<SEC-DOCUMENT>0001628280-21-008369.txt : 20210430
<SEC-HEADER>0001628280-21-008369.hdr.sgml : 20210430
<ACCEPTANCE-DATETIME>20210430113358
ACCESSION NUMBER:		0001628280-21-008369
CONFORMED SUBMISSION TYPE:	4
PUBLIC DOCUMENT COUNT:		1
CONFORMED PERIOD OF REPORT:	20210428
FILED AS OF DATE:		20210430
DATE AS OF CHANGE:		20210430

REPORTING-OWNER:	

	OWNER DATA:	
		COMPANY CONFORMED NAME:			DIMITRIEF ALEXANDER
		CENTRAL INDEX KEY:			0001614732

	FILING VALUES:
		FORM TYPE:		4
		SEC ACT:		1934 Act
		SEC FILE NUMBER:	001-39291
		FILM NUMBER:		21875180

	MAIL ADDRESS:	
		STREET 1:		GENERAL ELECTRIC COMPANY
		STREET 2:		41 FARNSWORTH STREET
		CITY:			BOSTON
		STATE:			MA
		ZIP:			02210

ISSUER:		

	COMPANY DATA:	
		COMPANY CONFORMED NAME:			Eos Energy Enterprises, Inc.
		CENTRAL INDEX KEY:			0001805077
		STANDARD INDUSTRIAL CLASSIFICATION:	MISCELLANEOUS ELECTRICAL MACHINERY, EQUIPMENT & SUPPLIES [3690]
		IRS NUMBER:				000000000
		STATE OF INCORPORATION:			DE
		FISCAL YEAR END:			1231

	BUSINESS ADDRESS:	
		STREET 1:		3920 PARK AVENUE
		CITY:			EDISON
		STATE:			NJ
		ZIP:			08820
		BUSINESS PHONE:		(732) 225-8400

	MAIL ADDRESS:	
		STREET 1:		3920 PARK AVENUE
		CITY:			EDISON
		STATE:			NJ
		ZIP:			08820

	FORMER COMPANY:	
		FORMER CONFORMED NAME:	B. Riley Principal Merger Corp. II
		DATE OF NAME CHANGE:	20200227
</SEC-HEADER>
<DOCUMENT>
<TYPE>4
<SEQUENCE>1
<FILENAME>wf-form4_161979682453797.xml
<DESCRIPTION>FORM 4
<TEXT>
<XML>
<?xml version="1.0"?>
<ownershipDocument>

    <schemaVersion>X0306</schemaVersion>

    <documentType>4</documentType>

    <periodOfReport>2021-04-28</periodOfReport>

    <notSubjectToSection16>0</notSubjectToSection16>

    <issuer>
        <issuerCik>0001805077</issuerCik>
        <issuerName>Eos Energy Enterprises, Inc.</issuerName>
        <issuerTradingSymbol>EOSE</issuerTradingSymbol>
    </issuer>

    <reportingOwner>
        <reportingOwnerId>
            <rptOwnerCik>0001614732</rptOwnerCik>
            <rptOwnerName>DIMITRIEF ALEXANDER</rptOwnerName>
        </reportingOwnerId>
        <reportingOwnerAddress>
            <rptOwnerStreet1>C/O EOS ENERGY ENTERPRISES, INC.</rptOwnerStreet1>
            <rptOwnerStreet2>3920 PARK AVENUE</rptOwnerStreet2>
            <rptOwnerCity>EDISON</rptOwnerCity>
            <rptOwnerState>NJ</rptOwnerState>
            <rptOwnerZipCode>08820</rptOwnerZipCode>
            <rptOwnerStateDescription></rptOwnerStateDescription>
        </reportingOwnerAddress>
        <reportingOwnerRelationship>
            <isDirector>1</isDirector>
            <isOfficer>0</isOfficer>
            <isTenPercentOwner>0</isTenPercentOwner>
            <isOther>0</isOther>
            <officerTitle></officerTitle>
            <otherText></otherText>
        </reportingOwnerRelationship>
    </reportingOwner>

    <nonDerivativeTable></nonDerivativeTable>

    <derivativeTable>
        <derivativeTransaction>
            <securityTitle>
                <value>Stock Option (Right to Buy)</value>
            </securityTitle>
            <conversionOrExercisePrice>
                <value>14.28</value>
            </conversionOrExercisePrice>
            <transactionDate>
                <value>2021-04-28</value>
            </transactionDate>
            <transactionCoding>
                <transactionFormType>4</transactionFormType>
                <transactionCode>A</transactionCode>
                <equitySwapInvolved>0</equitySwapInvolved>
            </transactionCoding>
            <transactionAmounts>
                <transactionShares>
                    <value>4737</value>
                </transactionShares>
                <transactionPricePerShare>
                    <value>14.28</value>
                    <footnoteId id="F1"/>
                </transactionPricePerShare>
                <transactionAcquiredDisposedCode>
                    <value>A</value>
                </transactionAcquiredDisposedCode>
            </transactionAmounts>
            <exerciseDate>
                <footnoteId id="F1"/>
            </exerciseDate>
            <expirationDate>
                <value>2026-04-28</value>
            </expirationDate>
            <underlyingSecurity>
                <underlyingSecurityTitle>
                    <value>Common Stock</value>
                </underlyingSecurityTitle>
                <underlyingSecurityShares>
                    <value>4737.0</value>
                </underlyingSecurityShares>
            </underlyingSecurity>
            <postTransactionAmounts>
                <sharesOwnedFollowingTransaction>
                    <value>4737</value>
                </sharesOwnedFollowingTransaction>
            </postTransactionAmounts>
            <ownershipNature>
                <directOrIndirectOwnership>
                    <value>D</value>
                </directOrIndirectOwnership>
            </ownershipNature>
        </derivativeTransaction>
    </derivativeTable>

    <footnotes>
        <footnote id="F1">(1)This option was granted on April 28, 2021 as an option to purchase 4,737 shares of the Issuer's common stock under the Issuer's 2020 Incentive Plan (the &quot;Plan&quot;) at an exercise price of $14.28 per share.  The option shall fully vest on the earlier of (i) the first anniversary of the Grant Date or (ii) immediately prior to the Issuer's next annual shareholders meeting following the Grant Date; provided, that, the option shall vest in full upon the consummation of a Change in Control.</footnote>
    </footnotes>

    <remarks></remarks>

    <ownerSignature>
        <signatureName>/s/ Sagar Kurada as attorney-in-fact for Alexander Dimitrief</signatureName>
        <signatureDate>2021-04-30</signatureDate>
    </ownerSignature>
</ownershipDocument>
</XML>
</TEXT>
</DOCUMENT>
</SEC-DOCUMENT>
