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                                                                    EXHIBIT 10.4

                                 PROMISSORY NOTE



Scottsdale, Arizona                                                 May 7, 2002



         PROMISE TO PAY: For value received, the undersigned, [Name] ("Issuer"),
promises to pay to the order of Mobility Electronics, Inc., a Delaware
corporation or its successors or assigns ("Payee"), the Principal Amount (as
defined below), together with interest on the unpaid balance of such amount, in
lawful money of the United States of America, in accordance with all the terms,
conditions, and covenants of this Note.

         ISSUER'S ADDRESS FOR NOTICE: 7955 East Redfield Road, Scottsdale,
Arizona 85260

         PAYEE'S ADDRESS FOR PAYMENT: 7955 East Redfield Road, Scottsdale,
Arizona 85260.

         PRINCIPAL AMOUNT: Seventy Thousand Dollars ($70,000) (the "Principal
Amount").

         INTEREST RATE: 6% per annum; provided that in no event shall the rate
hereunder be less than the mid-term applicable federal funds rate in effect at
the date of this Note using the lowest 3 month rate as defined in Section
1274(d)(2) of the Internal Revenue Code of 1986.

         PAYMENT TERMS: Except as otherwise provided in this Note, the principal
of, and all accrued but unpaid interest on this Note shall be due and payable on
May 7, 2005. Notwithstanding the above, upon the sale by Issuer of any Shares
(as defined in the Pledge Agreement (as defined below)), Issuer shall make a
prepayment on this Note equal to the product of (i) the number of Shares sold
multiplied by (ii) $1.40 per Share.

         Issuer may prepay all or any part of this Note without penalty or
premium. Issuer's payments shall be applied on the first business day after
Payee's receipt of such payments.

         1.       INTEREST PROVISIONS:

                  (a) Rate: The Principal Amount of this Note from time to time
remaining unpaid prior to maturity shall bear interest at the Interest Rate per
annum stated above.

                  (b) Maximum Lawful Interest: The term "Maximum Lawful Rate"
means the maximum rate of interest and the term "Maximum Lawful Amount" means
the maximum amount of interest that are permissible under applicable state or
federal law for the type of loan evidenced by this Note. If the Maximum Lawful
Rate is increased by statute or other governmental action subsequent to the date
of this Note, then the new Maximum Lawful Rate shall be applicable to this Note
from the effective date thereof, unless otherwise prohibited by applicable law.

                  (c) Spreading of Interest: Because of the possibility of
irregular periodic balances of principal or premature payment, the total
interest that will accrue under this Note cannot be determined in advance. Payee
does not intend to contract for, charge or receive more than the Maximum Lawful
Rate or Maximum Lawful Amount permitted by applicable state or


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federal law, and to prevent such an occurrence Payee and Issuer agree that all
amounts of interest, whenever contracted for, charged, or received by Payee,
with respect to the loan of money evidenced by this Note, shall be spread,
prorated, or allocated over the full period of time this Note is unpaid,
including the period of any renewal or extension of this Note. If demand for
payment of this Note is made by Payee prior to the full stated term, the total
amount of interest contracted for, charged, or received to the time of such
demand shall be spread, prorated, or allocated along with any interest
thereafter accruing over the full period of time that this Note thereafter
remains unpaid for the purpose of determining if such interest exceeds the
Maximum Lawful Amount.

                  (d) Excess Interest: At maturity (whether by acceleration or
otherwise) or on earlier final payment of this Note, Payee shall compute the
total amount of interest that has been contracted for, charged, or received by
Payee or payable by Issuer under this Note and compare such amount to the
Maximum Lawful Amount that could have been contracted for, charged, or received
by Payee. If such computation reflects that the total amount of interest that
has been contracted for, charged, or received by Payee or payable by Issuer
exceeds the Maximum Lawful Amount, then Payee shall apply such excess to the
reduction of the principal balance and not to the payment of interest; or if
such excess interest exceeds the unpaid principal balance, such excess shall be
refunded to Issuer. This provision concerning the crediting or refund of excess
interest shall control and take precedence over all other agreements between
Issuer and Payee so that under no circumstances shall the total interest
contracted for, charged, or received by Payee exceed the Maximum Lawful Amount.

                  (e) Interest After Late Payment: Unless an amount payable is
capitalized as provided herein, the unpaid principal balance shall bear interest
after it becomes due at the rate of 15% per annum; but never more than the
Maximum Lawful Rate or at a rate that would cause the total interest contracted
for, charged, or received by Payee to exceed the Maximum Lawful Amount.

         2.       DEFAULT PROVISIONS:

                  (a) Events Of Default And Acceleration Of Maturity: Payee may,
without notice or demand accelerate the maturity of this Note and declare the
entire unpaid principal balance and accrued interest at once due and payable if:

                           (i) there is default by Issuer in the payment of any
                  installment of principal, interest or any other sum required
                  to be paid under the terms of this Note, and such default
                  continues for a period of five (5) days following written
                  notice to Issuer specifying such default;

                           (ii) there is default by Issuer in the performance of
                  any covenant, condition, or agreement contained in this Note
                  or in the Pledge Agreement, and such default continues for a
                  period of thirty (30) days following written notice to Issuer
                  specifying such default;

                           (iii) if Issuer makes an assignment for the benefit
                  of creditors, or petitions or applies for the appointment of a
                  liquidator, receiver or custodian (or similar official) of it
                  or of any substantial part of its assets, or if Issuer
                  commences



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                  any proceeding or case relating to it under the Bankruptcy
                  Code or any other bankruptcy, reorganization, arrangement,
                  insolvency, readjustment of debt, dissolution or liquidation
                  or similar law of any jurisdiction, or takes any action to
                  authorize any of the foregoing; or

                           (iv) if any petition or application of the type
                  described in subparagraph (iii) immediately above is filed or
                  if any such proceeding or case described in subparagraph (iii)
                  is commenced against Issuer and is not dismissed within sixty
                  (60) days, or if Issuer indicates its approval thereof,
                  consents thereto or acquiesces therein, or if an order is
                  entered appointing any such liquidator or receiver or
                  custodian (or similar official), or adjudicating Issuer
                  bankrupt or insolvent, or approving a petition in any such
                  proceeding, or if a decree or order for relief is entered in
                  respect of Issuer in an involuntary case under the Bankruptcy
                  Code or any other bankruptcy, reorganization, arrangement,
                  insolvency, readjustment of debt, dissolution or liquidation
                  or similar law of any jurisdiction.

                  (b) Waiver By Issuer: ISSUER AND ALL OTHER PARTIES LIABLE FOR
THIS NOTE WAIVE DEMAND, NOTICE OF INTENT TO DEMAND, PRESENTMENT FOR PAYMENT,
NOTICE OF NONPAYMENT, PROTEST, NOTICE OF PROTEST, GRACE, NOTICE OF DISHONOR,
NOTICE OF INTENT TO ACCELERATE MATURITY, NOTICE OF ACCELERATION OF MATURITY, AND
DILIGENCE IN COLLECTION.

                  (c) Non-Waiver by Payee: Any previous extension of time,
forbearance, failure to pursue some remedy, acceptance of late payments, or
acceptance of partial payment by Payee, before or after maturity, does not
constitute a waiver by Payee of its subsequent right to strictly enforce the
collection of this Note according to its terms.

                  (d) Other Remedies Not Required: Payee shall not be required
to first file suit, exhaust all remedies, or enforce its rights against any
security in order to enforce payment of this Note.

                  (e) Attorney's Fees: If Payee requires the services of an
attorney to enforce the payment of this Note or the performance of the Pledge
Agreement, or if this Note is collected through any lawsuit, probate,
bankruptcy, or other judicial proceeding, Issuer agrees to pay Payee an amount
equal to its reasonable attorney's fees and other reasonable collection costs.
This provision shall be limited by any applicable statutory restrictions
relating to the collection of attorney's fees.

         3.       MISCELLANEOUS PROVISIONS:

                  (a) Successors and Assigns: The provisions of this Note shall
be binding upon the successors and assigns of Issuer, and shall inure to the
benefit of the successors and assigns of Payee; provided, however, that no
obligations of Issuer hereunder can be assigned without Payee's prior written
consent.

                  (b) No Duty or Special Relationship: Issuer acknowledges that
Payee has no duty of good faith to Issuer, and Issuer acknowledges that no
fiduciary, trust, or other special relationship exists between Payee and Issuer;
provided, however, the foregoing is not intended to abrogate any duties which
may exist as the result of that Issuer having been an executive officer of the
Payee. If Payee and Issuer are now engaged in or in the future engage in other
business



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transactions, such other business transactions are independent of this Note and
the indebtedness evidenced hereby and of the promises and covenants made by
Issuer in this Note, and vice versa.

                  (c) Security. This Note is secured by a security interest in
certain shares of common stock of Payee issued to Issuer, as granted by that
certain Pledge and Security Agreement, of even date herewith, by and between
Issuer and Payee (the "Pledge Agreement").

                  (d) Entire Agreement. Issuer warrants and represents to Payee
that this Note and the Pledge Agreement constitute the entire agreement between
Issuer and Payee with respect to the indebtedness evidenced by this Note and
agrees that no modification, amendment, or additional agreement with respect to
such indebtedness will be valid and enforceable unless made in writing signed by
both Issuer and Payee.

                  (e) Issuer's Address for Notice: All notices required to be
sent by Payee to Issuer shall be sent by U.S. Mail, postage prepaid, to Issuer's
Address for Notice stated on the first page of this Note, until Payee shall
receive written notification from Issuer of a new address for notice.

                  (f) Payee's Address for Payment: All sums payable by Issuer to
Payee shall be paid at Payee's Address for payment stated on the first page of
this Note, or at such other address as Payee shall designate from time to time.

                  (g) Partial Invalidity: The unenforceability or invalidity of
any provision of this Note shall not affect the enforceability or validity of
any other provision herein, and the invalidity or unenforceability of any
provision of this Note or the Pledge Agreement as to any person or circumstance
shall not affect the enforceability or validity of such provision as it may
apply to other persons or circumstances.

                  (h) Applicable Law; Venue & Jurisdiction: This Note shall be
construed in accordance with the applicable laws of the state of Delaware and
the laws of the United States of America applicable to transactions in Delaware
and venue for any action concerning this note shall be exclusively in Maricopa
County, Arizona.

         EXECUTED as of the date first set forth above.

                                 ISSUER:


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                                 [Name]



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