How long does a car battery last without an alternator

Batteries are vital parts of any automobile. A car battery’s main purpose is to change chemical energy into electrical energy when you start the car ignition. The battery keeps your vehicle’s energy system sustainable. It also plays a part in lighting and powering car accessories such as radio, clock, and alarm systems. So, how long does a car battery last without driving? This is one of the most common questions people ask about vehicles.

We don’t use our vehicles all the time. Sometimes we will leave them unused for some time for one reason or another. Vehicles have radios, clocks, and other accessories which drain the battery constantly, even when it is idle. These are some of the factors that make your vehicle die when not in use.

How long a battery last when the engine is off depends which how it is stored, how old it is, and how it is used. You, therefore, need to take extra caution to avoid the battery from getting damaged. Let us discuss how long the battery should stay unused and guide you on how to prevent the battery from damage when not in use.

Whenever you are planning a vacation or a business trip, one thing that you think about is how safe your vehicle is. You, of course, want your car battery to serve you without the need to buy another one when you get back from your vacation.

 New Car Batteries

A new and full car battery can stay for around two weeks without needing to be recharged from a generator. This battery will fully get discharged after approximately two to three months. If you leave the battery for roughly two and a half months, you will not be able to start the car engine.

The longevity of a new car battery depends on the devices that are functioning in the vehicle when it is not moving. Some of these devices include radio systems, headlamps, and alarm systems. This is because these devices need energy even when the car is off, and they get it from the vehicle battery.

When Battery is disconnected

You wonder how long it wills a car battery last if disconnected. A lead-acid battery dies when you continuously pull power from it after it has been discharged. How well you store your battery after disconnecting will determine how long it will last.

The temperature at which you preserve your battery is an essential factor after disconnecting it from the vehicle. When you put the battery at low temperatures, it tends to discharge much faster than when put at room temperature. Leaving a discharged battery in low temperatures after a long time will make it fail.

This is because the density of the electrolyte inside the car battery reduces significantly. This will result in crystallization and finally damage the battery plates when stored at optimum temperature; the car battery stays for a longer period depending on its capacity. A vehicle battery has a natural current leakage of 10mAh.

Causes of Battery Drain

There are things in contemporary vehicles that drain the power of your vehicle without knowing. They are called parasitic drains. Vehicles with plenty of gadgets and computers will stay for less than four weeks before the battery dies. This is because they will be getting power from the car battery even when it is off. This is why batteries lose charge even when the car is sitting. The life of a battery is difficult to predict. It will depend on the climate and also the age of the battery.

According to BMW, a car battery should sit for four weeks without removing the battery. When the battery is removed, it can stay for six weeks to 6 months. However, you need to keep recharging the battery over time. Ideally, the battery should be recharged every 12 weeks when the battery is disconnected.

How to Save Car Battery When Not in Use: Step-by-Step Guide

When the vehicle is not in use, you can either keep the car battery in the vehicle or keep it separately. Remember we said that car batteries in the vehicle discharge due to other devices running. Therefore, how to keep a car battery from dying when not in use:

When the car battery is in the vehicle

If you are not leaving the vehicle for long or you will be around the vehicle, then you would opt not to remove the battery. In that case, you need to keep on staring at the vehicle once in a while. Start the car for around 5 to 10 minutes at a neutral gear and for about 1000 RPM. This way, the battery will get the lost charge when the car is running. The engine juices up the car battery. When RPM goes to 1000, the car battery starts to recharge itself. Therefore, when you drive your vehicle frequently, you add the life of a battery. This may consume some fuel, but it is worth it if you want to keep the car battery safe.

The other way is to attach a battery maintainer to the battery. This will add some power to the battery often to prevent it from discharging. To use this process, you need to have AC power near the vehicle when using a battery maintainer. This is battery power with low power which checks the voltage of the battery often and tops it up if need be. The main advantage of a battery maintainer is that, unlike traditional batteries, it does not overcharge the car battery. It is also advisable to disconnect the accessories of the vehicle such as radios, alarms, and clocks to prevent the battery from discharging fast.

When the battery is removed

If you are going for a long period, then the best way to keep the battery safe is by removing it from the vehicle. Disconnecting it is not enough since it naturally self-discharges, but if you store it well, it will save you from buying a new battery when you come back. Follow these steps to store a car battery:

• Remove the battery from the vehicle
• Keep it out of reach of children and pets. When deciding on where to keep the battery ensures that no child can access or reach the area.
• Look for a Place you can control the environment. The place you keep the battery should not be too cold or too hot. The two extreme temperatures affect the battery negatively.
• Take a good look at the terminals. Check the battery terminals carefully since how you store the battery will depend on them.
• Ensure the battery is protected from moisture. The simplest way to do this is to put a moisture-resistant mat on a piece of plastic under the battery. Then you can clean it using baking soda to prevent leakage and corrosion.
• Keep the battery juiced. Once you have stored the battery, that is not the end of it. You have to lean on how to keep the car battery charged when not in use. You need to keep the car battery juiced. If you have placed it well, you can recharge it after every 12 weeks.

5 Symptoms Of A Bad Car Battery YouTube Video

Frequently Asked Questions (FAQ)

Q.  Does the Car Battery Die If Not Driven?

Yes. Car batteries will die even when the vehicle is sitting. This is because car batteries self-discharge naturally. The battery is not only used when the car is in motion. However, accessories in the vehicle tend to drain the car battery even when it is idle. If your vehicle has several accessories such as a radio, air conditioner, and clock, the battery will self-discharge, which will result in it dying.

Another thing that may cause the battery of an idle car to die is temperature. Very low temperatures will kill a car battery. This is because the temperature causes little amperage to get in the motor. The batteries can also get damaged by extremely high temperatures.

Q. What Can Drain a Car Battery When the Car is off?

There are several accessories in the vehicle that drain the battery when it is off. This is known as a parasitic drain. The devices that drain car batteries are radio systems, headlamps, air conditioning systems, and alarm systems. The only way to keep these devices from draining the car battery is by disconnecting it from the vehicle or turning off the devices.

Q. How Do I Know When My Car Needs a New Battery?

Various symptoms will show you that your vehicle battery needs to be replaced. When the battery fails to start, it is a result of its malfunctioning, and thus it needs to be replaced. Also, when the engine of the vehicle keeps on failing, it is a sign that something is wrong with the battery or its terminals.

The other sign is when the car accessories stop working correctly. The radio, wipers, speakers, and lights of the vehicle get their power from the battery. Therefore, when they stop working normally, it shows that you need to check on the car battery. The other sign is a foul smell like a rotten egg or a disgusting running smell.

That is the smell of sulfuric acid evaporating. This is a sign that a cell is almost dying. Finally, you will hear an annoying clicking sound anytime you turn on the ignition. If this happens, try to jumpstart. If it fails the second time, then the battery is about to die and needs to be replaced.

Q. How Many Years Do Car Batteries Last?

On average, a car battery can last between two to five years. However, if you take good care of the battery, it can go up to six years. If you live in an area with a cold climate, the battery will last much longer. Also, if the vehicle is driven daily, the battery lasts much longer. You should also keep the car battery fully charged to keep it longer. When you park the vehicle for a long time without using it, the lifespan of the car battery decreases.

Q. How Much Would it cost to replace a car Battery

The cost of replacing a battery depends on different things. The price will differ depending on the battery size, battery brand, where it is located, and the costs of installation in your area. The standard sizes of car batteries range from 24 to 75. The prices of these batteries are between $40 and $90. The price will also differ depending on the brand of the car battery you want to use.

The cheapest brand goes for approximately $50 labor costs also differ from place to place and the type of garage you go to. Most installation costs range between $50 and $100. However, you can save the cost of installation by learning how to install the battery by yourself.

Watch YouTube Video How to Test a Car Battery with a Multimeter

Final Words

With the above information, you are aware of how long a car battery stays without driving and how to keep it safe. At times during the winter season, you will not be using your vehicle. In that case, make sure that the car battery is well stored and safe to use after the winter season. Ensure that it is in a warm place and a comfortable environment.

The more your battery stays without being recharged, the more the situation worsens. If you can, run the vehicle regularly. This will increase the battery’s durability. Before storing the car batteries, always remember to clean them. Also, for safety purposes, check the date your battery was manufactured, do not short the terminals, and never store it near open flames or heaters.

Learn more:

• How to Charge a Car Battery Without a Charger
• Battery 101: how does a car battery work?