How to Fix a Car Stereo Draining Battery in 4 Easy Steps

Does your car struggle to start the engine this morning? Do the lights look dim and go out at times? Even when off, a car stereo system can drain out the battery because of faulty circuits, incompatible gadgets, and outdated devices. So, you might suddenly end up with a dead battery.

In this article, we will examine the causes of car gadgets’ energy overconsumption and walk you through a four-step tutorial on how to fix a car stereo draining battery.

How to Stop a Stereo Killing Car Battery

What to prepare

You can stop radio killing battery with the right guides and proper tools.

Firstly, inspect your dashboard to see whether it has two matching holes on the sides. If so, purchase a pair of DIN tools. Otherwise, grab a screwdriver.

Other than that, prepare a voltage continuity and current tester.

Step 1. Make sure the screen is not in sleep mode

In the default mode, an Android car stereo screen doesn’t shut down when you switch off your car. It goes into sleep mode for at least one day before automatically turning off.

In this mode, the system continuously draws power from the battery even when you don’t drive your car.

To turn it off, go to the Menu Settings. Then, choose Sleep in the left column. If you don’t find Sleep here, go to General. Finally, select Not Sleeping.

When you finish adjusting the setting, remove your key from the ignition, wait for a few seconds, then turn your car back on. If you have successfully turned off the sleep mode, the screen will start by showing an Android logo instead of the application you used previously.

Now, keep an eye on the battery level as you drive your car for a couple of days. If the battery light on the dashboard still runs, changing the setting doesn’t stop radio draining battery; you shall need to work with some wires.

Step 2. Inspect the wires


Faulty wires happen from time to time. The joints might become loose; the wires might wear out and malfunction. So, inspect them to ensure they are connected correctly.

You should start by detaching the dashboard. Use a pair of DIN tools if the radio is held in place by spring clips or a screwdriver if it is installed by bolts.

Note: Manufacturers don’t leave bolts exposed on the dashboard for aesthetic reasons. Thus, you might find pieces of trim covering them. Gently remove the trim before screwing out the bolts.

If you still keep the installation instruction for the stereo, refer to it to see if the wires are precisely connected. Every car has a different wiring system, but in general, the setup is as follows:

  • The ground wire is black and connected to the battery anode.
  • The power wire is red and connected to the ignition. You will remove this wire when you want to disconnect car radio from battery.
  • The constant power wire is either yellow or blue and connected to the cathode.

While you do this step, check the BUS decoder. BUS decoder draining battery happens when the wires are incorrectly connected. Make sure the red wires stay linked to the positive ports.

Step 3. Examine the fuse box


Fuses prevent high-voltage currents and other electrical incidents from damaging your stereo system. They are pivotal in any automobile setup. In your car, you will find a fuse box holding two kinds of fuses: a constant and an alternate/switched one.

The stereo wire must be connected to the alternate fuse; otherwise, radio amp fuse draining battery will happen.

To listen to radio without draining car battery, you must check if the fuse wire is connected correctly. Follow these steps:

  • Turn off your engine and open the fuse box.
  • Place your voltage continuity and current tester on the two fuses, one after the other.
  • The wire that lights up the tester is the constant fuse.

If you accidentally connected your stereo to the constant fuse, remove the wire and reconnect it with the alternate fuse.

Step 4. Check the battery


Is your battery in good condition? Does it charge fully and properly? Can a replacement improve the situation?

When you switch the pre-built stereo system for a larger speaker, HD dashboard screen, or high-quality subwoofer, car radio drawing more battery is more likely. Aftermarket stereo draining battery or car battery died after installing aftermarket radio are not new issues.

Before you install a gadget, ask yourself whether the car’s battery supply is sufficient for the new system. Do so by comparing the power requirement of the device to the capacity of the battery on your car. You’ll often find this information on the back of the products.

To keep amp from draining battery, consider installing an extra battery for car audio system when you upgrade it. Another option is to replace the battery with a more powerful one.

Warning: Working with electricity wires is a complex task. If you are unfamiliar with the wire setup, we advise seeking help from professionals. Don’t let carelessness cause further damage to your car.

How Can Car Stereo Drain Your Car’s Battery?

Your car battery provides power for multiple devices: the lighting, heater, fan, dashboard screen, and radio system. They consume the finite power source of your battery and eventually kill it.

Unfortunately, there isn’t a car battery drain preventer that you can install. What you should do is connect your car’s battery to a high-quality charger once a month to keep it fully powered and well-functioned, especially when you make adjustments to the pre-built system.

Remember that a double-din radio, powerful speaker, and subwoofer can all drain the battery more quickly than a standard car radio.

Causes of Car Stereo Draining Battery

Many things can cause your battery to drain out: faulty wires, damaged fuses, outdated devices, and incompatible gadgets. To keep subwoofer from draining battery, you need to find the root cause and apply a viable solution. Below are some common causes.

The head unit screen fails to shut down completely

Android dashboard screens can stay in sleep mode for several days even when your car is not in use. Follow step one in our guide to fix this problem.

The fuses are faulty

Fuses protect your car’s electrical components from electricity overload. But if you have a worn-out fuse, an incompatible fuse, or faulty fuse wiring, this gadget will do more harm than good.

The wires are connected improperly

If your battery starts to drain after you have just installed a brand-new stereo system, the problem might lie in the new wiring setup.

Loose joints, redundant wires, and incorrect connections can all damage your car’s battery.

The stereo system is outdated or incompatible with the battery

Outdated, worn-out, or incompatible stereos cause your car battery to drain faster. Consider switching to a new radio system when yours starts to produce abnormal noise, frequent static, strange electrical responses, and loud hisses.



What if the stereo keeps draining my car battery?

Sometimes, just turning off your head unit screen’s sleep mode will help. You should start with the first step we mentioned above. If that doesn’t work, you will need to examine the wires.

If you are not confident enough to carry out the other steps by yourself, seek help from a car electrician.

Can a car stereo drain your battery when running?

Yes, it can. Any in-car electronic devices can drain out your battery. So, whenever you notice that your battery dies more quickly than it used to, try to identify the root cause and seek a solution, especially before long trips. You don’t want to be stuck in an unknown place.

Are speakers and subwoofers capable of draining batteries?

All in-car electronic devices consume energy from your battery to function. In theory, they are all capable of draining the battery.

However, the energy consumption of speakers and subwoofers is insignificant compared to fans and heaters. You can listen to the radio without worrying much, especially if your car comes with an energy-efficient radio.

Useful tips if you need: 6 steps to remove a car stereo without din tools


Listening to the radio on daily commutes keeps you informed and helps relieve stress while driving. So, make sure your stereo system functions correctly and efficiently.

We hope our four-step guide on how to fix a car stereo draining battery provided you with the best solutions. But if you have any further questions, don’t hesitate to reach out via the contact page. See you around!

Leave a Comment