EV Battery Degradation Calculator
How much capacity has your electric car battery lost? Estimate degradation, check battery health, and project how long your EV battery will last — free, no sign-up.
Check Your EV Battery Health
Pick your vehicle, enter mileage and habits — get an instant degradation estimate.
Projected capacity over time
Tips to slow degradation for your situation
Estimate only. Real degradation varies by battery chemistry (NMC, LFP, NCA), software updates, and driving patterns. Our model is conservative and based on fleet-average aging curves.
Most EV warranties guarantee at least 70 percent capacity for 8 years or 100,000 miles. This projects when your battery will reach that 70 percent threshold under your conditions.
Projection assumes consistent driving and charging habits. LFP batteries (some Model 3, Mach-E standard range) typically degrade slower than shown here.
Answer a few quick questions for a 0 to 100 battery health score with a breakdown of what helps and what hurts.
What Is EV Battery Degradation?
EV battery degradation is the gradual loss of a lithium-ion battery’s ability to store energy. A brand-new electric car battery holds 100 percent of its rated capacity; over years of driving and charging, that capacity slowly declines. A car that started with 300 miles of EPA range might show 270 miles after several years — that 10 percent difference is degradation. It is normal, unavoidable, and happens to every EV from Tesla and Ford to Hyundai and Kia.
Degradation comes in two forms. Calendar aging happens simply with time — the battery chemistry slowly breaks down whether you drive or not, and heat accelerates it. A car parked for years in Phoenix will lose more capacity than one parked in Seattle. Cycle aging comes from charging and discharging: every full charge cycle wears the electrodes slightly, and deep discharges plus frequent DC fast charging add extra stress. Modern battery management systems (BMS) protect against the worst of both, which is why real-world degradation averages only about 1.8 to 2.3 percent per year across major EV fleets.
How This Degradation Estimate Works
Our calculator uses a transparent, conservative aging model built from published fleet studies. It starts with a base curve of roughly 2.3 percent capacity loss per year, tapering over time (batteries lose capacity fastest in year one, then the curve flattens — a pattern confirmed by Recurrent and Geotab fleet data). Then it adjusts for your situation:
- DC fast charging: frequent fast charging adds heat and high-current stress, increasing the annual rate by up to 35 percent.
- Climate: sustained heat is the biggest calendar-aging accelerator; hot climates raise the rate about 25 percent.
- Mileage: driving far above the 12,000-mile yearly average adds cycle wear on top of calendar aging.
- Garage storage: keeping the car out of extreme heat and cold trims the rate about 10 percent.
If you enter your measured full-charge range, we compare it against the estimate so you can see whether your battery is aging faster or slower than average for its age and use.
Typical Degradation by Age
These fleet-average figures show what most drivers can expect under normal mixed use:
| Vehicle Age | Typical Capacity Remaining | What It Feels Like |
|---|---|---|
| 1 year | 96 – 98% | Barely noticeable |
| 3 years | 90 – 94% | A few miles less range |
| 5 years | 87 – 92% | Noticeable on road trips |
| 8 years | 82 – 88% | Still very usable daily |
| 10+ years | 78 – 85% | Fine for commuting, tighter for trips |
How to Slow Battery Degradation
You cannot stop degradation, but you can meaningfully slow it:
- Charge to 80 percent daily. Lithium-ion cells are happiest between 20 and 80 percent state of charge. Save 100 percent charges for road-trip days.
- Limit DC fast charging. Use Level 2 home or workplace charging as your default; treat fast chargers as a road-trip tool.
- Avoid baking in heat. Park in shade or a garage during heat waves, and use scheduled departure so the car preconditions while plugged in.
- Do not store at 100 percent. Leaving for a trip? Leave the car near 50 to 60 percent charge, not full.
- Keep software updated. Automakers continuously improve battery management through over-the-air updates.
When Should You Worry?
Do not worry about single-digit degradation in the first few years — it is normal and fastest early on. Start paying attention if your range drops more than about 5 percent in one year after year two, if the car loses range while parked (beyond normal vampire drain), or if you see sudden large drops after a software update (often a recalibration, not real loss). Most manufacturers warranty the battery to at least 70 percent capacity for 8 years or 100,000 miles, so abnormal loss is usually covered.
Frequently Asked Questions
About 1.8 to 2.3 percent per year on average across major EV fleets, according to Geotab and Recurrent data. Loss is fastest in the first year (often 2 to 4 percent) and then tapers. Hot climates and frequent DC fast charging push you above average; garage-kept cars charged mostly on Level 2 do better.
Occasional fast charging has a small effect, but frequent DC fast charging does accelerate degradation because of heat and high charge currents. Studies show heavily fast-charged cars can degrade measurably faster than Level 2–charged ones. Use fast chargers for road trips and Level 2 for daily charging.
No. For NMC and NCA batteries (most Teslas, Mach-E, Ioniq 5), charge to 80 percent for daily use and only go to 100 percent before long trips. LFP batteries (some base Model 3 and Mach-E versions) are more tolerant — Tesla even recommends charging LFP to 100 percent weekly for calibration.
Most data suggests 12 to 20 years of useful life, or 150,000 to 300,000 miles, before capacity falls near 70 percent. Use the Battery Life Estimator tab above with your driving habits for a personalized projection. The battery usually outlasts the car body in normal use.
In the US, federal rules require at least 8 years or 100,000 miles of battery warranty. Most automakers guarantee at least 70 percent capacity over that period — if your battery degrades faster, the warranty covers repair or replacement. Hyundai, Kia, and some others offer 10-year coverage.
No — cold temporarily reduces available range (often 20 to 40 percent in extreme cold) but it is not permanent degradation; range returns when the battery warms up. Sustained extreme heat is the real permanent-aging enemy. Preconditioning while plugged in largely offsets winter range loss.
Compare your current 100-percent range to the original EPA rating — the percentage drop is your degradation. Apps and OBD dongles (like Recurrent reports or Scan My Tesla) give deeper state-of-health readings. Dealerships can also run a battery health diagnostic during service.
Yes, if it is abnormal. Warranties cover defects and excessive capacity loss — typically replacement or repair if capacity falls below 70 percent within 8 years or 100,000 miles. Normal gradual degradation above that threshold is not covered.
Generally yes. Lithium iron phosphate (LFP) chemistry tolerates full charges and high cycle counts better, showing slower calendar and cycle aging in fleet data. The trade-off is lower energy density, which is why LFP appears mostly in standard-range models.
Know Your Battery. Protect Your Range.
Run the degradation check above, then plan cheaper charging with our cost tools.
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