What is a Car Audio Battery? (Explained for Beginners)

If you love cars and are an audiophile, then that combination means you will at some stage want to upgrade your car audio. This can be at all levels of your audio system – head unit, pre-amplifiers, amplifiers, surround speakers, subwoofer, etc.

Upgrading your audio kit will also need a highly reliable power source which is why you will have to consider a car audio battery.

Here’s What a Car Audio Battery Is

Car audio batteries provide auxiliary power to boost your car audio system to reproduce that deep bass and high treble while giving sufficient reserve amperage to your car. Depending on the power rating of your audio system, there can be multiple car audio batteries installed in parallel that act as a dedicated power source.


You can either replace your original equipment manufacturer (OEM) battery with a high-capacity one, swap it with a powerful deep cycle battery or have a separate dedicated car audio battery.

Audio batteries from reputable brands are easier to mount in any position and are also capable of working perfectly in different weather conditions. Moreover, audio batteries make sure there is no compromise with your car’s electrical system or overall performance.


What Does a Car Audio Battery Do?

Varta car battery for Hyundai Tucson 12VDC 80Ah with positive and negative terminals
Varta car battery for Hyundai Tucson 12VDC 80Ah with positive and negative terminals

The main reason for getting a car audio battery is to use your audio system and accessories so it doesn’t put too much pressure on the car electrics (alternator) and the engine which drives the alternator to generate DC charging power for the battery.

You can enjoy listening to music or radio via the built-in audio system of your vehicle which will keep you entertained for hours.

The more the capacity of the battery in Amps, the greater the performance and longer usage of your audio system.

Having a longer lifespan and the audio battery being maintenance-free, it continuously provides a higher power output to efficiently drive your audio systems peaks and troughs.

If you own a small car but desire to for a big stereo, a good-quality, high-power audio battery will be required to do the job.

Batteries capable of a quick recharge, getting an audio battery can help your system sound better at higher volumes and can dramatically increase the performance and longevity of your amplifiers.

How to Set Up a Car Audio Battery With a Kit?

Red positive cable for car battery connection
Red positive cable for car battery connection

A standard car audio battery kit contains amplifiers, capacitors, connector terminals, distribution blocks, fuses, fuse holders, and interconnect cables. Some things to take care of are as below:

  • Correct grounding of the battery
  • Proper sheathing & shielding
  • Electrical protection for the batteries

Step-by-step Guide for Installing a Car Battery With a Kit

  • Start by screwing the battery tray onto a sturdy surface so that you can avoid any chances of battery movements when the car is in motion.
  • After screwing, start drilling holes near the tray for facilitating cable arrangements. Be careful not to hit and damage other components like the fuel tank while drilling and screwing.
  • Begin to work with wires by disconnecting both the negative and positive cables from the starter battery. This should be followed by unbolting or cutting off the wire connecting the alternator to the starter battery. Make sure to unsnap the negative cable first and then proceed to the positive one.
  • The next step is to connect your battery isolator. After disconnecting the alternator wire, connect it to one of the isolator’s side terminals. Fasten an extra wire to the central terminal of the isolator and connect it to the alternator. This wire reaches the battery’s positive terminal.
  • Proceed by connecting the wire that runs from the starter battery’s negative cable to the negative terminal of the auxiliary battery.
  • Continue by grounding the second battery. Give a wire connection from the second battery’s negative terminal to the chassis or other metal ground.
  • Continue the process by connecting your amplifier from the second battery, attaching a red 4-gauge wire to the secondary battery positive end to route it to an amplifier fuse, and then attaching another red wire from the fuse to the amplifier.
  • For safety purposes, make sure to cover all the positive end connections with a cap to stop any shortages or sparks that may be generated from the battery.
  • Conclude the setting up process by giving a final and thorough check. Verify all the connections properly as a wrong connection may lead to a short or problems starting the car.

How Long Does a Car Audio Battery Last?

If you are using a standard car battery, the radio can run for 8 hours before the car battery runs out. If your car is additionally packed with amplifiers and subwoofers, the battery may run out after 6 hours.

Older versions of car radios without amplifier facilities can draw 0.25 amps to 1.5 amps. 

If the car battery capacity is around 40Ah, it can last for a few more hours at lower volume levels. Modern car stereo systems can draw 1.6 amps and more, even with low volume. Playing music at maximum volume can draw above 10 amps.

If you use a battery capacity of 40 amp-hours, it can operate for 4-8 hours with maximum listening before running out.

What Are The Disadvantages of Having a Car Audio Battery?

There are however some disadvantages of instating a car audio battery and we would like you to be aware of them before you make a decision.

Additional Load on Alternator

Your car alternator is used for charging your regular car battery but if you install a car audio battery it will overload your alternator which could potentially damage it.

Upgrading the alternator to match the power rating of your system and the overall drain could be a solution.

Additional Space Required for Car Audio Battery and Kit

Car audio batteries are usually large in size so they need additional safe space. Car audio batteries can be safely installed in the car boot but unfortunately, that takes away from the car storage space.

Additional Weight of Car Audio Battery

Even when the car audio system is not in use, the car has to carry the weight of the battery, resulting in additional wear and tear and degrading the performance of your car.

Additional Cost of Installation

Car audio installations that include a car audio battery mean that you have opted for a high-end audio system. These installations require professionals and can be expensive.

Read here on how long it takes for car audio installation and why are they so expensive.

Additional Battery Maintenance

Your power-hungry audio system will require frequent charge cycles which means more battery maintenance.

Car Audio Battery Calculator

You can use a simple formula for determining the approximate length of time your car battery can last while running your stereo with the engine off:

Operating time = 10 X RC/Load

Where RC implies the battery Reserve Capacity measured in amp-hours indicates how much power the battery has available on a full charge, and load implies the sustained load power in watts.

For example, if your car audio system possesses a 500-watt load and your battery has a reserve capacity of 80 amp-hours, then the operating time is given by,

Operating time = 10 X RC/Load = 10 X 80/500 = 1.6 hours.

This implies that your car battery is suitable for operating for 1.6 hours without running the engine.

Car Audio Battery for 1500, 2000, 3000, 5000, and 8000-watt amp

Yuasa 5000 high amp car battery with 12VDC 110Ah
Yuasa 5000 high amp car battery with 12VDC 110Ah

In the case of a 1000-watt inverter, you’ll need at least a 100Ah battery so that you don’t run out of energy quickly.

If you know how long your battery will last, you can find the amount of energy your inverter uses per hour.

The formula for calculating the amount of energy your inverter uses is given by

Amps = Watts / Volts

For example, if you are using a 12-volt battery that draws 1000 watts then,

1000W / 12V = 83.3A.

This implies that, at full load, a 1000-watt inverter uses 83 Amps per hour. This leads to the conclusion that a 100Ah battery can last for over 1 hour.

So, this tells us the following:

  • For a 1500 watts inverter, you will need a 750Ah 12V battery
  • For a 2000 watts inverter, you will need a 1000Ah 12V battery
  • For a 3000 watts inverter, you will need a 1500Ah 12V battery
  • For a 4000 watts inverter, you will need a 2000Ah 12V battery
  • For a 5000 watts inverter, you will need a 2500Ah 12V battery
  • For an 8000 watts inverter, you will need a 4000Ah 12V battery

Can I Use a Regular Car Battery Instead of Car Audio Battery?

Using a regular factory-installed car battery may not be sufficient for running a powerful stereo system as they are designed to power the standard electrical components of the car.

It might be able to withstand for a few hours in optimal volume and engine conditions, but getting a car audio battery may prove to be better and more beneficial.

A random battery just cannot be used for car audio. You need to choose your battery by finding the right one that can supply sufficient and stable wattage.


Car audio batteries are available in various types and various power capacities.

They are available as calcium batteries, lead-acid AGM batteries, deep cycle batteries, wet cell batteries, and lithium-ion batteries.

Knowing the specifications and understanding the difference between them will help you determine which one best fits your car’s audio.

With the right kind of battery, you can power up your stereo and enjoy listening to loud music with great performance and long intervals.


Can You Use Any Battery for Car Audio?

How many batteries do I need for a 2000, 3000, 4000, 5000-watt inverter?

How Long Does an Inverter Battery Last?

How long will a 300, 500, 600, 750, 1000, 1500, 3000, 4000, 5000 watt inverter run?

How Long Does a Car Battery Last With Radio on? – Explained

Adding a Second Car Battery for High-Performance Audio

When One Battery Isn’t Enough: How to Install Second Battery for Improved Car Audio

How to install a second battery for car audio

Benefits of a Car Audio Battery [Before you Buy]

The Benefits of Adding an Auxiliary Battery to Your Audio System