How Long Can a Car Battery Sit Unused?

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Your car battery is important to get your car up and running. However, if you’re away for a long while or have left your car unused for a long time, you probably wonder if your car battery will still function. 

How Long Can a Car Battery Sit Unused? 

Generally, a car battery can sit unused for about two weeks. Others claim a battery can sit unused for around a month or two. It all depends on the condition of your car battery and if it’s new or old. 

Jumper cables attached to the car battery

When your car battery gets cold, you may need professional assistance to thoroughly check it. Your brakes are also affected by your car battery going cold and may not function properly. 

Hence the reason why it’s important that you let a professional check especially if you’re not knowledgeable about car repairs. 

Related Questions

Do Car Batteries Expire If Not Used?

Car batteries can usually last for about three to four years before it expires. However, if you leave your car sitting for too long, it may lessen its usual longevity. 

Therefore, you need to keep your car battery running and in good condition to last it for a long time. You can start the car battery once every two weeks if it’s just sitting in your garage. You also have to do regular maintenance to check if anything is wrong with it. 

You can also recycle your own car batteries to earn a little money and lessen the cost of getting a new one. It will also help conserve energy and lessen greenhouse gas emissions. 

Car battery

Why Does My Car Battery Die After Sitting for a Few Days?

If your car battery died within just days of sitting, there’s a problem with it. A study was done by J.D. Power that found 44% more car owners reported a battery failure in 2017. 

Batteries are the most commonly replaced component of your car and it’s important to identify what the problem is. These are some of the common reasons why your battery died just after sitting only for a few days:

  • You left the headlights or dome lights on for a long time
  • Your battery is already in a weak or poor condition
  • Unchecked corroded or loose battery connections
  • Undiscovered parasitic drains in your electrical system
  • Exposed to extreme hot or cold temperatures
  • Problems with the charging system


If you don’t use your car batteries for a certain period of time, it can go cold. This means you will have to spend more to get a professional to repair your car and make it running. Keep your car running regularly to avoid it going cold.