Now that you know what voltage the battery has, for the sake of argument we’ll say the charge was low. If the battery won’t take a charge additional steps need to be taken.
Use a hydrometer to check the levels of water and sulfuric acid in the electrolyte. This is where the exact battery charge is determined. If water levels are low add distilled water to fill the compartment. An important thing to remember when dealing with car batteries is safety. Electrolyte is extremely acidic and will burn a car’s paint. It will also burn holes in clothes. A good safety precaution to take when performing battery maintenance is to wear protective eye coverings like safety goggles.
If after all of these diagnostic tests, the car battery still won’t hold a charge it may be time to consider purchasing a new battery. However if the battery passed all of your hard fact hunting tests, and the car still isn’t starting on a reliable basis, the problem may be the battery connection.
In this situation the first thing to tackle is cleaning the clamps and cables. Taking a look at the clamps, use a mild solution of cold water and baking soda to clean with. A soft, non-abrasive toothbrush would be the best choice to use for scrubbing. Scrub gently to remove any gunk build up. Be sure to rinse the area thoroughly with clean water.
Next take the clamps off. If they are difficult to remove, don’t try to force them. It may be time to invest a special tool for this purpose, the battery clamp removal tool. Use the same method of water and baking soda to clean the clamps. Be sure to clean the top of the battery top, posts, and clamps adequately. It is important to keep a battery dry and clean to get the most life from it.
Maintaining a car battery may involve some time and effort on your part, but the pay off can be huge. Making battery maintenance part of your car care routine can prolong the life of the battery and save some frustration when you have to be somewhere immediately.