Sep.8 (GMM) Red Bull's alternator problems are back.
Sebastian Vettel's car broke down in the final practice session at Monza on Saturday morning.
He radioed the pits that the problem was battery-related.
"It's the same problem as Valencia," Dr Helmut Marko told Germany's Auto Bild Motorsport.
At Valencia, the Renault/Magneti Marelli alternator failed, costing Vettel victory, while a similar problem also struck Romain Grosjean's similarly-powered Lotus.