How do electric vehicle batteries work?

CARS have become an everyday sight in modern society, especially when it comes to travelling from one place to another. When you have your own car, you get to drive anywhere, anytime, and reach a variety of places where public transportation may not be able to take you. 

That being said, it’s not surprising that a lot of people rely on their vehicles to get through their day. For many of these car owners, the typical vehicle of choice is one that comes with an internal combustion engine (ICE). Petrol-powered cars have dominated the streets for years, but as the effects of climate change continue to worsen, many car owners are beginning to switch to electric vehicles (EVs).

Like what their name implies, electric vehicles run on electricity that’s stored in a battery pack. They don’t need to burn fuel to work, which means that they don’t produce any tailpipe emissions. This makes them more eco-friendly than ICEs. To keep their cars charged, EV owners take them to public charging stations. Some will charge them using privately owned stations, like the ones they have at home, or a semi-private charging station, such as a workplace EV charger installation unit.

All the EV owners have to do is connect their vehicle to the charger and wait until the battery pack is fully charged. But what can a fully charged battery pack actually do? Let’s have a closer look at how these battery packs work to get a better understanding of how they power EVs.

How do EV battery packs work?

When a driver engages the accelerator pedal, the battery pack releases stored electrical energy to the electric motor, initiating the movement of the vehicle. It does this by sending direct current (DC) energy through an inverter in its powertrain to convert the energy to AC so that it can power the vehicle’s alternating current (AC) motor. The power the motor receives is then sent to the wheels, allowing the driver to propel the vehicle forward, as well as use its features like the air conditioning and heating system, infotainment system and backup camera.  

Parts of an EV battery pack

Although an EV battery pack may look like a single component, it consists of several parts that work to store and deliver electrical energy. Here are some of its parts:

• Battery Cells. EV battery packs come with individual battery cells that are designed to store electrical energy through a chemical reaction. They allow for the reliable storage and release of power.
• Battery Management System (BMS). The BMS oversees the health and performance of the battery pack. It monitors individual cells, manages charging and discharging processes and ensures the overall safety and longevity of the battery.
• Cooling and Thermal Management Systems. EV battery packs incorporate cooling systems to dissipate heat generated during operation, preventing overheating and preserving the battery’s integrity. These systems maintain an optimal temperature range that ensures the efficiency of the component.
• Voltage Regulator. To ensure a consistent flow of power to the electric motor, a voltage regulator is employed to regulate the voltage output from the battery pack. This way, the EV will receive a stable electrical supply.
• Enclosure. The battery’s enclosure (or casing) provides it with structural support. It also protects the battery from external elements and impacts, contributing to the overall safety and integrity of the EV.

Types of EV battery packs

Electric vehicles (EVs) come equipped with various types of battery packs, and each one employs distinct technologies to store and deliver electrical energy. Let’s explore three types of battery packs used in EVs, as well as hybrid vehicles.

Lithium-ion batteries

Lithium-ion batteries are the most prevalent type of batteries used in modern electric vehicles. They operate on the principle of lithium ions moving from the negative to the positive electrode during discharge and vice versa during charging. These batteries offer a high energy density, allowing for a more extended driving range on a single charge. Plus, they’re lightweight, have a low self-discharge rate and most of their components can be recycled. As a result, lithium-ion batteries are used extensively in both pure electric vehicles (EVs) and hybrid vehicles. They’re also the go-to battery choice for many portable electronics like smartphones and laptops.

Nickel-metal hydride batteries

Nickel-metal hydride (NiMH) batteries were widely used in earlier generations of hybrid vehicles. They operate by storing energy through the absorption of hydrogen ions by a metal alloy. While less energy-dense than lithium-ion batteries, NiMH batteries are known for their reliability and safety. They’re more commonly found in hybrid vehicles and use petrol to recharge the vehicle’s onboard battery. NiMH batteries are cheaper and longer-lasting compared to lithium-ion batteries. However, they’re heavier and bulkier, which means they can impact the overall weight and design of EVs.

Lead-acid batteries

Lead-acid batteries are one of the oldest and most established battery technologies. They operate on the chemical reaction between lead dioxide and lead, immersed in a sulphuric acid solution. While not commonly used in pure electric vehicles due to their weight and limited energy density, they are found in some hybrid and low-speed electric vehicles.

To enjoy the benefits of EVs, their batteries need to be regularly charged. After all, battery packs serve as the heart of EVs and if they run out of power, the vehicles won’t move. Now that you are more knowledgeable about EV batteries and how they work, you’ll be more appreciative of your electric vehicle’s battery and take better care of it.