Tesla is locking down battery supply for its fast-growing energy storage business. The company announced on March 17 that it will purchase $4.3 billion in lithium iron phosphate (LFP) cells from LG Energy Solution, manufactured at a sprawling plant in Lansing, Michigan that LG took full ownership of after General Motors walked away from their joint venture in late 2024. The deal was revealed during the Indo-Pacific Energy Security Summit in Japan, where the Trump administration showcased $56 billion in private sector energy commitments. For Tesla, the agreement secures a dedicated domestic cell supply for its Megapack 3 utility-scale storage systems, which begin production at the company's Houston Megafactory later this year. For LG, the partnership gives new purpose to a 2.8-million-square-foot facility that sat largely idle after GM pulled out. The plant will now house dedicated LFP production lines, with cell shipments starting in 2027. AI-generated image The Lansing, Michigan plant will produce LFP prismatic cells for Tesla's Megapack 3 systems From GM's Exit to Tesla's Front Door The Lansing facility has had a turbulent history. GM and LG Energy Solution announced the plant in January 2022 as the third factory under their Ultium Cells joint venture, committing $2.6 billion to build it on GM-leased land in Delta Township. The U.S. Department of Energy backed the project with a $2.5 billion loan that covered all three Ultium plants. Construction peaked in 2024 with 1,700 union workers on site. But by December of that year, GM reached a non-binding agreement to sell its stake to LG as part of a broader retreat from electric vehicle investments. The automaker eventually took $7.6 billion in EV-related write-downs. LG completed the acquisition in early 2025 for roughly $2 billion. The plant sat mostly finished but underutilized, with production delayed by weak EV demand and shifting U.S. subsidy rules. LG retooled the facility for prismatic LFP cells, a departure from the original pouch-format Ultium design, and began searching for a customer large enough to fill the capacity. AI-generated image The deal was announced during the Indo-Pacific Energy Security Summit in Japan Tesla turned out to be that customer. The $4.3 billion figure reportedly matches the unnamed deal LG disclosed last year when it confirmed the LFP retooling. An LG spokesperson said the company "will establish dedicated production lines at our Lansing facility to deliver on this agreement." Why LFP, and Why Now Lithium iron phosphate chemistry has become the default for stationary energy storage. LFP cells contain no cobalt or nickel, which cuts raw material costs and simplifies the supply chain. They tolerate more charge cycles than NMC alternatives (often exceeding 10,000 full cycles), and their thermal stability reduces fire risk in dense utility installations. Tesla has used LFP in its Megapack line for years, sourcing cells primarily from CATL. The LG partnership diversifies that supply with a domestic manufacturer, reducing exposure to tariffs and shipping delays on Chinese-made cells. Tesla's CFO Vaibhav Taneja warned in January of "margin compression" from low-cost competition and tariff costs in the energy segment, making a U.S.-based supply chain more attractive. The new cells will use a larger 2.8-liter prismatic format that LG developed specifically for grid-scale applications. Bigger cells mean fewer connections per pack, simpler thermal management, and lower assembly costs at the system level. AI-generated image LFP prismatic cells on an automated production line Megapack 3: The Product Behind the Purchase Tesla unveiled the Megapack 3 in September 2025 as a major upgrade to its utility-scale storage platform. Each unit holds roughly 5 MWh of usable energy, up from 3.9 MWh in the Megapack 2. The company also introduced the Megablock, which bundles four Megapack 3 units with an integrated transformer into a single 20 MWh system. Specifications released so far point to over 10,000 cycle life, 91% round-trip efficiency, and operation from minus 40 to 60 degrees Celsius. Tesla says the simplified design allows 23% faster installation compared to the previous generation. The Houston Megafactory, where Megapack 3 systems will be assembled, is designed for up to 50 GWh of annual production capacity. At 5 MWh per unit, that translates to 10,000 Megapack 3 units per year at full throughput. AI-generated image Tesla Megapack 3 units at a utility-scale solar installation Tesla's energy business generated $12.8 billion in revenue last year, a 27% increase that made it the company's only growing segment as automotive revenue fell 10%. CEO Elon Musk told investors in January that the energy division would "have very high growth for as far into the future as we can imagine." The data center boom is a central driver: hyperscale operators like Google, Microsoft, and Amazon are all contracting battery storage to backstop power-hungry AI infrastructure. LG's Energy Storage Ambitions The Tesla deal fits neatly into LG Energy Solution's strategic pivot. The company expects to book 90 GWh of new grid-scale and energy storage system orders in 2026, and plans to expand production capacity past 60 GWh this year. More than 80% of that ESS capacity will sit in North America. LG has been reshuffling its customer base. Ford cancelled a $6.5 billion battery supply contract with the company in late 2025 as the automaker pulled back from EVs. Meanwhile, Mercedes-Benz signed an $11 billion multi-year deal for EV cells. The Tesla agreement now gives LG a major anchor customer on the storage side, balancing its portfolio between automotive and grid applications. Beyond Lansing, LG maintains significant manufacturing in Michigan. The company has invested over $3 billion in its Holland, Michigan operations, and continues to expand capacity there. The Competitive Picture Tesla is not the only company chasing utility-scale storage contracts. CATL, BYD, Samsung SDI, and a growing roster of Chinese manufacturers all compete aggressively on price. Samsung SDI announced its own $1 billion U.S. ESS cell supply deal this week. Canadian Solar's e-STORAGE division secured a 2.5 GWh contract for U.S. data center support on the same day. Newer entrants are targeting different chemistries entirely. Form Energy is building iron-air batteries that store energy for 100+ hours at a fraction of lithium-ion's cost per kilowatt-hour. Google recently backed a 30 GWh Form Energy project in Minnesota, the largest storage installation ever announced. The sheer scale of demand, however, suggests room for multiple winners. The SEIA projects 70 GWh of new U.S. battery storage deployments in 2026 alone. Data centers, grid modernization, and renewable energy integration are all pulling in the same direction. The question for Tesla is whether domestic LFP production can keep its costs competitive with Chinese imports while maintaining the margins investors expect. AI-generated image Data centers are driving unprecedented demand for utility-scale battery storage What Comes Next LG plans to have the Lansing production lines operational in 2027, feeding cells to Tesla's Houston assembly operation. Between now and then, Tesla will continue sourcing from existing suppliers, primarily CATL, while ramping Megapack 3 production with available inventory. The deal carries broader implications for U.S. battery manufacturing. A plant originally built for EV cells that GM no longer needed has found a second life in energy storage, a segment growing faster than anyone projected two years ago. If the pattern holds, other idled or underutilized EV battery facilities may follow a similar path, repurposed to serve a grid that can't build storage fast enough. For the workers of Lansing, Michigan, the result is the same either way: jobs building battery cells. The customer and chemistry have changed, but the factory floor stays busy. Key Numbers $4.3B