How It’s Done DIY guide – Replacing a Car Battery on Your Own

New Car Battery

Car batteries come as different types such as SLI, deep cycle, VRLA, wet cell (flooded) and more. SLI (Starting Lighting and Ignition) are the most commonly used car batteries since they have a shallow charge cycle and only deliver power in short bursts.

Deep cycle batteries work in an opposite manner than SLI batteries – delivering power continuously over a long period of time. This makes them better for small recreational vehicles, golf carts and marine vehicles.

VRLA (valve-regulated lead-acid) batteries require very little car battery maintenance since they are sealed, preventing spills when tipped or inverted.

Wet cell batteries contain a liquid that has the battery electrolyte – they are more affordable than most car batteries but they don’t have the same life cycle as VLRA batteries.

No matter the type of battery your vehicle is using, sooner or later you’ll need to replace it with a new one in order to keep the engine running with the adequate amount of power.

You will also avoid experiencing a sudden stop on the highway if you install a new battery.

But when do you need to replace your vehicle’s battery?

Related article: How to Jump-Start a car

When to Change Car Battery?

The most obvious way to tell whether or not your car battery needs to be replaced is to start the engine. You’ll need a car battery replacement if the engine starts cranking when you turn the key in the ignition and it won’t turn on.

This is known as fading which if it keeps happening time after time then you most definitely need to change the battery. A good indicator that the battery needs to be replaced is the variability in the day to day performance.

If the performance happens to change every day and especially if it’s accompanied by regular jump starts, it means that the terminals have loosened or corroded.

Car dashboard and warning lights.
Check engine and electricity warnings on a vehicle dashboard

Battery replacement should be considered when the case is bloated and when the lights and horn are not working. The latter usually comes with the addition of your car not being able to start.

The battery powers all the electronics inside the car too, so if some of them how no signs of life, that’s a good sign that you need a new battery. If you have trouble starting your engine in cold weather, it means that the CCA (cold cranking amps) rating is poor.

These amps allow you to measure the battery’s ability to start in cold weather. It can also mean that the battery needs to be replaced if the CCA rating is low.

How to Change Car Battery

What You’ll Need

To safely perform a car battery replacement you’ll need safety glasses, gloves, battery terminal protectors and a battery carrying strap. For the tools, you’ll need box or open-end wrenches, old rugs/ paper towels, terminal grease, terminal puller, stout wire brush and post grease. To locate your battery take a look at the vehicle owner’s manual – while some batteries may be in the trunk, others can be located behind a wheel wall or under the floorboard.

Removing The Old Battery

First, what you need to with this car fix is to locate the positive and negative post on the battery. This is done by locating the positive post first which usually has a red plastic cover over it or a red cable attached to it. You will also find a “+” sign next to the post.

Once you’ve identified both terminals, start loosening the nut/ bolt that secures the negative terminal and its cable using the wrench. Whilst doing this, make sure you do not touch both battery posts at the same time with the wrench or any metal part.

Also, avoid touching the positive terminal and the body or fender with your wrench at the same time.

Black gloves, metal wrench
adult car mechanic wearing protective gloves removes the terminals on a car battery

 2. After you’ve loosened the bolt/ nut take the terminal puller and remove the cable from the negative terminal – do the same with the bolt/ nut and cable of the positive terminal.

Remove the rest of the retaining system/ clamp that keeps the battery in place and set them apart, together with the fasteners to avoid spillage or misplacement. Use the battery carrying strap if the posts are located on top of the battery in order to lift it out without it bumping around too much.

Installing the New Battery

Before you place the new battery in the vehicle, you need to inspect the terminals and clean them off any corrosion or dust using the stout wire brush.

The cleaner you make them the better the performance of the battery. Once that’s done position the battery so that you have the positive (red) post matching with the positive terminal and cable location.

Car battery for vehicle's electricity.
corroded terminals on a car battery

2. Insert the battery and secure it with the clamp/ retaining system which you removed earlier on. Then, remove the protective plastic caps covering the posts and install the anti-corrosion washers in their place.

Make sure you apply a thin layer of grease on the posts and terminals before you connect them. Connect the positive post first and tighten the connector firmly with the wrench.

Do the same with the negative post and try to move the battery a little bit. In case it moves, you’ll need to tighten the clamp/ retaining system.

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