How do EV batteries work?
A guide explaining how electric vehicle (EV) batteries work and how best to care for them.
Last updated: Jun 27, 2025 • 8 min read
Summary
All cars, whether they’re electric, petrol, or diesel, have a rechargeable lithium-ion battery, similar to the one you would find in your phone or laptop. But the key difference with electric cars is that the battery does more than just start the engine or provide power to the onboard electrics.
Instead, an EV battery provides all the power needed to drive the car. In other words, you can think of the battery as the car’s fuel tank.
How does an EV battery work?
Electric cars get the power to move from their lithium-ion battery pack, unlike petrol and diesel which use traditional fossil fuels.
Just like in a mobile phone, this battery has a bunch of battery cells inside it which can store and release energy. When you start the car, the battery cells produce an electrical current via a complex electrochemical process. This current powers the motor, which in turn drives the car’s wheels.
Importantly, the flow of energy can work in both directions. In other words, when you’re driving, the battery cells are releasing energy. But when you plug the EV into a charger, the reverse happens; the battery cells are being recharged, storing the energy ready for the next drive.
Essentially, the battery is the most important part of electric vehicles, which are otherwise much simpler machines than equivalent petrol or diesel cars. The battery is fundamentally where the majority of the cost of an EV comes from.
Tip: there are other costs that come into owning an EV, such as buying and installing a dedicated home charging system, which can sometimes be pricey. But with our all-inclusive Pod Drive subscription, you can cut down the upfront cost to just £40 a month and a one-off £99 fee. In return, you’ll get our award-winning Solo 3S smart charger, fully installed with a lifetime warranty, and up to 7,500 miles paid for.
How long do EV batteries last?
You’ve no doubt noticed that the older your mobile phone is, the more often you need to charge it. This is because the cycle of discharging (i.e. using) and recharging the energy cells causes the battery to lose capacity over time.
The exact same thing happens with electric vehicles, meaning that gradually the battery will start to degrade. This could mean your EV’s maximum range decreases over time.
However, the good news is, EV batteries are designed to last for a long time. How long? Well, most batteries will last around 10 years, although it’s not uncommon for electric car batteries to last 20 years before needing to be replaced.
In fact, most manufacturers offer a warranty on the battery, typically either for a set amount of time (around 8+ years) or a set number of miles driven (around 100,000 miles). And this makes sense. After all, if EV batteries couldn’t last long, they wouldn’t be popular, and it would cost manufacturers (and thus owners) a fortune to replace them.
With batteries being the key component of an electric car, manufacturers are pumping thousands of resources towards improving battery technology, including researching alternatives. At the very least, this should mean EVs of the future have more efficient and longer-lasting batteries, and we can already see this happening today. Modern electric car batteries are significantly better in terms of efficiency and size (and thus driving range) than they were even 20 years ago. So, who knows where we’ll be in another 20 years?
The key takeaway from this is: yes, you’ll likely see a slight reduction in range year-on-year. But unless you drive long distances regularly, it’s unlikely you’ll notice a difference.
Tip: frequently charging on fast chargers (7 kW to 22 kW) won’t have a significant impact on your driving range over time, but using rapid chargers (50+ kW) can. That’s why it’s best to use rapid chargers every now and then, rather than relying on them solely as a means of charging.
Tips to make your EV battery last longer
To avoid the potentially costly endeavour of replacing your car’s battery (although it’s highly unlikely you’ll need to), there are plenty of things you can do now to keep your battery healthy and make it last longer:
- Avoiding charging your battery to 100% frequently, as this puts stress on the battery. Similarly, avoid charging it from 0%. Instead, aim for the sweet spot, which is charging from 20% to 80%.
- Stick to fast chargers (up to 22 kW) for the majority of your charging, as high-powered rapid chargers (anywhere from 50 kW and upwards) can wear down the battery faster.
- Allow the battery and car to warm up first before driving it in colder weather. And, if possible, plug your EV in to charge whilst it’s heating up to keep the battery topped up.
With just a little planning and some good battery care habits, your electric car’s battery will last a lot longer. You can also follow our steps to optimising your EV charging.
How long does it take to charge an EV battery?
There are a few key factors that determine how long it will take for your electric car’s battery to charge:
- What charging rate the charger has
- How big the battery is
- What its current state of charge is, and what level you’re aiming for
As a rough guide, a typical EV battery is about 60 kWh. On a standard 7 kW home charger, this will take about 8 hours for a full charge from 0% to 100%. But you can find out more about how long it takes to charge an EV battery in our handy guide.
Can an electric car battery be replaced, and how much does it cost?
In the unlikely event that you’ll need to, and assuming it isn’t covered by a warranty, replacing an EV battery can set you back around £7235. This isn’t an insignificant amount of money, but it can depend on the battery and the car.
Thankfully, if the battery does need replacing, most of its components can be recycled – as much as 95% of its components in some cases, such as cobalt and nickel. That said, the recycling process isn’t perfect yet, as it’s not easy to recycle current batteries. But don’t worry, the industry is working on a range of solutions to deal with this challenge.
Tip: if you’re buying a second-hand EV and are worried about having to replace the battery, there are some things you can look out for to determine whether it’s worth buying a used EV.
The technical bit - EV battery capacities and voltages
For those who are interested to go further, it’s worth talking briefly about capacities and voltages. Not all EV batteries are the same, and when you’re buying one you sometimes have the option to choose a bigger or smaller battery.
For example, some batteries have different voltages, and this may sound confusing. Essentially, the higher the voltage, the more efficient the battery. In other words, it will charge faster, but at a higher cost to buy. Most EV batteries are between 300 and 800 volts.
Then there’s capacity, which is measured in kilowatts-per-hour (or kWh for short). In technical terms, capacity is “the amount of energy you’d use to keep a 1000 watt appliance running for an hour”. This sounds complicated, but it’s really just a measure for how much energy the battery can store, and how much you have to use – in other words, how far the car can travel.
Most EVs have a battery capacity between 40 kWh and 100 kWh, with the average electric car having a capacity of 60 kWh. Just like voltage, a higher capacity means more efficiency and a higher driving range, but again with the added cost.
For comparison, these are some popular electric vehicles and their battery specifications:
Electric car make/model | Voltage | Capacity |
355 V | Up to 82 kWh | |
400 V | 64 kWh | |
400 V | Up to 82 kWh |
If you want to see what your particular car’s battery specifications are, check out our Vehicle Guides.