It will be a long time before you have to replace it. Probably never. Current battery models are expected to outlive the vehicle they were manufactured for. Some Teslas are still on the road after 500,000 miles of fast charging. Some batteries have proven to be defective, but those were replaced by the manufacturer while under warranty. The federal government requires at least an 8 year or 80,000-mile warranty for EV batteries. I recently sold an EV with 110,000 miles on it, and the battery was getting about 90 percent of the original battery’s range (they do lose a little range over time, but they do not become unusable).
Range loss occurs primarily in the first year of ownership (see graph); thereafter it flattens out for as long as data have been collected. Note that the scale in the graph below drops only to around 90 percent, and that fast charging has negligible impact on the range of Model 3s and most new BEVs. This graph records extreme fast-charging behavior: < 10% or > 90%.
