How Long Do EV Batteries Actually Last?

What the data actually shows

This question used to be answered with guesswork. It no longer has to be, because there are now datasets covering tens of thousands of real vehicles.

Degradation runs at roughly 2.3% per year on average. A 2025 to 2026 analysis of more than 22,700 vehicles found that figure, which projects to around 81.6% capacity remaining after eight years, comfortably above the 70% threshold most warranties guarantee.

Older cars are holding up better than expected. A UK study of more than 8,000 cars and vans, described as the largest analysis of EV battery condition undertaken here, found older vehicles retained a median 85% of their capacity. Even very high-mileage examples rarely came close to troubling their warranty threshold.

Replacement is uncommon. Across large tracked fleets, the real-world battery replacement rate sits at roughly 2.5%, and those replacements are heavily concentrated in first-generation cars now well over a decade old.

Put together: the pessimism most people carry about EV batteries was formed when the only evidence available was early Nissan Leafs. The data has moved on considerably.

Degradation isn't linear

One thing that surprises people is that batteries don't lose capacity at a steady rate. Most packs shed a little more in the first year or two, then settle into a much slower, steadier decline.

That means a car showing 95% at two years old isn't on track to hit 90% at four. It's more likely to be somewhere around 92% to 93%, because the steep bit is already behind it.

Rough expectations, though individual cars vary considerably:

What makes the difference between one car and the next

Two identical models of the same age can differ by ten percentage points or more. The variables that matter most:

Thermal management. Liquid-cooled packs generally age better than passively air-cooled ones. This is the main reason early Nissan Leafs have the reputation they do.

Charging habits. Heavy reliance on DC rapid charging ages a pack faster than mostly slower AC charging at home. Occasional rapid charging is fine and expected.

Heat exposure. Sustained high temperatures are hard on lithium-ion cells. Less of an issue in the UK than in hotter climates, but a car's history matters.

Time spent at extremes of charge. Regularly sitting at 100%, or being left near empty for long stretches, adds stress compared with a moderate middle band.

Chemistry. LFP packs generally tolerate frequent full charging better than NMC.

Notice what isn't top of that list: mileage. It matters, but far less than people assume, which is why a high-mileage EV with good habits behind it can easily beat a low-mileage one that's lived on rapid chargers.

What happens after 80%?

A common misconception is that a battery reaching 80% is somehow finished. It isn't. It's a car with 80% of its original range, which for most drivers is still perfectly usable, and it will carry on working for years beyond that.

There's no cliff edge. Packs decline gradually rather than failing suddenly, and many go on to second-life applications in energy storage long after leaving a car.

What this means if you're buying used

The averages are reassuring, but you're not buying an average. You're buying one specific car, and the spread between individual examples is the whole point.

That's the practical takeaway from all this data: the question "how long do EV batteries last" is far less useful than "what condition is this battery in". The first has a comforting answer. The second has a number, and it's the number that decides what the car is worth and how far it'll take you.