Samsung and Tesla May Have Struck Agreement on ESS Battery Supply

Samsung SDI and Tesla may have reached an agreement to supply batteries for energy storage systems (ESS) in the United States. If true, the Korean battery maker will play a big role in boosting Tesla’s ESS operations. However, details of the contract, such as its value and duration, remain under wraps.

Samsung SDI makes prismatic LFP cells for ESS

According to a report from TheElec, Samsung SDI recently announced it finalized a large-scale battery supply contract in the United States. While the company did not disclose the client’s name or other contract details, it cited business confidentiality as the reason for withholding them until January 1, 2030.

“This announcement was made because the contract was finalized regarding an issue that was previously disclosed in November of last year,” said a Samsung SDI official. “We cannot disclose the specific contracting party, contract amount, or contract period.”

In November 2025, a report suggested that Samsung SDI was in talks with Tesla over the supply of lithium iron phosphate (LFP) batteries for energy storage. Tesla was reportedly seeking alternative suppliers to reduce its dependence on Chinese battery makers such as CATL (for prismatic LFP batteries in its ESS products).

Tesla’s prismatic LFP battery production line at the Nevada facility has an annual capacity of around 10 GWh. However, if production efficiency fails to reach targeted levels, the company may need more external suppliers (beyond CATL ), and Samsung SDI could be a solid candidate to fill that role. All these points that the two companies may have now inked a deal.

Meanwhile, Samsung SDI continues to expand its production base for prismatic batteries for ESS in the United States. The firm plans to begin phased operations of a new 24 GWh LFP battery line for ESS in Q4 2026. This expansion could help meet the increasing demand for energy storage in stateside.