How to Wire a Car Stereo to a 12v Battery

Car battery

Yes, you can connect a car stereo directly to a battery. However, you will have to make sure that the battery that you are connecting it to is a 12-volt battery. Preferably, it should also be a car battery. 

Why Can You Connect Car Stereo Directly to the Battery?

You have to remember that car radios will drain a lot of life from the battery.

The reason why car batteries do not drain when you are driving your vehicle is that the vehicle constantly charges them.

So, while it is possible to connect a car stereo directly to a battery, bear in mind that it is going to drain that battery very quickly and you will forever be charging it. 

How to Wire a Car Stereo to a 12v Battery

Wiring a 12v battery to a car stereo will require some preparation.

In order to do the job properly, you will need the following tools:

  • Wire strippers
  • Crimping tool
  • Alligator Clips

While you could just tie the wires directly to the battery terminals, we wouldn’t really recommend it. It is dangerous.


Follow these steps to connect your car stereo up to the battery:

1. Strip the wires

You should have three wires coming from your car stereo; black, yellow, and red.

Strip about an inch off of the end of each of them.

2. Pair up the red and yellow wires

These two wires will eventually attach on to the ‘positive’ terminal on your battery.

Twist these wires together. At this point, you can attach them directly to the battery’s terminal, if you wish. Although, it really is not recommended.

Your best option is to crimp the yellow and red wires onto an alligator clip.

3. Crimping the black wire

The black wire just needs to be crimped onto an alligator clip.

4. Connect to a battery

As mentioned before, the red and yellow wire combination will attach to the terminal marked as ‘positive’ on the battery.

The black wires will attach to the opposite terminal on the battery.

5. Connect the car stereo to speakers

If your car stereo does not have speakers, you will need to hook it up to some. Preferably, you should be choosing speakers that have been designed to be used in a vehicle. These will have a low-power drain.

If you use other types of speakers, do remember that you may have to power these separately.

6.  Turn on the radio

Once everything is hooked up, you can switch on the radio.


If you have done everything correctly, then it should switch on. If it doesn’t, then you likely have one of these problems:

  1. The battery is not charged. To tell if the battery is charged you can use a multimeter, alternatively, you can tell by the strength of the headlights.   
  2. You have connected up the wires incorrectly – See the correct way to connect your battery terminals.
  3. The radio doesn’t work – This could be because of a large number of factors. 

It’s likely that the wiring will be the issue. Even a small amount of charge left in a battery should be enough to power the radio. So, check the wiring. If everything is good, charge the battery. If it still doesn’t work, you have a broken radio.

Final thoughts

As long as you have wire strippers, a crimping tool, and Alligator Clips you should be able to connect the car stereo directly to a battery with minimal trouble. 

If for any reason the radio is still not showing power you should, systematically cross out parts by checking if the battery is charged, then checking connections, and then finally ruling that the radio is defective.  

Picture of Alex
I loved my car but was frustrated with my media system. So I upgraded my stereo, making silly wires and precarious phone mounts a thing of the past. The Apple Car Play stereo was so good I wanted to show more people how this could be done and truly upgrade their cars multimedia system! Founder
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