Can A Car Battery Die If You Leave The Key In The Ignition?

Car owners often make mistakes like leaving the key in the ignition. But does leaving the key in the ignition really cause any damage to the car's battery? In this article, we've done the research to bring you answers!

Leaving the keys in the ignition can drain the battery, eventually killing it. This happens due to the constant flow of electricity, which can overheat the ignition coil and cause it to fail over time. If the ignition is left in the ACC position, the battery will drain even faster.

A dead or damaged battery is never good! Please read on to understand how to avoid this and more about this subject. Here, we have provided an elaborate discussion while also answering common questions that some of you may have.

A car key stuck on the car ignition, A car key stuck on the car ignition,. Can A Car Battery Die If You Leave The Key In The Ignition?

What happens when you leave keys in the ignition?

In general, it's a good habit to take your keys out of the ignition and put them in your pocket or purse as soon as you turn off your engine. But why?

As mentioned before, leaving your keys in the ignition can drain your battery. If the key is turned to the OFF position, this drain will be tiny and unlikely to damage a battery in good condition. However, over time, the drain will add up.

However, there are reasons beyond the battery to make sure you remove the keys. You may accidentally lock your keys in the vehicle. Even worse, a thief may see it as an invitation to steal your car.

For all of these reasons, it's best to make removing your keys from the ignition second nature.

What happens if I leave my key fob in the car?

A car key left in the keyhole

A key fob left inside a car could drain the battery. The key fob's ongoing communication with the vehicle requires a small amount of electricity. This will cause a small drain on the batter which can become worse over time.

Additionally, if the remote is left inside the vehicle, the door won't lock. To secure your car and your belongings inside, it's better to always bring with you your key fob and close the door of your vehicle.

To emphasize, leaving the key fob in the car while the engine is on may result in the following:

  1. Fuel consumption will continue since the engine is running. This can eventually burn through all of the gas.
  2. The battery will most likely be drained if left for too long, as it regularly supplies power to the engine.
  3. Leaving the engine running for too long may also cause overheating. However, this is typically the result of mechanical issues and needs to be taken to a mechanic for inspection.

Can you leave the key in the ignition while pumping gas?

Driver inserting the car key

Make sure you never leave your engine running while you are pumping fuel! You should turn off your car and put your keys in your pocket as soon as you pull up to the gas station. This is due to the static electricity and heat that are both generated when your car is operating, both of which can cause a fire or explosion.

Therefore, make sure your car is in park mode, and the engine is off before you fill it up.

Leaving your keys in the ignition while the vehicle is off is unlikely to cause a fire. However, making a habit of taking your keys out of the ignition will ensure you don't accidentally forget. Furthermore, it will keep your vehicle safe from theft.

Additionally, even though fuel fires are uncommon, you should switch off any 12-volt power sources, such as cigarette lighters and phone chargers. 

To ensure your safety, make it a habit to turn off your car and keep your keys close by whenever you start filling your car with gas. Building habits will make sure you have a safe fueling routine.

Can leaving the ignition on cause damage?

As mentioned earlier, leaving your vehicle on while running to the store or in traffic isn't harmful. However, there are certain levels that, if exceeded, may be hazardous. Why? Because mechanical problems may arise.

Prolonged use of an already-started vehicle with the ignition key in the "Start" position may cause damage to the "starting motor," which has a mechanical overrunning clutch that only transmits the power in one direction.

It is possible to start your engine by delivering power to the motor, which in turn rotates the flywheel to crank it up. If the "starting motor" is left on "start" or "ignition" for an extended period of time, it will continue to charge itself, potentially causing an engine to overheat.

How long does it take for a car battery to die with ignition on?

A car key fob left in the car seat

Every vehicle has a different average battery life. With that, the length of time a car battery lasts primarily depends on:

  1. The capacity of the car's battery - the higher the battery capacity, the more time a battery can operate with the ignition turned 'on'.
  2. The type of vehicle - different battery types is available for each car model.
  3. The accessories turned on in the vehicle- the battery's lifespan decreases as more accessories draw power from the car's battery. In this case, limit your use of your car's accessories if you want your car's battery to last longer.
  4. The condition of the battery - good quality batteries will last longer compared to weak and old ones. 

A few reminders! 

Turning off your car's ignition whenever you stop will help keep your battery from draining. You may also want to switch off unnecessary accessories if the car's ignition is on. 

Can I leave my car in accessory mode?

Leaving your car in accessory mode will always drain your battery. The rate that your batter drains will depend on factors such as the accessories you use and any external devices plugged in.

You can, however, leave your vehicle in the accessory mode for short periods of time. To reduce the risk of excessive battery depletion, it is advisable to keep your car's accessory mode to only 30 to 60 minutes.


A car key stuck on the car ignition

Leaving your keys in the ignition for an extended period may result in a drained and, in some instances, a damaged battery.

For better battery life and to prevent other technical issues, turning the engine off while not in use is advisable.

Also, it's important to make sure your lights have been switched off before you exit the car, and always keep in mind to ensure that all of the car's accessories have been turned off. Healthy battery, saving money!

If you found this article helpful, check out these great posts:

How Long Does It Take To Charge A Car Battery?

How Long Can A Car Battery Run An Air Conditioner?

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