Tesla sold $430 million worth of its giant backup batteries called Megapacks to xAI, Elon Musk's artificial intelligence startup, in 2025, according to a filing on Thursday. The sales to xAI accounted for around 3.4% of Tesla's energy business revenue, which climbed 27% to $12.8 billion last year from $10.1 billion in 2024, the filing said. Tesla's energy division, which sells solar photovoltaics and battery storage systems of various sizes, was a bright spot for the company, as auto revenue