The world of electric vehicles (EVs) is evolving, and with it, our understanding of battery degradation. While concerns about battery health are valid, the reality is that ultra-high-mileage EVs are proving to be more resilient than many anticipated. These vehicles, with hundreds of thousands of miles on the clock, are not just surviving but thriving, challenging the notion that battery degradation is an insurmountable issue for EV owners.
One of the most striking examples is the Tesla Model 3, a three-year-old taxi with an impressive 217,500 miles under its belt. Despite its rigorous use, the car still boasts an 88.5% battery capacity and over 300 miles of real-world range. This is a testament to the slow degradation of modern EV batteries, which can remain perfectly usable long after many gas-powered cars have been sold to their third owner. The Tesla Model S, with its 430,000 miles and original battery, further reinforces this point, having lost only about 65 miles from its original range rating.
The key to understanding this phenomenon lies in the nature of battery degradation. It's not the miles themselves that are the culprit, but rather the activities that the battery undergoes during those miles. Repeated charging and discharging, thermal stress, fast charging, and frequent high or low states of charge are the real factors that contribute to battery wear. 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 to 100% in hot climates.
Battery type also plays a significant role. LFP batteries, which are cheaper and more durable, appear to be holding up better than NMC batteries. A Tesla Model 3 Standard Range with an LFP pack and 189,000 miles, despite being fast-charged more than 90% of the time, still showed around a 91-92% state of health. This is positively surprising, but it is aligned with what the science says. LFP batteries are less affected by frequent topping up to 100% and fast charging, which is confirmed by the data.
The proliferation of liquid cooling for batteries in the modern EV era has also made a big difference. Even on cars that are more than 10 years old, as long as the battery pack is liquid-cooled, it is good. The worst results are seen on older Nissan Leafs and similar vehicles with air-cooled architectures, not because of the battery chemistry or the cell itself, but due to the cooling system.
However, it's important to note that none of this means that EV batteries will last forever, or that every high-mileage electric car is automatically a safe buy. Battery degradation is real and worth looking into if you're buying a used EV. But mileage itself doesn't tell the whole story. The degradation curve is getting better in newer cars, and some of the best results are seen in older Model S and Model X models, which may be due to their lower volumes and different product types.
In my opinion, the resilience of ultra-high-mileage EVs is a fascinating development. It challenges the notion that battery degradation is an insurmountable issue and opens up exciting possibilities for the future of EV ownership. As we continue to push the boundaries of EV technology, it's crucial to consider the broader implications and hidden insights that these high-mileage vehicles offer. The degradation curve may be getting better, but the real story lies in the resilience and longevity of these vehicles, which could revolutionize the way we think about EV ownership.
