What Does the Largest EV Battery Study Reveal About Long-Term Battery Health?
A comprehensive study analyzing more than 500,000 independent electric vehicle (EV) battery tests uncovers key insights into how batteries age across popular EV models. Contrary to common fears about rapid battery degradation, most EVs maintain around 90% or more of their original battery capacity after approximately 150,000 kilometers (93,000 miles). This suggests EV battery longevity is stronger than many owners expect, easing concerns about reduced range and costly battery replacements.
How Does the Hyundai Ioniq 5 Compare to Tesla and Other EVs?
The standout model from the study is the Hyundai Ioniq 5, which retains a median State of Health (SoH) of 97.2% at 50,000 km (31,000 miles), 95% at 100,000 km (62,000 miles), and still holds 92.8% SoH even after 150,000 km (93,000 miles). This performance surpasses Tesla’s Model Y, which shows a median SoH of 90.3% at 150,000 km, and Tesla Model 3 at 88.94%. EVs with smaller battery packs, like the Nissan Leaf ZE1 and Renault Zoe, exhibit somewhat lower capacity retention, generally around mid to high 80%s at similar mileage.
Why Is Battery Health Variability Between Individual EVs So Significant?
One of the most critical findings is the wide variation in battery health among individual vehicles of the same model and mileage. For example, 99% of Tesla Model Ys at 150,000 km ranged from roughly 83% to 95% battery SoH. Similarly, BMW i4’s ranged between 87.5% and 96.9%. This variability means two users with identical models and mileage could experience markedly different real-world range and battery performance.
Factors influencing this variability include climate conditions, charging habits, battery chemistry, and how often the battery remains at high charge levels. These elements can accelerate or decelerate battery degradation, underscoring that simple mileage-based assumptions do not fully predict battery health.
What Are the Practical Implications for EV Owners and Buyers?
For current and prospective EV owners, the data highlights the importance of evaluating battery health on a case-by-case basis rather than relying solely on average model statistics or onboard State of Health indicators, which may not fully reflect actual capacity. Independent battery diagnostics can uncover hidden degradation and guide buyers towards better-value used EVs.
Furthermore, the relatively strong battery health of models like the Hyundai Ioniq 5 signals that well-engineered battery systems and proper usage habits can substantially extend EV longevity. This strengthens the case for EV adoption by mitigating concerns over battery replacement costs and resale value depreciation.