High Mileage = High Degradation? - EcoSwift LearnEV Series (Battery Life)
- Ryan Woon
- Aug 6
- 2 min read
Have you bought a used car or lorry and based its value on mileage before? Im certainly guilty as charged. Whenever I am purchasing a used car, the mileage clocked by the vehicle is the first thing I look at. I was recently asked this question that if a high mileage EV meant higher battery degradation.
My answer? "No".
Debunking “High Mileage Means High Degradation”
❌ The Myth:
High mileage = high battery degradation
This misconception stems from how we assess internal combustion engine (ICE) vehicles. With ICEs, mileage is a reliable proxy for wear and tear. But EV batteries operate under a different set of rules
✅ The Reality:
Battery degradation is more influenced by calendar age and environmental conditions than mileage alone.
To understand why, we need to distinguish between two types of aging:
🔍 Types of Battery Aging
Aging Type | Description | Key Influencers |
Calendar Aging | Natural degradation over time, even when the battery is idle | Temperature, storage conditions |
Cycle Aging | Degradation from charging/discharging cycles (i.e., usage) | Depth of Discharge, C-rate, heat |
Battery capacity loss occurs due to the gradual depletion of active lithium electrolytes, reducing lithium inventory and overall capacity.
📉 Why Mileage Isn’t the Whole Story
Studies show only minor differences in degradation between high- and low-mileage EVs — especially when usage is well-managed. In fact, many high-mileage EVs maintain healthy battery performance.
Cycle aging is influenced by how the vehicle is used:
Temperature during operation
Depth of Discharge (DoD)
C-rate (charging/discharging speed)
We’ll explore these three stress factors in detail in upcoming articles.
Calendar aging, however, is often more impactful — especially when the vehicle is parked. During rest, chemical reactions continue inside the battery, degrading the electrodes and electrolyte. And here’s the kicker:
Temperature is the most critical factor.
Modern EVs actively regulate battery temperature during driving and charging. But when parked, cooling systems are inactive — allowing cell temperatures to rise and accelerate degradation. Ironically, a low-mileage EV parked in a hot climate may degrade faster than a high-mileage EV with good thermal management.
🧠 Key Takeaway
Mileage alone isn’t a reliable indicator of battery health. It's how — and where — the vehicle lives that matters.
-Ryan Woon
LearnEV is EcoSwift’s knowledge hub for all things electric mobility.
In this series, we break down the myths, mechanics, and best practices behind EV technology — from battery health to charging protocols, performance tuning to sustainability. Whether you're an industry insider or a curious newcomer, LearnEV delivers clear, actionable insights to help you drive smarter, cleaner, and further.
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