Tesla Roadster Uses Redesigned 4680 Pack for Fast Charging

Tesla engineering chief Lars Moravy said the Roadster uses redesigned 4680 cells and an improved battery pack that aim to make it Tesla's fastest-charging battery, targeting 10 minutes to charge from 10% to 80% and 20 minutes of sustained track use.

Moravy discussed the pack in an interview with Hagerty and described the cells as "special cells" with a special chemistry; he did not disclose the chemistry or full cell specifications.

Tesla is addressing prior thermal limits at pack level. The Roadster uses aluminum cell cans instead of steel for better heat dissipation and lower weight, and the pack includes a titanium upper plate.

The most visible change is a cooling architecture with double-sided cooling jackets so every cell is surrounded by cooling lines to provide a more uniform heat flux across the pack.

Tesla introduced the 4680 format at Battery Day 2020, promising larger capacity, higher power and a dry battery electrode process acquired from Maxwell; those material and process changes proved difficult to deploy in volume, leaving many 4680s functionally as larger 2170-style cells with challenging thermal behavior.

Thermal problems became apparent in production. A 2023 Model Y AWD built in Austin used 4680 cells and owners reported poor charging performance; Tesla canceled the 4680 Model Y program in September 2023 but proceeded with Cybertruck deliveries in November 2023 using 4680 cells.

For the Cybertruck Tesla marketed second-generation 4680 "Cybercells" with a claimed 10% increase in energy density, yet owners reported 35 minutes or more to charge from 10% to 80% in practice.

A 2024 software update and access to 800-volt Tesla Superchargers improved Cybertruck charging times only modestly; meaningful gains required starting a charge from below about 5% state of charge.

Moravy said the Roadster's pack and cooling should allow 20 minutes of continuous track running and enable 10-to-80% charging in no more than 10 minutes; those performance targets appear on the Roadster spec sheet but Tesla has not disclosed the cell chemistry and has not confirmed series production timing.

These performance claims are manufacturer statements attributed to Lars Moravy and await independent verification when production cars and standardized charging tests are available.