The owner of a 7 year old Tesla Model S says their batteyr is at 98% battery capacity today while always charging it up to 90%
— Read on cleantechnica.com/2019/09/15/7-year-old-tesla-model-s-at-98-battery-capacity-today/
I found similar results in the 2013 Model S P85. At 6 years old it was still holding charge in the high ninetieth percentile after 75,000 miles.
The P85 was mostly driven around town at reasonable speeds and usually charged to 90% every night on a 40a circuit.
That said, it had many 0-60 and 0-100 sprints at full speed as well as an extended run at 140.
Turns out all the predictions about battery life and long term costs of maintaining it were overly pessimistic. Maybe the batteries will suddenly start an exponential decline in charge capacity, but that is very unlikely. Yes the battery will need to be replaced but not any time soon; With battery prices continually dropping it will likely end up costing far less than the combined maintenance of an ICE vehicle over the same period of ownership.