The original Tesla Roadster battery pack contained 6,831 individual lithium-ion battery cells.
Tesla built the first Roadster using thousands of small cylindrical lithium-ion cells rather than a single large custom battery. The cells were arranged into modules and integrated into a pack positioned low in the vehicle, helping the two-seat sports car achieve a low center of gravity.
The approach was unusual for a production electric car at the time, because many observers associated electric vehicles with large, specialized battery units. Tesla’s design adapted commercially available cell technology and added sophisticated monitoring and thermal-management systems.
The Roadster used a 53-kilowatt-hour battery pack and was based on the Lotus Elise’s chassis. Its battery architecture influenced later Tesla vehicles, although subsequent models used different pack sizes, cell arrangements, and structural designs.