Overview
- London‑based diagnostics firm Generational analyzed more than 8,000 battery tests across 36 manufacturers, spanning vehicles from new to 12 years old with mileages up to over 160,000.
- Average battery state of health measured 95.15%, while 8–9‑year‑old vehicles showed a median near 85% usable capacity.
- High‑mileage cars with over 100,000 miles frequently recorded 88–95% health, showing mileage alone is a weak predictor of condition.
- Typical warranty thresholds of 70% state of health after eight years or 100,000 miles were rarely approached in the dataset.
- With pack replacements expensive, the market is pivoting to verified battery disclosure, from OEM certificates and trials of battery passports to third‑party grading, ahead of EU/UK mandates taking effect in February 2027.