United States securities and exchange commission logo March 11, 2021 Sagar Kurada Chief Financial Officer Eos Energy Enterprises, Inc. 3920 Park Avenue Edison, New Jersey 08820 Re: Eos Energy Enterprises, Inc. Form S-1 filed March 8, 2021 File No. 333-254001 Dear Mr. Kurada: This is to advise you that we have not reviewed and will not review your registration statement. Please refer to Rules 460 and 461 regarding requests for acceleration. We remind you that the company and its management are responsible for the accuracy and adequacy of their disclosures, notwithstanding any review, comments, action or absence of action by the staff. Please contact Charles Eastman, Staff Accountant, at (202) 551-3794 with any questions. Sincerely, Division of Corporation Finance Office of Manufacturing