EV car batteries explained

The government's target to end the sales of conventional cars by 2030 may be ambitious, but in this context, it's perfectly reasonable. Sales of electric vehicles are still relatively small but they are growing rapidly. In 2022 15% of all new cars were electric. Investment in the UK's charging infrastructure isn't yet high enough to serve the needs of the new generation of clean transport, but the technology exists, so we can be hopeful that the money will follow.

Electric vehicles (EVs) are more than just an alternative to the internal combustion engine, they are radically different machines. And the single most important component is the electric car battery. However, although the idea is that one day we'll all be using them, there's quite a bit of myth and mystery surrounding this remarkable technology.

What sort of batteries do EVs use?

The vast majority of today's EVs are powered by large, heavy batteries which consist of hundreds of individual cells. The largest can be several metres long and weigh hundreds of kilos, which means they are usually fitted underneath the floor of the car.

They fall into two categories: lithium-ion in electric-only cars and nickel-metal hydride in hybrids. The industry didn't invent them, but adapted the tiny versions we're used to in appliances such as smartphones to create huge cell collections with enough power to drive a car that's significantly heavier than its petrol or diesel counterparts.

Battery capacity

The energy of a battery is measured in kilowatt-hours, so a battery rated at 100kWh can deliver 100 kilowatts of power for one hour's continuous driving. Most routine journeys need a lot less than that, so it isn't necessary to recharge the battery for several hours.

How much does it cost to charge an electric car battery?

It's a lot cheaper than petrol or diesel. If you multiply the size of your battery by the unit charge from your electricity supplier, you'll get the cost of filling up your electric 'tank' at home. For example, a car with a 77.4kWh battery at a unit price of 52p will cost £40.24 to recharge.

How long will the charge last?

In our experience, it depends on your usage of course, but also on the capacity of the battery. If you're going to be driving long distances, you should get the largest you can afford, which at the moment is 100kWh. If you're just doing short trips then a 30kWh is probably sufficient, provided that you have a home charger or easy access to a public charging point. A 35kWh battery will typically give you about 130 miles, while an 85kWh model could take you nearly 300 miles on one charge.

What does it cost to replace battery packs?

Batteries don't last forever because their ability to retain a charge reduces over time. But because there are so many cells in each one, they can work well for hundreds of thousands of miles. That means you could get 10 years' performance from your battery. This is just as well because they are very expensive to replace, currently £5,500 on average. Just as the price of electric cars is coming down, we can expect the same to happen for batteries, but as things stand, a replacement is a major financial investment.

Electric Car Servicing

Just because EVs are clean and quiet, that doesn't mean they don't need maintenance. Protyre's mechanics are fully qualified in servicing electric cars so you can have complete confidence in our ability to keep your electric car and its battery in excellent condition.

Don't forget that we also offer a free tyre check to make sure your car is not just legal but safe and efficient. We'll inspect all aspects of your tyres, with no obligation to buy from us if we recommend replacement. However, we carry an extensive range of tyres to suit every budget, including Pirelli, Sumitomo and Bridgestone. Choose from our wide selection and our qualified fitters will get you back on the road in no time at all.

Remember, Protyre is your local garage with the skills and resources of a leading national chain.