Does Accessory Mode Drain Battery? Interesting Facts You Should Know!

We have heard this question quite too often – “Does accessory mode drain battery?”

Also, this one – “Do subwoofers drain car battery?”

Perhaps you would like to do the best you can to save your car battery. Or at least, not use a lot of it when completely unnecessary.

If this is something that you have been thinking about, then you have come to the right place. Today, we will discuss whether the accessory mode does use up and drain so much of your battery, and if so, what you can do to avoid it. 

Let’s get started.

does accessory mode drain battery

Does Accessory Mode Drain Battery

When you are just sitting in your car and waiting around, you may want to keep your vehicle in the accessory mode. After all, you want to probably use some electronics in your vehicle, especially those that do not consume  a lot of energy. 

Perhaps, you want to be in this situation for a few hours or so, while in your car. Typically, when you use low-consumption electronics, and you have a healthy battery, you should not have any problem doing this for several hours.  But if the conditions are unfavorable, then you may run the risk of having a dead battery after just a couple of hours.

It all varies on your particular situation.

Do Subwoofers Drain Car Battery

Your vehicle’s ignition have four different positions. The first one is off or lock. When you move it in the second position, this means accessory while the third one means on. And lastly, the fourth position engages the starter, which then starts your engine. 

So, when we talk about accessory mode, this is when you have your key in the second position. What this means is that some electricity flows from your vehicle’s battery, yet this does not mean your vehicle is operational. 

Hence, you are unable to drive it around. But, you should not have any problem with listening to your car radio or even charge your devices while inside your vehicle. You get power from your car battery.

Now, since your engine is not running, your alternator is not running, as well. This component is responsible for recharging the battery while you drive. When you are idle, it can recharge slightly, but the real charging happens when you have load on your engine and you are driving your vehicle.. 

With this in mind, there have been questions on whether leaving your car in accessory mode is going to drain your battery since it is not charging. Think about it – when your battery is not being recharged by the alternator, how else can it continue to have power?

This is why you need to jumpstart it and have the alternator running just so you can get power to your battery once more. The most important thing is to get it out of accessory mode to allow charging to happen. 

While you may be able to use some lights, charge your device using a USB cable, or play some music, you can most definitely not charge your car battery. So, when you find yourself in an emergency, and you have to charge your device, the accessory mode proves to be useful.

You can also continue to keep your car idle, in case you want the battery to continue charging. The only drawback to this is that it is not environment-friendly since you are wasting gas while idling.

So, subwoofers drain car battery as long as you are in accessory mode. 

As for the length of time it takes for your battery to last when you are in accessory mode, let us talk about a few conditions that impact the battery life. Among these things are the following:

  • Outside temperature
  • Battery health and life
  • How many components are currently being powered
  • The types of devices being powered

With this in mind, it is important to check your battery life before you leave it in accessory mode or in idle for an extended period. This way, you can prevent having any issues with a dead battery, especially if you need to power some items. 

Also, realize that when the weather outside is very cold, you will need to run a few components that tend to use up a lot of energy. Thus, if you already have a low battery life, this does not help if you are looking to keep your vehicle in accessory mode.

On the other hand, if the temperature is mild, and you are only using low-consumption devices, along with a relatively new battery, you should not have any issues with leaving your car in accessory mode. When in favorable conditions, your battery life should be okay for about 10 hours. Under poor conditions, however, you are looking at only about 4 hours. 

Other Points To Consider

There is nothing ultimately wrong about leaving your vehicle in accessory mode even when done routinely. After all, it is your vehicle’s built-in feature, which is why you should be fine with using this feature. 

Furthermore, it may even be better to keep your vehicle in accessory mode than to leave it in idle, especially if you can get the same results anyway. 

But at the same time, there are a few things to keep in mind when you do leave your car in accessory mode for a few hours. First, you should consider the type of subwoofer you have. If you have big ones installed, then these can definitely use up a lot of your car’s battery.

Additionally, power seats use your vehicle’s battery. This is why if you move them when you have the vehicle in accessory mode, your battery should die quickly. The same holds true with rolling your windows up and down a few times. 

Some plug-in navigation systems also use up battery. The drain may not be too much, yet it still uses power, so it is best to avoid using these when in accessory mode.

Bottom Line

Overall, these are the things you should keep in mind when thinking about leaving your vehicle in accessory mode. There are most definitely some perks, yet there are also some drawbacks to think about. This is why it is best to weigh your options and to minimize power consumption when you are in this mode to prevent draining your battery life

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