SECURITIES AND EXCHANGE COMMISSION
                             WASHINGTON, D.C. 20549

                                  Schedule 13G

                    Under the Securities Exchange Act of 1934

                                     EnerSys
                                (Name of Issuer)

                                  Common Stock
                         (Title of Class of Securities)

                                    29275Y102
                                 (CUSIP Number)

                                December 31, 2006
             (Date of Event Which Requires Filing of this Statement)

Check the appropriate box to designate the rule pursuant to which this Schedule
is filed:

                                [X] Rule 13d-1(b)
                                [ ] Rule 13d-1(c)
                                [ ] Rule 13d-1(d)





CUSIP No. ............................................................29275Y102

1)  Name of Reporting Person.......................Lehman Brothers Holdings Inc.

     S.S. or I.R.S. Identification No. of Above Person................13-3216325

2)   Check the Appropriate Box if a Member of a Group.................(a)  [   ]
                                                                      (b)  [   ]
3)   SEC Use Only

4)   Citizenship or Place of Organization...............................Delaware

Number of Shares Beneficially Owned by Each Reporting Person With:

5)   Sole Voting Power.................................................2,655,496

6)   Shared Voting Power.....................................................-0-

7)   Sole Dispositive Power............................................2,655,496

8)   Shared Dispositive Power................................................-0-

9)   Aggregate Amount Beneficially Owned by Each Reporting Person......2,655,496

10)  Check if the Aggregate Amount in Row (9) Excludes Certain Shares......[   ]

11)  Percent of Class Represented by Amount in Row 9.....................5.7%(1)

12)  Type of Reporting Person.................................................HC

(1) Based on 46,869,295 shares of Common Stock outstanding as of
November 3, 2006 as reported on Form 10-Q filed by the Issuer on
November 8, 2006.

CUSIP No. ............................................................29275Y102

1)  Name of Reporting Person................................Lehman Brothers Inc.

     S.S. or I.R.S. Identification No. of Above Person................13-2518466

2)   Check the Appropriate Box if a Member of a Group.................(a)  [   ]
                                                                      (b)  [   ]
3)   SEC Use Only

4)   Citizenship or Place of Organization...............................Delaware

Number of Shares Beneficially Owned by Each Reporting Person With:

5)   Sole Voting Power.................................................2,655,496

6)   Shared Voting Power.....................................................-0-

7)   Sole Dispositive Power............................................2,655,496

8)   Shared Dispositive Power................................................-0-

9)   Aggregate Amount Beneficially Owned by Each Reporting Person......2,655,496

10)  Check if the Aggregate Amount in Row (9) Excludes Certain Shares......[   ]

11)  Percent of Class Represented by Amount in Row 9.....................5.7%(1)

12)  Type of Reporting Person.................................................BD


(1) Based on 46,869,295 shares of Common Stock outstanding as of
November 3, 2006 as reported on Form 10-Q filed by the Issuer on
November 8, 2006.


Item 1(a).        Name of Issuer:

                  Enersys

Item 1(b).        Address of Issuer's Principal Executive Offices:

                  2366 Bernville Road
                  Reading PA 19605


Item 2(a).        Name of Person(s) Filing:

                  Lehman Brothers Holdings Inc.
                  Lehman Brothers Inc.


Item 2(b).        Address of Principal Business Office:

                  Lehman Brothers Holdings Inc.
                  745 Seventh Avenue
                  New York, New York 10019

                  Lehman Brothers Inc.
                  745 Seventh Avenue
                  New York, New York 10019



Item 2(c).        Citizenship or Place of Organization:

                  Lehman Brothers Holdings Inc. ("Holdings") is a corporation
                  organized under the laws of the State of Delaware.

                  Lehman Brothers Inc. ("LBI") is a corporation organized under
                  the laws of the State of Delaware.


Item 2(d).        Title of Class of Securities:

                  Common Stock

Item 2(e).        CUSIP Number:

                  29275Y102

Item 3.  If this statement is filed pursuant to Rules 13d-1(b) or 13d-2(b) or
         (c), check whether the person filing is a:

              (a) [   ]    A broker or dealer under Section 15 of the 1934 Act
              (b) [   ]    A bank as defined in Section 3(a)(6) of the 1934 Act
              (c) [   ]    An insurance company as defined in Section 3(a)(19)
                           of the 1934 Act
              (d) [   ]    An investment company registered under Section 8 of
                           the Investment Company Act of 1940
              (e) [   ]    An investment advisor in accordance with Rule
                           13d-1(b)(1)(ii)(E)
              (f) [   ]    An employee benefit plan or endowment fund in
                           accordance with Rule 13d-1(b)(1)(ii)(F)
              (g) [ X ]    A parent holding company or control person in
                           accordance with Rule 13d-1(b)(1)(ii)(G)
              (h) [   ]    A savings association as defined in Section 3(b) of
                           the Federal Deposit Insurance Act
              (i) [   ]    A church plan that is excluded from the definition of
                           investment company under Section 3(c)(14)Of the
                           Investment Company Act of 1940
              (j) [   ]    A group, in accordance with Rule 13d-1(b)(1)(ii)(J)


Item 4.       Ownership

(a)      Amount Beneficially Owned

         See Item 9 of cover page.

(b)      Percent of Class:

         See Item 11 of cover page.

(c)      Number of shares as to which the person has:

         (i)      sole power to vote or to direct the vote
         (ii)     shared power to vote or to direct the vote
         (iii)    sole power to dispose or to direct the disposition
         (iv)     shared power to dispose or to direct the disposition

                  See Items 5-8 of cover page.

Item 5.       Ownership of Five Percent or Less of a Class

                  If this statement is being filed to report the fact that as
                  of the date hereof the reporting  person has ceased to be
                  the beneficial owner of more than five percent of the class of
                  securities, check the following [  ].

Item 6.       Ownership of More than Five Percent on Behalf of Another Person

                  Not Applicable

Item 7.       Identification and Classification of the Subsidiary which Acquired
              the Security being Reported on by the Parent Holding
              Company or Control Person

                  LBI, a Broker-Dealer registered under Section 15 of the
                  1934 Act, is a wholly-owned subsidiary of Holdings.

                  LBI is the actual owner of all of the shares of Common Stock
                  reported herein.

                  Under  the rules  and  regulations  of the  Securities  and
                  Exchange  Commission,  Holdings  may be deemed to be the
                  beneficial owner of the shares of Common Stock owned by LBI.

Item 8.       Identification and Classification of Members of the Group

                  Not Applicable

Item 9.       Notice of Dissolution of Group

                  Not Applicable


Item 10.      Certification

[X]  By signing  below I certify  that,  to the best of my knowledge and belief,
     the  securities  referred to above were  acquired and are held in the
     ordinary  course of  business  and were not  acquired  and are not held for
     the purpose of or with the effect of changing or influencing  the control
     of the issuer of the securities and were not acquired and are not held in
     connection with or as a participant in any transaction having that purpose
     or effect.

[ ]  By signing  below I hereby  certify  that,  to the best of my knowledge
     and belief,  the  securities  referred to above were not acquired  and are
     not held for the  purpose of or with the effect of  changing  or
     influencing  the control of the issuer of the securities and were not
     acquired and are not held in connection with or as a participant in any
     transaction  having that purpose or effect.

After  reasonable  inquiry and to the best of the  undersigned's  knowledge  and
belief,  the  undersigned  hereby  certifies  that the information set forth in
this statement is true, complete and correct.

Dated: February 9, 2007

LEHMAN BROTHERS HOLDINGS INC.


By:   /s/ Rashid Alvi
      Name:  Rashid Alvi
      Title: Vice President

LEHMAN BROTHERS INC.


By:   /s/ Rashid Alvi
      Name: Rashid Alvi
      Title:Vice President




                       EXHIBIT A - JOINT FILING AGREEMENT

         The undersigned hereby agree that the Statement on Schedule 13G filed
herewith (and any amendments thereto), is being filed jointly with the
Securities and Exchange Commission pursuant to Rule 13d-1(k) (1) under the
Securities Exchange Act of 1934, as amended, on behalf of each such person.

Dated: February 9, 2007

LEHMAN BROTHERS HOLDINGS INC.


By:   /s/ Rashid Alvi
      Name:  Rashid Alvi
      Title: Vice President

LEHMAN BROTHERS INC.


By:   /s/ Rashid Alvi
      Name: Rashid Alvi
      Title:Vice President