Eos Energy Enterprises, Inc.

Item 2.02 Results of Operations and Financial Condition. On July 15, 2026, the Company issued a press release providing its preliminary results for the quarter ended June 30, 2026 and certain other business updates. A copy of the press release is furnished herewith as Exhibit 99.1. The information furnished under this Item 2.02 and in the accompanying Exhibit 99.1 shall not be deemed “filed” for purposes of Section 18 of the Securities Exchange Act of 1934, as amended (the “Exchange Act”), or incorporated by reference in any filing under the Securities Act of 1933, as amended, or the Exchange Act regardless of any general incorporation language in such filing, unless expressly incorporated by specific reference in such filing.

Item 7.01 Regulation FD Disclosure.

Item 8.01 Other Events. Based on preliminary financial information, Eos currently expects: • Revenue of $68 million to $69 million for the three-month period ended June 30, 2026, driven by a more than three-fold increase in shipments compared to the prior-year period. • Gross margin loss between 69% and 73%, for the three-month period ended June 30, 2026 reflecting continued progress in manufacturing scale and operational execution. The second quarter marked the Company's transition to operating two commercial production lines across two manufacturing facilities. Battery Line 2 commenced commercial production in late June and has delivered strong initial results, with yield performance and cycle times exceeding those already achieved on Battery Line 1. While start-up costs and lower initial production volumes are expected to create near-term cost absorption pressure, as is typical during the early stages of a production ramp-up, the expansion significantly increases capacity and establishes the foundation for stronger unit economics and expected margin improvement over time. • Total Cash, including restricted cash, of approximately $364 million as of June 30, 2026. These preliminary results for the second quarter ended June 30, 2026 are preliminary and estimated based on the information available to us at this time, and should not be viewed as a substitute for our interim unaudited condensed consolidated financial statements prepared in accordance with GAAP. Actual financial results for the second quarter ended June 30, 2026, may differ materially from the preliminary financial results. Accordingly, you should not place undue reliance on these preliminary results. The preliminary results for the second quarter ended June 30, 2026 have been prepared by and are the responsibility of management. Neither our independent registered public accounting firm, nor any other independent accountants, have audited, reviewed, compiled or performed any procedures with respect to the preliminary results, nor have they expressed any opinion or any other form of assurance with respect thereto.