Tesla provides an eight-year warranty for its batteries. We've seen survey data that suggests most Teslas retain more than 90% of their capacity after 100,000 miles, which is pretty impressive. You probably shouldn't be concerned about the cost of replacement batteries. Unless you cover high miles, it's unlikely to be an issue for at least 10 years. By which time, you'll have saved a lot of money in maintenance and fuel compared to a petrol or diesel car. Teslas generally hold their value very well, too - and as the uptake of electric cars increases, this is unlikely to change anytime soon.