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How to Power A Car Stereo With A Car Battery Charger?

How to Power A Car Stereo With A Car Battery Charger
How to Power A Car Stereo With A Car Battery Charger?

Sometimes, you want to listen to music in the vehicle while it’s not running.

In normal circumstances, you can put the car into accessory mode and play music for an extended period.

But what if you want to play music with a full-fledged audio system or your battery is too weak?

Although not ideal, you can power the car stereo with a battery charger in such cases.

Here’s what you’ll need to do:

  • Find the power requirement of your car stereo.
  •  Disconnect the car stereo power cables from the car battery terminal.
  •  Connect the car stereo positive wire to the positive terminal of the battery charger.
  •  Connect the car stereo ground/negative wire to the negative terminal of the battery charger.
  •  Plug the battery charger and turn it on.

This article will discuss this method and its potential issues in detail.

What is Car Battery Charger?

The car battery charger is a device used to revive the dead car battery.

Just like our phone charger replenishes the smartphone battery, the car battery charger charges the car battery.

Many people confuse it with the jump starter, but in reality, these are two different devices that serve the same purpose.

Unlike a jump starter, the battery charger is plugged into an electric outlet while charging the battery. And it can take several hours for the charger to fully charge the battery instead of sending a single powerful jolt.

How to Power a Car Stereo with a Car Battery Charger?

Power a Car Stereo with a Battery Charger

Although originally intended to be used for charging, a battery charger can also be used to power up a car stereo.

Things required:

These are the tools you’ll need to complete this process.

  • A Battery charger with at least 12 volts of DC.
  •  Alligator Clips
  •  A Wire Stripper
  •  A car stereo
  •  A crimping tool

Step 1. Check Car Stereo Power Requirements

The first step is checking the power requirements of your head unit. You need to review the owner’s manual to find your car stereo’s voltage and current requirements. And make sure that the battery charger can provide that voltage and current.

Step 2. Disconnect the Car Stereo

After that, disconnect the car stereo wires that go to the battery (red, yellow, and black wires) and take it out of the dashboard.

Step 3. Prepare The Car Stereo Wires

Cut half-inch insulations off the red, yellow, and black wires. These are the wires for power, accessory, and grounding, and are needed to be connected to the battery charger. If your head unit has a separate wire for the built-in amplifier, strip that one too.

Step 4. Turn off the Battery Charger

To avoid risks of short circuits and electrical shocks, we’ll turn off the charger and unplug it from the outlet at this stage. 

Step 5. Connect the Car Stereo Wires to the Battery Charger

Connect the positive and accessory wire of the car stereo to the battery’s positive terminal. If your head unit has a cable for the amp, connect that as well. You can twist these wires and use a crimper to form a single connection.

Similarly, you need to connect the negative car stereo wire to the battery’s negative terminal.

Step 6. Connect Amplifier Wires To The Battery Charger (Optional)

If you want to power your car amplifier with the battery charger, you’ll need to connect some additional wires. You also need to ensure that the battery charger can handle the extra load of the amplifier.

The car amps come with three power-related wires: power, remote turn-on, and ground wire.

You’ll need to connect the positive and remote-turn wires to the positive terminal of the battery charger,

Similarly, you’ll need to connect the ground wire to the positive terminal of the battery charger,

Step 7. Turn on the Battery Charger and Test the System

Once you’re sure about all the connections, plug in the battery charger. Turn it on to see if the system is working as expected.

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Common Problems in Powering a Car Stereo With a Battery Charger

Powering your car stereo with a battery charger has several downsides too.

Damage Risk

The first issue with the battery charger is the risk of damaging it and the car stereo.

The battery chargers are not designed to give consistent power for an extended period, and forcing them to do so can make them overheat.

Furthermore, it may sometimes damage the car stereo, as many models are not designed to handle the power fluctuations caused by a battery charger.

Safety Concern

Using a battery charger with a car stereo can be risky, especially if you’re inexperienced with electrical wiring and DIY stuff.

Connecting any car stereo wires to the battery charger incorrectly can cause short circuits, overheating, or even fire in some cases.

You also need to ensure that none of these wires touch each other, as you may get an electrical shock otherwise.

Not A Long-term Solution

Lastly, the battery charger is not a long-term solution for powering up a car stereo. And it should be used in exceptional circumstances.

That’s because even if you use it consistently with any significant issue, the sound quality will not be up to the mark, and you’ll get an unpleasant humming. The battery charger also requires access to an electrical outlet to plug in, which reduces its portability.

Moreover, many battery chargers cannot power an external amplifier, so you can’t use them with a full-fledged audio system.


So this is how you can use a battery charger to power your car audio system.

This method is interesting because you can follow it and use your car’s audio system in various locations, including your home.

On the other hand, it has some clear downsides you should be aware of before proceeding.


How long can a car battery power a car stereo?

The amount of time a car battery can power a car stereo typically ranges from four to six hours. However, this timespan may be affected by the type and size of the car battery as well as the wattage of the stereo system. To maximize the life of your car’s battery, ensure that all lights, accessories, and other electrical components are turned off when the vehicle is not in use. Additionally, if you plan to listen to your stereo for long periods, investing in a power inverter or battery charger may be best.

What is the best power supply for a car stereo in the house?

An adjustable DC power supply is the best power supply for a car stereo in the house. These types of power supplies can output voltage from 12V to 13.8V, which is ideal for powering up most car stereos. They will also provide enough current to ensure your car stereo runs appropriately and efficiently. Make sure you select one with the correct voltage and current ratings to ensure safe and reliable operation.

How many watts does it take to power a car stereo?

The amount of watts it takes to power a car stereo depends on the size and type of the system. On average, an entry-level car stereo will require around 50 watts per channel, while more powerful systems may require up to 200 watts. For reference, most factory-installed car stereos have output power between 18 and 45 watts per channel. To determine the exact power requirements of your stereo, consult the manufacturer’s documentation.

How many watts does a 20A stereo use?

A 20A Stereo Typically Uses Around 2,400 Watts Of Power. A 220V Outlet Usually Provides This Amount Of Power. However, It Can Be Powered At Lower Voltages With Appropriate Conversion Hardware. For Example, A 20A Stereo Operating On 110V Will Require 4,800 Watts Of Power To Achieve The Same Performance Level.

John is an automotive enthusiast who has been passionate about cars and car audio systems for over 25 years.

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