Mercedes Reveals Cause of Kimi Antonelli’s Painful Barcelona DNF

Moments after Kimi Antonelli passed his Mercedes teammate George Russell for P2 in Catalunya, a battery failure brought his race to a halt on Lap 62.

The 19-year-old remains the youngest championship leader in F1 history and still heads the standings, but his gap over Lewis Hamilton has been cut to 41 points after Hamilton’s maiden Ferrari victory made the whole thing considerably more dramatic than it needed to be.

Antonelli said he never saw it coming: “All of a sudden I was at the apex of Turn 5 and the car just gave up,” he said at the time.

After diagnostics after the race, Mercedes technical director James Allison confirmed in a podcast by the Mercedes team, that they had pinpointed the issue to its power unit’s battery, and a permanent fix is being worked on.

“I think anyone who’s a keen watcher of the sport will have seen that this has laid a few Mercedes-engined cars low over the season so far,” Allison said. “They’re not all identical, but they they do originate in the same broad part of the battery.”

Barcelona was the third race in a row in which one of Mercedes’ drivers failed to finish due to power unit problems.

Customer squad McLaren has also dealt with its share of electrical trouble. Lando Norris needed a battery swap at Monaco and retired from the race, while both Norris and Oscar Piastri failed to start the Chinese GP with separate electrical faults.

New Battery Modules Are the Plan, and They Can’t Arrive Soon Enough

Allison’s message was clear enough: the team understands the vulnerability, and the solution is on its way.

“I think that most of the areas of risk have been understood, and with a bit of luck when we start to phase in the new modules into the racing season – we call the battery ‘the module’ – then our fortunes as a fleet should pick up.” The word “luck” in a technical briefing is usually a sign that nobody wants to over-promise. “These DNFs are very, very painful,” he added.

His explanation of the short-term response is fair, if not exactly reassuring: when a failure like this happens, part of the team dials back the demands on the affected hardware while another group hunts the root cause. In Allison’s words, “you do a first intervention that is just to try to give the vulnerable thing an easier life while then working on a proper cure that lets you really cane it.”

The uncomfortable part is doing it mid-championship fight, with Ferrari now clearly capable of winning and the gap to Hamilton at less than half a race’s worth of points.

Mercedes has won six of seven grands prix under the new 2026 regulations, which softens the immediate damage but doesn’t eliminate the risk. A car quick enough to lead from the front only matters if it survives to the checkered flag. Getting the replacement modules into cars before the summer break is the real deadline – and Allison knows it.