Mercedes F1 faces battery reliability challenges amid rising power demands

Mercedes’s Formula 1 power units are experiencing a surge in battery failures after the amount of energy recovered under braking rose sharply from about 120 kW to roughly 350 kW. Although the maximum battery capacity remains at 4 MJ, the higher charge‑and‑discharge rate has increased thermal stress and induced micro‑vibrations within the cells.

The problems have shown up in the cars of drivers such as George Russell and Kimi Antonelli, and earlier in the season affected other teams including McLaren and Williams. Team technical director James Allison says the issue has a common origin and expects the next batch of batteries introduced during the season to provide initial solutions. The reliability question is especially critical as the sport moves toward the 2026 regulation changes that will make the hybrid battery a central component of the car’s performance.