UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 SCHEDULE 13G Under the Securities Exchange Act of 1934 (Amendment No. 5*) (Name of Issuer) ACTIVE POWER INC (Title of Class of Securities) Common Stock (CUSIP Number) 00504w100 Check the following box if a fee is being paid with this statement. (A fee is not required only if the filing person: (1) has a previous statement on file reporting beneficial ownership of more than five percent of the class of securities described in Item 1; and (2) has filed no amendment subsequent thereto reporting beneficial ownership of five percent or less of such class.) (See Rule 13d-7). *The remainder of this cover page shall be filled out for a reporting persons initial filing on this form with respect to the subject class of securities, and for any subsequent amendment containing information which would alter the disclosures provided in a prior cover page. The information required in the remainder of this cover page shall not be deemed to be filed for the purpose of Section 18 of the Securities Exchange Act of 1934 (Act) or otherwise subject to the liabilities of that section of the Act but shall be subject to all other provisions of the Act (however, see the Notes). 1 NAME OF REPORTING PERSON S.S. OR I.R.S. IDENTIFICATION NO. OF PERSON THOMSON HORSTMANN & BRYANT, INC. 22-3508647 2 CHECK THE APPROPRIATE BOX IF A MEMBER OF A GROUP* N/A 3 SEC USE ONLY 4 CITIZENSHIP OR PLACE OF ORGANIZATION A DELAWARE CORPORATION NORWALK, CT 06851 5 SOLE VOTING POWER 0 6 SHARED VOTING POWER 0 7 SOLE DISPOSITIVE POWER 0 8 SHARED DISPOSITIVE POWER NONE 9 AGGREGATE AMOUNT BENEFICIALLY OWNED BY EACH REPORTING PERSON 0 10 CHECK BOX IF THE AGGREGATE AMOUNT IN ROW (9) EXCLUDES CERTAIN SHARES* N/A 11 PERCENT OF CLASS REPRESENTED BY AMOUNT IN ROW 9 0% 12 TYPE OF REPORTING PERSON * IA ITEM 1. (A) ACTIVE POWER INC (B) 2128 WEST BRAKER LANE, BK12 AUSTIN TX 78758 ITEM 2. (A) THOMSON HORSTMANN & BRYANT, INC. (B) 501 MERRITT 7, NORWALK, CT 06851 (C) A DELAWARE CORPORATION (D) COMMON (E) 872391107 ITEM 3. (E) INVESTMENT ADVISER REGISTERED UNDER SECTION 203 OF THE INVESTMENT ADVISERS ACT OF 1940 ITEM 4. (A) 0 (B) 0 (C) (I) 0 (II) 0 (III) 0 (IV) NONE ITEM 5. N/A ITEM 6. N/A ITEM 7. N/A ITEM 8. N/A ITEM 9. 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 acquired in the ordinary course of business and were not acquired for the purpose of and do not have the effect of changing or influencing the control of the issuer of such securities and were not acquired in connection with or as a participant in any transaction having such purposes 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. James Kennedy Date: 1/21/15