All you need to know about electric car batteries

What truly sets an electric car apart from a petrol or diesel model? The answer lies under the hood - in the battery. But what exactly is meant by terms like “battery size” or “battery capacity”? And how long does an EV battery truly last?

Below, we’ll unpack all you need to know about this groundbreaking tech that’s changing our world for the better.

Jump to:

• How do electric car batteries work?
• EV battery capacity and sizes
• What is the average EV battery capacity in the UK?
• Finding your ideal EV battery capacity
• How long do EV batteries last?
• Can EV batteries be recycled or repurposed?

Instead of burning fuel, electric cars rely on a lithium-ion battery pack. Although it may look like a single unit, it’s actually made up of thousands of individual cells, all working together to power the electric motor that drives the wheels.

As you drive, the battery releases energy, sending power to the motor. Then, when you plug into a charger (whether at home, work, or a public charging station) the process reverses, and the battery recharges, ready for your next journey.

Over time, continuous use gradually reduces the battery’s maximum capacity (a lot like a smartphone). However, modern EVs are designed to retain most of their capacity for at least a decade of typical driving, so you can expect reliable performance for many years before any significant drop-off occurs.

When we talk about “EV battery capacity” or “EV battery sizes,” we’re referring to how much energy the battery can store, measured in kilowatt-hours (kWh).

But why do these matter to an EV owner? Or someone considering an EV? Well, here’s why:

1. Range - generally, the larger the kWh, the further you can drive on a single charge. A smaller battery of around 28 kWh might offer around 100-120 miles of range, while a bigger 100+ kWh pack can exceed 300 miles.
2. Cost - Batteries can be one of the most expensive parts of an EV, so larger-capacity packs can push up the car’s purchase price or monthly lease cost. That said, as tech advances, prices are gradually coming down, making bigger-battery EVs more accessible.
3. Charging speed and time - Larger batteries store more energy and may take a bit longer to fully charge on a standard 7kW home charger. However, rapid chargers can significantly shorten that wait - so the actual charging experience might still be quite manageable, even with a large-capacity battery.

Most electric vehicles in the UK range from 20 kWh at the smaller end to over 100 kWh at the top end. But if you’re curious about the sweet spot for the majority of drivers, 40-60 kWh is very common. This capacity bracket typically yields 150-250 miles per charge - enough for day-to-day commutes and weekend trips without a sky-high price.

Think about how you plan to use your EV. If your daily driving is more local, you may not need a big 70+ kWh pack. But if you’re a road-tripper or just want peace of mind, opting for a larger EV battery capacity could be worth the investment.

Choosing the right EV battery size or EV battery capacity depends on your personal needs and driving habits.

Some good things to consider, include:

• Lifestyle - if you rarely drive more than 20-40 miles per day and have easy charging access, a smaller (cheaper) battery may be sufficient.
• Budget - bigger batteries cost more. If you value extended-range or long road trips, the extra expense might be worth it.
• Leasing vs. buying - Unsure about future battery tech? A personal car lease lets you upgrade to newer models every few years, so you’ll stay on top of the latest innovations without the long-term commitment.

Worried about forking out for a new battery every few years? Not to worry. Lithium-ion batteries in EVs commonly last around 10 years, and many survive for 15-20 years before replacement becomes necessary. You’ll also find most manufacturers offering 8-year or 100,000-mile warranties, giving you peace of mind that your EV’s battery capacity won’t plummet overnight.

As battery technology advances, degradation rates (where the battery loses a bit of its maximum capacity each year) continue to improve, meaning both smaller and larger battery packs stay robust for the majority of an EV’s life.

A common question about EV batteries; is what happens when the battery no longer holds enough charge for daily driving. Luckily, the UK is evolving quickly in terms of recycling and repurposing. And EV batteries are either being recycled or reused for energy storage.

You can read more about EV batteries and their effect on the environment, in our blog: Are EVs bad for the environment?