An Audi e-tron GT with its body made transparent and the battery visible underneath.
An Audi e-tron GT with its body made transparent and the battery visible underneath.

EV car batteries last longer than expected, according to new study

Barney Cotton

Barney Cotton

Consumer Editor

5 minute read|20th Feb 2026

Electric vehicle batteries appear to be holding up far better than many predicted, according to a UK study of EV battery health. 

The analysis, carried out by London-based company, Generational, covered 8,000 electric cars from 36 different brands. It covered everything from new vehicles to used cars up to 12 years old and mileages from zero to over 160,000 miles.  

Across the entire sample, researchers found an average battery state of health (SoH) of 95%, which is significantly higher than the 70% threshold that typically triggers a warranty replacement. 

Even the oldest vehicles in the study, those between eight and 12 years old, performed strongly.  

Their median battery health sat at 85%, with the lower quartile averaging 82%.  

Meanwhile, the best-cared-for cars in this age bracket were still operating at around 90% of their original capacity. 

High-mileage vehicles (100,000+ miles) showed results between 88% and 95% battery health, highlighting that mileage alone is not a reliable predictor of battery condition. 

The first edition of the Generational 2025 Battery Performance Index aims to show why battery condition transparency is becoming essential to EV infrastructure, as well as supporting decision making across the industry. 

Oliver Phillpott, CEO of Generational, said: “The Generational Battery Performance Index definitively shows that EV batteries are performing far better than many consumers and industry stakeholders have been led to believe. 

“With an average state of health of over 95%, and even older vehicles comfortably exceeding warranty thresholds, the underlying fundamentals are extremely strong.” 

He continued: “Transparency in battery condition is the main challenge facing the market today, and essential infrastructure for a healthy used EV sector; as vehicles age, the variance between the best and worst performers widens, and that dispersion defines risk. 

“By establishing clear benchmarks for what is typical, above and below average as we look to drive further growth in 2026, we are giving the market the reference points it needs to price risk accurately, strengthen residual values and accelerate adoption.” 

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