How Long Can You Leave a Car Without Starting It?

After having a relaxing month-long trip to Switzerland, when I was about to resume my office from Monday working, I got a shock when my one-year-old car didn’t start. It was so horrifying and tensed moments until I met my car mechanic.

I had no idea what happens when a car sits too long? It was in the rest period during the entire month and nobody used it. That’s when the question popped up, how long can you leave a car sit without starting it?

how long can you leave a car without starting it
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I asked the mechanic and searched the info on the internet for the same topic. It was a sigh of relief when I found that I was not the first to ask, “how long can my car sit before the battery dies?” There are thousands of people who have experienced similar problems and are not having full knowledge of the issue.

It was then I decided to find, collect info and present you a complete study, know-how on “what happens if your car sits too long” and “how long can you let a car sit before the battery dies”. This will help in informing the causes, precautionary measures, and remedies in case of such an incident with you.

Also read: How Long Can a Car Go without an Oil Change? 100% Facts

General Reasons for Not Using the Car

It is found that most of the time, people buy a new car when they are learning ABC yet to get a license for the same. They are not aware of how long can you leave a car without starting it? Once they pass the test and try their hands on their own new car, they face car ignition issues. The car doesn’t start but their panic does. It is very important for all car owners to know about how long can a car battery sit unused?

While people go out for a long vacation, their cars remain unattended in the garage. It also does not come in use when the owner or the driver gets ill and uses the pool or other means to communicate. Reasons may vary, but one must make it a point to use the car at least once every fortnight if not every week.

Role of Battery in a Car

When a car is being driven, a sort of current passes through the batteries which charge them during the process. However, when the car is not in use for any reason, the battery dies out for multiple reasons. I know that the first query that comes to your mind is “how many days can a car sit before the battery dies?”

Well, that depends on car models. Electrochemical reactions take place that makes the battery in a car work. Just by switching off the engine and putting the car in a shed, it doesn’t stop the battery to be consumed. There are various features of the car that consumes the battery in sitting mode too.

The latest models of cars come loaded with battery-hungry characteristics that suck all the battery charge even if the car is not being used. Features like an alarm signal, chip-based lighting, and siren features, saving preference of position of seats and temperature control and other such data needs to be in memory of car-chip. There are mini- control board panels installed for various reasons that need power which comes from these batteries.

What Happens When a Car Sits Too Long?

The simplest answer to this query is: the battery dies. You either need to recharge or in some cases, you may have to change the entire battery. In off mode, lots of car features need the power to retain the data and execute certain tasks like keeping the alarm awake, sensing any collisions, auto-siren process and few others.

All these are responsible for draining the battery out. However, old car models were not so much sophisticated and hence used to have longer battery life. However, with new models, new gadgets, and various new features, the battery doesn’t live longer without regular use of the car.

How to Know if the Battery is Dead

There are different symptoms of a dead car battery and varies from different models but most basics are mentioned here. Dome light bulbs do not turn on or door chime doesn’t work when keys are unlocked. Neither radio or headlight will be on. Headlight may appear dim but won’t be useful at all.

Nothing fruitful happens to start the car when the ignition key is turned on. If the battery is dead, no major activity will take place. You need to make sure that it’s not the case of dead battery only, but the trouble could be for any other alternate reason.

More Info about Car Battery

By now, you are well informed about the role of battery and its usage along with details on how long can you leave a car without starting it? And it is easy to calculate the exact duration and time when the battery will end the charge.

A new car battery when installed can last for 20 to 30 days without any charge whereas it still gets discharged fully within a span of 90 to 100 days. However, it is not a good idea to disconnect the battery if you pre-planned of not using the car for a long period. Battery disconnection for a long period will result in malfunctioning of various features which is not recommended.

How to Save Car Battery Life When Not in Use

Make sure that your car battery is fitted properly and all the cables are in order. Improper cell connected can result in a short circuit. Regular health checkups for your car battery will ensure its longevity. It is also very important to keep the battery in proper working condition with a battery tester.

Check during warranty periods and renew the same in case of warranty expiry. Switch off the air conditioner, radio, GPS or any other feature when not in use. Turn off all other features that you may not need when you go out for vacation. This will certainly answer how long can a car sit before the battery dies.


No matter how careful steps we take with our car, we may sometime end up with being casual and car battery has to suffer. How long can you leave a car without starting it and how long can a car sit before the battery dies, it simply depends on the type of car and cares we take for our beloved car and its maintenance.

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About Amy Cuban

I am an automotive enthusiast who loves to be around cars. I enjoy working on cars in my spare time and love anything related to automobiles. I like using different types of car accessories, car gadgets, and innovative car care products.

1 thought on “How Long Can You Leave a Car Without Starting It?”

  1. You completed certain nice points there. I did a search on the issue and found the majority
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