The average car battery has a life-expectancy of 3.5–5 years, meaning that you’re probably going to have to deal with the process of replacing one at least once during your ownership of your car. Replacing a defunct battery is not difficult, but can be dangerous. Be sure to wear insulated gloves and protective eye-gear, and to consult your vehicle’s owner manual before you begin the process.
Make sure that the car is turned off completely before beginning the procedure. Start by opening your car’s bonnet and locating the battery. Use battery pliers or a battery wrench to loosen the nut holding the black cable in place. Twist the black cable while pulling up on it to remove it from the wire (if the cable doesn’t come free, you may either have to scrub away some of the corrosion holding it in place, or use a battery terminal puller, so as not to damage the cables). Using the same method, detach the red cable.
Use a socket wrench to remove the clamp holding the battery in place. Lift the battery free from its housing, and set it aside (do not throw the battery away; instead, take it to a local automotive store and have them recycle it). If there is corrosion left behind after removing the battery, use a mixture of bi-carbonate soda and water to scrub it away. Allow the casing to dry. Place the new battery in the tray, and re-secure the holding clamp. Attach and secure the red cable to the positive (+) connector, and then attach and secure the black cable to the negative (-) connector. Make sure that both cables are totally secure and immovable. Test the battery connections by starting your car. Close the bonnet.