Honda yet to find cause of Stroll battery failure

Lance Stroll retired from the Sao Paulo Grand Prix after 30 laps when another battery problem hit his Aston Martin, his 13th retirement of the season. He had been running 18th, 28 seconds behind team-mate Fernando Alonso. The issue followed a battery problem on Saturday, meaning he suffered the same fault on consecutive days.

Honda trackside general manager and chief engineer Shintaro Orihara said the team knows what happened but not the root cause. He said data and the battery will be checked, and that finding the cause may take a few weeks. Honda's earlier reliability struggles included engine vibrations that repeatedly damaged battery components at the start of the season.

Alonso finished 12th after slipping out of the points on the opening lap. Orihara said the wet conditions had masked some of the engine's weaknesses, while Honda still needs to improve drivability.