A Guide To Car Battery Replacement

By laura.cox

Posted in: 

November 2, 2022

Any car owner will tell you that there are a few simple things you need to learn to do on your own if you want to save $1000s at the repair shop. The ones that top the list are being able to change a car tire, charge a car’s battery, and being able to handle a car battery replacement on your own. 

Did you know that car battery replacement alone can cost you anywhere from $50 to $250! That’s no small amount. Now, this might seem like a complex and frightening task to undertake on your own, but we’re here to help you. In this article, you will find all you need to know about car battery replacement, the safe way.

When is car battery replacement required?

If you have a brand-new car, then you don’t need to worry about car battery service or auto battery replacement. When your car hits the 3–5-year mark is when you’ll see signs of issues. The first sign is that your battery won’t be able to hold a charge. This means that you will find the car battery draining out rapidly soon after a charge. Here are a few signs that can help you figure out if your car battery is weak and can’t hold the charge like it used to:

  • When you try starting the car you notice that the engine takes more time than usual to start up. 
  • When you try starting the car, the engine doesn’t even start. 
  • When you turn the ignition, you might notice the dash lights flicker or are more dim than usual.
  • If the engine suddenly turns off when you use the power windows, or the power windows are slower and take longer to open and close.
  • If the headlights and dash lights are dim when the engine is idle and when you rev the engine, they get brighter.
  • If your car has a battery warning light and the light is on. 
  • If you look at the battery and notice a lot of corrosion or oxidation on the battery terminals.

The car battery can be found in a corner of the engine bay, near the windshield or the front bumper. It is a rectangular battery box which has 2 cables attached to it. At times, the box is underneath a plastic cover, so you will need to remove the cover to get to it. Some cars have the battery in the trunk rather than under the hood, so if you can’t find it check here and then in your owner’s manual.

Any of these signs is an indication that your battery is not able to produce enough power to carry out the actions it is meant to.

Still unsure if it is car battery replacement time? You can get a car battery service done before getting it replaced OR you can chat with an expert mechanic on JustAnswer. The mechanics can help you via chat or call, they will help you decode the signs your battery is displaying, and you can get the help you need, without a visit to the repair shop. 

Buying the right automotive battery for your car

Before you start the car battery replacement process, you need to first pick out the right car battery for your car. When it comes to car batteries, one size does not fit all. A battery that can power a hatchback will not work on an SUV. You need to be mindful of the power needs of your vehicle as the battery needs to be able to efficiently power your car's electronics. 

Understandably, it is confusing, apart from the power needs of your car, the battery needs to be of the right size and have the right CCA (Cold Cranking Amps) for your car. Sounds confusing? Don’t worry, we’re here to guide you through the process of choosing the right battery – 

Finding the right car battery size – there is an international standard sizing chart available that helps you choose the right automotive battery for your car. This battery equivalent chart by the Battery Council International (BCI) is easily found online and here batteries are grouped into standard sizes. The BCI has assigned a code to each battery that refers to the physical dimensions, terminals, and requirements for the car. Along with the code, you can find numbers and letters for each group size, and this signifies the car’s make, model, and engine size. It’s important to note that some cars and trucks can accommodate a battery of more than one group size, but it’s important to find one that is meant for your car.

Find the right car battery size for your vehicle
Finding the right CCA – 
If you live in a place where it can get very cold during the winter, you do not want to make the mistake of purchasing a battery with a low CCA for your car. If you accidentally buy a car battery below the recommended minimum Cold Cranking Amps for your make and model, you will notice that starting the engine, especially in cold climates will be tough or impossible.

Finding the right car battery design – There are 3 main battery designs you can find in the market – Flooded, Absorbed Glass Mat (AGM), and Thin Plate Pure Lead (TPPL) AGM. 

  1. Flooded batteries usually have lower CCAs, they don’t work too well in extreme heat or cold, and are not the best option for cars with a lot of electronic accessories like remote start, heated seats, etc. 
  2. AGM batteries have higher CCAs than flooded batteries, they work well in extreme heat or cold and are ideal for cars with a lot of electronic accessories. 
  3. Thin Plate Pure Lead (TPPL) AGM batteries have the highest CCAs, perform excellently in any weather condition, and can last 3x longer than flooded batteries.


Tip- if all this is too confusing, just look for the owner’s manual. Here you will have the exact battery details needed to buy the right used car battery or new car battery for your vehicle. If you don’t have an owner’s manual or have misplaced it, the next best thing would be to open up the car and take pictures of the battery. Most often you will find the battery information will be displayed on the top and sides of the battery. Take the image with you to the discount auto parts store or any auto parts store, also share the make, model, year, and engine size of your car. Based on this information they will source the right replacement car battery.

Can’t find the battery information on your own? Don’t worry, you can chat with an expert mechanic on JustAnswer. They will need a few basic details about your vehicle and based on this they will look up the battery equivalent chart and find the right battery. They might even ask you to share pictures of the existing battery or car and suggest batteries that can help you get the best performance for your vehicle. This way, you get the right battery and keep car battery replacement costs low. 

Steps to follow for car battery replacements

Now that you know a car battery recharge is not working, you’ve picked out your new replacement battery, and car battery replacement is the only option left, here’s what you need to do – 

Preparation tasks before replacing a car battery 

  1. Pick a spot to work – if you’re going to replace an automotive battery, it’s not something you would do on the fly. You would not do it in an emergency on the side of the road. Most likely you would do it at home, and even there you need to find the right spot to work. Choose a place like your garage or your driveway, somewhere away from traffic, sparks, open flames, and water. The place you choose also needs to be well-lit and well-ventilated.
  2. Park safely – when you’re busy with the car battery, your car should not roll away from you. Choose a level surface, engage the parking brake, and turn off the car. It’s even advised that you remove the keys from the ignition, this will ensure no power is going to the battery, even by accident.
  3. Get alarm codes – in most cars, disconnecting the car battery will reset all electric devices in the car like the clock, radio, navigation, and even alarm. If you don’t know your car’s alarm code, you should check the owner’s manual and note it down before you begin to change an automotive battery, or you’ll have to deal with a blaring alarm until you figure the code out. 
  4. Check the temperature – before replacing the car battery, do check the temperature of the car under the hood. Don’t attempt to work on a car after a long drive, ensure the car and the battery is cool to the touch. 
  5. Get ready for things to get messy – while dealing with any kind of car maintenance or repair, you must be prepared for things to get a little messy. You will be dealing with grease, oil, dirt, and more. Wear clothes that you don’t mind getting dirty or greasy. You could even lay down a tarp if you want to keep the place you’re working in extra clean.
  6. Safety first – before you begin to go about handling the car battery or battery parts, it’s best you put on some safety gear. Remember, car batteries contain a sulfuric acid electrolyte solution, this is corrosive and can burn your skin. It also produces flammable hydrogen gas. Wear some insulated work gloves and safety goggles and remove any jewelry that you have on your hands like rings, bracelets, and bangles, especially if they are made from any kind of metal. 


Replacing the car battery

  1. Disconnect the car battery – find the negative cable first (it will have a minus sign (-) near it and the terminal will mostly be black. Remove the negative cable from the terminal first so that there are no electrical shorts. You can use a wrench to loosen the cable clamp and slide it off the terminal. If the battery terminals have quick-release clamps, you should be able to get the cables off without any tools. Secure the cable so that it does not come into contact with anything metal. Once the negative cable is secure, follow the same procedure for the positive cable. The positive cable terminal is usually marked in red and has a positive sign near the terminal (+). IMPORTANT - the positive and negative cables should NOT touch each other. Do not allow them to get in contact with anything made of metal as this can cause an electrical short.
  2. Remove the car battery from the car – the battery is usually held in place with a bracket, remove connectors that hold the battery to the bracket. To loosen the connectors, you might need a socket wrench. When that’s done, lift the battery out of the engine bay and place it in a safe spot. IMPORTANT – the battery is about 20 pounds or more so you might need a helping hand to get it out. 
  3. Clean up the terminals – if you purchased a used car battery, then clean the car battery terminals to remove any corrosion or signs of it. You might find some powdery build up that is either green, blue, gray, or white. Cloth or sandpaper can get the corrosion off from the terminals. IMPORTANT - battery acid is corrosive, don’t get it on your skin or clothes.
  4. Place the new battery into the car – place the new battery into the tray, in the same direction the old one was. Tighten the clamps so that the battery can’t move or vibrate when driving. Lastly, coat each of the terminals in a thin layer of lithium grease, this will help to prevent corrosion.


Place the battery into the bracket

5. Reconnect the car battery cables – first, undo the positive cable, place it on the right terminal and tighten it fully. Once done, do the same with the negative cable. Then replace the plastic cover if there was one. IMPORTANT - the positive and negative cables should NOT touch each other. Do not allow them to get in contact with anything metal. ALWAYS connect the positive cable first so as not to inadvertently complete the electrical circuit before everything is connected. 

6. Test the battery – when the car battery replacement process is complete you can close the hood and start the car. If the car starts up without a hitch, you know that the battery is working, and your car battery installation was completed successfully. Now you can go about checking all the electronic devices and resetting the clock, radio, alarm, and navigation system.

If your car is not starting and you’re wondering where you went wrong, just ask a mechanic on JustAnswer. You can describe your issue and get quick answers that will help you figure out what went wrong and where. This will still save you $1000s at the repair shop and give you a car battery that functions as it should. The mechanics here are all verified, so you’ll be talking to folks with years of experience, without having to waste time on appointments, and without having to tow your vehicle to the shop. Don’t hesitate to get professional help here, it’s fast, safe, and easy.