What Gauge Cable Wire From Battery To Starter?

Key Points:

  • The cables from the battery to the starter are needed to be very thick as they carry a high amount of current.
  • Typically, you should use 4-gauge wires for the positive battery terminals and 2-gauge wires for the negative battery terminals. 

A cable is a wire from the vehicle’s battery to the starter in order to run the starter. The cable is one of the most important elements within the battery management system.

But, what gauge wire from battery to starter will ensure a smooth operation?

Well, high-quality battery cables are a prerequisite to ensure the vehicle has constant power and to avoid battery drain. For that, you need to install the perfect sized cable. Generally, the positive battery cable that runs to the starter is 4 gauge and the negative one is 2 gauge.

If you’re looking for the perfect cable size before installing a wire connection from the battery to the starter and many more, this article is worthy to go through.

What is Wire Gauge?

Before starting with the size of the wire, let us talk about what wire gauge actually means. Wire gauge is basically a way of measurement of a wire’s thickness or diameter. It is often known as the American Wire Gauge or AWG in short.

The AWG provides information on the diameter of a wire in a form of a specific number. The higher the number will be, the thinner the wire’s thickness is. That means that a wire with a low AWG number carries more electricity than a high AWG wire.

The following chart shows how the wire gauge number works.

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What are the Determining Factors for Wire Size?

Now, there are some determining factors that are needed to be discussed for the right wire size. The thicker the wires get, the more current they can carry for long distances. The reason behind this is that the wire’s internal resistance increases as its diameter decreases or the length increases.

Therefore, the size of the cable depends on two major factors that are how much current it needs to carry and how long the cable needs to run. A wire gauge that is too thick can prevent a proper current distribution. On the other hand, a thinner gauge wire may cause short-circuit in extreme cases.

When choosing the length, you should consider the amount of voltage that drops over the length. With an increase in the length of the cable, electrical resistance increases. The higher gauge cables have a higher voltage drop than smaller gauge cables as the resistance is based on its cross-sectional area over the length.

This is why the AWG chart lists cables with different current capacities at different lengths. As the length increases, the required cable thickness follows.

What Gauge Wire Goes from Battery to Starter?

Now that we know that choosing the right wire gauge depends on the current and distance, you need to calculate the current requirement and voltage drop from Ohm’s Law.

You also need to calculate how far the cables are needed to run from the battery to the starter. Always follow the shorter distance as you already know shorter cables have low resistance. It also makes you pay less as the shorter the cables are the lower your costs will be.

When you know both the length of the cable and the required current, you can quickly decide the right wire gauge directly from the chart.

As the battery needs to flow a huge amount of current to the starter to start, you need to pick a thick cable.

Typically, the positive cable of the battery is 4 gauge even though some prefer even lower than that. On the other hand, the negative cable of the battery is 2 gauge.

While installing, you must make sure that the cables don’t touch the exhaust which may cause accidents. If you need to know the proper installation steps, you may look at how to wire a battery to a starter.

Frequently Asked Questions (FAQs):

What Happens If The Battery Cable Size Is Too Small?

If the cable is too thick, the resistance will be significantly low. Voltage drops at the end of the wire as compared to the voltage of the battery.

What Happens If The Battery Cable Size Is Too Big?

When the battery cable size is too long, it will increase your costs and weight. The longer the cable will be, the more you need to pay. Also, longer cables increase its weight which you might not want.

What Size Wire Is A Battery Cable?

Battery cable size should be able to carry the highest amount of current and preferably the thickest.


Battery cables that go directly to the starter carry a high amount of current to start the engine in the first place. So, the cables should be able to withstand a high current flow with considerably low resistance.

It is very important to choose the right wire gauge for the battery. Otherwise, there may be chances of physical and material damage. I hope this article helps you find what gauge wire from battery to starter.

Hope you liked it. If so, sharing it with others will be highly appreciable. Thank you. 

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