The component every used EV buyer worries about most — and the one where Tesla's own fleet data, backed by extensive independent owner tracking, tells a genuinely reassuring story for most vehicles.
Large-scale, independently crowdsourced degradation data collected from thousands of real-world Tesla owners consistently shows battery capacity loss slowing significantly after an initial dip in the first 25,000–50,000 miles, with most packs retaining roughly 90% of original capacity even past 150,000 miles. This is a genuinely different picture from early, more pessimistic predictions about EV battery longevity, and it's backed by enough independently gathered data points that it's not simply taking the manufacturer's word for it.
Not a guarantee, but a pattern seen consistently across owner forums and independent-garage reporting.
The steepest portion of typical degradation occurs here, often 5–8% of original capacity.
Degradation rate slows substantially; most tracked vehicles show only modest further loss across this entire range.
Vehicles in independently tracked data sets commonly retain roughly 85–90% of original capacity even at this stage.
Ask for or run a battery health check showing current range versus original EPA-rated range for that specific configuration — this is the clearest single data point available.
Ask about typical charging habits, since frequent DC fast-charging in hot climates is associated with somewhat faster degradation.
Check remaining battery warranty coverage (years and mileage both matter, and the cap varies by trim) for additional peace of mind on a newer used example.
Model-specific pages, with notes on how it behaves in that particular car.