For years, the biggest anxiety holding back prospective EV buyers wasn’t range – it was battery degradation. We’ve been covering this concern since EVXL’s founding, watching the narrative shift from “EV batteries die after 5 years” to something far more nuanced. Now, a comprehensive new study from fleet telematics company Geotab analyzing over 22,700 electric vehicles delivers the data that every used EV shopper, current owner, and fence-sitter needs to see – and it’s not what most people expected.

The headline finding: modern EV batteries degrade at just 2.3% per year on average, meaning after eight years of ownership, you’ll still have roughly 82% of your original battery capacity. That’s barely noticeable in daily driving. But buried in the data is a warning that changes everything about how you should think about charging your EV.

The Fact: Average annual EV battery degradation is 2.3%, up from 1.8% in Geotab’s 2024 study.

The Reality: That increase isn’t because batteries are getting worse. It’s because drivers are using DC fast charging (DCFC) above 100 kW far more frequently, and that habit comes with measurable consequences.

Why Did Battery Degradation Rates Increase From 1.8% to 2.3%?

The short answer: we’re charging faster than ever. Geotab’s 2025 analysis, which examined several years of aggregated telematics data across 21 EV models from fleets in North America and Europe, found that charging behavior has overtaken climate as the dominant factor affecting battery longevity. Vehicles heavily relying on high-power DC fast charging above 100 kW experienced degradation rates up to 3.0% per year – double the rate of vehicles primarily using Level 2 AC charging.

“EV battery health remains strong, even as vehicles are charged faster and deployed more intensively,” said Charlotte Argue, Senior Manager for Sustainable Mobility at Geotab. “What has changed is that charging behavior now plays a much bigger role in how quickly batteries age.”

This makes intuitive sense when you consider the physics. High-power charging pushes more current through battery cells, generating more heat and stress. But here’s what the mainstream coverage missed: the increase reflects how EVs are being used in the real world, not any regression in battery technology. In fact, eight of the 11 models Geotab tracked since 2023 have stabilized at just 1.4% annual degradation – better than ever.

How Much Does DC Fast Charging Actually Impact Battery Life?

The data is unambiguous. Vehicles that relied heavily on DC fast charging above 100 kW – defined as more than 40% of DCFC sessions exceeding that threshold – averaged 3.0% annual degradation. Vehicles primarily using AC charging or lower-power DC sessions degraded at roughly half that rate, around 1.5% per year.

For context, that’s the difference between having 76% battery capacity after eight years versus 88%. In a 300-mile EV, that translates to roughly 36 miles of range – meaningful, but not catastrophic. Both scenarios leave you with a perfectly usable vehicle well beyond typical ownership cycles.

The study found that even vehicles with less than 12% of total charging on DC fast chargers showed only 1.5% annual degradation, while those exceeding 12% DCFC usage jumped to 2.5%. The takeaway for owners: occasional road trip charging won’t kill your battery, but making fast charging your primary method will accelerate wear.

This finding arrives at a critical moment. As we’ve documented extensively, Tesla’s Supercharger network has expanded dramatically to over 75,000 stalls globally, with 18 non-Tesla brands now accessing the network through NACS adapters or native ports. The convenience of fast charging has never been better – but Geotab’s data suggests that convenience comes with a battery health trade-off worth understanding.

Does Climate Still Matter For EV Battery Health?

Yes, but less than you might think. Geotab found that EVs operating in hot climates degraded around 0.4% faster per year than those in mild conditions. That’s measurable but modest – far less impactful than charging habits.

The data challenges the old assumption that Arizona or Texas ownership automatically dooms your EV battery. While heat remains a stressor on lithium-ion cells, modern thermal management systems have largely mitigated the problem. What matters more is whether you’re hammering your battery with 250 kW Supercharger sessions every day or topping up overnight with a Level 2 charger in your garage.

What About the 20-80% Charging Rule?

Here’s where Geotab’s findings challenge conventional wisdom. The study found that moderate exposure to state-of-charge (SOC) extremes – spending up to 80% of cumulative time above 80% charge or below 20% – had essentially no meaningful effect on battery aging. Degradation rates for low-exposure and medium-exposure groups were virtually identical at 1.4% and 1.5% per year.

Only when vehicles spent more than 80% of their time at very high or very low charge levels did degradation accelerate meaningfully, rising to 2.0% per year. The practical implication: charging to 100% for a road trip or occasionally running down to 10% won’t hurt your battery. What matters is habitual, prolonged storage at extreme charge levels.

Modern battery management systems (BMS) deserve credit here. As Geotab noted, a displayed 100% charge isn’t chemically full, and a displayed 0% isn’t truly empty. Built-in buffers protect cells from the most damaging extremes, making strict adherence to the 20-80% rule less critical than previously believed.

How Do Different Vehicle Types Compare?

Geotab’s data revealed notable differences between vehicle categories. Multi-purpose vehicles (MPVs) including light vans averaged higher degradation at 2.7% per year, while light passenger cars – sedans and SUVs – exhibited 2.0% annual decline. The difference likely stems from battery chemistry choices, energy density optimization, and thermal management approaches tailored to different vehicle priorities.

For prospective used EV buyers eyeing the wave of lease returns flooding the market in 2026, this distinction matters. A used passenger EV like a Tesla Model 3 or Chevrolet Bolt is likely to have retained more battery capacity than a commercial van that’s been worked harder.

EVXL’s Take

This study validates what we’ve been telling readers for years: EV battery anxiety is mostly obsolete. The data from 22,700 real-world vehicles proves that modern batteries are robust enough to outlast typical vehicle ownership cycles, even under demanding conditions. The average EV will still have over 80% capacity after eight years – that’s better than what most people experience with their smartphone batteries after two years.

But the study also delivers a warning we think will reshape buyer behavior. As Tesla’s V4 Superchargers roll out with 500 kW capability and charging networks compete to offer ever-faster speeds, the temptation to treat every charge like a pit stop will grow. Geotab’s data shows that’s the wrong approach for battery longevity. The drivers who will get the most life out of their EVs are those who charge at home whenever possible and save fast charging for when they actually need it.

For the used EV market, this is unambiguously good news. As we documented in our coverage of the flood of affordable used EVs hitting dealerships, battery health concerns have been a persistent barrier to adoption. Geotab’s fleet-scale data showing 80-90% capacity retention after 36,000 miles should finally put those fears to rest. The 243,000+ lease returns arriving in 2026 represent genuine value for buyers who understand what they’re getting.

Looking ahead, expect this data to influence everything from insurance rates to residual values. As the industry digests Geotab’s findings, the narrative around EV ownership costs should shift toward reality: these batteries last, and they last well.

Editorial Note: This article was researched and drafted with the assistance of AI to ensure technical accuracy and archive retrieval. All insights, industry analysis, and perspectives were provided exclusively by Haye Kesteloo and our other EVXL authors, editors, and Youtube partners to ensure the “Human-First” perspective our readers expect.