EV Batteries Are Aging Better Than Expected: What the New Data Really Shows

A Good-News Summer for Used EV Owners

Over the past several months, three independent sources - one Swedish, one British, one American - have published data pointing the same way: electric car batteries are aging far more slowly than the used-vehicle market has feared. That matters well beyond their home markets. Fear of early battery failure remains one of the top reasons shoppers rule out a used EV before ever checking a real State of Health (SOH) figure, in Italy just as much as anywhere else.

The Swedish Study: 1,366 Cars Under Kvdbil's Microscope

The most solid data point comes from Kvdbil, a Swedish used-vehicle marketplace that analyzed 1,366 electrified vehicles - 723 fully electric and 643 plug-in hybrids - measuring remaining battery capacity against the manufacturer's original rating. The result: eight cars out of ten retain more than 90 percent of their starting capacity by the end of the standard warranty period, typically eight years. Martin Reinholdsson, Kvdbil's head of testing, credits the slow fade to advances in battery management systems (BMS) and cell cooling - the two factors that, more than any other, determine how gracefully a pack ages.

The Wider European Picture: UK Data and Average Annual Fade

The Swedish numbers are not an outlier. A UK analysis covering more than 8,000 battery tests found an average SOH of 95.15 percent against original capacity, even among older, higher-mileage cars. On an even larger scale, telematics data from Geotab, built from hundreds of thousands of monitored commercial and passenger EVs, puts average degradation at roughly 1.8 percent per year. In practice, a car rated for 150 miles of range loses under three miles a year on average. At that pace, a battery still holds around 85 percent of its original capacity after eight to nine years - entirely adequate for daily driving.

Recurrent's 2026 Report: What's Happening Outside Europe (and Why It Matters Here)

The pattern holds up across the Atlantic too. Recurrent's 2026 EV Market and Trends Report, built on analysis of over a billion miles driven by real-world EVs, finds that the average pack retains 97 percent of its range after 3 years and 95 percent after 5. Even more telling is the drop in outright battery replacements: while roughly one in twelve EVs built between 2011 and 2016 needed a new pack, that rate has collapsed to just 0.3 percent for model-year 2022-and-later vehicles. The report also underlines how much cooling technology matters: early Nissan Leaf models, air-cooled with no liquid thermal system, aged noticeably faster than later designs that moved to active liquid cooling, from the Ariya to the redesigned Leaf - a useful flag for anyone eyeing a first-generation EV on today's used market.

Which Brands Hold Up Best (and Why Cooling Beats Badge)

In Kvdbil's ranking of models with the best average battery health, the top two spots go to Kia, with the EV6 and e-Niro, closely followed by the Tesla Model Y. The common thread is not the badge on the bonnet but the thermal architecture underneath it: packs with active liquid cooling, BMS-managed charging and software limits on maximum state of charge consistently age better, regardless of manufacturer. That is a more useful filter than brand loyalty when shopping used: before fixating on the badge, it is worth checking whether that specific model, in that specific production year, already used liquid cooling.

How to Read State of Health Before Buying Used

SOH remains the number that matters more than mileage. It is calculated by comparing the estimated range at a full charge against the manufacturer's original rated range: a small EV originally rated for 190 miles that now shows 170 miles at full charge has an SOH of roughly 90 percent. As a rule of thumb: above 90 percent is excellent; 85 to 90 percent is good and typical for a car a few years old; below 70 percent, most warranties consider the pack eligible for replacement, and real-world range starts to be noticeable in daily use. Many market analysts point to 3- to 4-year-old EVs with 88 to 92 percent SOH as the sweet spot - the steepest depreciation has already happened, while the pack still has roughly 8 to 10 years of useful life ahead of it before nearing that critical threshold.

The Charging Habits That Actually Protect a Battery

Sellers can document, and buyers can ask about, a few habits that Kvdbil's data associates with slower fade: not routinely charging past 80 percent on AC unless the full range is genuinely needed, avoiding heavy reliance on DC fast charging, and not leaving a car parked for long stretches at 100 percent or near empty. These are simple things worth stating explicitly in a listing - a charging history that is mostly slow and moderate is a concrete selling point, and one that is often verifiable through the automaker's app or dealer service records.

What the New EU Battery Regulation Changes

On the regulatory side, the EU Battery Regulation (2023/1542) will bring tighter requirements by 2027 on labeling, traceability and the durability data manufacturers must disclose, aimed at making exactly the kind of degradation figures discussed here far less buried in technical manuals. For the used-EV market, that is good medium-term news: more standardized, comparable official data means less uncertainty for buyers who lack the tools to independently verify a pack's health.

The Takeaway for Buyers and Sellers Right Now

The 2025-2026 numbers describe a far tougher battery than the one buyers feared just a few years ago: average degradation under 2 percent a year, eight packs out of ten still above 90 percent capacity at the end of warranty, and replacement rates that are now marginal on recent models. Sellers should start listing SOH as routinely as they list mileage; buyers should ask for it before looking at any other spec. The old assumption that an EV battery quietly dies within a few years is no longer supported by the data - what is left is bringing that data into the actual negotiation.