New data on battery degradation in Tesla cars indicate that the batteries can retain some 90 percent of their capacity even after 300,000 km. This is the conclusion of an analysis on 350 vehicles from all over the world, which is continuously carried out by the Dutch-Belgian Tesla Forum and reported by electrek.co. This data is publicly available at Google.
Furthermore, most of the loss occurs during the first 100,000 kilometres, when degradation stands at about 5 percent. After that, capacity only declines gradually. The resulting trend line suggests that the average battery pack could cycle through over 300,000 km retaining about 90 percent capacity.