The future of electric vehicles (EVs) is here, and it's an exciting one! But for many, the fear of battery degradation looms large, casting a shadow over the otherwise promising outlook. However, a closer look at ultra-high-mileage EVs reveals a more nuanced story. These vehicles, often Teslas with hundreds of thousands of miles on the clock, demonstrate that battery degradation is not the looming catastrophe it's often made out to be. In fact, modern EV batteries generally degrade slowly, and even high-mileage cars can remain perfectly usable long after many gas cars would have been traded in. This is a revelation that could change the way we think about EVs and their longevity. So, what's the secret behind these high-mileage EVs' resilience? Let's dive in and explore the fascinating world of EV battery degradation.
The Slow Degradation of EV Batteries
After examining numerous high-mileage EVs, a clear pattern emerges: modern EV batteries tend to degrade slowly. This is a significant finding, as it challenges the common perception that EV batteries are inherently prone to rapid degradation. The data shows that even very high-mileage cars can retain a substantial portion of their original battery capacity, often exceeding what's expected from gas cars. For instance, a three-year-old Tesla Model 3 with 217,500 miles, used as a taxi and frequently fast-charged, still boasts an impressive 88.5% battery capacity and over 300 miles of real-world range.
The Longevity of Tesla Models
Tesla models, in particular, have demonstrated remarkable longevity. A Tesla Model S from the UK, with around 430,000 miles on its original battery and motors, has only lost about 65 miles from its original range rating. This is despite being used as an airport taxi and frequently fast-charged. Similarly, a 2019 Tesla Model 3 Standard Range Plus with 380,000 miles still runs its original battery pack, albeit with a 34.2% decrease in displayed range from 240 to 158 miles. While this is significant degradation, it doesn't render the car unusable for daily commuting and local driving.
The Role of Battery Type
Battery type plays a crucial role in EV longevity. LFP (lithium iron phosphate) batteries, which are cheaper and more durable, have shown better performance over time compared to NMC (nickel manganese cobalt) batteries. Voltest, a company specializing in EV battery testing, has observed high-mileage Tesla Long Range models with NMC batteries at around 200,000 miles, with a state of health in the high-70% to low-80% range. In contrast, LFP-powered cars with 200,000 miles have shown over 90% battery health, which is positively surprising but aligns with scientific expectations.
The Impact of Charging Habits
Charging habits and environmental conditions significantly influence battery health. High mileage doesn't inherently damage a battery; it's the charging and discharging cycles, thermal stress, fast charging, and frequent high or low states of charge that matter. A high-mileage EV that lives in a garage, charges mostly at home, and avoids extreme heat will have a healthier battery than one that has spent years being fast-charged in hot climates. This is why testing a car's battery health is crucial, as it can reveal surprises, both good and bad.
The Role of Liquid Cooling
The proliferation of liquid cooling for batteries in modern EVs has been a game-changer. Even older vehicles, over 10 years old, can benefit from liquid-cooled battery packs. Voltest has seen the worst results on older Nissan Leafs with air-cooled architectures, but this is not due to battery chemistry or cells. Instead, it's the cooling system that matters.
The Impressive Longevity of EV Batteries
Davide Giacobbe, the co-founder and CEO of Voltest, is impressed by the resilience of EV battery packs over hundreds of thousands of miles. His company has tested vehicles with 300,000 miles and found that some still retained around 75% of their battery capacity. This is a remarkable achievement, challenging the longevity of internal-combustion cars.
In conclusion, the fear of battery degradation in EVs is not entirely unfounded, but it's not the insurmountable issue it's often made out to be. Modern EV batteries are designed to degrade slowly, and with proper care and attention to charging habits, high-mileage EVs can remain perfectly usable. As the EV market continues to evolve, these findings offer a glimmer of hope for those considering the switch to electric vehicles.
