Can a Car Battery Go Dead from Sitting?

Can a car battery go dead from sitting? Yes, it can. It often happens that you go to start your car after a few weeks and it doesn’t turn over. The engine just cranks and cranks but never starts. In the winter months, it’s not uncommon for cars to sit in storage for weeks or even months at a time without being driven. Leaving the car in the garage for a long time could save money on gas and maintenance expenses but damage the battery.

The fact is when left idle for an extended period of time your battery will slowly lose its charge. However, this doesn’t mean it’ll die completely in a matter of days or weeks. Let’s find out why this happens and what you can do to prevent this issue.

How Can a Car Battery Go Dead from Sitting?

The main reasons for a car battery dead after sitting are electrical system malfunction and parasitic draining. When a system is not working properly, it can draw more battery power than necessary.

Even when the car is not running and the engine is off, power gets drained from the battery by the various electrical systems. The alternator, lights, radio, and several other fixtures continue to draw power from the battery.

Especially, modern cars have loads of systems that are responsible for huge parasitic battery drain. Vehicles these days are tech-heavy, including anti-theft, GPS, proximity sensors, vehicle condition monitoring, and many other systems. These features keep using the battery power even when the engine is off.

A car battery also drains faster when the weather is colder or hotter than the normal temperature. So, the surrounding temperature and weather conditions play a big role in determining whether a battery unit will still be functional after a long inactive period.

car battery dead after sitting
Hot weather can drain a battery faster. (Credit: Abhinav Thakur / PixaHive)

How Long Can a Car Sit Before the Battery Dies?

How long can a car battery sit? It can take anywhere from a few days to a couple of weeks. However, the actual timing will vary from car to car because the battery’s resilience depends on its condition and the vehicle’s make and model.

For example, leaving a Mercedes-Benz S550 Cabriolet for a few days is enough to drain the battery. Leave the car idle for one week and the battery won’t have any juice to even activate the door locks.

For a Ford Expedition, it will take around five days for the battery to become inactive. The timing could extend to nine days if the battery is new. On the other hand, you can expect the car battery dead after sitting 2 weeks in the case of a Toyota Sequoia SUV.

Can a car battery go dead from sitting? Yes, it can. But the sitting period absolutely depends on your vehicle’s model and the battery condition. It appears that the battery pack of a luxury vehicle goes flat quickly because various sophisticated features keep running despite the car being parked somewhere.

It’s advised for drivers who regularly park in colder climates during winter months to have their batteries checked before parking each time. Cold weather can lead to more frequent dying of the battery over time. For those living in warmer climates, it may take longer for the battery to be drained completely.


How to Protect a Car Battery from Going Dead?

The best way to protect the battery from going dead is by using small car chargers. Occasional charging with a trickle charger will keep up charge levels. The battery will also stay alive if you take the car out and drive once in a while by running the engine.

If you cannot arrange for these measures, leave the car in storage by disconnecting the negative battery terminal. It will prevent various electronics from using the battery for parasitic draining.

Another option is to remove the battery from the vehicle. A detached unit will last a maximum of 6 months if you can store it properly. The storage space should have room temperature and free of moisture. Also, recharge it every two weeks is a good practice to keep the unit healthy.

If the battery disconnection is not an option, bring a small charger into your garage and plug the battery into it occasionally. This will help the battery maintain its charge level without giving up completely.

Taking proper care and driving the car regularly will keep a battery pack functioning for three to four years. However, an unused new battery will also go flat within weeks or months if not recharged frequently.


Can a car battery go dead from sitting? You already know that it’s highly possible. Understanding the reason behind why it can drain over time and being mindful of potential solutions will not only help you extend the life span, but also prevent any concerns before they happen!