Can A Car’s Battery Charger Run A Car Stereo?


If you have a car stereo that you love, but you don’t have it installed in a car yet, you might be wondering if you can still listen to music or FM/AM radio on it. If you have a car battery charger, you are in luck.

Can a car’s battery charger run a car stereo? Though not ideal, powered a car stereo with a battery charger is possible. The battery itself typically powers car stereos, but they can also be powered via a battery charger as long as it delivers a minimum of 12 volts. For the best audio possible, use a quality battery charger.

Not only should you be using a quality battery charger to run your car stereo at home, but you also need to make sure that you are properly setting up your system, so you don’t end up ruining your stereo. Continue reading to find out how to set up a car battery to a stereo system and what other alternate methods you can use.

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How To Set Up Your Battery Charger And Car Stereo

If you are running a car stereo outside of your car, the chances are that you really love the sound system. One of the worst things that could happen is that you don’t properly set up the battery charger to the stereo and end up ruining the sound system. To avoid this, make sure that you carefully follow the steps below to ensure that you don’t mess up any of the wiring.

First of all, make sure that you have a battery charger that administers at least 12 volts DC or more; otherwise, your stereo won’t turn on. Also, make sure that you have a good amount of space so that you can separate the wires. You don’t want the wires colliding with one another as these could short them out.

It is best to find a location that has a wooden or insulated surface since these materials are poor conductors of electricity. Make sure that the space you are using is also away from any wet areas. If the wires get wet at all, they could short circuit and ruin the stereo.

Then, you will need to acquire all of the necessary tools, which include:

  • A wire cutter with a grip span of 6cm to 9cm
  • A crimping tool
  • Alligator/Crocodile clips
  • Insulating tape
  • Battery charger with a minimum of 12 volts DC

If you have all the proper supplies, then you can get started. Find all of the wires on the back of the car stereo; there are usually 2-3 of them. Take the wire cutters and cut about half an inch of insulation off the red and yellow wires.

Locate the black wire as well and take off half an inch of the insulation. The red and yellow wires are for the positive DC input, and the black wire is used for the negative or ground input. Now, twist the red and yellow wires together and clip the positive or red alligator clip to the intertwined wires. You can use the crimping tool to crimp the wires into the clip.

You will now take the black wire and clip it with the negative or black alligator clip. Use the crimping tool as necessary. While making all of these connections, make sure that the wires are not touching one another or the stereo. Once you have put the clips over the wires, you can start working on the battery charger. Ensure that the power is completely off.

Connect the red and yellow intertwined wires to the positive input of the battery charger. Then, connect the black wire to the negative input, and ensure that none of the wires touch one another in this process. You can use the insulation tape to make sure that the copper connections aren’t bare.

Once you have connected the wires to the battery charger inputs, ensure that none of the wires are touching one another. Once you have done this step, you are free to turn on the battery charger and see if the car stereo works.


How To Connect A Car Amplifier To A Battery Charger

If you are trying to use a car battery to power your car stereo, you’ll also need some good speakers. To have better speakers, you will need to learn how to connect a car amplifier to the battery charger. It’s pretty simple to add an amp to your car stereo and battery charger, so let’s break down the steps.

  • Identify the three terminals: positive, negative, and remote ON.
  • Match car amp and battery chargers positive and then negative terminals.
  • To use the remote ON, simply create a wire loop between the positive and remote ON of the amp.

That’s all that it takes to hook up your amp to your battery charger.


Disadvantages Of Using A Battery Charger To Power A Car Stereo

One of the main disadvantages of using a battery charger to run a car stereo is that you might not get quality sound and possibly ruin the system. If you are using a low-quality battery charger, then it will most likely have an unsteady current. You can tell if you have a low-quality battery charger if the stereo makes an unpleasant humming sound. Be sure to disconnect your car stereo from the battery charger so that it doesn’t ruin your sound system.

Another big disadvantage of using a battery charger-powered car stereo is the safety hazards that can occur while they are connected. You have to ensure that there is enough room so that the wires do not touch. Otherwise, you may get shocked. Not only do the wires cause electrical shock if the red and yellow wires are not wound together tightly, but they can also short circuit and ruin your stereo. Another safety issue is that a car stereo powered by a faulty battery can cause a fire.

All in all, make sure that you are using quality battery chargers to power your car stereo to get the best sound and prevent safety hazards.


Quality Battery Chargers

Since we have talked about the importance of good battery chargers, let’s look at some of the best battery chargers on the market. They might be a bit more pricey, but you don’t want to run the risk of ruining your car stereo or even creating safety hazards. Take a look at the table below to see the best battery chargers.

Battery Charger Model (links to check the price on Amazon)Volt CapacityAmperage
NOCO Genius 16V and 12V1 A
Battery Tender Junior12V750 mA
Schumacher SC12816V and 12V30 A
CTEK 40-20612V4.3 A
Optima Digital 40012V4 A
Schumacher Battery Charger with Engine Starter, Boost, and Maintainer6V and 12V200 A

The Schumacher and Battery Tender Junior have the highest amperage. They might work the best for powering your car stereo, but the NOCO Genius 1 and CTECK 40-206 are highly rated and recommended by many users. It’s important to mention that car stereos don’t need much amperage to work. In fact, they only use 2 to 5 amps at full power, so whichever battery charger you go with will be the perfect option to power your car stereo.


Other Items That Can Power A Car Stereo

If you don’t have a battery charger, there is no need to go out and buy one. You might have other household objects, like a laptop charger or a computer power supply (also known as ATX) that can power your stereo. When looking for another source to power your stereo, make sure that it has at least 12 V. Anything more will work great, but it isn’t necessary and can be a bit more costly.

When looking for a power source, make sure that it has direct current (DC). If it has an alternating current (AC), you can always use an AC-DC converter or adapter, but it would be best to use a power source that is DC.

You can use an AC-DC wall adapter, like a laptop charger or any other wall adapter. Still, it isn’t highly recommended since it can be hard to differentiate the positive and negative wires. If you do mix up the wires, you could end up ruining your car stereo due to reverse polarity.

Also, AC-DC wall adapters are not the most powerful source, so the voltage might begin to drop as you turn your car radio up. Usually, these wall plugs only have 1 amp, which does not make them great power sources.

If you are going to use a household item to power your car stereo, it would be best to use a computer power supply. A computer power supply (ATX) is a much better power source than an AC-DC wall adapter. Most of the time, ATX has enough voltage to power a car stereo and a car amplifier or speakers since it has 12V DC. An ATX requires a specific wiring method, so let’s talk about how you can hook up a car stereo to a computer power supply.

First, take the car stereo’s red and yellow wires and cut the insulation off about a half-inch. If you are going to use the power on and off switch on the ATX, then jumper the blue wire to the yellow wire.

On the ATX cord (also known as a pinout), you will take the green wire and then cut and take off the insulation. Do the same thing to the black wire and intertwine the green and black wires together. Make sure to use the crimping tool to make sure that the wires have a good connection. Once you have done this, you will have power to your car stereo. After completing this, you can add some car speakers to have a better sound experience.

To set up speakers on your ATX, you will first need to look at the speaker’s nominal impedance (the number of ohms). If it is less than 4, it will not work.

Make sure that the speaker is either a 4-ohm or 8-ohm. The 8-ohm speaker won’t be as loud, but it will still work. Once you have located the speakers that you will use, take a look at the colours of the wires. Each coloured wire will hook up to a specific speaker connection. Take a look at the table below to see where each wire connects.

To learn more about impedance, check out the following My New Microphone articles:
The Complete Guide To Speaker Impedance (2Ω, 4Ω, 8Ω & More)
What Is Amplifier Impedance? (Actual Vs. Rated Impedance)

Place each wire in its respective place on the speakers. Once you have done this, you should have power to your speakers and can listen to the radio from your car stereo.

Wire ColourLocation on Speakers
White and White/BlackFront Left
Gray and Gray/BlackFront Right
Green and Green/BlackLeft Rear
Violet and Violet/BlackRight Rear

Conclusion

One way to power a car stereo without an actual car (running on the car battery itself) is to use a battery charger. Some battery chargers on the market may work better than others, so make sure to find a quality product.

If you don’t have a quality battery charger, there are other household options to choose from. Although you may be able to use a wall adapter, it will not work well, and it can possibly ruin your sound system. Instead, you should use an ATX or computer power supply if you do not have a battery charger.

If you decide to use one of these methods to power your car stereo, be sure to take some precautions while wiring the power source to the sound system.

Arthur

Arthur is the owner of Fox Media Tech and author of My New Microphone. He's an audio engineer by trade and works on contract in his home country of Canada. When not blogging on MNM, he's likely hiking outdoors and blogging at Hikers' Movement (hikersmovement.com) or composing music for media. Check out his Pond5 and AudioJungle accounts.

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