SpaceX spent $295 million on Tesla Megapack batteries in the second quarter of 2026, bringing its total for the year to $329 million, according to the company's earnings report released on August 4, 2026. Megapacks are large, shipping-container-sized battery units designed to store electricity at power plants and other large facilities. The spending confirms that SpaceX's battery buying has accelerated sharply since it acquired xAI, an artificial intelligence company, earlier in 2026 (TechCrunch).

The buying spans multiple quarters and companies. In the first quarter of 2026, xAI, then still a separate company, purchased $34 million worth of Tesla Megapacks. After SpaceX acquired xAI, the combined company bought an additional $269 million of Megapacks in April 2026 alone, as shown in SpaceX's IPO filing published around June 4, 2026 (Electrek). Before the merger, xAI had already spent $430 million on Tesla Megapacks for its data centers (TechCrunch).

The buying relationship extends beyond batteries. SpaceX reported that as of December 2025 it had purchased $131 million worth of Tesla Cybertrucks at full retail price, per its regulatory filing. Tesla's 2025 annual report states it recorded $285 million in revenue from xAI's purchases during that year. SpaceX bought $506 million of Tesla Megapacks in 2025, nearly triple the previous year's total (TechCrunch).

The reason AI data centers need large battery storage is practical. AI workloads draw power unevenly, with demand surging when models are being trained and dropping when they are simply answering user requests. Tesla Megapacks can deliver backup power in under a second, acting like a shock absorber that smooths out those spikes. This lowers electricity costs and prevents power surges from overwhelming on-site generators (TechCrunch).

The battery purchases sit alongside heavy use of natural gas. xAI has relied extensively on gas turbines to power its data centers, including dozens of turbines operating without permits at a site in Mississippi near its Colossus data center project. According to TechCrunch reporting, xAI has gone all in on natural gas for power, while SpaceX is focused on orbital data center concepts (TechCrunch).

The financial stakes are substantial. Google agreed to pay SpaceX $920 million per month for access to xAI's computing power, according to a report published June 5, 2026 (CNBC). SpaceX's IPO filing states that if it fails to deliver the promised computing capacity by September 30, 2026, Google can immediately cancel the agreement. The deal places a hard deadline on infrastructure readiness, and the Megapack purchases suggest SpaceX is spending aggressively to meet that power delivery requirement.

The corporate structure connecting these transactions is complex. Elon Musk is CEO and largest shareholder of SpaceX and also runs Tesla. Tesla disclosed in a January 28, 2026 shareholder letter that it invested $2 billion in xAI. xAI, which makes the Grok chatbot, had previously acquired Musk's social media platform X in 2025 before being absorbed into SpaceX in early 2026 (TechCrunch). The result is a set of interlocking transactions in which one Musk-controlled company buys hardware from another, finances a third, and absorbs a fourth.

SpaceX's IPO disclosures frame data centers as a core growth area. The company published an IPO roadshow presentation on its website that discusses data centers and cites U.S. Energy Information Agency data (SpaceX). A Japanese-language prospectus, amended June 8, 2026, references documents titled "Data Center Growth," "Special Report: Energy and AI," and "America's Power Grid." An Australian filing as part of the IPO covers energy production on the Moon and Mars, manufacturing on celestial bodies, asteroid mining, and interplanetary activities (SpaceX). An EU prospectus, approved by Germany's BaFin on June 5, 2026, describes SpaceX's business as manufacturing, testing, and launching rockets, satellites, and spacecraft (SpaceX).

Tesla's energy storage business is also hitting new records. The company achieved its highest quarterly energy storage deployments in Q4 2025, driven by record Megapack deployments, with energy storage revenue reaching $1.1 billion (Tesla IR). The SpaceX purchases, while a subset of overall Megapack demand, represent a concentrated and growing buyer channel that also happens to be controlled by Tesla's own CEO.

The broader context here is a convergence of three infrastructure-intensive businesses under overlapping ownership. SpaceX needs power for orbital ambitions and data center operations. xAI needs power for the computer clusters that train AI models. Tesla needs energy storage customers to sustain its growth. The transactions are disclosed in regulatory filings and priced at retail, which provides some transparency on pricing, though the volume concentrated in a single related-party buyer raises questions about dependency in both directions. If Google's compute agreement ends due to missed delivery deadlines, the demand for xAI's data center infrastructure, batteries included, could shift quickly.

The September 30 deadline is the pressure point. Everything else, from the gas turbines in Mississippi to the $329 million in Megapacks, is in service of meeting it.