Electric Car Battery Ultimate Guide

How do EV batteries work? 

Unlike petrol and diesel models that are powered by fuel, electric vehicles get their energy from batteries. It’s similar to the batteries you have in a mobile phone or laptop, just on a larger scale.

An electric car battery comprises thousands of Lithium-ion cells, which convert electricity into the energy needed to power your journey.

Another benefit of EVs compared to conventional cars is that they don’t produce tailpipe emissions, and the technology is designed to create an efficient and comfortable ride, whether on the daily commute or popping into town.

Explore how EV batteries work below:

Current electric car battery tech

An electric car battery works via cycles of charge and discharge. This process is repeated numerous times during the battery’s useful life; over time, it decreases – just like any other battery. Most car manufacturers provide a warranty of between five to eight years. However, it is predicted that most batteries will last between 10 and 20 years before they deplete.

The battery works alongside electric motors, converting energy to power the wheels. Regenerative braking systems also push back energy to the battery to improve the range.

The main types of batteries used in electric cars are:

This is the most common type of battery in EVs. Similar to what you find in portable electric devices, this battery is rechargeable on a larger scale. In addition, manufacturers use this technology to reduce the space needed for battery packs, as they have a higher-density composition than other types of batteries. 

Due to the size of the battery packs, they usually sit underneath the floor which can actually assist with handling and traction.

In addition, lithium-ion is one of the safer batteries, and carmakers fit systems in the car in the case of battery failure.

Nickel-metal hydride batteries are not as commonly used as lithium-ion. However, some manufacturers, particularly Toyota, still use them in full hybrid vehicles. The batteries work in a similar way with a charge and discharge reaction.

Other benefits of nickel-metal hydride technology are that it’s extremely safe and it has a high energy density. However, it is more expensive to make.

Modern electric car batteries have come a long way in the past decade, especially in terms of range. The average electric car now has a range of over 200 miles, with some models topping 300 miles and above.

Battery power is measured in kilowatt-hours. So, the higher the kWh battery in an EV, the more range it has.

Electric car efficiency is often referred to as WLTP. WLTP, or Worldwide Harmonised Light Vehicle Procedure, is a laboratory test that measures energy consumption in EVs.

This test provides findings from realistic driving conditions to give consumers essential efficiency information before buying a vehicle.

So all electric cars will have an WLTP estimate driving range which should offer a good representation of what you'll actually get.

EV batteries are predicted to last between 10 and 20 years, depending on use, driving conditions and environmental factors. When the battery has reached the end of its useful life, it can be replaced but it's typically much more cost-effect to move onto your next car.

Most manufacturers provide a warranty for EV batteries – typically covering up to eight years or 100,000 miles, whichever is sooner. So, if something happens during this time, you’re covered for the cost of a replacement.

In most instances, EV drivers won’t need to worry about replacing the battery pack unless their car falls outside the warranty period and completely depletes.

If you decide to keep an EV outside of this period and it requires replacement batteries, they tend to be expensive. In 2021, the cost of an EV battery was approximately £87 per kWh. So, for example, if you have a Tesla Model S, the cost to replace the battery is just under £9,000.

However, the cost of batteries has come down in the past decade. Therefore, in the future, prices for replacements could be more affordable.

But for now, it's much more common for drivers to get their next car.

Charging an EV is really simple. You have the option of installing a wall box at home for affordable and convenient charging or you can simply plug in to a standard wall socket

There are plenty of public acround the country too, with rapid chargers providing a quick 30-minute boost while you’re on the go.

Charge times differ depending on the charging location. For example, charging at home varies depending on the model. But most cars take between 8 – 12 hours to charge fully. The average cost of this is around £20*. In addition, public charge points sometimes offer free charging while you shop or go to the gym. 

*Cost based on 60kWh car at 34p per kWh tariff.

Rapid electric chargers are typically found in service stations and dedicated charging points. Here you can recharge for a fee and get up to 80% charge in 30 minutes. The average cost for a rapid chargepoint is 53p per kWh.

So, if you have a 60kWh battery, it’ll cost approximately £21 to charge up.

This is a great option if you're in desperate need of instant battery power. But a word of warning: you shouldn't rely on using rapid chargers regularly as longterm use can damage battery capacity.

Your electric car battery degrades slowly over time. But there are some things you can do to optimise the battery’s health. It’s also helpful to monitor your battery health via your onboard vehicle systems.

Many EVs also have battery management systems to avoid being charged and discharged at an extreme state of charge.

Keeping the state of charge between 20% and 80% is a great way to optimise battery health. This means topping up more regularly rather than completing depleting the battery and fully recharging it.

It’s also more convenient and easier to fit charging into your lifestyle and it's much quicker than charging from 0%-100% every time.

The weather can affect charging speeds and battery health. Extreme hot and cold temperatures affect your battery capacity.

If you're regularly in temperatures under 4ºc or over well over 25ºc you should try to store your car under cover if possible.

Topping up with a rapid charger is a great way to get a quick boost. But, over time, they can degrade batteries faster with regular use due to their extreme rate of charging.

Experts advise using a chargepoint suited to the maximum output rating for your car to optimise battery health.

Unlike conventional cars, EV battery components can’t be scrapped under normal conditions due to the materials inside. Currently, car manufacturers are researching ways to recycle EV batteries or repurpose them for other uses.

When EV batteries reach the end of their useful life in a car, they’ll be recycled accordingly. This typically involves separating the materials such as cobalt, stainless steel, copper and plastic.

Around 50% is recycled, but car manufacturers are looking at improving this rate so batteries can ultimately be nearly fully recyclable in the future.

Disposing of batteries safely and without harming the planet is essential, and manufacturers provide ways to do this. Instead of throwing them into landfill, initiatives are coming into play to repurpose components to give the technology a second life.