. In an accident, a loose battery can go flying through the car. The hold-down system should be tight enough to secure the battery, while not putting so much pressure on it as to crack the battery case. Rusty hold-down systems invite the formation of corrosion. Make sure the hold-down mechanism has a heavy coat of paint and coat bolts and nuts with gease or spray-on protectant so they remain easy to remove.
Be aware that the designs of some old-car batteries have changed slightly. For instance, the long, narrow EEE batteries used in some ‘40s and ‘50s cars are being manufactured today with the terminals spaced further apart. If the battery still has a factory-installed metal cover, the terminals on the newer-design battery may hit against the metal cover. This condition has been known to cause electrical shorts and fires. Make sure that your battery terminals and bare braided cables aren’t touching any part of a metal hold-down system.
When installing a battery in an old car, make sure that it is of the proper voltage for the car and correctly grounded. Many old cars right through the ’50s ised 6-volt electrical systems and require a 6-volt battery. Some old cars also came from the factory with positive-ground electrical systems. If you own a positive ground car, the + cable is the one that goes to the car’s frame – not the one that goes to the solenoid or starter! Reversed polarity can cause and explosion or can damage your car’s electrical system components.