Exhibit 31.1



Chief Executive Officer Certification



I, Joseph F. Pinkerton III, President and Chief Executive Officer of Active
Power, Inc., certify that:



|1. | I have reviewed this Annual Report on Form 10-K of Active Power, Inc. (the Registrant);
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|2. | Based on my knowledge, this Annual Report does not contain any untrue statement of a material fact or omit to state a material fact necessary to make the statements made, in light
of the circumstances under which such statements were made, not misleading with respect to the period covered by this Annual Report;
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|3. | Based on my knowledge, the financial statements, and other financial information included in this Annual Report, fairly present in all material respects the financial condition,
results of operations and cash flows of the Registrant as of, and for, the periods presented in this Annual Report;
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|4. | The Registrants other certifying officer and I are responsible for establishing and maintaining disclosure controls and procedures (as defined in Exchange Act Rules 13a-14 and
15d-14) for the Registrant and have:
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| | a) | designed such disclosure controls and procedures to ensure that material information relating to the Registrant, including its consolidated subsidiaries, is made known to us by
others within those entities, particularly during the period in which this Annual Report is being prepared;
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| | b) | evaluated the effectiveness of the Registrants disclosure controls and procedures as of a date within 90 days prior to the filing date of this Annual Report (the
Evaluation Date); and
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| | c) | presented in this Annual Report our conclusions about the effectiveness of the disclosure controls and procedures based on our evaluation as of the Evaluation Date;
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|5. | The Registrants other certifying officer and I have disclosed, based on our most recent evaluation, to the Registrants auditors and the audit committee of
Registrants board of directors (or persons performing the equivalent functions):
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| | a) | all significant deficiencies in the design or operation of internal controls which could adversely affect the Registrants ability to record, process, summarize and report
financial data and have identified for the Registrants auditors any material weaknesses in internal controls; and
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| | (b) | any fraud, whether or not material, that involved management or other employees who have a significant role in the Registrants internal controls; and
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Dated: February 19, 2004



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|/s/    JOSEPH F. PINKERTON, III                                                                                    
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|Joseph F. Pinkerton, III Chairman of the Board, President and Chief Executive Officer (Principal Executive
Officer)