Tesla Starts Megapack 3 Production in Texas

Tesla's first Megapack 3 has rolled off the production line at its new Megafactory in Brookshire, Texas, marking the start of initial production at the site.

The factory is designed for 50 GWh of annual capacity, representing a significant expansion of Tesla’s utility-scale energy storage manufacturing footprint. Each Megapack 3 provides approximately 5 MWh of AC energy, while four units can be integrated with a transformer and switchgear to form a 20 MWh Megablock.

Compared with the previous generation, Megapack 3 features a substantially simplified thermal system, with 78% fewer connections. Tesla also states that the Megablock platform can reduce installation time by 23% and construction costs by up to 40%.

Battery cell and supply-chain perspective: Megapack 3 adopts a new 2.8-liter large-format LFP cell platform, with cell supply spanning the United States, Southeast Asia and China. Tesla has not publicly disclosed the nominal Ah capacity of the new cell. However, based on market checks, the platform is moving into the 356 Ah cell class.

Chinese battery manufacturers are expected to remain central to Tesla’s near-term energy-storage supply chain. CATL has been reported as Tesla’s largest energy-storage battery supplier, while BYD and EVE Energy have also joined its supplier pool. At the same time, Tesla is accelerating localization through its Nevada LFP production line and its future U.S. supply agreement with LG Energy Solution.

Market Comment: The launch of Megapack 3 production is more than a manufacturing milestone. It reflects Tesla’s transition toward the 5 MWh product standard, larger-format LFP cells and a geographically diversified supply chain. Chinese cell manufacturers remain strategically important, although Tesla’s sourcing structure is becoming increasingly regionalized.