What is a battery cable?

A battery cable connects your car’s battery terminal to the different electrical systems your vehicle needs to start and run. Essentially, without it, your car can’t go anywhere. So, it’s important to know what a battery cable does and potential issues to look out for.

Let’s take a look at what your battery cable does, how to take care of it, and when you need to replace it.

What does a car battery cable do?

Every car with a 12V battery will have two battery cables, otherwise known as a positive and negative battery lead. These two car battery cables connect the battery to the starter motor, which allows the electrical current to be distributed to the car’s electrical parts. They power the starter motor, ignition system, lights and other electrical parts of your car, giving your car the power to drive.

What size cable do I need for my battery?

A 6-gauge (or 6ga) is the average car battery cable size for a small-to-midsize car, while a larger car will need 8 or 10-gauge wiring. The exact battery cable size you need will depend on the size of your car and its engine, as larger batteries will need higher gauge wiring (or cabling) to sufficiently transfer energy. Your user manual will have the exact sizing you need for replacing your cables, or simply contact your local mycar for help.

Do I need a different gauge for a dual battery cable?

What size cable for a dual battery, then? To ensure you don’t get a voltage drop, you’ll need to accommodate the additional appropriate dual battery cable size. The exact dual battery cable size you need depends on your dual battery setup, so it’s best to consult a qualified mechanic.

Is there a difference between positive and negative battery cables?

Positive and negative battery cables do two different jobs, so they are quite different. The positive battery cable with a red lead is the slightly bigger of the two and attaches to the positive terminal, while the negative cable, or black lead, connects to the negative terminal. Aside from the colour, you can tell the positive cable by looking for a plus sign, while a negative battery lead will have a minus sign.

Are shorter battery cables better?

Generally speaking, the shorter the cable for car battery, the better as it means less weight and lower cost. However, you’ll need to calculate the correct current and distance to ensure you are getting the best battery cable for your power needs.

How to clean car battery cable connectors

To properly clean your car battery cable connectors:

1. Make sure the car is off.

2. Carefully disconnect the cables from the battery, using a wrench, starting with the negative cable and then the positive cable. This will help prevent electrical shock.

3. Mix together baking soda and water, and using a small brush, like a toothbrush, apply the mixture to the cable and scrub any corroded areas. It should bubble slightly as the baking soda neutralises the corrosion.

4. You can also remove the battery and gently remove any corrosion from the casing using this same formula.

5. Carefully rinse off the mixture from the cable and battery with clean water, then let it air dry.

6. Once dry, apply a thin layer of petroleum jelly over the battery terminals to help shield it from future corrosion.

7. Lastly, reconnect the cables, starting with the positive cable and then the negative cable.

Cleaning corrosion from your leads will help maintain proper battery cable connection and extend the life of your cables. If you’re not sure, feel free to drop into your local mycar for help!

How to replace car battery cables

The exact steps for replacing your car battery cables will change slightly from car to car. However, it generally includes:

Ensure you check your owner’s manual before you replace your car battery cables or ask one of our friendly mechanics at mycar to ensure you’re following the correct instructions for your car.

How to replace dual battery cables

Replacing dual battery cables is similar to replacing cables for a singular battery. However, you want to unhook the batteries at the same time. To do so:

To reconnect the new cables, follow these steps in reverse.

How to extend a car battery cable

While it’s recommended to replace car battery cables over extending them, you can extend them by connecting two cables. To connect two car battery cables, you can use a mounted insulated stud or a pair of lugs crimped together to connect the leads. The safer option is to replace the entire cable though, so it’s always a good idea to invest in a longer one and install it yourself, or call on a qualified mechanic to do it for you.

Still not sure? Drop into mycar for help

When in doubt about replacing, cleaning or diagnosing what’s wrong with battery cables, our team at mycar are always here to help. Our store network of more than 275 locations Australia-wide means we always have what you need in stock and help right around the corner.

Book in a battery check today and get the quality advice and service you deserve.