How to Calculate EV Battery Degradation

What is EV Battery Degradation?

The EV Battery Degradation Calculator estimates how much capacity your electric vehicle battery will lose over time and mileage, helping you project future range and battery health.

Formula

Remaining Capacity (%) = 100 - (Degradation Rate x Years) or 100 - (Degradation per Mile x Total Miles)

C0: Original Battery Capacity (kWh) — Factory-rated usable battery capacity
N: Cycle Count (cycles) — Number of equivalent full charge-discharge cycles completed
k: Degradation Coefficient (%/sqrt(cycle)) — Battery chemistry-specific degradation rate constant
T: Temperature Exposure (F) — Average ambient temperature; extreme heat accelerates degradation

Step-by-Step Guide

1Enter your EV battery size and the vehicle age or mileage
2Select the battery chemistry type (NMC, LFP, NCA) for appropriate degradation curves
3The calculator applies research-based degradation models to estimate remaining capacity
4View projected range loss at 5, 8, and 10-year milestones

Worked Examples

Input

75 kWh battery, NMC chemistry, 5 years / 60,000 miles

Result

Estimated remaining capacity: 90% (67.5 kWh), range reduced from 263 to 237 miles

Input

60 kWh LFP battery, 8 years / 100,000 miles

Result

Estimated remaining capacity: 88% (52.8 kWh), LFP degrades slower at mid-range SOC

Common Mistakes to Avoid

✕Assuming linear degradation — most EV batteries lose capacity faster in the first 2 years then stabilize
✕Not considering that frequent DC fast charging and charging to 100% daily accelerates degradation
✕Confusing displayed range (which recalibrates) with actual battery capacity degradation

Frequently Asked Questions

How long do EV batteries last before they need replacement?

Most modern EV batteries retain 80-90% capacity after 10 years and 150,000 miles. Major studies show average degradation of about 2.3% per year, meaning batteries far outlast original fears.

Does fast charging damage the battery?

Frequent DC fast charging can accelerate degradation by 5-10% over the battery lifetime compared to exclusively home charging. Occasional DCFC use has minimal impact.

What battery chemistry degrades the slowest?

LFP (Lithium Iron Phosphate) batteries generally degrade slower than NMC and NCA chemistries, especially when regularly charged to 100%, making them ideal for daily full charges.

Ready to calculate? Try the free EV Battery Degradation Calculator

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