Every lithium-ion battery loses capacity over time. Your EV's battery is degrading right now, at a rate of roughly 1–2% per year. But "degrading" sounds scary when the reality is benign — batteries fade gracefully, and most cars are scrapped long before the battery becomes a real problem.
Here's how EV battery degradation really works, backed by fleet data.
The science: why batteries lose range
An EV battery stores energy through chemical reactions. Over time and use, some lithium ions become permanently "locked" — unable to participate in charging and discharging. That's degradation.
Two types:
- Calendar aging — happens just by existing, especially in heat, at high state of charge
- Cycle aging — happens through charging and discharging, especially at high rates and deep cycles
How fast do batteries actually degrade?
| Usage | Capacity after 50k mi | After 100k mi | After 150k mi |
|---|---|---|---|
| Mild (80% limit, home AC charging) | ~94% | ~90% | ~87% |
| Typical | ~92% | ~88% | ~85% |
| Heavy (frequent fast charging, hot climate) | ~90% | ~85% | ~80% |
The headline number: real-world EVs retain 85–90% capacity after 100,000 miles. Tesla, Nissan and third-party fleet studies all land in this range.
The degradation curve you should know
Degradation is fastest in the first 6–12 months, then slows dramatically. A new battery drops to ~95% quickly, then holds for years. That initial dip is normal chemistry, not a problem.
This means a 3-year-old used EV with 90% capacity has most of its "fast" degradation behind it — the next 5 years will lose much less. It's one reason used EVs are such good value.
What accelerates degradation (in order)
- Heat + high state of charge — the worst combination. A battery parked at 100% in 95°F sun ages fastest.
- Deep discharges — regularly draining to near zero stresses cells
- Daily fast charging — adds heat and micro-stress
- Very cold weather — slows chemistry (temporary range loss, not permanent damage)
What does NOT matter much
- Charging to 100% occasionally — fine for road trips
- Regenerative braking — actually healthy for the battery
- AC home charging daily — the mildest form of cycling
- Moderate cold — temporary range reduction, not degradation
How to slow degradation (the simple version)
- Keep daily charge limit at 80%
- Recharge before ~20% when you can
- Park in shade in summer
- Charge to 100% only before long trips, then drive
Estimate your own battery's health
Our battery degradation calculator models capacity loss based on your climate, charging habits and mileage. For current status, ask the car — most EVs show battery health in the app or menu, and many used EVs come with a battery report.
FAQ
How fast do EV batteries lose range? Roughly 1–2% per year under normal use. After 10 years, most EVs still have 80–88% of original range — still perfectly usable.
Can you reverse battery degradation? No — chemical capacity loss is permanent. But you can slow it dramatically with good charging habits.
Is 90% battery health good? Excellent. A 10% loss after years of driving is right on the normal curve, and the car remains completely usable.
The bottom line
EV battery degradation is real but gentle: ~1–2% per year, faster at first, slower later. With 80% daily charge limits and shade in summer, your battery will outlive your ownership. It's the component EV owners worry about most and should worry about least.
