Tesla is rolling out updates to its utility-scale battery lineup with the launch of Megapack 3 and Megablock, aiming to revitalize its struggling energy-storage business.
Revealed Monday, Megapack 3 boosts capacity by around 1 megawatt-hour over Tesla’s largest current model, while also promising improved longevity. Tesla also unveiled Megablock, a four-unit grouping of Megapack 3s that delivers 20 megawatt-hours, enough to power 4,000 homes for four hours. The bundled design is expected to cut installation time by 23% and slash construction time by up to 40%.
The new thermal management system allows operation from –40°F to 140°F, broadening use across climates. Manufacturing will take place at Tesla’s new Megafactory near Houston, with production slated for late 2026. The site will be capable of producing up to 50 gigawatt-hours annually.
The update comes as Tesla’s energy-storage sales slide, logging two consecutive quarters of decline despite the industry’s broader growth. In 2024, Tesla led the global market for stationary storage, but its edge has since narrowed, per Wood Mackenzie.
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Tesla has at least one built-in customer: Musk’s AI company, xAI, which has installed 168 Megapacks at its South Memphis data center. Still, the firm is reportedly weighing gas turbines for additional capacity.
With Megapack 3 and Megablock, Tesla is betting it can win back utilities and data center developers increasingly hungry for reliable large-scale storage.
