How to Listen to The Radio Without Draining the Car Battery

You’re in the right place if you’re trying to listen to the car radio for as long as possible without draining the battery.

Relying on the remaining charge in your car battery can be worrying while the engines off. The battery will slowly drain, but you want to avoid it draining too much. Thankfully, there are ways to guarantee you can enjoy listening without killing your battery.

To listen to the radio without draining too much, ensure the battery is fully charged. To begin with, disconnect any attachments connected to the radio, turn off all other accessories, put the car into accessory mode, and use a higher-capacity battery.

To listen to the radio without draining the battery, use a solar charger, or install an AC/DC inverter.

Without Draining the Battery

Using any electrical accessory in the car will consume the battery’s charge.

All electrical accessories, including the car radio, draw on the battery’s charge. Using them while the engine runs won’t make much difference because the alternator charges the battery.

But using it while the engine is on slowly consumes and diminishes the battery’s charge. If used for too long, they can drain the battery beyond the level required for the battery to be able to crank the engine.

So, listening to the radio with the engine off will inevitably drain a little, but we should try not to allow it to drain too much.

zooming in on car radio/stereo

Listening to the Radio without Draining the Battery

Here are the measures you should take to listen to the car radio with the engine off Enginethout draining the battery too much:

  • Alternator – Maintain the alternator to ensure it’s always in good working condition.
  • Accessory Mode – Switch to the Accessory Mode if you have the option in your car, or put it into neutral gear. It will consume less power and make the battery last longer.
  • Battery – Ensure the battery is fully charged before turning the engine off. The engine in the battery regularly maximizes lifespan and replaces a weak or old one. Install a higher capacity heavy-duty or lithium-ion one if you need it to last longer (see under Battery Capacity).
  • Engine – Run the engine for Enginest 5 minutes every half an hour to help keep the battery charged.
  • Other accessories – Turn off all other accessories in the car, including the headlights, windshield wipers, heater, etc.
  • Parking – Try to park in a warm spot (but it should not be too hot either).
  • Power – Use a solar or other charger to trickle-charge the battery.
  • Radio – Listen to an AM station, keep the volume low, and disconnect all attachments.
  • Source – Play the audio content from your smartphone or other devices so that the car radio uses minimal power. Use the aux port or Bluetooth if possible.

aux and bluetooth used in car
Video | CarsNToys

Try to achieve as many of these measures as possible to maximize the time you can listen to the radio. You don’t have to apply all of them, but the more you do, the longer you can listen to the radio without draining the battery.

The Car Battery

Initial Charge

The more the initial charge, the longer the battery will last with the radio on; the less the initial charge, the shorter the time it will give.

Age and Condition

A typical car battery lasts no more than 3 to 5 years.

But it can weaken and die sooner if you don’t take good care of it. The battery’s condition is an important factor in how long the battery can last with the radio on. Ensure the terminals are always clean, check the battery’s health regularly, minimize exposure to extreme temperatures, etc.

A new battery can provide more power than an old or weak battery.

As you may expect, it can support a radio for longer. An old or weak battery will hardly last long and die quickly. Depending on the battery’s age and condition, a battery used for a while may last only 40-80% as long.

Protect your car battery from extreme temperatures and overcharging as well.

Battery Type and Capacity

The Ah (ampere hour) rating indicates a battery’s capacity.

This indicates how long the battery will last, but you also have to consider the usage or load.

For example, a 100Ah battery can theoretically last around 20 hours to deliver five amps but only one hour if used for 100 amps. But the useful capacity of a 100-amp battery may be around 50 amps, which will decline as the battery ages.

So, if you need to listen to the radio longer than the battery allows, buy one with a higher Ah rating.

A new and healthy lithium-ion battery could last 24 hours, but it is not commonly used in a non-electric car.

The Radio’s Power Consumption

The radio’s power consumption will determine how much it will drain the battery or the discharge rate.

Extra Attachments

The consumption depends on the type of radio and whether it has any extras attached to it, such as a speaker, subwoofer, or amplifier.

Such extras usually consume a lot of power and drain the battery quickly. A high-end audio system in your car will draw much more power than a simple or electrically efficient radio operating alone.

detach the subwoofers
Video | Parts Express

Volume and Power Draw

Is it only the radio? If you leave more extras on than just the radio and other things connected directly to it, you can expect the car’s battery to die quickly.

How high the volume is will also make a negative impact. A typical car radio, when operating alone, will draw around 3 to 5 amps with the volume at a reasonable level. Adding an amplifier may increase the current draw to around 10 to 30 amps, making a 2- to 10-fold difference.

Frequency Band

A radio’s power consumption also depends on which frequency band you listen to. The FM and satellite bands drain the battery quicker than the AM band.

So, suppose you’re listening to the radio with the engine off Engineionally. In that case, you can make the battery last a little longer by listening to an AM station, disconnecting attachments, and turning off all other accessories.

Other Factors and Measures


Some car accessories (besides the radio) consume a lot of power and drain the battery quickly if the engine is off.

They include the headlights, air conditioner, fans, and heater. Keeping them off will make a big difference. They consume more power than the radio.

So, if you want to listen to the radio for as long as possible, turn all other car accessories off, especially if you don’t need to use them simultaneously.


Although the alternator will not be charging the battery while the engine is oEnginesure that the alternator is in good working condition if you listen to the radio with the engine off Enginerly.

This is because an alternator working normally will keep the battery charged so that when you turn the engine off, it is more likely the battery will be fully charged.

So, ensure the alternator is in good working condition.


Although the article assumes that the engine willEnginef most of the time, turning it on for about 5 minutes every half an hour would be better.

This will help keep the battery charged and allow you to listen to the radio longer.

turning the car switch on/off
Video | Diycarmodz


Put the car into accessory mode or neutral gear if you have that option.

Doing either or both of them may help save energy and reduce the battery drain. The accessories mode on modern cars makes the battery drain slowly.

To put your car into accessories mode, turn the engine off Engine then turn the radio on.

Creative Options

Rewire the Battery

If you’re fond of listening to the radio in your car for long periods with the engine off, rewire the battery.

Rewiring the battery will allow you to turn the radio on even when the key is not in the ignition.

However, I don’t recommend you do this unless you have a good, healthy battery with a high capacity. Consider the alternative method below for a better solution.

Install an AC/DC Converter

You can install an AC/DC converter in your car and attach it to a nearby AC power source.

This is a good permanent solution for a car parked in your home besides the solar charger. You won’t need to use the car’s battery, so it will not drain even a little. You will rely completely on your home’s electrical supply as an alternative energy source.

This solution will allow you to listen to the car’s radio for as long as possible.

an AC/DC car inverter
An AC/DC car inverter

Radio Problems

If you have to listen to the radio unintentionally, fix the problem quickly before it drains your battery completely.

It would be best to keep the radio running to fix a problem such as too much noise. Or, perhaps the radio is stuck in operating and won’t turn off. Either way, the battery will keep draining until you fix the problem.

Turning the Radio Off

Here’s what to do to turn the radio off if it doesn’t turn off easily:

Open the fuse box near the brake pedal, find the fuse that controls the radio, and remove it. This will instantly shut off the radio and stop it from draining the battery further.

Reinsert the fuse when you need to listen to the radio again. It might start working properly this time, i.e., you should be able to turn it off normally, but if not, get the radio fixed.


AC/DC car inverter:

Video References



diycarmoz youtubechannel

Parts Express

Peter Finn, the Car Doctor

How helpful was this article?

Were Sorry This Was Not Helpful!

Let us improve this post!

Please Tell Us How We Can Improve This Article.

About Alex Robertson

c3c9d43f1f0d14c4b73cb686f2c81c4e?s=90&d=mm&r=gCertifications: B.M.E.
Education: University Of Denver - Mechanical Engineering
Lives In: Denver Colorado

Hi, I’m Alex! I’m a co-founder, content strategist, and writer and a close friend of our co-owner, Sam Orlovsky. I received my Bachelor of Mechanical Engineering (B.M.E.) degree from Denver, where we studied together. My passion for technical and creative writing has led me to help Sam with this project.

| Reach Me