How to Fix Car Stereo Draining Battery? – 4 Methods


Written by

Rafeal Hart


Fact-checked by

Norris Howe

how to fix car stereo draining battery

In modern times, car stereos are no longer just devices for playing music. They are now part of an infotainment system with useful features such as navigation assistance.

However, this increased functionality can cause a parasitic draw, draining your car battery even with the ignition off.

While it can be surprising and confusing, in most cases, the common cause is car stereo.

For a deeper insight, read on as we delve into how to fix car stereo draining battery. We will also look at how to tell if the radio is draining the battery, the common causes, and solutions.

Ways to Fix Car Stereo Draining Battery

There are various potential fixes for the car stereo drainage issue. But before you begin, here are some items that may be necessary:


  • Multimeter
  • Battery charger
  • Wiring plan
  • Hand tools like screwdrivers, wire cutters or pliers

Here are the possible ways to fix the car stereo-draining battery:

1. Turn Off Sleep Mode


Car stereo draining battery when off is very common on sleep mode. On sleep mode, your Android car stereo doesn’t completely shut down. As a result, the car stereo constantly draws power from your car until it is completely drained.

To fix this issue and prevent the car stereo from constantly draining your battery, here are the steps to follow:

Step 1. Open your “Car Stereo.”

Step 2. Go to your “Menu Settings.”

Step 3. Scroll down and tap on the “Sleep”

Step 4. Click on “Not Sleep”

Step 5. Turn off your car

Step 6. Wait a while, turn on your car and check.

If your screen comes on immediately and boots automatically, your car was in sleep mode.

2. Remove and Check the Fuse

If your fuse is misconnected or blown out, the car stereo may likely drain your battery. A faulty fuse could constantly lead to a power draw even if the car stereo is not in use, eventually killing battery.


There are two possible ways to fix this issue: If the fuse is blown out, remove and replace it. However, if it is wrongly connected, get a multimeter or a wire tester and follow the below steps to fix the issue:

Step 1. Switch off your car.

Step 2. Remove the Car Battery”.

Step 3. Set your multimeter to “Continuity.”

Step 3. Using a “Multimeter”, find and ground a naked metal portion on it.

Step 4. Test the fuses.

The multimeter would fire up if the car stereo was wrongly attached to the wrong fuse (constant fuse). But if either fuse lights up the multimeter, it is a case of switched fuses. Reconnect them to fix the issue.

3. Replace the Car Stereo.

If you have tried to fix the fuses, but the stereo is still draining your battery, you may need to replace it. Sometimes when the car stereo ages, it might be very difficult to fix it; the only solution remaining is to remove it. Here is how to do it:

Step 1. Switch Off the stereo and remove the car battery.

Step 2. Check around the “Trim” and remove any bolts or screws.

Step 3. Remove the “Stereo Trim”.

Step 4. Bring out the “Dashboard cover”.

Step 5. Remove the slots of the stereo and pull it out.

Step 6. Fix a “New Stereo” and secure it.

4. Check Your Battery

If your car battery died after installing an aftermarket radio or replacing the factory stereo system, it is time to check your battery.

Check whether the car’s battery supply is enough for the new system. You can do this by comparing your device’s power requirement and your car’s battery.

If that is the case, to keep the amp from draining the battery, there are two ways to fix it.

Either install a secondary battery for your car’s audio system or replace it. To replace it, you can follow the below steps:

Step 1. Locate the “Car battery.”

Step 2. Find the two terminals (Negative and Positive).

Step 3. Detach the cables starting with “Negative Terminal” from the battery.

Step 4. Disconnect the “Old Battery” from your car.

Step 5. Fix theNew Battery” and attach the negative terminal.

Step 6. Switch on your car and test if the car stereo has been fixed.

  • Note: Before you can connect or disconnect your car battery, switch off your car.

5 Common Causes and the Solutions for Each Cause

Car battery drains can be caused by various factors, each with its own solutions. And understanding the common causes can help find a suitable solution. Here are five most common causes and the respective car battery drain solutions:

1. The car stereo.


If you are still using the factory radio and suddenly experience battery drainage issues, the first culprit could be the stereo.

Chances are your stereo has aged, some of its components are worn out or might have even stopped working.

As a result, your stereo might not turn off as required. This might drain the battery even if the car is off.

  • Solution: The only quick and reliable solution when the car stereo is aged or stops working is to replace it. While you can repair damages, it can be very complex and might not even be possible.

2. Incorrect wiring


Similarly, If you recently installed a new car stereo and start experiencing battery drain, that’s the cause. If you did the setup yourself, you might have incorrectly set up the stereo.

For instance, the car stereo has a fuse, and each port serves one function. One is switched, while the other is constant. If you accidentally interchange the connection of the two ports, you will experience a battery drain.

The switched fuse only receives power when the engine is on. However, a constant fuse is always powered even when the car is off.

  • Solution: Set up your fuses correctly. You might have to manually test them using a voltage continuity device to do this.

3. Highly powered car stereo

If your car battery is drained even after ensuring your installation is flawless, then the likely cause is a high-powered stereo. Familiar with Kenwood radio and Alpine stereo.

Large speakers or bass may be too much for specific cars to handle. Such may draw too much power, destroying the battery’s major function.

  • Solution: Minimize the use of such devices, especially when the car is turned off. And, if you want to use them, ensure your engine is turned on.

4. Extreme weather

Your car battery can be damaged and drained if exposed to extreme temperatures, whether too hot or too cold.

  • Solution: Protect the battery from extreme temperatures to prevent this. Consider using battery insulation blankets when the battery is parked or stored in the garage.

5. Parasitic Drain


If your car’s electrical system remains active when turned off, it will slowly drain your battery. Poorly installed interior lights, subwoofers, or aftermarket stereos are common culprits.

  • Solution: To fix a parasitic draw, turn off your headlights and other accessories before leaving the car. You might also have to repair or replace faulty components.



How Do I Know if My Car Stereo Is Draining the Battery?

There are various ways to know if car stereo drains the battery. However, the most obvious ones include:

  • Trouble Starting Your Car On

If your car is having trouble starting, it’s possible that your battery is draining. Frequent or heavy use can lead to issues with starting the vehicle.

  • Cranking Noise Before Your Car Starts

If you experience difficulty starting your car and hear unusual noises, it could be a sign that your battery is drained. This may be due to the recent installation of the stereo, which is a common cause.

  • The Battery Light Shows on Your Dashboard.

If your car’s battery is being used abnormally, a warning light will appear on your dashboard to notify you. This is common when the car stereo drains the battery, and you will notice a red light on the dashboard.

  • Problem With Lights

headlights and interior lights appearing dimmer than usual, it may be a sign that the car stereo is draining the battery. Generally, when the battery is being drained, all the lights in the car will be affected.

Preventing Car Stereo Battery Drain

These are the possible ways you can prevent car stereo from draining the battery :

  • Consider Investing in or Using Power-Saving Modes. Using power-saving modes can lower the car stereo’s power consumption and prevent it from draining the battery when not in use for an extended period of time.
  • Disconnect Car Radio From Battery. This is the quickest way to fix the stereo, draining the battery. When you disconnect the car stereo from the battery, all the features that consume energy power off.
  • Limit Your Car’s Idle Time. If you want to use your car idle, consider periodically starting the vehicle to recharge the battery. If not, limit the time the car stereo is turned on while in idle mode to prevent battery drainage.
  • Turn Off the Car Stereo When Not in Use. When you are not using the car stereo, ensure you turn it off and any other unnecessary features to prevent battery drainage.

How Much Does It Cost to Fix Car Stereo Draining Battery

A parasitic battery drain fix cost commonly ranges between $100-$300. However, the price may vary based on factors such as the specific component affected and the installation fees in your area.

The extent of the damage and your car’s energy requirements can also impact the final cost. For instance, fixing a loose wire or ground connection might cost less than fixing an alternator problem.


Now you know how to fix car stereo draining battery. A regular check on your battery or car stereo, wiring, or car mode can save your battery from dying.

As with cars, the key to fixing an issue is detecting and diagnosing the root cause. You must do so to prevent the problem from developing, costing you a lot of money.

That said, the fixing costs vary depending on various factors, including the extent of the damage. However, by carefully following our steps, you can quickly fix and prevent the car stereo from draining your battery.

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