Are Car Batteries AC or DC? [Explained]

There are two types of batteries in a car. One is the system backup battery and another one is a battery that runs the car. The 2nd one is used in hybrid or electric cars. We all know there are two types of batteries. But do you know what types of batteries are used in a car? Are car batteries AC or DC?

This is an essential question when you want to know about a car battery or you want to replace the battery for your car. Here in this discussion, we are going to talk about the type of battery used in a car. So, let’s start a knowledgeable discussion.

Are Car Batteries AC Or DC?

All batteries that can store charge are DC. You will not get a single battery that can store AC voltage. So, a car battery must be a DC battery. But still, there is confusion because some batteries have an inbuilt circuit that converts DC current to AC current.

In some sections of a car, it requires AC current. For example, the spark plug. For these areas, AC converting circuit is used. Even some car has more than one battery and among them one is AC and another one is DC. 

So, we must say that car batteries are DC batteries. But in some parts, DC to AC converting circuits are used to meet the need. 

Why A DC Battery Is Used In A Car?

We all know what types of battery is used in a car.  But you should know why this type of battery is used in a car. Why you can not use AC batteries to control the whole system inside the car?

A DC battery is used in a car because it has the ability to generate an extremely high amperage. This allows for all sorts of electrical devices and accessories to be connected, such as headlights, taillights, turn signals, and more. An AC battery will not run these parts of a car.

Moreover, DC batteries also have a longer lifespan than other types of batteries due to their low internal resistance. For all these reasons, a DC battery is used in a car.

What If A Car Battery Was AC?

The internal system of a car engine is very complex and compact. There are so many components that are interconnected. Besides that, the whole body of a car is made of metal. And we all know that AC current generates a current that shocks humans and some other animals.

If AC batteries were used in a car, the whole system would form an electric field that will shock and injure you. Besides that, all the components are not AC components. 

Among them, all the lights and other control modules need DC current. So, if a car battery was an AC battery, the whole system would collapse and you would not enjoy driving.

What Is DC Battery?

A DC battery is a type of electric battery that uses direct current (DC) to power devices. It was traditionally used in vehicles but has since been replaced by more reliable types of batteries.

The biggest advantages of using DC batteries are their low self-discharge and high energy density. This means that they can hold a lot of charge for a long time and still work properly. 

Additionally, they have a very short discharge time which makes them ideal for applications where quick response is required, such as smart sensors or remote controls. DC batteries are also generally safer than other types of electric batteries.

What Is An AC Battery?

An AC battery is a type of battery that uses alternating current or electricity. It’s most commonly used in households and businesses to power things like lights, appliances, and heating systems. An AC battery is mainly a DC battery that has an inbuild DC to AC converting circuit.

An AC battery typically has two electrodes – an anode (positive) and a cathode (negative). The biggest advantage of using an AC battery is that it can be easily recharged by plugging it into the electrical outlet.

Differences Between AC And DC Battery

There are so many basic differences between an AC battery and a DC battery. You should know about them because we are using them in our daily life. Besides that, we also should know these differences to understand why a DC battery is used in a car. 

There are so many differences between these two types of batteries. Among them, most differences are told in the definition of both the battery types. Let’s learn some more differences between them.

  • AC battery uses alternators to work.
  • DC battery does not use alternators and works on direct current.
  • AC battery has a longer lifespan than compared to DC battery.
  • DC battery is more powerful than compared to AC battery.
  • DC battery has a faster charging time than an AC battery.

There are pros and cons to both types of systems; however, you should follow only the manufacturer’s guide while selecting batteries for your car. If your car has both types of battery then replace the DC battery with a DC one and vice versa.


The battery is a vital part of a car. So, while changing it, be careful about its type. We hope now you know what types of battery is used in a car. There are some more discussions on our site about cars. You may read them too for a better understanding of cars’ problems and their solutions. Thanks for reading from us.

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