8-K

                                  UNITED STATES
                       SECURITIES AND EXCHANGE COMMISSION
                             Washington, D.C. 20549

                                    FORM 8-K

                                 Current Report
     PURSUANT TO SECTION 13 OR 15(d) OF THE SECURITIES EXCHANGE ACT OF 1934

                Date of Report (Date of earliest event reported):

                               September 21, 2005

                            ULTRALIFE BATTERIES, INC.
                            -------------------------
             (Exact name of registrant as specified in its charter)

                                    Delaware
                                    --------
         (State or other jurisdiction of incorporation or organization)

        0-20852                                         16-1387013
        -------                                         ----------
(Commission File Number)                    (I.R.S. Employer Identification No.)

                 2000 Technology Parkway, Newark, New York        14513
                 ------------------------------------------------------
               (Address of principal executive offices)         (Zip Code)

                                 (315) 332-7100
                                 --------------
              (Registrant's telephone number, including area code)


Check the appropriate box below if the Form 8-K filing is intended to
simultaneously satisfy the filing obligation of the registrant under any of the
following provisions:

[ ] Written communications pursuant to Rule 425 under the Securities
Act (17 CFR 230.425)

[ ] Soliciting material pursuant to Rule 14a-12 under the Exchange
Act (17 CFR 240.14a-12)

[ ] Pre-commencement communications pursuant to Rule 14d-2(b) under the Exchange
Act (17 CFR 240.14d-2(b)

[ ] Pre-commencement communications pursuant to Rule 13e-4(c) under the Exchange
Act (17 CFR 240.13e-4(c))


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Item 7.01. Regulation FD Disclosure.

Ultralife Batteries, Inc. (the "Company") has adjusted its outlook for revenue
in the second half of 2005 to approximately $35 million, consisting of
approximately $15 million for the third quarter and $20 million for the fourth
quarter, due to ongoing uncertainty regarding the timing and quantity of BA-5390
battery orders from the U.S. Defense Department for the reminder of this year.
The Company's press release is attached as Exhibit 99.1 to this Form 8-K, and
the information set forth therein is furnished under Item 7.01.


Item 9.01. Financial Statements, Pro Forma Financials and Exhibits.

       (a)   Financial Statements of Business Acquired.

             Not applicable.

       (b)   Pro Forma Financial Information.

             Not applicable.

       (c)   Exhibits.

             99.1     Press Release dated September 21, 2005.




                                    SIGNATURE

     Pursuant to the requirements of the Securities Exchange Act of 1934, the
registrant has duly caused this report to be signed on its behalf by the
undersigned hereunto duly authorized.

                                             ULTRALIFE BATTERIES, INC.

Dated:  September 21, 2005                   By: /s/Robert W. Fishback
                                                 -------------------------------
                                                 Robert W. Fishback
                                                 Vice President of Finance & CFO



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                                INDEX TO EXHIBITS

(99)     Additional Exhibits

         99.1     Press Release dated September 21, 2005.



                                       3

EX-99.1

                                                                    Exhibit 99.1

        Ultralife Batteries Updates Guidance for the Second Half of 2005

    NEWARK, N.Y.--(BUSINESS WIRE)--Sept. 21, 2005--Ultralife
Batteries, Inc. (NASDAQ: ULBI) has adjusted its outlook for revenue in
the second half of 2005 to approximately $35 million, consisting of
approximately $15 million for the third quarter and $20 million for
the fourth quarter, due to ongoing uncertainty regarding the timing
and quantity of BA-5390 battery orders from the U.S. Defense
Department for the reminder of this year. The company previously
anticipated revenue for the second half of 2005 of approximately $46
million, assuming a modest level of BA-5390 orders. Along with
lowering its revenue guidance, the company is taking action to reduce
overhead costs by up to $4 million on an annualized basis starting in
the fourth quarter.
    "The U.S. military has informed us that they are keeping
inventories lean until they finalize plans to transition to the
BA-5390 with the state-of-charge indicator, the major item in the Next
Gen II, Phase IV Contract award. Because usage continues at a steady
rate for the current version, however, they have informed us that they
anticipate some procurement in the fourth quarter to maintain supply
levels," said John D. Kavazanjian, president and chief executive
officer. "Nevertheless, given the uncertainty about both the volume
and timing of orders, combined with the continued delays in the
procurement process, we are moving forward with our near-term business
plans assuming that we will not have any BA-5390 revenue for the rest
of the year. These plans include taking action to reduce overhead
costs in order to return to profitability in the fourth quarter."
    Kavazanjian continued, "We have been working diligently with the
U.S. military on qualifying the new version of the BA-5390 and are
still on track to complete testing in the third quarter. Pending the
completion of its product transition plan, the U.S. military has
informed us that we should expect to begin supplying the BA-5390 under
the Next Gen II, Phase IV contract in the first quarter of 2006 at the
earliest."
    "Our commercial business continues to expand and we expect to see
growth from key target markets such as automotive telematics, search
and rescue and medical in the second half of 2005," concluded
Kavazanjian. "Looking toward 2006, we are aggressively pursuing our
initiatives to further diversify our areas of growth and enhance
revenue predictability."

    About Ultralife Batteries, Inc.

    Ultralife is a global provider of power solutions for diverse
applications. The company develops, manufactures and markets a wide
range of non-rechargeable and rechargeable batteries, charging systems
and accessories for use in military, industrial and consumer portable
electronic products. Through its range of standard products and
engineered solutions, Ultralife is able to provide the next generation
of power systems. Industrial, retail and government customers include
General Dynamics, Philips Medical Systems, General Motors, Energizer,
Kidde Safety, Lowe's, Radio Shack and the national defense agencies of
the United States, United Kingdom and Germany, among others.
    Ultralife's headquarters, principal manufacturing and research
facilities are in Newark, New York, near Rochester. Ultralife (UK)
Ltd., a second manufacturing facility, is located in Abingdon,
England. Both facilities are ISO-9001 certified. Detailed information
on Ultralife is available at the Company's web site,
www.ultralifebatteries.com.

    This press release may contain forward-looking statements based on
current expectations that involve a number of risks and uncertainties.
The potential risks and uncertainties that could cause actual results
to differ materially include: worsening global economic conditions,
increased competitive environment and pricing pressures, disruptions
related to restructuring actions and delays. Further information on
these factors and other factors that could affect Ultralife's
financial results is included in Ultralife's Securities and Exchange
Commission (SEC) filings, including the latest Annual Report on Form
10-K.

    Ultralife(R) is a registered trademark of Ultralife Batteries,
Inc.

    CONTACT: Ultralife Batteries, Inc.
             Robert Fishback, 315-332-7100
             bfishback@ulbi.com
             or
             Investor Relations:
             Lippert/Heilshorn & Associates, Inc.
             Jody Burfening, 212-838-3777
             jburfening@lhai.com
             or
             Media:
             Lippert/Heilshorn & Associates, Inc.
             Chenoa Taitt, 212-201-6635
             ctaitt@lhai.com