Tesla recently made the 350kW charging speed of its latest V4 Superchargers official, compared to the 250kW or 150kW of the current V3 or V2 Supercharger crop in the US. Those charging speeds, however, won't degrade a Tesla car battery more than charging slow on Destination Chargers or overnight at home, it turns out.
According to a new study by Recurrent, there is no difference in range degradation over time on Tesla vehicles whose owners top up at fast DC chargers more than 90% of the time, and those who only do it every now and then. These are two far-out cases, of course, as most Tesla owners use a combination of the two, but Recurrent focused on the extremes precisely to determine if Superchargers have a real-life effect on the battery's remaining capacity.
They probed 12,500 Tesla vehicles and found out that there is "no statistically significant difference in range degradation between Teslas that fast charge more than 90% of the time and those that fast charge less than 10% of the time."
Recurrent has initial data that shows a similar conclusion for cars of other EV brands, but since Teslas are the most ubiquitous electric vehicles, they wanted to have a large enough representative sample. "In short, the robust thermal, voltage, and battery management systems that EV makers have invested in do protect their batteries from damage with routine fast charger use," they add.
There are, of course, extreme use scenarios which would definitely degrade the battery faster, such as Supercharging in overly hot or cold weather without preconditioning. The Tesla vehicles should be preconditioning the battery when a Supercharger station is set as a destination, though, or just driving there warms it up in cold weather, so these extremes are usually covered in terms of battery degradation over time as well.
Tesla itself has enough statistics and long-term observations of its electric vehicles now to confidently state in its latest Impact Report that it takes 200,000 miles for its cars' battery to degrade 12% on average, which jibes with the findings of the current study as well, and bodes well for current EV batteries' longevity in general.