How fast do EV batteries degrade?

Most modern EV batteries lose about 2-3% of capacity per year under normal use. After 8 years, a typical battery retains 80-90% of its original capacity. Battery chemistry has improved significantly, and newer cars degrade more slowly than early EVs.

What affects battery degradation the most?

The three biggest factors are: regularly charging to 100% (stresses the cells), frequent DC rapid charging (generates heat), and exposure to extreme temperatures. Keeping the battery between 20-80% for daily use and avoiding extreme heat significantly extends battery life.

What is the warranty on EV batteries?

Most manufacturers offer an 8-year or 100,000-mile battery warranty guaranteeing at least 70% capacity. Some brands like Toyota offer 10-year warranties. If your battery drops below the guaranteed capacity, it should be replaced under warranty.

Can a degraded battery be replaced?

Yes, but it is expensive — typically £5,000-£15,000 depending on the car. However, most batteries last well beyond the warranty period. As the EV market matures, battery replacement costs are expected to decrease significantly.

How long does an EV battery last?

Most EV manufacturers warrant their batteries for 8 years or 100,000 miles. Real-world data shows most batteries retain 80-90% capacity at this point. Many will last 150,000-200,000 miles before needing replacement. Battery technology is improving with each generation.

CarCalcs

Battery Degradation Calculator

Estimate how your EV battery capacity will decrease over time.

Original Battery Capacity

Age of Battery

Annual Mileage

Charging Habit

Climate

How We Calculate This

This calculator estimates battery degradation based on multiple factors that affect battery health.

The Calculation

Base degradation: ~2.3% per year (industry average)
Charging habit adjustment: Charging to 100% regularly adds ~0.5%/year; staying under 80% reduces by ~0.3%/year
Climate adjustment: Hot climates add ~0.4%/year; cold climates add ~0.2%/year
High mileage adjustment: Over 15,000 miles/year adds ~0.3%/year
Remaining capacity = Original capacity x (100% - Total degradation)

Frequently Asked Questions

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Last updated: February 2026

All calculations are estimates. Actual figures may vary based on driving conditions, vehicle specifications, and other factors.