After successfully removing the old, dead battery from your car, it is time to install the new one. The first step in this process is to purchase the correct battery for your vehicle. Automotive batteries are available in a variety of sizes and electrical capacities, and the exact model you need will depend on the car or truck you drive. You can use the old battery as a reference for finding the correct replacement, but it is always wise to double check in the owner's manual, just in case.
When you go to buy a new battery, bring the old one along. In some states, drivers are required to hand over old batteries in order to get new ones. This can also cancel out a fee that is charged for the purchase of a battery in certain states. Most auto parts stores are equipped to properly recycle the used battery, as you cannot just toss it in the trash. Otherwise you'll need to find a special waste drop-off site that accepts car batteries.
You will need a few other products to install the battery, so this trip is a good time to purchase anything you're missing. Battery terminal cleaner, corrosion protector and a hard-bristle brush should be all you need, as long as you've got a wrench or pliers ready to go at home.
Once you've secured your new battery, the time has come to install it and get your car running again. With the car parked on a flat surface, pop the hood and check to make sure you've thoroughly cleaned the tray and terminal clamps. Then, place the battery in the tray with the positive and negative terminals on the correct sides. Refer to the owner's manual for assistance if you are unsure which way to place the battery. The terminals may have colored caps to help you remember which side is positive and which is negative. Leave these on until you're ready to connect the terminal clamps.
The process of installing the battery is precisely the opposite of removing the old one. Start by securing the bracket to hold the battery in place. Then, remove the plastic cap (red) from the positive terminal and give the terminal post a once over with a brush and battery terminal cleaner. Doing so will scratch the surface of the post to make it easier to secure the clamp, which also helps the battery recharge while the engine is running. Add a coat of corrosion protector to prevent excessive corrosion from forming around the terminals, which may happen over time if you are not vigilant when it comes to battery maintenance.
After prepping the terminal post, grab the positive terminal clamp and slide it over the post. Lower it to the base and then secure whatever support your car provides to hold the clamp in place. This prevents the clamp from sliding off the post, which can occur when you drive over bumpy roads if it is not secured. Repeat these steps for the negative terminal. As with removing the old battery, be careful not to touch your tools to any metal parts of the car.
You're done once the negative terminal clamp is secure. Hop in the driver's seat, put the key in the ignition, cross your fingers and try to start the car. If your initial diagnosis was correct, the vehicle should start right up. If not, check the terminal connections one more time. If they look fine, you may be dealing with other ignition issues. When this is the case, address the problem as soon as possible or your new battery could be drained and you'll have to replace another one sooner than you'd like.