<?xml version="1.0"?>
<ownershipDocument>

    <schemaVersion>X0202</schemaVersion>

    <documentType>4</documentType>

    <periodOfReport>2007-02-21</periodOfReport>

    <notSubjectToSection16>0</notSubjectToSection16>

    <issuer>
        <issuerCik>0000808064</issuerCik>
        <issuerName>C&amp;D TECHNOLOGIES INC</issuerName>
        <issuerTradingSymbol>CHP</issuerTradingSymbol>
    </issuer>

    <reportingOwner>
        <reportingOwnerId>
            <rptOwnerCik>0001358623</rptOwnerCik>
            <rptOwnerName>SCSF Equities, LLC</rptOwnerName>
        </reportingOwnerId>
        <reportingOwnerAddress>
            <rptOwnerStreet1>5200 TOWN CENTER CIRCLE, SUITE 470</rptOwnerStreet1>
            <rptOwnerStreet2></rptOwnerStreet2>
            <rptOwnerCity>BOCA RATON</rptOwnerCity>
            <rptOwnerState>FL</rptOwnerState>
            <rptOwnerZipCode>33486</rptOwnerZipCode>
            <rptOwnerStateDescription></rptOwnerStateDescription>
        </reportingOwnerAddress>
        <reportingOwnerRelationship>
            <isDirector>0</isDirector>
            <isOfficer>0</isOfficer>
            <isTenPercentOwner>1</isTenPercentOwner>
            <isOther>0</isOther>
            <officerTitle></officerTitle>
            <otherText></otherText>
        </reportingOwnerRelationship>
    </reportingOwner>

    <reportingOwner>
        <reportingOwnerId>
            <rptOwnerCik>0001344696</rptOwnerCik>
            <rptOwnerName>Sun Capital Securities Offshore Fund Ltd</rptOwnerName>
        </reportingOwnerId>
        <reportingOwnerAddress>
            <rptOwnerStreet1>5200 TOWN CENTER CIRCLE, SUITE 470</rptOwnerStreet1>
            <rptOwnerStreet2></rptOwnerStreet2>
            <rptOwnerCity>BOCA RATON</rptOwnerCity>
            <rptOwnerState>FL</rptOwnerState>
            <rptOwnerZipCode>33486</rptOwnerZipCode>
            <rptOwnerStateDescription></rptOwnerStateDescription>
        </reportingOwnerAddress>
        <reportingOwnerRelationship>
            <isDirector>0</isDirector>
            <isOfficer>0</isOfficer>
            <isTenPercentOwner>1</isTenPercentOwner>
            <isOther>0</isOther>
            <officerTitle></officerTitle>
            <otherText></otherText>
        </reportingOwnerRelationship>
    </reportingOwner>

    <reportingOwner>
        <reportingOwnerId>
            <rptOwnerCik>0001288467</rptOwnerCik>
            <rptOwnerName>SUN CAPITAL SECURITIES FUND L P</rptOwnerName>
        </reportingOwnerId>
        <reportingOwnerAddress>
            <rptOwnerStreet1>5200 TOWN CENTER CIRCLE, SUITE 470</rptOwnerStreet1>
            <rptOwnerStreet2></rptOwnerStreet2>
            <rptOwnerCity>BOCA RATON</rptOwnerCity>
            <rptOwnerState>FL</rptOwnerState>
            <rptOwnerZipCode>33486</rptOwnerZipCode>
            <rptOwnerStateDescription></rptOwnerStateDescription>
        </reportingOwnerAddress>
        <reportingOwnerRelationship>
            <isDirector>0</isDirector>
            <isOfficer>0</isOfficer>
            <isTenPercentOwner>1</isTenPercentOwner>
            <isOther>0</isOther>
            <officerTitle></officerTitle>
            <otherText></otherText>
        </reportingOwnerRelationship>
    </reportingOwner>

    <reportingOwner>
        <reportingOwnerId>
            <rptOwnerCik>0001358621</rptOwnerCik>
            <rptOwnerName>Sun Capital Securities Advisors, LP</rptOwnerName>
        </reportingOwnerId>
        <reportingOwnerAddress>
            <rptOwnerStreet1>5200 TOWN CENTER CIRCLE, SUITE 470</rptOwnerStreet1>
            <rptOwnerStreet2></rptOwnerStreet2>
            <rptOwnerCity>BOCA RATON</rptOwnerCity>
            <rptOwnerState>FL</rptOwnerState>
            <rptOwnerZipCode>33486</rptOwnerZipCode>
            <rptOwnerStateDescription></rptOwnerStateDescription>
        </reportingOwnerAddress>
        <reportingOwnerRelationship>
            <isDirector>0</isDirector>
            <isOfficer>0</isOfficer>
            <isTenPercentOwner>1</isTenPercentOwner>
            <isOther>0</isOther>
            <officerTitle></officerTitle>
            <otherText></otherText>
        </reportingOwnerRelationship>
    </reportingOwner>

    <reportingOwner>
        <reportingOwnerId>
            <rptOwnerCik>0001358622</rptOwnerCik>
            <rptOwnerName>Sun Capital Securities, LLC</rptOwnerName>
        </reportingOwnerId>
        <reportingOwnerAddress>
            <rptOwnerStreet1>5200 TOWN CENTER CIRCLE, SUITE 470</rptOwnerStreet1>
            <rptOwnerStreet2></rptOwnerStreet2>
            <rptOwnerCity>BOCA RATON</rptOwnerCity>
            <rptOwnerState>FL</rptOwnerState>
            <rptOwnerZipCode>33486</rptOwnerZipCode>
            <rptOwnerStateDescription></rptOwnerStateDescription>
        </reportingOwnerAddress>
        <reportingOwnerRelationship>
            <isDirector>0</isDirector>
            <isOfficer>0</isOfficer>
            <isTenPercentOwner>1</isTenPercentOwner>
            <isOther>0</isOther>
            <officerTitle></officerTitle>
            <otherText></otherText>
        </reportingOwnerRelationship>
    </reportingOwner>

    <reportingOwner>
        <reportingOwnerId>
            <rptOwnerCik>0001193052</rptOwnerCik>
            <rptOwnerName>LEDER MARC J</rptOwnerName>
        </reportingOwnerId>
        <reportingOwnerAddress>
            <rptOwnerStreet1>5200 TOWN CENTER CIRCLE, SUITE 470</rptOwnerStreet1>
            <rptOwnerStreet2></rptOwnerStreet2>
            <rptOwnerCity>BOCA RATON</rptOwnerCity>
            <rptOwnerState>FL</rptOwnerState>
            <rptOwnerZipCode>33486</rptOwnerZipCode>
            <rptOwnerStateDescription></rptOwnerStateDescription>
        </reportingOwnerAddress>
        <reportingOwnerRelationship>
            <isDirector>0</isDirector>
            <isOfficer>0</isOfficer>
            <isTenPercentOwner>1</isTenPercentOwner>
            <isOther>0</isOther>
            <officerTitle></officerTitle>
            <otherText></otherText>
        </reportingOwnerRelationship>
    </reportingOwner>

    <reportingOwner>
        <reportingOwnerId>
            <rptOwnerCik>0001193057</rptOwnerCik>
            <rptOwnerName>KROUSE RODGER R</rptOwnerName>
        </reportingOwnerId>
        <reportingOwnerAddress>
            <rptOwnerStreet1>5200 TOWN CENTER CIRCLE, SUITE 470</rptOwnerStreet1>
            <rptOwnerStreet2></rptOwnerStreet2>
            <rptOwnerCity>BOCA RATON</rptOwnerCity>
            <rptOwnerState>FL</rptOwnerState>
            <rptOwnerZipCode>33486</rptOwnerZipCode>
            <rptOwnerStateDescription></rptOwnerStateDescription>
        </reportingOwnerAddress>
        <reportingOwnerRelationship>
            <isDirector>0</isDirector>
            <isOfficer>0</isOfficer>
            <isTenPercentOwner>1</isTenPercentOwner>
            <isOther>0</isOther>
            <officerTitle></officerTitle>
            <otherText></otherText>
        </reportingOwnerRelationship>
    </reportingOwner>

    <nonDerivativeTable>
        <nonDerivativeTransaction>
            <securityTitle>
                <value>Common Stock, par value $0.01 per share</value>
            </securityTitle>
            <transactionDate>
                <value>2007-02-21</value>
            </transactionDate>
            <transactionCoding>
                <transactionFormType>4</transactionFormType>
                <transactionCode>J</transactionCode>
                <equitySwapInvolved>0</equitySwapInvolved>
                <footnoteId id="F1"/>
            </transactionCoding>
            <transactionAmounts>
                <transactionShares>
                    <value>1507</value>
                </transactionShares>
                <transactionPricePerShare>
                    <value>0</value>
                </transactionPricePerShare>
                <transactionAcquiredDisposedCode>
                    <value>A</value>
                </transactionAcquiredDisposedCode>
            </transactionAmounts>
            <postTransactionAmounts>
                <sharesOwnedFollowingTransaction>
                    <value>1507</value>
                </sharesOwnedFollowingTransaction>
            </postTransactionAmounts>
            <ownershipNature>
                <directOrIndirectOwnership>
                    <value>I</value>
                </directOrIndirectOwnership>
                <natureOfOwnership>
                    <value>See footnotes</value>
                    <footnoteId id="F1"/>
                    <footnoteId id="F2"/>
                    <footnoteId id="F3"/>
                </natureOfOwnership>
            </ownershipNature>
        </nonDerivativeTransaction>
        <nonDerivativeHolding>
            <securityTitle>
                <value>Common Stock, par value $0.01 per share</value>
            </securityTitle>
            <postTransactionAmounts>
                <sharesOwnedFollowingTransaction>
                    <value>3123834</value>
                </sharesOwnedFollowingTransaction>
            </postTransactionAmounts>
            <ownershipNature>
                <directOrIndirectOwnership>
                    <value>D</value>
                    <footnoteId id="F5"/>
                </directOrIndirectOwnership>
            </ownershipNature>
        </nonDerivativeHolding>
        <nonDerivativeHolding>
            <securityTitle>
                <value>Common Stock, par value $0.01 per share</value>
            </securityTitle>
            <postTransactionAmounts>
                <sharesOwnedFollowingTransaction>
                    <value>3123834</value>
                </sharesOwnedFollowingTransaction>
            </postTransactionAmounts>
            <ownershipNature>
                <directOrIndirectOwnership>
                    <value>I</value>
                </directOrIndirectOwnership>
                <natureOfOwnership>
                    <value>See footnotes</value>
                    <footnoteId id="F2"/>
                    <footnoteId id="F3"/>
                </natureOfOwnership>
            </ownershipNature>
        </nonDerivativeHolding>
    </nonDerivativeTable>

    <derivativeTable>
        <derivativeTransaction>
            <securityTitle>
                <value>Stock Option (Right to Buy)</value>
            </securityTitle>
            <conversionOrExercisePrice>
                <value>5.53</value>
            </conversionOrExercisePrice>
            <transactionDate>
                <value>2007-02-21</value>
            </transactionDate>
            <transactionCoding>
                <transactionFormType>4</transactionFormType>
                <transactionCode>J</transactionCode>
                <equitySwapInvolved>0</equitySwapInvolved>
                <footnoteId id="F4"/>
            </transactionCoding>
            <transactionAmounts>
                <transactionShares>
                    <value>1334</value>
                </transactionShares>
                <transactionPricePerShare>
                    <value>5.53</value>
                </transactionPricePerShare>
                <transactionAcquiredDisposedCode>
                    <value>A</value>
                </transactionAcquiredDisposedCode>
            </transactionAmounts>
            <exerciseDate>
                <value>2007-02-01</value>
            </exerciseDate>
            <expirationDate>
                <value>2017-02-01</value>
            </expirationDate>
            <underlyingSecurity>
                <underlyingSecurityTitle>
                    <value>Common Stock</value>
                </underlyingSecurityTitle>
                <underlyingSecurityShares>
                    <value>1334</value>
                </underlyingSecurityShares>
            </underlyingSecurity>
            <postTransactionAmounts>
                <sharesOwnedFollowingTransaction>
                    <value>1334</value>
                </sharesOwnedFollowingTransaction>
            </postTransactionAmounts>
            <ownershipNature>
                <directOrIndirectOwnership>
                    <value>I</value>
                </directOrIndirectOwnership>
                <natureOfOwnership>
                    <value>See footnotes</value>
                    <footnoteId id="F2"/>
                    <footnoteId id="F3"/>
                    <footnoteId id="F4"/>
                </natureOfOwnership>
            </ownershipNature>
        </derivativeTransaction>
    </derivativeTable>

    <footnotes>
        <footnote id="F1">The shares of common stock were granted to Michael H. Kalb (&quot;Kalb&quot;), a Vice President of SCSF Equities, LLC, a Delaware limited liability company (&quot;SCSF Equities&quot;), in his capacity as a director of the Issuer. Pursuant to an agreement between Kalb and SCSF Equities dated February 21, 2007 (the &quot;Agreement&quot;), Kalb holds such shares of common stock for the sole benefit of SCSF Equities and, upon the sale of such shares of common stock (at Kalb's sole discretion), all net after-tax cash proceeds received by Kalb therefrom (if any) promptly shall be remitted by Kalb to SCSF Equities. SCSF Equities may, therefore, be deemed the indirect beneficial owner of all such shares of common stock.</footnote>
        <footnote id="F2">Such securities may also be deemed to be indirectly beneficially owned by Sun Capital Securities Offshore Fund, Ltd., a Cayman Islands corporation (&quot;Sun Offshore Fund&quot;), Sun Capital Securities Fund, LP, a Delaware limited partnership (&quot;Sun Securities Fund&quot;), Sun Capital Securities Advisors, LP, a Delaware limited partnership (&quot;Sun Advisors&quot;), Sun Capital Securities, LLC, a Delaware limited liability company (&quot;Sun Capital Securities&quot;), Marc J. Leder (&quot;Leder&quot;) and Rodger R. Krouse (&quot;Krouse&quot;). Leder and Krouse may each be deemed to control SCSF Equities, Sun Securities Fund and Sun Advisors, as Leder and Krouse each own 50% of the membership interests in Sun Capital Securities, which in turn is the general partner of Sun Advisors, which in turn is the general partner of Sun Securities Fund. Sun Offshore Fund owns a majority of the membership interests in SCSF Equities.</footnote>
        <footnote id="F3">Leder and Krouse may each be deemed to control the Sun Offshore Fund by virtue of their being the only directors of the Sun Offshore Fund. Sun Securities Fund, Sun Advisors, Sun Capital Securities, Leder and Krouse expressly disclaim beneficial ownership of such securities, except to the extent of any pecuniary interest therein. The filing of this form shall not be deemed an admission that any of Sun Offshore Fund, Sun Securities Fund, Sun Advisors, Sun Capital Securities, Leder or Krouse is, for Section 16 purposes or otherwise, the beneficial owner of such securities.</footnote>
        <footnote id="F4">The options were granted to Kalb, a Vice President of SCSF Equities, in his capacity as a director of the Issuer. Pursuant to the Agreement, Kalb holds all such stock options for the sole benefit of SCSF Equities and, upon the sale of the shares of common stock issued upon exercise of such reported options (at Kalb's sole discretion), all net after-tax cash proceeds received by Kalb therefrom (if any) promptly shall be remitted by Kalb to SCSF Equities. SCSF Equities may, therefore, be deemed the indirect beneficial owner of all such reported options.</footnote>
        <footnote id="F5">SCSF Equities is the direct beneficial owner of such shares of common stock.</footnote>
    </footnotes>

    <ownerSignature>
        <signatureName>SCSF EQUITIES, LLC, By: /s/ Marc J. Leder, its Co-CEO</signatureName>
        <signatureDate>2007-02-21</signatureDate>
    </ownerSignature>

    <ownerSignature>
        <signatureName>SUN CAPITAL SECURITIES OFFSHORE FUND, LTD., By: /s/ Marc J. Leder, its Director</signatureName>
        <signatureDate>2007-02-21</signatureDate>
    </ownerSignature>

    <ownerSignature>
        <signatureName>SUN CAPITAL SECURITIES FUND, LP, By: Sun Capital Securities Advisors, LP, Its: General Partner, By: Sun Capital Securities, LLC, Its: General Partner, By: /s/ Marc J. Leder, its Co-CEO</signatureName>
        <signatureDate>2007-02-21</signatureDate>
    </ownerSignature>

    <ownerSignature>
        <signatureName>SUN CAPITAL SECURITIES ADVISORS, LP, By: Sun Capital Securities, LLC, Its: General Partner, By: /s/ Marc J. Leder, its Co-CEO</signatureName>
        <signatureDate>2007-02-21</signatureDate>
    </ownerSignature>

    <ownerSignature>
        <signatureName>SUN CAPITAL SECURITIES, LLC, By: /s/ Marc J. Leder, its Co-CEO</signatureName>
        <signatureDate>2007-02-21</signatureDate>
    </ownerSignature>

    <ownerSignature>
        <signatureName>/s/ Marc J. Leder</signatureName>
        <signatureDate>2007-02-21</signatureDate>
    </ownerSignature>

    <ownerSignature>
        <signatureName>/s/ Rodger R. Krouse</signatureName>
        <signatureDate>2007-02-21</signatureDate>
    </ownerSignature>
</ownershipDocument>
