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

                                    FORM 8-K

     PURSUANT TO SECTION 13 OR 15(D) OF THE SECURITIES EXCHANGE ACT OF 1934

                Date of Report (Date of earliest event reported):

                                 April 14, 2004

                            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)


                                       1

Item 7. 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 April 14, 2004 Item 9. Regulation FD Disclosure. The Company will report its first quarter 2004 results for the period ended March 27, 2004 before the market opens on Thursday, April 29, 2004. Refer to the attached Exhibit 99.1 for the entire text of the release, which Exhibit is being furnished but not filed in accordance with Regulation FD. 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: April 14, 2004 By: /s/Peter F. Comerford Peter F. Comerford Vice President - Administration & General Counsel 2

Index to Exhibits (99) Additional Exhibits 99.1 Press Release dated April 14, 2004 3

                                                                    Exhibit 99.1

  Ultralife Batteries, Inc. to Report First Quarter Results on April 29, 2004;
    Investor Conference Call to be Webcast at Ultralife Batteries' Web Site

    NEWARK, N.Y.--(BUSINESS WIRE)--April 14, 2004--Ultralife
Batteries, Inc. (NASDAQ: ULBI) will report its first quarter 2004
results for the period ended March 27, 2004 before the market opens on
Thursday, April 29, 2004. Ultralife management will host an investor
conference call at 10:00AM ET also on April 29, 2004. Investors are
invited to access a live webcast of the conference call in the
Investor Info - Event Calendar section of the company's website:
http://www.ultralifebatteries.com/invest.asp. A replay of the webcast
will be available shortly after the call at the same location and will
be archived for 90 days.

    About Ultralife Batteries, Inc.

    Ultralife is a leading developer, manufacturer, and marketer of
standard and customized lithium primary (non-rechargeable), lithium
ion and lithium polymer rechargeable batteries. Ultralife's
high-energy batteries use advanced lithium technology and are used in
military, industrial and consumer portable electronic products.
Through its range of standard products and ability to customize for a
wide range of applications, Ultralife is able to provide the next
generation of battery solutions. OEM, retail and government customers
include Energizer, Kidde Safety, Philips Medical Systems, Radio Shack
and the national defense agencies of the United States and United
Kingdom, among others.
    Ultralife's headquarters, principal manufacturing and research
facilities are in Newark, New York, near Rochester. Ultralife (UK)
Ltd., a second manufacturing and research facility, is located in
Abingdon, U.K. Both facilities are ISO-9001 certified.
    Detailed information on Ultralife is available at the Company's
web site, www.ultralifebatteries.com.

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