Why Does Leaving Keys in Ignition Drain Battery?

The reason your car’s battery drains when you leave the keys in the ignition is that there is a constant power draw on the battery when it is running. The car is constantly looking for a key to operate, and it uses energy to do so.

When you leave the keys in the ignition, the car’s computer will keep trying to find a key and it uses up more of your battery. This happens even if you’ve turned off the engine.

If you have an older model car with a manual transmission and no anti-theft device installed, there’s also another reason why leaving your keys in the ignition can drain your battery. If you forget to turn off your lights or radio before exiting your vehicle, that too will continue running as long as your keys are still in place.

What are the causes of a dead battery?

Leaving keys in the ignition is one of the top causes of a dead battery. The most common reason for this is that you have left your lights on, which drains your battery. If you leave your lights on, your car will automatically shut off after about 10 minutes, but this does not mean that it has recharged itself.

If you do not start your car for any length of time or drive it at all, it will drain the battery. Another common cause of a dead battery is corrosion on the terminals. Corrosion occurs when there are water leaks under the hood or around the battery and terminals.

This can occur if there is rust in the cooling system or if a radiator hose has come loose causing leaks to form around the area near where it connects to other parts such as hoses or clamps so make sure to check these areas carefully if this happens in order to avoid future issues.

The third most common cause of a dead battery is having too many accessories turned on while driving so try turning off anything like GPS units etc until after you’ve parked for a while.

What do you do if your car won’t start?

The first thing to check is to make sure that the lights are off and all doors are closed. If they aren’t, then try turning them off. Make sure that the key is in the on position some older models have a separate off position for the key when it’s not in use.

If neither of those steps works, try moving the key up and down while turning on your engine. This can help start a dead battery. If none of those steps work, then you might need to call a tow truck or roadside assistance service.

What is the best way to keep your car from draining its own battery?

The best way to keep your car from draining its own battery is to leave the keys in the ignition. When you park and turn off your car, but leave the keys in the ignition, it is called leaving the lights on. Leaving the lights on drains your battery and can cause damage to other components of your vehicle.

If you are going to be leaving your vehicle for an extended period of time, such as overnight or while on vacation, be sure to remove all items from the car including loose change and house keys, as well as remove any valuables from view through windows or sunroofs. If you have a garage door opener or remote entry fob, make sure they are turned off as well so they do not drain battery power when not in use.

How long should you leave your keys in the ignition before the battery dies?

If so, it’s not likely to have a modern ignition system, which means that leaving it running for five minutes or so won’t drain your battery nearly as much as it would if you were driving around in a newer vehicle. The reason for this is that older vehicles have mechanical parts that use energy from the engine to keep them running.

The more modern your car is, though, the more likely it is that it has an electronic ignition system that requires less energy than older systems do.

If it’s been a while since you’ve replaced it, then you’re more likely to drain its power over time even if you don’t leave your keys in the ignition for very long at all especially if you live somewhere with harsh winters and/or frequent cold snaps.

This will make a difference too. If you have an electric motor instead of a gas-powered engine, then leave your keys.

Facts about leaving keys in the ignition

Leaving your keys in the ignition for long periods of time can lead to a drained battery. It’s important to remember that if you leave your keys in the ignition, even when the car is turned off, the battery will lose power.


Leaving your car keys in the ignition can cause a significant drain on your car’s battery. To avoid this problem, make sure you have a fully charged battery and remove the keys as soon as you’re finished using your car.

Steven Hatman
Steven Hatman

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