Does Radio Drain Car Battery? How Long Can it Last?

We all love listening to the radio whether we are driving or sitting in a parking lot. It’s good entertainment and a great time pass.

But a radio running for an hour or so does get us questioning. Does the radio drain the car battery? How long can it last? 

Does the Radio Drain Your Car Battery?

Yes, the radio drains battery power as it needs electricity to run. The amount of electricity it drains depends on your radio, sound system, and use time.  

Radios are electronic devices that need electricity to operate. That electricity is provided by the battery all the time, meaning whether your engine is on or off it’s your battery that’s providing the necessary power. 

When your engine is running, the battery is also getting charged as it is drained. But when your engine is off, the car electronics including the radio runs on the battery, which is getting drained only. Also, to operate the radio you need to keep your key on ON. 

So while your engine is not running, other car electronics such as the dash light, DRLs, sensors are also activities that would be draining the battery along with the radio.  

If you keep your engine on to keep the battery from discharging, it would start consuming fuel. Even when you are driving, just like using AC consumes more fuel, using the radio while driving will also consume more fuel but at a very smaller scale.  

Also read: Does Car Battery Brand Matter? Which One is the Best?

How Long Can a Car Battery Last with the Radio on?

A car battery can last for more than 10-12 hours when using a 12-volt radio unit. 

The amount of backup your battery can provide depends on the amount of power your radio chugs in. As car radios are rated at 12 Volts, they consume very little power to operate. On any normal day, you can use your radio for more than 10 hours or 600 mins before completely discharging the battery. 

Do note that this time frame can change depending on different factors. On hot days, batteries get hot faster and the efficiency reduces. If you use your radio at a higher volume, your speaker would need more power and drain batteries faster. This can also depend on the number of speakers you have. Normally, A small AM/FM radio 4 speaker set would last longer than one with 6 or 12 speakers.  

Older radios also tend to consume more power as compared to modern ones. The backup you get also depends on the condition of your battery. 

How to Listen to Radio Without Draining too Much Car Battery?

Using the radio to a minimum with just enough volume while avoiding using any other car electronics should keep your batteries from draining. 

How long you listen to your radio depends on the amount and speed of the battery drain. If you don’t want your batteries to drain as much, avoid listening to the radio for more than an hour. Even at 60%-80% speaker output, you would have enough juice for your batteries to run the starter motor and get you going. 

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But if you have to listen to the radio for a longer period, say more than 3-4 hours, then you must make a few sacrifices. The obvious one is to avoid using any other amenities. Things like the fan, headlights, interior lights, should all be turned off. Also, you should avoid playing the radio at a higher volume. 

Do note that if your car is, let’s say 10-15 years older, and so are your batteries, listening to the radio for 3-4 hours wouldn’t be a good choice. This doesn’t have to be true for modern cars, as they are very well optimized for power uses. Modern cars have smarter computers that ensure that you use the least amount of power required. 

So if you have a new car, or even a new battery, by avoiding higher volumes and use of other amenities, you can listen to your radio for longer hours without draining too much battery.  

Also read: Does Car Radio use Gas? Well, Yes… 

Is it OK to Turn On Your Car to Listen to the Radio without Draining Battery?

Turning on your car just for the sake of listening to the radio is a very stupid decision.

Unless you are driving an electric car, turning your car for anything other than the AC/heater is an unnecessary waste of fuel. You see, with AC or heater the coolant needs to be moving, and the radiator needs to be on, both of which will drain too much battery, so you need your vehicle on. The same is true if you have halogen lights because they also drain too much power when they are on.  So keeping the car on keeps the battery charged as it is drained. 

But when listening to the radio which generally uses around 10 watts as compared to halogen’s 90 watts, power use means that you can run a radio for 9 hours for 1 hour of halogen lights. Due to radio’s way lesser power consumption, keeping your car on when listening to one is simply overkilling. 

There is a situation in which you would have to keep your car on unless you have an external power source. That is when you are also running a stereo.  

A car stereo is generally rated at 3-5 amps of power or 360 watts to 600 watts. And a typical 12-volt battery is rated around 600 watts -720 watts. So at full power, a 3 amp stereo would drain the battery completely in just 2 hours. In such scenarios, you should keep your car on or just get a bigger battery.