v3.26.1
Cover - shares
3 Months Ended
Mar. 31, 2026
May 11, 2026
Cover [Abstract]    
Document Type 10-Q  
Document Quarterly Report true  
Document Period End Date Mar. 31, 2026  
Document Transition Report false  
Entity File Number 001-39291  
Entity Registrant Name EOS ENERGY ENTERPRISES, INC.  
Entity Incorporation, State or Country Code DE  
Entity Tax Identification Number 84-4290188  
Entity Address, Address Line One 3920 Park Avenue  
Entity Address, City or Town Edison  
Entity Address, State or Province NJ  
Entity Address, Postal Zip Code 08820  
City Area Code 732  
Local Phone Number 225-8400  
Title of 12(b) Security Common stock, par value $0.0001 per share  
Trading Symbol EOSE  
Security Exchange Name NASDAQ  
Entity Current Reporting Status Yes  
Entity Interactive Data Current Yes  
Entity Filer Category Non-accelerated Filer  
Entity Small Business false  
Entity Emerging Growth Company false  
Entity Shell Company false  
Entity Common Stock, Shares Outstanding (in shares)   339,514,027
Entity Central Index Key 0001805077  
Amendment Flag false  
Current Fiscal Year End Date --12-31  
Document Fiscal Period Focus Q1  
Document Fiscal Year Focus 2026