EV Battery Degradation Calculator
Estimate your EV battery's current health and project range degradation over time. Understand how climate, charging habits, and state of charge patterns affect long-term battery performance.
Disclaimer
This calculator provides estimates for informational purposes only. Actual solar production, savings, and payback periods depend on site-specific conditions including local weather, roof condition, shading, equipment selected, installer pricing, utility rate structures, and policy changes. Always obtain multiple quotes from qualified solar installers and consult a tax professional for incentive eligibility. Results should not be considered financial advice.
Base Annual Degradation Rate
Industry average of 2.3% per year, based on Recurrent Auto analysis of 15,000+ EVs and EV Battery Aging report data.
Modifiers Applied
- Hot climate (above 95°F summer avg): +0.3%/year
- Frequent DC fast charging (daily): +0.2%/year
- Mostly L2 home charging: −0.1%/year
- Narrow SoC range (20–80%): −0.3%/year
- Wide SoC range (0–100%): +0.2%/year
Battery Health Formula
Battery Health (%) = 100% − (Years Owned × Annual Rate)
Projected Range = Original EPA Range × (Battery Health / 100)
Important Limitations
This is a simplified statistical model based on industry averages. Actual battery degradation varies significantly by vehicle, individual usage patterns, specific battery chemistry, and maintenance history. Use a battery diagnostic tool (OBDII + EV-specific app or dealer scan) for an accurate current state of health measurement.
Understanding EV Battery Degradation
Battery degradation is one of the most important long-term considerations for EV ownership. Unlike a gasoline engine that can be rebuilt or replaced relatively easily, an EV battery pack is a major component with significant replacement costs. Understanding how degradation works, what factors affect it, and how to minimize it helps EV owners get the most value from their vehicles over time.
Real-World Degradation Data
Real-world EV battery data is more reassuring than many buyers fear. Analysis of tens of thousands of EVs shows that most batteries retain 80 to 90 percent of their original capacity after 100,000 miles or 8 years. Tesla's 2022 impact report showed their fleet averages only 12% degradation at 200,000 miles. Newer models with improved battery chemistry and thermal management systems are performing even better.
The 20-80% Charging Rule
The most impactful thing most EV owners can do to extend battery life is to limit daily charging to 80% and avoid consistently depleting the battery below 20%. Modern EVs typically have charge limit settings that make this easy to implement automatically. Keeping the battery in this range reduces stress on the cells and slows the electrochemical aging that causes capacity loss. This is less important for LFP (lithium iron phosphate) chemistry EVs like certain Tesla Standard Range models, which are designed to routinely charge to 100%.
Warranty Protection
Federal regulations require automakers to warranty EV battery packs for at least 8 years or 100,000 miles, whichever comes first. This warranty covers capacity falling below the manufacturer's minimum threshold, typically 70 to 75 percent. If your battery degrades faster than expected and drops below the warranty threshold during the coverage period, the manufacturer must repair or replace it. Keep records of charging habits, software updates, and any unusual range loss to support potential warranty claims.
Frequently Asked Questions
How fast do EV batteries degrade?
EV batteries degrade at an average rate of about 2 to 2.3 percent per year under typical conditions. This means a battery that starts at 100% health will retain approximately 80% capacity after 8 to 10 years. Real-world data from Recurrent Auto's analysis of over 15,000 EVs shows most models perform at or above manufacturer warranty thresholds. Premium EVs with thermal management systems often show slower degradation.
What factors accelerate EV battery degradation?
Key factors that accelerate battery degradation include: hot climate exposure (adds 0.2 to 0.5% per year), frequent DC fast charging (adds 0.2 to 0.4% per year beyond occasional use), regularly charging to 100% or discharging near 0%, high ambient temperatures while parked, and age even without driving. The battery chemistry (NMC vs LFP) also plays a role — lithium iron phosphate (LFP) batteries are more tolerant of full charges.
What is the EV battery warranty?
Federal law requires EV manufacturers to warranty battery packs for at least 8 years or 100,000 miles, whichever comes first. The warranty covers battery failure and typically guarantees a minimum state of health of 70 to 80 percent of original capacity. Some manufacturers exceed the minimum: Hyundai and Kia warrant their batteries for 10 years/100,000 miles at 70% capacity. Tesla warrants Model 3 Standard Range for 8 years/100,000 miles at 70% capacity.
How can I slow down battery degradation?
To minimize battery degradation: (1) Keep daily charge level at 20-80% rather than 0-100% — most EVs have a charge limit setting for this purpose. (2) Avoid leaving the vehicle at very high or very low charge states for extended periods. (3) Limit DC fast charging to road trips rather than daily use. (4) Park in shade or a garage in hot climates to reduce thermal stress. (5) Enable battery preconditioning in cold weather before fast charging.
Does DC fast charging damage the battery?
Occasional DC fast charging does not significantly damage modern EV batteries. Studies show that regular fast charging (daily use) may increase degradation by 0.1 to 0.2% per year compared to exclusive Level 2 charging. Tesla's fleet data has shown minimal additional degradation from Supercharger use. However, charging to 100% using any charger and then letting the battery sit at full state of charge for extended periods is more problematic. Modern EVs with active thermal management systems handle DC fast charging much better than earlier generation EVs.
What happens to an EV battery at end of life?
When an EV battery degrades below about 70 to 80% capacity, it may be replaced under warranty or purchased as an aftermarket replacement. Retired EV battery packs still have significant value for stationary energy storage applications — storing solar energy at homes or providing grid services. Companies like Nissan have repurposed leaf battery packs for home storage, and large-scale second-life battery storage projects exist at the utility scale. Eventually, batteries are recycled to recover lithium, cobalt, nickel, and manganese.
How does climate affect battery degradation?
Climate has a significant impact on battery longevity. Hot climates (average above 95°F in summer) accelerate chemical aging of battery cells, adding an estimated 0.3% per year to the degradation rate. Cold climates can temporarily reduce range by 20 to 40% but don't necessarily accelerate long-term degradation as severely as heat. EVs with active thermal management systems (heating and cooling the battery) are much less affected by climate extremes than those with passive thermal management.
Data Sources
Data current as of February 2026. Rates and incentives are subject to change.