Revealed: the truth about electric car battery degradation

Anyone with a  or  will have experienced the inevitable reduction in the charge held by the battery and how long the device can subsequently run before it needs a top up. Unsurprisingly, this is also a common worry among people that are looking to buy their first .

Read on to discover what our latest research shows and whether you should be worried about battery degradation in electric cars.

Do electric car batteries degrade?

Like all batteries, the cells that power an EV will degrade over time. However, our data shows that while battery degradation in EVs is an issue, it’s not as bad as you might think in the first few years of ownership. 

In our latest survey, we asked more than 3,595 owners of EVs to tell us by how much the range of their car had decreased since they bought it.*

*Source: , conducted April-June 2024. Based on 3,595 EV owners who bought their car brand new and self-reporting how much range the car has now versus when they first purchased it. 

As you can see, even for cars around seven years old (first registered in either 2017 or 2018) the average range decrease was just 7%. 

So, if your car's range when new was 180 miles (around the average for all EVs we've tested), you could expect this to drop to 167 miles.

Keep in mind, though, that our data doesn't show how many miles the EVs have done overall as it's the number of times you charge your car (and, to an extent, how fast your charger is) that will affect the battery's lifespan. 

The average annual mileage for all EV respondents in our survey was 6,001 miles, so if you drive fewer miles than that in a year, you may see better figures than the above table shows. 

: see the models that scored best in our latest survey

Does cold weather affect EV range?

Cold weather can affect EV range, but it depends on the car and the temperature.

Some studies have shown that vehicles can lose as much as 40% of their range in cold weather, although it varies car by car. Not only do EVs not go as far in cold weather, they also charge more slowly. 

Many EVs now come with a battery pre-heating option that will warm the battery up based on a schedule you can choose, and some let you do this via an app so your car is ready to go before you head out.

If you're buying used, check whether the model you're looking at comes with this feature. 

Electric car battery warranties

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Manufacturers typically offer a seven or eight-year warranty for their EV batteries (or around 100,000 miles, whichever comes sooner). The terms of the warranty may also require a specific threshold of range to be met. Some might say if the battery's 'health' is below 70%, you'd be entitled to a free replacement. 

Keep in mind, though, that a 30% drop in range is significant and could affect the ability to make some journeys free of interruptions for charging stops.

So if you're buying an EV now and plan on keeping it long term, consider the worst-case scenario where your battery is at 70% health and it's a cold day. 

What to look out for when buying a used EV

Additionally, find out whether the current or previous owner has done anything to the car that could invalidate that warranty, for example by not taking it to a main dealer for a battery inspection or making modifications to it or its software that could affect battery usage.

Drive smarter and cut costs using our expert advice. 

source https://www.which.co.uk/news/article/revealed-the-truth-about-electric-car-battery-degradation-a0Qqs8Q0lX4B