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                                                                 Exhibit 10.2


                  AMENDMENT NO. 1 TO THE REGISTRATION AGREEMENT


         This Amendment No. 1 to the Registration Rights Agreement (as defined
herein) (this "AMENDMENT") is made and entered into as of May 25, 2001, among
SatCon Technology Corporation, a Delaware corporation (the "COMPANY"), and the
parties who have executed this Amendment and whose names appear on Schedule I
hereto.

         WHEREAS, on August 25, 1999 each of the Company, Brown Simpson
Strategic Growth Fund, L.P. ("Brown Simpson L.P.") and Brown Simpson Strategic
Growth Fund, Ltd. ("Brown Simpson Ltd.") entered into a registration rights
agreement (the "Registration Rights Agreement").

         WHEREAS, the Company has approved the issuance of a warrant (the "New
Warrant") to Brown Simpson Partners I, Ltd.("Brown Simpson Partners"),
exercisable into 438,750 shares of common stock, par value $0.01 per share, of
the Company.

         WHEREAS, in connection with the issuance of the New Warrant, each of
the Company, Brown Simpson Ltd. and Brown Simpson L.P. have agreed to this
Amendment and to make Brown Simpson Partners a party to the Registration Rights
Agreement.

         NOW THEREFORE, in consideration of these premises and for other good
and valuable consideration, the receipt and sufficiency of which are hereby
acknowledged, the parties hereto agree as follows:


1. The definition of Registrable Securities as set forth in Section 1 of the
Registration Rights Agreement shall be amended and restated as follows:

         "REGISTRABLE SECURITIES" means the shares of Common Stock issued or
issuable upon (i) conversion of or with respect to the Securities, (ii) payment
of interest or any other payments in respect of the Securities, (iii) exercise
of the Warrants, (iv) exercise of the New Warrant and (v) any shares of the
Company's capital stock issued with respect to (i), (ii), (iii) or (iv) as a
result of any stock split, stock dividend, recapitalization, exchange or similar
event or otherwise; provided, that Registrable Securities shall not include any
such shares that are eligible for sale under Rule 144(k).

2. Section 1 of the Registration Rights Agreement shall be supplemented to
include the following additional definitions:

         "NEW WARRANT" means the warrant issued to Brown Simpson Partners I,
Ltd. on May 25, 2001.

         "WARRANT SHARES" means the shares of Common Stock issuable upon
exercise of the New Warrant.


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3. The provisions of Section 2 of the Registration Rights Agreement shall apply
to all Registrable Securities other than the Warrant Shares. In lieu of Section
2, the following provisions shall apply only to the Warrant Shares:

         (a) FILING AND EFFECTIVENESS OBLIGATIONS. On or prior to the June 29,
2001, the Company shall prepare and file with the Commission a Registration
Statement (the "INITIAL REGISTRATION STATEMENT") which shall cover all Warrant
Shares, without regard to any limitation on the holders ability to exercise the
New Warrant, for an offering to be made on a continuous basis pursuant to a
"Shelf" registration statement under Rule 415. The Initial Registration
Statement shall be on Form S-3 or any successor form (except if the Company is
not then eligible to register for resale the Registrable Securities on Form S-3,
in which case such registration shall be on another appropriate form in
accordance herewith, subject to the reasonable consent of Brown Simpson
Partners). The Company shall use commercially reasonable efforts to cause the
Initial Registration Statement to be declared effective under the Securities Act
on or prior to August 29, 2001, and, except as provided herein, to keep such
Initial Registration Statement continuously effective under the Securities Act
until the date which is two years after the date that such Initial Registration
Statement is declared effective by the Commission or such earlier date when all
Warrant Shares covered by such Initial Registration Statement have been sold or
may be sold without volume restrictions pursuant to Rule 144 as determined by
counsel to the Company pursuant to a written opinion letter, addressed to the
Holders and the Company's transfer agent to such effect. If at any time the
number of shares of Common Stock issuable upon exercise of the Warrant Shares is
adjusted, pursuant to the terms of the New Warrant, and more shares are issuable
then remain available for sale pursuant to the Initial Registration Statement,
which shares are not registered under the Initial Registration Statement, the
Company shall immediately, but in no more than five (5) Business Days, file a
Registration Statement sufficient to register such additional shares of Common
Stock.

         (b) FORM S-3 ELIGIBILITY. The Company represents and warrants that it
currently meets the registrant eligibility and transaction requirements for the
use of Form S-3 (for primary and secondary offerings) for the registration of
the sale of the New Warrant Shares by Brown Simpson Partners and the Company
shall file all reports required to be filed by the Company with the Commission
in a timely manner so as to maintain such eligibility for the use of Form S-3.

4. Except as otherwise specifically set forth herein, the Registration Rights
Agreement shall remain in full force and effect and shall incorporate the New
Warrant Shares as Registrable Securities.



<PAGE>



         IN WITNESS WHEREOF, the parties have executed this Registration Rights
Agreement as of the date first written above.

                          SATCON TECHNOLOGY CORPORATION


                                          By: /s/ Sean F. Moran
                                              ------------------------------
                                              Name:  Sean F. Moran
                                              Title: Chief Financial Officer



<PAGE>



                          BROWN SIMPSON STRATEGIC GROWTH FUND, LTD.


                            By: /s/ Peter D. Greene
                                ---------------------------------------------
                                Name:  Peter D. Greene
                                Title: Managing Principal, Investment Manager


                          BROWN SIMPSON STRATEGIC GROWTH FUND, L.P.


                            By: /s/ Peter D. Greene
                                ---------------------------------------------
                                Name:  Peter D. Greene
                                Title: Managing Principal, General Partner


                          BROWN SIMPSON PARTNERS I, LTD.

                            By: /s/ Peter D. Greene
                                ---------------------------------------------
                                Name:  Peter D. Greene
                                Title: Attorney-in-fact




<PAGE>






                                                                      SCHEDULE I




SATCON TECHNOLOGY CORPORATION
161 First Street
Cambridge, MA 02142-1221
Attn: President and Chief Executive Officer
Fax:  (617) 576-7455

BROWN SIMPSON STRATEGIC GROWTH FUND, L.P.
152 West 57th Street, 21st Floor
New York, New York 10019
Attn: Peter Greene
Fax: (212) 817-5391

BROWN SIMPSON STRATEGIC GROWTH FUND, LTD.
152 West 57th Street, 21st Floor
New York, New York 10019
Attn: Peter Greene
Fax: (212) 817-5391

BROWN SIMPSON PARTNERS I, LTD.
152 West 57th Street, 21st Floor
New York, New York 10019
Attn: Peter Greene
Fax: (212) 817-5391