How long will an electric car battery last? The lithium-ion battery pack in the Tesla Roadster is projected to have a lifespan of about 5 years or 100,000 miles. At the end of that time the pack will need to be replaced, at a cost of approximately $10,000. Sure, that's expensive, but the Roadster itself will cost almost $100,000, which makes the cost of the battery pack seem affordable.