New studies show EV batteries could last over two decades

Jet Sanchez
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Busting the myth: Your EV’s battery might outlive its combustion rivals.

Busting the myth: Your EV’s battery might outlive its combustion rivals.

As electric vehicles (EVs) gain traction globally, concerns about their long-term viability - specifically battery longevity - continue to dominate conversations.

Contrary to early fears that EV batteries would rapidly degrade and render vehicles obsolete, mounting evidence suggests that these batteries may outlast their fossil-fuel counterparts.

Shattering myths

Tesla Supercharger

Early scepticism about EV batteries largely stemmed from experiences with lithium-ion technology in consumer electronics.

Many assumed that, like smartphone batteries, EV cells would degrade quickly, leading to costly replacements. This belief contributed to the sharp depreciation seen in the second-hand EV market.

However, as WIRED reports, recent studies challenge this narrative, showing that EV batteries often maintain a high percentage of their capacity even after significant use.

“There is an immense amount of consumer concern around the state of the battery that you buy in a second-hand vehicle,” says James Wallace, cofounder of Fortescue’s battery intelligence division, Elysia. He emphasises that providing buyers with clearer insights into battery health could bolster confidence in used EVs.

Elysia, originally Williams Advanced Engineering, is developing software to enhance battery transparency across various applications, including motorsport and mining.

Surpassing expectations

Tesla Model Y
Tesla Model Y

Consulting firm P3, in collaboration with Austrian battery specialist Aviloo, analysed 7000 fleet EVs. The findings were striking: after 100,000km, EV batteries retained 90% of their capacity. Even at 300,000 km, they still held 87% of their original charge.

Supporting this, Geotab, a telematics firm, observed a consistent reduction in degradation rates over the years.

In their most recent study involving over 5000 vehicles, the average annual degradation was just 1.8%, down from 2.3% in 2019. “This most recent study didn't have as many of the early-gen vehicles,” says Charlotte Argue, senior manager for sustainable mobility at Geotab, “telling us that battery management systems are getting better, and batteries are lasting longer.”

If this rate continues, an EV could retain 82% of its battery capacity after 10 years and 64% after 20 years. For a car starting with around 500km of range capacity, this equates to roughly 320 two decades later - still practical for many users.

Lessons from early EVs

BMW i3 New Zealand
BMW i3

While most current EVs are under a decade old, early examples like the BMW i3 offer insights.

A 2013 BMW i3 with a 22.6kWh battery reportedly retains 83% of its capacity after nearly 10 years.

Similarly, some Tesla Model S vehicles from 2013 boast over 250,000 miles (402,336km) on their original batteries, with approximately 86% of capacity intact.

However, Argue warns against overconfidence. “We can’t predict the future. It's 1.8% per year to date,” she explains. “There is an argument that there could be what we call a heel curve towards the end of the life of the vehicle, where the battery starts degrading faster than it did for most of its life."

Factors influencing degradation

While mileage appears to have little impact on degradation, frequent DC rapid charging and high temperatures can accelerate wear.

Geotab’s research found that cars in hot climates using rapid charging degraded three times faster than average. Yet even under such conditions, some batteries showed annual losses as low as 1%.

Improved thermal management and charging protocols are mitigating these risks. “Battery tech has gotten much better, particularly around management systems,” says Neil Cawse, CEO of Geotab. For instance, advanced systems now regulate charging rates during cold weather, preventing undue stress on cells.

Implications for the industry

The longevity of EV batteries has implications beyond consumer confidence. Reduced degradation could enable automakers to shrink battery buffers, cutting production costs. “OEMs are oversizing these batteries,” argues Wallace. Smaller buffers would reduce battery size, making EVs more affordable without compromising usability.

Moreover, maintenance costs for EVs are significantly lower than for internal combustion engine (ICE) vehicles. With fewer moving parts, EVs mainly require brake pad replacements and wiper changes. This, combined with longer-lasting batteries, could disrupt the traditional lifecycle of vehicles, challenging the industry’s reliance on replacement cycles.

Looking ahead

Although long-term data on EVs is still emerging, the current trajectory is promising.

With annual degradation rates remaining low and management systems improving, a 10-year-old EV might perform almost like new, while a 20-year-old model could still be functional.

As Argue succinctly puts it: “You shouldn’t be afraid to use your EV.” The era of EVs lasting well beyond expectations may already be here, reshaping the way we think about vehicle ownership and sustainability.