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How to Connect Car Audio Capacitor to the Car Battery?

If you are looking to improve the sound quality of your car audio system, a car audio capacitor may be the perfect solution, especially if your amplifier is heavily loaded by the subwoofer.

But how should you connect the car audio capacitor to the car battery? Let’s find out.

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Connecting the car capacitor to the battery is straightforward, and the only thing to do is to connect the capacitor’s + (positive) terminal to the battery’s + (positive) terminal and connect the capacitor’s – (negative) terminal to the car’s ground.

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Tip: Connect a car audio capacitor as close to the amplifier as possible, with the recommended length of the power wire between both items not exceeding 18″. This will help maximize the sound quality of the system.

Also, make sure to use good power wires depending on the capacitor’s size, and as a general rule, it should be 8AWG for 1 Farad, 6 AWG for 2 Farad, 4AWG for 3 Farad, 2AWG for 4 Farad, 1AWG for 5 Farad.

I use OFC Knukonceptz Kollosus wires (link to Amazon), and I like them for the excellent shielding and flexibility needed in tight spots.

In this article, I will share some tips on connecting a car audio capacitor to the battery.

Can I Connect the Capacitor to Any Car Battery?

You can connect the capacitor to any type of car battery, including lead-acid, lithium-ion, and AGM batteries.

Technology in which batteries are made has advanced over the years, and today’s car batteries are more resistant to corrosion and vibration.

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Because all types of car batteries store and release electricity in the same way, you can connect the capacitor to any battery without any issues.

Can I Connect Multiple Car Audio Capacitors Together?

Multiple capacitors can be connected together, and this is called a “capacitor bank.” This can be useful if you want to increase the amount of power stored in the capacitor bank.

When connecting multiple capacitors with each other, it is important to connect them in parallel.

This means that you will connect their positive terminals together and the negative terminals together.

When you make the connections, it is a good practice first to connect all the positive terminals together and then all the negative ones. This will help to prevent any sparks from happening when making the connections for each item.

Can a Car Audio Capacitor Drain the Battery?

A capacitor will not drain the battery unless it has an internal short circuit.

If you connect the capacitor to the battery, the only thing that will happen is that the capacitor will start charging. Once the capacitor is charged, it will stop drawing power from the battery.

This however looks different if there is an internal fault in the capacitor. In this case, the capacitor will start to draw power from the battery even when it is not used.

A connected faulty capacitor can eventually lead to the battery being drained if it is not noticed in time. That is why it is always a good idea to check your capacitor regularly to ensure there are no internal shortcuts.

Do I Need to Charge the Capacitor Before Connecting It to the Battery?

It is always a good idea to charge the capacitor before connecting it to the battery.

This will help to prevent any sparks from happening when making the connection. Also, when you try to connect an empty capacitor to the battery, it can cause damage to your electrical system.

Audiopipe ACAP-6000 Car Audio 6 Farad 24 Volt Surge Power Capacitor Kit for Car Stereo Amplifier with Digital Display and Electronic Protection, Black

To charge the capacitor, you need to connect its positive terminal to the resistor or the bulb and then to the positive battery’s terminal.

Then connect the negative terminal to the ground in the car. Once the connection is made, the capacitor will start charging, and you will see the voltage level rising.

As soon as the capacitor is charged and you see the voltage of at least 13.4V on its screen or the connected voltmeter, you can disconnect the positive terminal from the battery and remove the resistor or bulb.

Now the capacitor is ready to be permanently connected to the car battery.

How Do You Hook up a Capacitor With an Extra Battery?

If you have an extra battery in your car, you can use that to power your amplifier and connect the car audio capacitor to it.

Additional battery dedicated to powering the car audio system is a good idea because it will help keep your car’s electrical system, and especially the main battery, from being overloaded.

To connect the capacitor to the extra battery, connect the positive terminal of the capacitor to the positive terminal of the extra battery, and connect the negative terminal of the capacitor to the negative terminal of the extra battery.

Remember to charge a capacitor before connecting to the battery in any case.

Why Is Capacitor Not Directly Connected to a Battery?

When the capacitor is connected to the positive and the negative power wires, it is connected to the power circuit, and even if its wires do not go directly to the battery, it is still “seeing” the total voltage of the system.

In reality, it does not matter if you connect the capacitor to the battery or the amplifier.

The only difference is the length of the wires, but the best results you will achieve when the positive wire between the capacitor and the amplifier is no longer than 18″.

You can of course, use a distribution block and make a connection to the amplifier and run the other wire to the battery, but this is not needed and will not make any benefit.

Also, by doing this, you will have to spend more money on the power wires that are not needed.


A car audio capacitor can be a great addition to your car’s audio system. 

It can help to prevent your battery from being overloaded, and it can also give your amplifier the extra power it needs to produce excellent sound quality.

One and the most important thing you have to remember is to always charge the capacitor before connecting it to the battery.