Car Batteries Guide: Components, Types, and Functions

The batteries are an essential component of any vehicle; they are the power storage components of the car. Whether a fuel engine or an electric vehicle, you can only start the car if the battery is functioning. The batteries are more than a regular box, they store energy. So, upon ignition, they release the stored energy, allowing the car to function. In this article, we will discuss parts of car batteries in detail.

What is a Car Battery?

A battery refers to any device that converts chemical energy to electrical energy. The car or automobile battery stores chemical energy but immediately converts it to electricity upon ignition.

The typical car battery is rechargeable and designed to be a wet-cell battery. Regardless of the car type, all batteries perform similar operations – power the vehicle and all its electrical components.

When you start your car, the battery supplies electric current that initiates the internal chemical engines needed to drive the car. In addition, other electronic parts of the vehicle, like lights, radios, wipers, etc., require the battery to function optimally.

parts of the car batteryComponents of a Typical Car Battery

A typical automobile battery is enclosed in a battery box or case. However, the interior parts of the car battery consist of different components. Below are the essential car battery parts.

Battery Acid

The acid is a solution of sulfuric acid and water (36 to 40 percent). The resulting mixture serves as the electrolyte that triggers the chemical reaction, which produces the electric current that powers the vehicle. It is often of high purity, as the presence of contaminants may alter its effectiveness for car power generation.

The acid and water react upon igniting the car, producing the suitable voltage needed to kick-start the vehicle. The voltage produced will be insufficient for driving the car engine if the battery is weak.

Battery Terminal

It is also called battery bushing. The battery terminal is the connection point linking the battery with the car’s electrical components. Like any electrical device, it has two terminals – the positive and negative straps of the battery end cells.

Battery Case

Both fuel and electric vehicles have parts of the batteries enclosed within a box. The case protects the contents and parts of the car battery. For fuel batteries, cast-on-straps are often designed with polypropylene resins. In EVs, the battery enclosure box is usually created with aluminum alloys. The battery case offers protection for its contents and minimizes the impact effects on the battery, thereby extending its life.

Battery Plates

A typical car battery consists of negative and positive plates. Either plate consists of a metal grid, though the positive end contains lead dioxide material, with the negative end having a spongy lead. Either plate has a cast-on strap on top, linking each component to the battery cells.

Battery Separator

As the name indicates, the separator creates a distinction between the positive and negative plates. Also, it is often made of polyethylene or other plastic polymers.

car battery working principleWorking Principles of Car Batteries

The primary function of the automobile battery is to provide the electric current required for powering all the vehicle’s electrical components. Even when the car is turned off, it gives enough energy to power some elements, such as the lights and radio. However, it’s only possible to drive the car after igniting it.

Here is what happens when you start your car.

First, a chemical reaction occurs in the battery, causing it to transform chemical energy into electrical energy for powering the vehicle and providing voltage to the car starter.

The battery then starts a stabilizing action – it keeps the electric current in a steady state by regulating voltage. If voltage is unregulated, current continues to develop, which may cause adverse and harmful reactions in your car.

Note, only about three percent of the battery capacity is required to start a car. Therefore, most automobile batteries just deliver maximum electric current for a short while to power the engine and other electrical aspects of the car. The batteries are sometimes called SLI – starting, lighting, and ignition because they are the device’s main functions.

Different Types of Auto Batteries

The type of battery your automobile uses may affect the overall performance. Therefore, it is vital that you select the correct time of batteries for your car. Below is a brief review of the different kinds of vehicle batteries to give you an insight into which is best for your auto engine.

Primary Cell Batteries

They are single-use batteries – the typical AA or triple-a batteries – often used in remotes. They are alkaline batteries made with song and carbon, and it is unlikely that you will find these kinds of batteries in automobiles. The batteries are already reducing in popularity because they are not rechargeable and must be disposed of after use.

Secondary Cell Batteries

Unlike primary cell batteries, secondary cell batteries are rechargeable, supporting use for extended periods. They consist of several electrolytic materials – the electrolyte and electrodes – essential for powering the vehicle. They are the go-to battery type for automobiles, the common ones being; lead acid batteries, lithium-ion (Li-ion) batteries, and lithium-iron-phosphate batteries.

lead-acid batteriesLead-acid Batteries

They are the typical batteries you find in fuel engines. The lead-acid batteries kickstarted the introduction of rechargeable battery tech. In relation to their size and weight, they have a high power generation. Besides their use in cars, they are suitable for use in hospitals and cell phone towers because they generate significant power. They are typically used as a backup power source.

Lithium-Ion (Li-ion) Batteries

Li-ion batteries are also standard in automobiles., especially in electric vehicles. They can hold a lot of power, allowing EVs to travel for a long trip before needing to recharge. Also, they tend to maintain their power, even when the cars are not used for extended periods.

Generally, secondary batteries are better than primary ones because they are rechargeable and environmentally friendly.

Solid-State Battery

The solid-state battery is relatively new in the world of batteries and energy storage devices. This solid-state battery tech looks to avoid the need for a liquid base electrolyte which explains the name “solid-state.” The batteries use solid ceramic-like materials as its electrode, making them relatively quick to charge and easier to transport. The batteries are already penetrating the world of electric vehicles because of their superiority.

Functions of Car Batteries

The battery performs some essential functions, such as starting the engine and lighting up other electrical components. Below is a summary of the functions of car batteries.

functions of car batteriesEngine Starter

Without batteries, it is almost impossible to start auto-engines. The battery acts as the car’s powerhouse, storing chemical energy that immediately converts to electrical upon igniting the car. The batteries then distribute this power to parts of the vehicle that require it.

Power Storage

The battery stores the power needed to restart the car and run other electronics. An ideal battery, even after long-term storage, should be able to power the vehicle when properly connected. As soon as the car starts working, the alternator recharges the battery to ensure enough power to run all parts of the car. Also, the battery begins to store chemical energy again for future use.

Collaboration With Alternator to Power Other Electrical Components

The alternator is responsible for controlling the actions of the car’s electrical parts, like lighting, air conditioner, wipers, etc. The battery provides the needed power for the alternator to power the other electronics in the vehicle.

Regulates Voltage

There are cases where other car components may overwork, which can lead to accruing overly high voltage, which is harmful to the vehicle. The modern-day battery is equipped with features that allow it to absorb some of this energy, thereby regulating the developing voltage. Hence, the car gets protection based on this battery function.

Get Car Battery Parts at WayKen

The battery case is an essential component of the battery as it protects users from the contents of the battery and ensures that all parts of the battery in the car are in place. When manufacturing a typical battery enclosure box, especially for your electric vehicles, WayKen is here to help you.

At WayKen, we help you achieve your EV battery box design that fits perfectly into your car, even if you want customized car battery housing. Besides manufacturing battery boxes, we can also help you manufacture car parts like headlamps and backlights, amongst other car components.

We have highly knowledgeable engineers and mechanics who are experienced in the latest manufacturing technology required for fabricating your car parts. Also, we offer industry-standard CNC machining, injection molding, and 3D printing services.
Just upload your CAD files and let’s bring your idea to life.


The batteries need to be in optimum condition for you to have full access to the car’s functionalities. If there are missing parts of a car battery, such as electrodes or electrolytes, it cannot function. The battery case ensures that all the components of the battery are kept intact and protects users from exposure to the battery components.


What are the basic components of a car battery?

The essential components of any battery are the electrolyte – the sulfuric acid or lithium salt – the positive plate (anode), and the negative plate (cathode). However, the battery case is also an essential component of any battery. The battery cannot just be exposed; the content needs to be kept intact to prevent spillage or even accidents, as it is toxic.

What is the liquid inside a car battery?

The fluid in a typical car battery – lead-acid battery – is the electrolyte, and it is sometimes called battery acid, as it’s an acidic substance. On the other hand, the liquid in a lithium-ion battery is the dissolution of lithium salt, like LiPF6, LiClO4, or LiBF4.

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