EV Battery Degradation Estimator
Pick your electric vehicle, enter your current mileage, and see an estimated battery health percentage plus how much range you have left - today and projected 5 and 10 years from new. Accounts for charging habits and climate. Nothing uploaded.
Projected battery health from new
Model uses Geotab fleet average degradation rates adjusted for your charging habits and climate. Actual results vary by usage, temperature history, and battery management software updates. 70% SoH is the industry warranty floor.
Is this normal? ?
Understanding EV battery health over time
How mileage, charging habits, and climate affect SoH
Battery degradation is driven by how many times the battery is cycled (charged and discharged), not by mileage on its own. A vehicle driven 36,000 miles at highway speeds with mostly Level 2 home charging degrades slower than one driven 36,000 miles in stop-and-go city driving with frequent DC fast charging.
The calculator uses Geotab's fleet analysis of over 22,700 EVs for its baseline degradation rates, and adjusts them for your charging behaviour and climate. That study found high-power DC fast charging (over 100kW) was the single largest stressor, with affected vehicles degrading at roughly 3.0% per year versus 1.5% for vehicles that mostly charged more slowly, a gap covered in more depth by MOTORWATT's writeup on the fast-charging science.
Example: a Tesla Model 3 Long Range new in 2020 with 36,000 miles, charged occasionally at DC fast-charge stations in a temperate climate (San Francisco) might show 95% SoH. The same model with 36,000 miles, charged 50% of the time via DC fast charging in a hot climate (Phoenix) might show 88% SoH. The same model with 100,000 miles and frequent DC fast charging in a cold climate (Minnesota) might show 82% SoH.
Why some EVs age faster than others
Battery chemistry is only part of the story - how the pack is cooled matters just as much. The Nissan LEAF 40kWh has no active liquid cooling for its battery, so it degrades at roughly 2.5% per year at baseline.
The Tesla Model 3 Long Range, which does have a liquid thermal management system, sits closer to 1.1% per year for the same driving pattern. That is more than double the wear rate between two cars with similar-sized packs, purely down to how well each design keeps the cells cool under load.
This is why the calculator's fleet-average baseline rate changes depending on which vehicle you pick, before your own charging habits and climate are even factored in.
Why projections are estimates, not guarantees
This calculator uses fleet-average degradation patterns, which means individual vehicles will vary. Your actual degradation depends on factors the calculator cannot see: how much you charge to 100% (frequent full charges degrade faster), how hot your battery got during charging and driving, how aggressively you drive, and software updates from the manufacturer that improve battery management.
A vehicle in the calculator showing 88% SoH at 50,000 miles might actually show 90% or 85% depending on these unmeasured factors. Use this calculator to understand general trends and compare vehicles, not to predict your exact battery health.
What this means when buying or selling a used EV
Mileage alone tells you less about a used EV's battery than it would about a gas car's engine. Two cars with identical mileage can carry very different battery health depending on how each was charged and where each spent its life.
A high-mileage car charged mostly at home in a mild climate can have a healthier pack than a low-mileage car that lived on fast chargers through hot summers. When you're shopping for a used EV, ask the seller about their typical charging routine and where the car was driven, and use those answers - not just the odometer - to judge whether the battery is likely to be in good shape.
Recharged's guide to checking battery health before buying makes the same point: heavy dependence on DC fast charging and extended parking at 100% charge in hot climates are red flags worth asking about, separate from mileage.
TopSpeed's coverage of how battery life affects resale value adds a practical check anyone can do without special tools: compare the dashboard's predicted range after a full charge against the car's original EPA figure.
FAQ
How is State of Health (SoH) calculated?
State of Health is the percentage of the original battery capacity that remains. A new battery is 100% SoH. At 80% SoH, the battery holds 80% of the energy it could hold when new. The calculator uses Geotab's fleet-average degradation curves based on mileage and adjusts them for your DC fast-charging habits and climate. Example: a Tesla Model 3 Long Range with 36,000 miles of highway driving with occasional DC fast charging in a temperate climate might show approximately 95% SoH. A similar vehicle with 100,000 miles of city driving with frequent DC fast charging in a hot climate might show 85% SoH.
Why does DC fast charging affect battery degradation so much?
DC fast charging (50kW and above) charges the battery much faster than home charging, which generates more heat inside the battery cells. Heat accelerates chemical degradation and reduces the number of times the battery can be charged and discharged before capacity loss becomes significant. A battery charged exclusively on Level 2 home chargers (7-11kW) at cool temperatures experiences less heat stress and degrades more slowly than one charged 50% of the time at a DC fast-charge station in hot weather.
What does the 70% SoH warranty threshold mean?
Most EV battery warranties (Tesla, Nissan, Chevy, etc.) cover the battery until SoH drops to 70% or the warranty period expires (typically 8-10 years), whichever comes first. At 70% SoH, a car that originally had 300 miles of range now has about 210 miles of range. The warranty does not mean the battery fails at 70% - it means the manufacturer will replace or repair it. Real-world data shows batteries typically remain usable well below 70%, but degradation accelerates as they age.