A car battery is one of the most important parts of a car. Without the charge it provides, the engine of a vehicle won't start and, consequently, the vehicle won't get anyone anywhere. For this reason, properly maintaining a car battery is crucial if a person wants to travel in his own vehicle.
Make sure that the terminals of the battery are free from dirt and corrosion. Corrosion happens on battery terminals when the metal of the terminal oxidizes. Some corrosion is normal, since it is impossible to prevent exposure of the terminals completely. Usually it looks like green fuzz, but this depends on precisely what the terminals are made of and what oxidizing agent they are exposed to, since oxidization is a chemical process. Clean off the terminals with a wire brush until all the corrosion is gone. Then wipe the terminals with a baking soda paste and wipe clean.
Check to see that the battery is not wet and that it is clean. All batteries eventually lose some charge because it is impossible to keep every electron in the atoms of the battery material from transferring a charge; neutrality is always sought in nature. Dirt and moisture act as conductive agents that allow energy to seep out of the battery prematurely. Keeping the battery dry and clean therefore helps to maintain the battery charge.
Make sure the water level in the battery reaches the filler neck. This applies only to batteries that can be opened (ones that have caps). Car batteries require an electrolyte solution to convert energy for use by the car. If the solution is too low, then the battery cannot make the energy conversion, so add some distilled water (not tap) to the battery if the level is low.
Check the charge of the battery occasionally with a tester. The result you get on the tester may indicate that the charge of the battery is not optimal even if the battery is still functioning. This can serve as a signal to you that the battery is leaking energy somewhere or that the condition of the battery does not allow for proper energy conversion (e.g., low electrolyte solution level). You then can take appropriate action to clean terminals and the battery and to check the electrolyte solution if applicable.
Follow the manufacturer's instructions when using a battery charger. It's never ideal to charge a dead battery, but if you have to do so, then make absolutely sure that you are connecting your charging device properly. Improper connections can damage the battery to the point of uselessness.
