Musa bin Abdullah bin Yazid said that Sayyiduna Ali (may Allah be pleased with him) offered the funeral prayer over Sayyiduna Abu Qatadah (may Allah be pleased with him) and said seven takbirs over him, and he had been at Badr.
It was narrated like this, but it is an error, because Sayyiduna Abu Qatadah (may Allah be pleased with him) lived on for a long time after Sayyiduna Ali (may Allah be pleased with him). It is also reported from Sayyiduna Ali (may Allah be pleased with him) that he said four takbirs over Yazid bin al-Mukaffaf.
Hadith Referenceالسنن الكبرى للبيهقي / كتاب الجنائز / 6943