The fear vs the data

"What happens when the battery dies?" is still the most common worry I hear about EVs. It's a fair question. The battery is the most expensive component in the car, and replacing one out of warranty can cost €5,000-15,000.

But the data is reassuring. Fleet telematics studies tracking thousands of EVs have consistently found average degradation around 1.8% per year. At that rate, a 10-year-old EV still has roughly 80% of its original capacity. Most batteries will outlast the car they're installed in.

What the warranty actually promises

Nearly every manufacturer offers a battery warranty of around 8 years or 160,000 km (100,000 miles), guaranteeing at least 70% capacity. A few go further.

Read the fine print on two things:

What counts as a claim: usually capacity dropping below 70%, not "my range feels lower"
Whether the warranty transfers to a second owner (most do, but check)

If you're buying used, the remaining warranty is a real part of the car's value. I covered how to check battery health before buying in what I wish I knew before buying my first EV.

What actually wears a battery out

Degradation isn't random. A few things drive most of it:

Heat: consistently hot climates age batteries faster. Cars with liquid cooling handle it much better than air-cooled designs.
Sitting at 100% (or 0%): lithium batteries dislike extremes. Parking for weeks fully charged is worse than the charging itself.
Heavy DC fast charging: frequent fast charging adds some wear, though modern thermal management has shrunk this effect a lot. Occasional road-trip fast charging is a non-issue.
Calendar time: batteries age even if you barely drive. This is why low-mileage older EVs aren't automatically pristine.

Notice what's not on the list: normal driving. Cycling the battery between roughly 20% and 80% is gentle on it.

LFP changes the rules a bit

Many newer EVs, especially standard-range models, use LFP (lithium iron phosphate) batteries. They tolerate full charges much better, which is why manufacturers often recommend charging LFP packs to 100% regularly. They also tend to handle more charge cycles before degrading.

The practical takeaway: follow your car's manual rather than generic battery advice from forums. The right habit depends on the chemistry.

What replacement actually costs

Out-of-warranty replacements are rarer than the horror stories suggest, but they happen. As of 2026:

Full pack replacement: roughly €5,000-15,000 depending on the car, less for smaller packs
Module-level repair: many failures affect one module, not the whole pack. Independent specialists increasingly fix these for a fraction of the full-pack price.
Refurbished packs: a growing market, especially for popular models

Battery prices per kWh have kept falling, so the picture in year 10 of ownership will likely be better than today's quotes.

What this means for your wallet

For a total cost of ownership calculation, battery replacement is a low-probability, high-cost event, not a guaranteed expense. Most owners will never pay for one within their ownership period.

If you're comparing an EV against a petrol car over 5-10 years, the realistic inputs are energy, insurance, service, and depreciation. The ownership calculator lets you put all of that side by side. And if it's the day-to-day running costs you're curious about, start with the fuel cost calculator.