UNITED STATES
                       SECURITIES AND EXCHANGE COMMISSION
                              WASHINGTON, DC 20549

                                  SCHEDULE 13G

                    Under the Securities Exchange Act of 1934
                                (Amendment No. 1)


                               Active Power, Inc.
- --------------------------------------------------------------------------------
                                (Name of Issuer)


                         Common Stock, par value $0.001
- --------------------------------------------------------------------------------
                         (Title of Class of Securities)


                                    00504W100
- --------------------------------------------------------------------------------
                                 (CUSIP Number)


                                 August 1, 2009
- --------------------------------------------------------------------------------
             (Date of Event Which Requires Filing of this Statement)


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

          [_]  Rule 13d-1(b)

          [X]  Rule 13d-1(c)

          [_]  Rule 13d-1(d)



CUSIP No. 00504W100
- ---------------------

1.   NAME OF REPORTING PERSONS
     I.R.S. IDENTIFICATION NOS. OF ABOVE PERSONS (ENTITIES ONLY)

     Stephen J. Clearman

2.   CHECK THE APPROPRIATE BOX IF A MEMBER OF A GROUP (SEE INSTRUCTIONS)
                                                                 (a)  [_]
                                                                 (b)  [X]

3.   SEC USE ONLY



4.   CITIZENSHIP OR PLACE OF ORGANIZATION

     United States of America

NUMBER OF SHARES BENEFICIALLY OWNED BY EACH REPORTING PERSON WITH

5.   SOLE VOTING POWER

     0

6.   SHARED VOTING POWER

     6,000,000

7.   SOLE DISPOSITIVE POWER

     0

8.   SHARED DISPOSITIVE POWER

     6,000,000

9.   AGGREGATE AMOUNT BENEFICIALLY OWNED BY EACH REPORTING PERSON

     6,000,000

10.  CHECK BOX IF THE AGGREGATE AMOUNT IN ROW (9) EXCLUDES CERTAIN
     SHARES (SEE INSTRUCTIONS)

                                                                      [_]

11.  PERCENT OF CLASS REPRESENTED BY AMOUNT IN ROW 9

     9.0%

12.  TYPE OF REPORTING PERSON (SEE INSTRUCTIONS)

     IN


CUSIP No. 00504W100
- ---------------------

1.   NAME OF REPORTING PERSONS
     I.R.S. IDENTIFICATION NOS. OF ABOVE PERSONS (ENTITIES ONLY)

     Tushar Shah

2.   CHECK THE APPROPRIATE BOX IF A MEMBER OF A GROUP (SEE INSTRUCTIONS)
                                                                 (a)  [_]
                                                                 (b)  [X]

3.   SEC USE ONLY



4.   CITIZENSHIP OR PLACE OF ORGANIZATION

     United States of America

NUMBER OF SHARES BENEFICIALLY OWNED BY EACH REPORTING PERSON WITH

5.   SOLE VOTING POWER

     0

6.   SHARED VOTING POWER

     6,000,000

7.   SOLE DISPOSITIVE POWER

     0

8.   SHARED DISPOSITIVE POWER

     6,000,000

9.   AGGREGATE AMOUNT BENEFICIALLY OWNED BY EACH REPORTING PERSON

     6,000,000

10.  CHECK BOX IF THE AGGREGATE AMOUNT IN ROW (9) EXCLUDES CERTAIN
     SHARES (SEE INSTRUCTIONS)

                                                                      [_]

11.  PERCENT OF CLASS REPRESENTED BY AMOUNT IN ROW 9

     9.0%

12.  TYPE OF REPORTING PERSON (SEE INSTRUCTIONS)

     IN



CUSIP No. 00504W100
- ---------------------

1.   NAME OF REPORTING PERSONS
     I.R.S. IDENTIFICATION NOS. OF ABOVE PERSONS (ENTITIES ONLY)

     Kinderhook GP, LLC

2.   CHECK THE APPROPRIATE BOX IF A MEMBER OF A GROUP (SEE INSTRUCTIONS)
                                                                 (a)  [_]
                                                                 (b)  [X]

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

     0

6.   SHARED VOTING POWER

     6,000,000

7.   SOLE DISPOSITIVE POWER

     0

8.   SHARED DISPOSITIVE POWER

     6,000,000

9.   AGGREGATE AMOUNT BENEFICIALLY OWNED BY EACH REPORTING PERSON

     6,000,000

10.  CHECK BOX IF THE AGGREGATE AMOUNT IN ROW (9) EXCLUDES CERTAIN
     SHARES (SEE INSTRUCTIONS)

                                                                      [_]

11.  PERCENT OF CLASS REPRESENTED BY AMOUNT IN ROW 9

     9.0%

12.  TYPE OF REPORTING PERSON (SEE INSTRUCTIONS)

     OO


CUSIP No. 00504W100
- ---------------------

1.   NAME OF REPORTING PERSONS
     I.R.S. IDENTIFICATION NOS. OF ABOVE PERSONS (ENTITIES ONLY)

     Kinderhook Partners, LP

2.   CHECK THE APPROPRIATE BOX IF A MEMBER OF A GROUP (SEE INSTRUCTIONS)
                                                                 (a)  [_]
                                                                 (b)  [X]

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

     0

6.   SHARED VOTING POWER

     6,000,000

7.   SOLE DISPOSITIVE POWER

     0

8.   SHARED DISPOSITIVE POWER

     6,000,000

9.   AGGREGATE AMOUNT BENEFICIALLY OWNED BY EACH REPORTING PERSON

     6,000,000

10.  CHECK BOX IF THE AGGREGATE AMOUNT IN ROW (9) EXCLUDES CERTAIN
     SHARES (SEE INSTRUCTIONS)

                                                                      [_]

11.  PERCENT OF CLASS REPRESENTED BY AMOUNT IN ROW 9

     9.0%

12.  TYPE OF REPORTING PERSON (SEE INSTRUCTIONS)

     PN


CUSIP No. 00504W100
- ---------------------

THIS  SCHEDULE  13G IS BEGIN  FILED AS AN  AMENDMENT  BY  STEPHEN  J.  CLEARMAN,
KINDERHOOK GP, LLC AND KINDERHOOK  PARTNERS,  LP. IT IS THE INITIAL SCHEDULE 13G
BEING FILED BU TUSHAR SHAH.

Item 1(a).  Name of Issuer:

            Active Power, Inc.
            --------------------------------------------------------------------

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

            2128 W. Braker Lane, BK12
            Austin, TX 78758
            --------------------------------------------------------------------

Item 2(a).  Name of Person Filing:

            Stephen J. Clearman
            Tushar Shah
            Kinderhook GP, LLC
            Kinderhook Partners, LP
            --------------------------------------------------------------------

      (b).  Address of Principal Business Office, or if None, Residence:

            1 Executive Drive
            Suite 160
            Fort Lee, NJ 07024
            --------------------------------------------------------------------

      (c).  Citizenship:

            Stephen J. Clearman - United States of America
            Tushar Shah - United States of America
            Kinderhook GP, LLC - Delaware
            Kinderhook Partners, LP - Delaware
            --------------------------------------------------------------------

      (d).  Title of Class of Securities:

            Common Stock, par value $0.001
            --------------------------------------------------------------------

      (e).  CUSIP Number:

            00504W100
            --------------------------------------------------------------------



Item 3.     If This Statement is filed pursuant to ss.240.13d-1(b) or
            240.13d-2(b), or (c), check whether the person filing is a:

     (a) [_]  Broker or dealer registered under Section 15 of the Exchange
              Act (15 U.S.C. 78c).

     (b) [_]  Bank as defined in Section 3(a)(6) of the Exchange Act (15
              U.S.C. 78c).

     (c) [_]  Insurance company as defined in Section 3(a)(19) of the Exchange
              Act (15 U.S.C. 78c).

     (d) [_]  Investment company registered under Section 8 of the Investment
              Company Act of 1940 (15 U.S.C. 80a-8).

     (e) [_]  An investment adviser in accordance with s.240.13d-1(b)(1)(ii)(E);

     (f) [_]  An employee benefit plan or endowment fund in accordance
              with s.240.13d-1(b)(1)(ii)(F);

     (g) [_]  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 (12 U.S.C.1813);

     (i) [_]  A church plan that is excluded from the definition of an
              investment company under Section 3(c)(14) of the Investment
              Company Act of 1940 (15 U.S.C. 80a-3);

     (j) [_]  Group, in accordance with s.240.13d-1(b)(1)(ii)(J).

Item 4.  Ownership.

        Provide the following information regarding the aggregate number and
percentage of the class of securities of the issuer identified in Item 1.

          (a)  Amount beneficially owned:

               Stephen J. Clearman - 6,000,000
               Tushar Shah - 6,000,000
               Kinderhook GP, LLC - 6,000,000
               Kinderhook Partners, LP - 6,000,000
               -----------------------------------------------------------------

          (b)  Percent of class:

               Stephen J. Clearman - 9.0%
               Tushar Shah - 9.0%
               Kinderhook GP, LLC - 9.0%
               Kinderhook Partners, LP - 9.0%
         ----------------------------------------------------------------------

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

               (i)  Sole power to vote or to direct the vote

                    Stephen J. Clearman - 0
                    Tushar Shah - 0
                    Kinderhook GP, LLC - 0
                    Kinderhook Partners, LP - 0
                                                        -----------------------,


               (ii) Shared power to vote or to direct the vote

                    Stephen J. Clearman - 6,000,000
                    Tushar Shah - 6,000,000
                    Kinderhook GP, LLC - 6,000,000
                    Kinderhook Partners, LP - 6,000,000
                                                        -----------------------,


               (iii) Sole power to dispose or to direct the disposition of

                    Stephen J. Clearman - 0
                    Tushar Shah - 0 Kinderhook GP, LLC - 0
                    Kinderhook Partners, LP -0
                                                        -----------------------,


               (iv) Shared power to dispose or to direct the disposition of

                    Stephen J. Clearman - 6,000,000
                    Tushar Shah - 6,000,000
                    Kinderhook GP, LLC - 6,000,000
                    Kinderhook Partners, LP - 6,000,000
                                                        -----------------------,


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.

     If any other person is known to have the right to receive or the power to
direct the receipt of dividends from, or the proceeds from the sale of, such
securities, a statement to that effect should be included in response to this
item and, if such interest relates to more than five percent of the class, such
person should be identified. A listing of the shareholders of an investment
company registered under the Investment Company Act of 1940 or the beneficiaries
of employee benefit plan, pension fund or endowment fund is not required.


     N/A
     --------------------------------------------------------------------------


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

     If a parent holding company or Control person has filed this schedule,
pursuant to Rule 13d-1(b)(1)(ii)(G), so indicate under Item 3(g) and attach an
exhibit stating the identity and the Item 3 classification of the relevant
subsidiary. If a parent holding company or control person has filed this
schedule pursuant to Rule 13d-1(c) or Rule 13d-1(d), attach an exhibit stating
the identification of the relevant subsidiary.


    N/A
    ---------------------------------------------------------------------------

Item 8.  Identification  and  Classification  of Members of the Group.

     If a group has filed this schedule pursuant to ss.240.13d-1(b)(1)(ii)(J),
so indicate under Item 3(j) and attach an exhibit stating the identity and Item
3 classification of each member of the group. If a group has filed this schedule
pursuant to ss.240.13d-1(c) or ss.240.13d-1(d), attach an exhibit stating the
identity of each member of the group.


    N/A
    ---------------------------------------------------------------------------

Item 9.  Notice of Dissolution of Group.

     Notice of dissolution of a group may be furnished as an exhibit stating the
date of the dissolution and that all further filings with respect to
transactions in the security reported on will be filed, if required, by members
of the group, in their individual capacity. See Item 5.


     N/A
     --------------------------------------------------------------------------

Item 10.  Certification.

                By signing below I 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 such purpose or effect.






                                    SIGNATURE

     After reasonable inquiry and to the best of my knowledge and belief, I
certify that the information set forth in this statement is true, complete and
correct.


                                                      August 28, 2009
                                                    -----------------------
                                                          (Date)


                                                    KINDERHOOK PARTNERS, LP

                                                    By: Kinderhook GP, LLC
                                                        General Partner

                                                    By: /s/ Stephen J. Clearman
                                                        -----------------------
                                                            Stephen J. Clearman
                                                            Managing Member


                                                    KINDERHOOK GP, LLC

                                                    By: /s/ Stephen J. Clearman
                                                        -----------------------
                                                            Stephen J. Clearman
                                                            Managing Member


                                                    /s/ Stephen J. Clearman
                                                    -----------------------
                                                    Stephen J. Clearman


                                                    /s/ Tushar Shah
                                                    -----------------------
                                                    Tushar Shah




                                                                       Exhibit A



                                    AGREEMENT


     The undersigned agree that this Schedule 13G dated August 28, 2009 relating
to the Common Stock, par value $0.001 of Active Power, Inc. shall be filed on
behalf of the undersigned.

                                                    KINDERHOOK PARTNERS, LP

                                                    By: Kinderhook GP, LLC
                                                        General Partner

                                                    By: /s/ Stephen J. Clearman
                                                        -----------------------
                                                            Stephen J. Clearman
                                                            Managing Member


                                                    KINDERHOOK GP, LLC

                                                    By: /s/ Stephen J. Clearman
                                                        -----------------------
                                                            Stephen J. Clearman
                                                            Managing Member


                                                    /s/ Stephen J. Clearman
                                                    -----------------------
                                                    Stephen J. Clearman


                                                    /s/ Tushar Shah
                                                    -----------------------
                                                    Tushar Shah


SK 21702 0001 1026210