Replacing a car battery is a relatively simple procedure most people can complete themselves in about half an hour or less. Using the appropriate tools and working in a well-ventilated area is important. The process also requires knowledge of the battery itself, how to remove the old one, how to install the new one, and important safety precautions.
Purchasing the correct automotive battery for the car ensures it will fit and work appropriately. Before replacing the car battery, the battery group number, reserve capacity, and cold-cranking amps should be written down. An automotive store or mechanic can advise customers on what type of battery to purchase based on the year, make, and model of the car if that information is not in the owner's manual. As long as it is the correct size, the new battery can have a higher reserve capacity and cold-cranking amps number. This may be helpful for people living in cold climates or those who want the car to be able to run longer if the alternator that charges the battery while driving stops working.
Before replacing a car battery, rubber gloves, a wrench, rags, baking soda, water, and a stiff bristled brush should be on hand. Wearing rubber gloves while removing the old battery and installing the replacement car battery protects the skin from battery acid, which can cause serious burns. Disconnecting the negative cable first is extremely important, as removing the positive cable first could start a fire. Using a sturdy wrench to completely loosen the clamps attached to the battery terminals makes it easier to pull the clamps off the battery and remove it from the car. Before taking out the old battery, the way it is facing should be noted to ensure proper installation of the new one.
Mixing a small amount of baking soda with warm water will help clean any corrosion off the clamps and battery tray. Using a stiff brush dipped in the mixture makes it easier to scrub off any rust or corrosion that could prevent the new battery from working. Carefully wipe away any excess moisture or battery acid. Wiggle the new battery slightly after placing it in the battery tray to make sure it is tight and facing the correct direction.
Always connect the positive cable first when replacing a car battery. Make sure the clamps are tight and are pushed all the way down on the battery terminals. If the car does not start after replacing the new battery, turn the vehicle off and re-tighten the cables. Since old car batteries contain dangerous acid and chemicals, it is best to consult a mechanic or auto parts store on correct disposal methods. Many stores that sell car batteries will recycle an old one for a small fee or for free.