Used electric vehicles are better value than most buyers realise. The gap between perception and reality, though, is costing sellers money and slowing the market. New research suggests a single document may be the most effective tool for closing that gap.
Austrian battery diagnostics company AVILOO surveyed automotive businesses across ten European countries for its 2026 B2B study. Of the dealerships, fleet operators and trading companies questioned, 93.4% said an independent battery certificate increases credibility in the sales process. A near-identical 92.9% cited transparency as a key reason for using them. Perhaps most tellingly, 84.4% reported that buyers are now actively requesting one before purchase.
Does an independent certificate actually change outcomes?
The short answer, according to the data, is yes. Among surveyed companies using AVILOO certificates, 46.2% reported higher sale prices and 44% saw shorter standing times for used electric stock. One respondent described the impact clearly: a Fiat 500e that had sat unsold for two to three months shifted within four days of an AVILOO certificate being uploaded.
The reason is straightforward. Battery condition is the single biggest unknown for used EV buyers, and most have no reliable way to assess it themselves. A manufacturer-independent assessment removes that uncertainty. It also protects sellers. Almost three quarters, 74.7%, said they use pre-purchase battery testing to minimise the risk of complaints and returns.
AVILOO’s FLASH Test is central to its proposition. The company claims it is the only genuinely independent battery quick test on the market, completing a full diagnostic in around three minutes. Unlike other quick assessments that simply read data from the vehicle’s Battery Management System, AVILOO says its method uses separate calculation techniques that remove the possibility of manufacturer bias. All results are TUV and CARA certified, and the company currently covers more than 96% of available brands.
“We differ from all other quick tests, which merely read out the BMS, by using precise calculation methods that truly guarantee independence and transparency,” said Marcus Berger, CEO of AVILOO.
What does independent data say about used EV batteries?
The case for transparency is strengthened by what the real-world battery data actually shows. Performance is consistently better than buyers fear.
The Generational 2025 Battery Performance Index, the largest study of used EV battery condition undertaken in the UK to date, drew on more than 8,000 assessments across 36 manufacturers. It found an average battery state of health of 95.15% across all tested vehicles. Even at eight to nine years old, vehicles retained around 85% median capacity, above the thresholds typically set by OEM warranties.
High-mileage vehicles with over 100,000 miles on the clock frequently returned state-of-health readings between 88% and 95%. Mileage, the study concluded, is not a reliable predictor of battery condition.
Oliver Phillpott, CEO of Generational, said the data showed transparency in battery condition was the main challenge facing the used EV market today, and essential infrastructure for a healthy used vehicle sector.
A separate fleet analysis by Geotab, drawing on data from more than 22,700 electric vehicles across 21 models, found an average annual battery degradation rate of 2.3%, with the average battery projected to retain 81.6% of its original capacity after eight years.
Philip Nothard, Chair of the Vehicle Remarketing Association, put it directly: “Transparency will prove crucial in building future consumer confidence and dispelling the many misconceptions that have gained currency around EV batteries.”
Is regulation about to make this the norm?
The direction of travel from European regulators points toward mandatory disclosure. From 18 February 2027, all EV batteries with a capacity greater than 2 kWh placed on the EU market must carry a digital battery passport, accessible via a QR code. The passport will be required to include state-of-health data and expected lifetime information, making independent verification a structural part of the used EV transaction.
That regulatory deadline is still two years away. In the meantime, the AVILOO study suggests the market is already moving in this direction under commercial pressure rather than legal obligation.
Why does this matter for buyers?
If you are in the market for a used EV, a battery certificate from an accredited independent provider tells you something no range estimate or BMS readout can: the actual condition of the battery, verified by a methodology that carries no manufacturer interest. The AVILOO study found that 94.4% of companies using such certificates were satisfied with the results, and 92.4% would recommend them.
The underlying picture from independent fleet data is broadly reassuring. EV batteries are degrading more slowly than the secondhand market has assumed. The problem is that without a verifiable way to demonstrate that to buyers, best-case assumptions rarely win against worst-case fears. An independent battery certificate is increasingly the tool that bridges that gap, and given the regulatory direction across Europe, it is unlikely to remain optional for long.
