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                                                                    EXHIBIT 10.1


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                 CONVERTIBLE PREFERRED STOCK PURCHASE AGREEMENT

                                    Between

                               KA INVESTMENTS LDC

                                      and

                               TANISYS TECHNOLOGY



                           Dated as of June 30, 1998



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        CONVERTIBLE PREFERRED STOCK PURCHASE AGREEMENT (this "Agreement"), dated
as of June 30, 1998, between Tanisys Technology, Inc., a Wyoming corporation
(the "Company"), and KA Investments LDC, a Cayman Islands corporation (the
"Purchaser").

        WHEREAS, subject to the terms and conditions set forth in this
Agreement, the Company desires to issue and sell to the Purchaser and the
Purchaser desires to purchase from the Company, shares of the Company's 5%
Series A Convertible Preferred Stock, par value $1.00 per share (the "Preferred
Stock"), which are convertible into shares of the Company's common stock, no par
value (the "Common Stock").

        IN CONSIDERATION of the mutual covenants contained in this Agreement,
and for other good and valuable consideration the receipt and adequacy are
hereby acknowledged, the Company and Purchaser agree as follows:


                                    ARTICLE I
                      PURCHASE AND SALE OF PREFERRED STOCK

        1.1 The Closing.

            (a) The Closing. (i) Subject to the terms and conditions set forth
in this Agreement, the Company shall issue and sell to the Purchaser and the
Purchaser shall purchase 400 shares of Preferred Stock (the "Shares") for an
aggregate purchase price of $4,000,000. The closing of the purchase and sale of
the Shares (the "Closing") shall take place at the offices of Robinson Silverman
Pearce Aronsohn & Berman LLP (the "Escrow Agent"), 1290 Avenue of the Americas,
New York, New York 10104, immediately following the execution hereof or such
later date as the parties shall agree. The date of the Closing is hereinafter
referred to as the "Closing Date."

               (ii) At the Closing, the parties shall deliver or shall cause to
be delivered such items as are required to be delivered by them in accordance
with the terms of this Agreement, including the following: (A) the Company shall
deliver (1) stock certificates representing the Shares, registered in the name
of the Purchaser, (2) a Common Stock purchase warrant, in the form of Exhibit D,
registered in the name of the Purchaser, pursuant to which the Purchaser shall
have the right at any time and from time to time thereafter through the fourth
anniversary date of the Original Issue Date to acquire 133,333 shares of Common
Stock at an exercise price per share of $3.00 (the "Warrant"), (3) the legal
opinion of Audie Long, counsel to the Company, substantially in the form of
Exhibit C, and (4) all other documents, instruments and writings required to
have been delivered at or prior to the Closing Date by the Company pursuant to
this Agreement, including an executed Registration Rights Agreement, dated the
date hereof, between the Company and the Purchaser, in the form of Exhibit B
(the "Registration Rights Agreement"), and the Irrevocable Transfer Agent
Instructions, in the form of Exhibit E, delivered to and acknowledged by the
Company's transfer agent (the "Transfer Agent Instructions"); and (B) the
Purchaser shall deliver (1) $4,000,000 in United States dollars in immediately
available funds by wire transfer to an account designated prior to the Closing
Date in writing by the Company for such purpose, and (2) all documents,
instruments


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and writings required to have been delivered at or prior to the Closing Date by
the Purchaser pursuant to this Agreement, including, without limitation, an
executed Registration Rights Agreement.

             1.2 Form of Preferred Stock. The Preferred Stock shall have the
rights preferences and privileges set forth in Exhibit A, and shall be
incorporated into an Articles of Amendment ("Articles of Amendment"), in form
and substance mutually agreed to by the parties.

             For purposes of this Agreement, "Conversion Price," "Original Issue
Date," "Conversion Date" and "Trading Day" shall have the meanings set forth in
Exhibit A;"Business Day" shall mean any day except Saturday, Sunday and any day
which shall be a federal legal holiday or a day on which banking institutions in
the State of New York are authorized or required by law or other governmental
action to close.


                                   ARTICLE II
                         REPRESENTATIONS AND WARRANTIES

         2.1 Representations, Warranties and Agreements of the Company. The
Company hereby makes the following representations and warranties to the
Purchaser:

             (a) Organization and Qualification. The Company is a corporation,
duly incorporated, validly existing and in good standing under the laws of the
State of Wyoming, with the requisite corporate power and authority to own and
use its properties and assets and to carry on its business as currently
conducted. The Company has no subsidiaries other than as set forth in Schedule
2.1(a) (collectively the "Subsidiaries"). Each of the Subsidiaries is an entity,
duly incorporated or otherwise organized, validly existing and in good standing
under the laws of the jurisdiction of its incorporation or organization (as
applicable), with the full power and authority to own and use its properties and
assets and to carry on its business as currently conducted. Each of the Company
and the Subsidiaries is duly qualified to do business and is in good standing as
a foreign corporation in each jurisdiction in which the nature of the business
conducted or property owned by it makes such qualification necessary, except
where the failure to be so qualified or in good standing, as the case may be,
could not, individually or in the aggregate, (x) adversely affect the legality,
validity or enforceability of the Securities (as defined below) or any of this
Agreement, the Articles of Amendment, the Registration Rights Agreement or the
Warrant (collectively, the "Transaction Documents"), (y) have or result in a
material adverse effect on the results of operations, assets, prospects, or
condition (financial or otherwise) of the Company and the Subsidiaries, taken as
a whole, or (z) adversely impair the Company's ability to perform fully on a
timely basis its obligations under any of the Transaction Documents (any of (x),
(y) or (z), a "Material Adverse Effect").

             (b) Authorization; Enforcement. The Company has the requisite
corporate power and authority to enter into and to consummate the transactions
contemplated by each of the Transaction Documents, and otherwise to carry out
its obligations thereunder. The execution and delivery of each of the
Transaction Documents


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                                                        Stock Purchase Agreement
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has been duly executed by the Company and, when delivered (or filed, as the case
may be) in accordance with the terms hereof, will constitute the valid and
binding obligation of the Company enforceable against the Company in accordance
with its terms. Neither the Company nor any Subsidiary is in violation of any of
the provisions of its respective certificate of incorporation, by-laws or other
charter documents.

             (c) Capitalization. The number of authorized, issued and
outstanding capital stock of the Company is set forth in Schedule 2.1(c). No
shares of Common Stock are entitled to preemptive or similar rights, nor is any
holder of the Common Stock entitled to preemptive or similar rights arising out
of any agreement or understanding with the Company by virtue of any of the
Transaction Documents. Except as disclosed in Schedule 2.1(c), there are no
outstanding options, warrants, script rights to subscribe to, calls or
commitments of any character whatsoever relating to, or, except as a result of
the purchase and sale of the Shares and the Warrant, securities, rights or
obligations convertible into or exchangeable for, or giving any Person any right
to subscribe for or acquire any shares of Common Stock, or contracts,
commitments, understandings, or arrangements by which the Company or any
Subsidiary is or may become bound to issue additional shares of Common Stock, or
securities or rights convertible or exchangeable into shares of Common Stock. To
the knowledge of the Company, except as specifically disclosed in the SEC
Documents (as defined below) or Schedule 2.1(c), no Person or group of related
Persons beneficially owns (as determined pursuant to Rule 13d-3 promulgated
under the Securities Exchange Act of 1934, as amended (the "Exchange Act")) or
has the right to acquire by agreement with or by obligation binding upon the
Company beneficial ownership of in excess of 5% of the Common Stock. A "Person"
means an individual or corporation, partnership, trust, incorporated or
unincorporated association, joint venture, limited liability company, joint
stock company, government (or an agency or subdivision thereof) or other entity
of any kind.

             (d) Issuance of the Shares and the Warrant. The Shares and the
Warrant are duly authorized, and, when issued and paid for in accordance with
the terms hereof, shall have been validly issued, fully paid and nonassessable,
free and clear of all liens, encumbrances and rights of first refusal of any
kind (collectively, "Liens"). The Company has on the date hereof and will, at
all times while the Shares and the Warrant are outstanding, maintain an adequate
reserve of duly authorized shares of Common Stock, reserved for issuance to the
holders of the Shares, to enable it to perform its conversion, exercise and
other obligations under this Agreement, the Articles of Amendment and the
Warrant. Such number of reserved and available shares of Common Stock is not
less than the sum of (i) 200% of the number of shares of Common Stock which
would be issuable upon conversion in full of the Shares, assuming such
conversion occurred on the Original Issue Date or the Filing Date (as defined in
the Registration Rights Agreement), whichever yields a lower Conversion Price,
(ii) the number of shares of Common Stock issuable upon exercise of the Warrant,
and (iii) the number of shares Common Stock which would be issuable upon payment
of dividends on the Shares, assuming each Share is outstanding for three years
and all dividends are paid in shares of Common Stock (such number of shares, the
"Initial Minimum"). All such authorized shares of Common Stock shall be duly
reserved for issuance to the holders of such Shares and Warrant. The shares of
Common Stock issuable upon conversion of the Shares, as payment of dividends
thereon and upon exercise of the Warrant are collectively referred to herein as
the "Underlying Shares." The Shares, the Warrant and the Underlying Shares are,
collectively, the "Securities." When issued in accordance with the 


                                      -3-                  Convertible Preferred
                                                        Stock Purchase Agreement

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Articles of Amendment and the Warrant, in accordance with their respective
terms, the Underlying Shares shall have been duly authorized, validly issued,
fully paid and nonassessable, free and clear of all Liens.

             (e) No Conflicts. The execution, delivery and performance of the
Transaction Documents by the Company and the consummation by the Company of the
transactions contemplated thereby do not and will not (i) conflict with or
violate any provision of its certificate of incorporation, bylaws or other
charter documents (each as amended through the date hereof), or (ii) subject to
obtaining the Required Approvals (as defined below), conflict with, or
constitute a default (or an event which with notice or lapse of time or both
would become a default) under, or give to others any rights of termination,
amendment, acceleration or cancellation (with or without notice, lapse of time
or both) of, any agreement, credit facility, indenture or instrument (evidencing
a Company debt or otherwise) to which the Company or any Subsidiary is a party
or by which any property or asset of the Company or any Subsidiary is bound or
affected, or (iii) result in a violation of any law, rule, regulation, order,
judgment, injunction, decree or other restriction of any court or governmental
authority to which the Company is subject (including Federal and state
securities laws and regulations), or by which any property or asset of the
Company is bound or affected, except in the case of each of clauses (ii) and
(iii), as could not, individually or in the aggregate, have or result in a
Material Adverse Effect. The business of the Company is not being conducted in
violation of any law, ordinance or regulation of any governmental authority,
except for violations which, individually or in the aggregate, could not have or
result in a Material Adverse Effect.

             (f) Consents and Approvals. Neither the Company nor any Subsidiary
is required to obtain any consent, waiver, authorization or order of, give any
notice to, or make any filing or registration with, any court or other Federal,
state, local or other governmental authority or other Person in connection with
the execution, delivery and performance by the Company of the Transaction
Documents, other than (i) the filing of the Articles of Amendment with the
Secretary of State of Wyoming, (ii) the filings required pursuant to Section
3.12, (iii) the filing of a registration statement meeting the requirements set
forth in the Registration Rights Agreement (an "Underlying Securities
Registration Statement") with the Securities and Exchange Commission (the
"Commission") meeting the requirements set forth in the Registration Rights
Agreement and covering the resale of the Underlying Shares by the Purchaser,
(iv) the application(s) to the Nasdaq SmallCap Market (the "NASDAQ") for the
listing of the Underlying Shares with the NASDAQ (and with any other national
securities exchange or market on which the Common Stock is then listed), (v)
applicable Blue Sky filings and, and (vi) in all other cases where the failure
to obtain such consent, waiver, authorization or order, or to give such notice
or make such filing or registration could not have or result in, individually or
in the aggregate, a Material Adverse Effect (the consents, waivers,
authorizations, orders, notices and filings referred to in (i)-(vi) of this
Section are, collectively, the "Required Approvals").

             (g) Litigation; Proceedings. Except as specifically disclosed in
the SEC Documents, there is no action, suit, notice of violation, proceeding or
investigation pending or, to the knowledge of the Company, threatened against or
affecting the Company or any of its Subsidiaries or any of their respective
properties before or by any court, governmental or administrative agency or
regulatory authority (Federal, state, county, local or foreign) which (i)
adversely affects or

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                                                        Stock Purchase Agreement

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challenges the legality, validity or enforceability of any of the Transaction
Documents or the Securities or (ii) could, individually or in the aggregate,
have or result in a Material Adverse Effect.

             (h) No Default or Violation. Neither the Company nor any Subsidiary
(i) is in default under or in violation of (and no event has occurred which has
not been waived which, with notice or lapse of time or both, would result in a
default by the Company or any Subsidiary under), nor has the Company or any
Subsidiary received notice of a claim that it is in default under or that it is
in violation of, any indenture, loan or credit agreement or any other agreement
or instrument to which it is a party or by which it or any of its properties is
bound, (ii) is in violation of any order of any court, arbitrator or
governmental body, or (iii) is in violation of any statute, rule or regulation
of any governmental authority, except as could not individually or in the
aggregate, have or result in a Material Adverse Effect.

             (i) Private Offering. Assuming the accuracy of the representations
and warranties of the Purchaser set forth in Sections 2.2(b)-(h), the offer,
issuance and sale of the Securities to the Purchaser as contemplated hereby are
exempt from the registration requirements of the Securities Act of 1933, as
amended (the "Securities Act"). Neither the Company nor any Person acting on its
behalf has taken any action could subject the offering, issuance or sale of the
Securities to the registration requirements of the Securities Act.

             (j) SEC Documents; Financial Statements. The Company has filed all
reports required to be filed by it under the Exchange Act, including pursuant to
Section 13(a) or 15(d) thereof, for the three years preceding the date hereof
(or such shorter period as the Company was required by law to file such
material) (the foregoing materials being collectively referred to herein as the
"SEC Documents" and, together with the Schedules to this Agreement the
"Disclosure Materials") on a timely basis or has received a valid extension of
such time of filing and has filed any such SEC Documents prior to the expiration
of any such extension. As of their respective dates, the SEC Documents complied
in all material respects with the requirements of the Securities Act and the
Exchange Act and the rules and regulations of the Commission promulgated
thereunder, and none of the SEC Documents, when filed, contained any untrue
statement of a material fact or omitted to state a material fact required to be
stated therein or necessary in order to make the statements therein, in light of
the circumstances under which they were made, not misleading. All material
agreements to which the Company is a party or to which the property or assets of
the Company are subject have been filed as exhibits to the SEC Documents as
required. The financial statements of the Company included in the SEC Documents
comply in all material respects with applicable accounting requirements and the
rules and regulations of the Commission with respect thereto as in effect at the
time of filing. Such financial statements have been prepared in accordance with
generally accepted accounting ("GAAP") principles applied on a consistent basis
during the periods involved, except as may be otherwise specified in such
financial statements or the notes thereto, and fairly present in all material
respects the financial position of the Company and its consolidated subsidiaries
as of and for the dates thereof and the results of operations and cash flows for
the periods then ended, subject, in the case of unaudited statements, to normal,
immaterial, year-end audit adjustments. Since December 31, 1997, except as
specifically disclosed in the SEC Documents, (a) there has been no event,
occurrence or development that has had or that could have or result in a
Material Adverse Effect, (b) the Company has not incurred any liabilities
(contingent or otherwise) other than (x) liabilities 


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                                                        Stock Purchase Agreement

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incurred in the ordinary course of business consistent with past practice and
(y) liabilities not required to be reflected in the Company's financial
statements pursuant to GAAP or required to be disclosed in filings made with the
Commission, (c) the Company has not altered its method of accounting or the
identity of its auditors and (d) except as set forth in Schedule 2.1(j), the
Company has not declared or made any payment or distribution of cash or other
property to its stockholders or officers or directors (other than in compliance
with existing Company stock option plans) with respect to its capital stock, or
purchased, redeemed (or made any agreements to purchase or redeem) any shares of
its capital stock. The Company last filed audited financial statements with the
Commission on December 29, 1997, and has not received any comments from the
Commission in respect thereof.

             (k) Investment Company. The Company is not, and is not an Affiliate
(as defined in Rule 405 under the Securities Act) ) of, an "investment company"
within the meaning of the Investment Company Act of 1940, as amended.

             (l) Certain Fees. Except for certain fees payable by the Company to
Midori Capital Corporation, no fees or commissions will be payable by the
Company to any broker, financial advisor or consultant, finder, placement agent,
investment banker, or bank with respect to the transactions contemplated by this
Agreement. The Purchaser shall have no obligation with respect to any fees or
with respect to any claims made by or on behalf of other Persons for fees of a
type contemplated in this Section that may be due in connection with the
transactions contemplated by this Agreement. The Company shall indemnify and
hold harmless the Purchaser, its employees, officers, directors, agents, and
partners, and their respective Affiliates, from and against all claims, losses,
damages, costs (including the costs of preparation and attorney's fees) and
expenses suffered in respect of any such claimed or existing fees, as such fees
and expenses are incurred.

             (m) Solicitation Materials. Neither the Company nor any Person
acting on the Company's behalf has (i) distributed any offering materials in
connection with the offering and sale of the Securities, or (ii) solicited any
offer to buy or sell the Securities by means of any form of general solicitation
or advertising.

             (n) Form S-3 Eligibility. The Company is eligible to register
securities for resale with the Commission under Form S-3 promulgated under the
Securities Act.

             (o) Exclusivity. The Company shall not issue and sell the Shares to
any Person other than the Purchaser other than with the specific prior written
consent of the Purchaser.

             (p) Seniority. No class of equity securities of the Company is
senior to the Shares in right of payment, whether upon liquidation or
dissolution, or otherwise.

             (q) Listing and Maintenance Requirements Compliance. The Company
has not, in the two years preceding the date hereof, received notice (written or
oral) from the NASDAQ or any other stock exchange, market or trading facility on
which the Common Stock is or has been listed (or on which it has been quoted) to
the effect that the Company is not in compliance with the listing or maintenance
requirements of such exchange or market. The Company is in compliance with all
such maintenance requirements.


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                                                        Stock Purchase Agreement

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             (r) Patents and Trademarks. The Company has, or has rights to use,
all patents, patent applications, trademarks, trademark applications, service
marks, trade names, copyrights, licenses and rights (collectively, the
"Intellectual Property Rights") which are necessary or material for use in
connection with its business, and which the failure to so have would have a
Material Adverse Effect. To the best knowledge of the Company, all such
Intellectual Property Rights are enforceable and there is no existing
infringement by another Person of any of the Intellectual Property Rights.

             (s) Registration Rights; Rights of Participation. Except as set
forth on Schedule 6(b) to the Registration Rights Agreement, (i) the Company has
not granted or agreed to grant to any Person any rights (including "piggy-back"
registration rights) to have any securities of the Company registered with the
Commission or any other governmental authority which has not been satisfied and
(ii) no Person has any right of first refusal, preemptive right, right of
participation, or any similar right to participate in the transactions
contemplated by the Transaction Documents.

             (t) Regulatory Permits. The Company and its Subsidiaries possess
all certificates, authorizations and permits issued by the appropriate Federal,
state or foreign regulatory authorities necessary to conduct their respective
businesses as described in the SEC Documents, except where the failure to
possess such permits could not, individually or in the aggregate, have or result
in a Material Adverse Effect ("Material Permits"), and neither the Company nor
any such Subsidiary has received any notice of proceedings relating to the
revocation or modification of any Material Permit.

             (u) Title. The Company and the Subsidiaries have good and
marketable title in fee simple to all real property and personal property owned
by them which is material to the business of the Company and its Subsidiaries,
in each case free and clear of all Liens, except for liens, claims or
encumbrances as do not materially affect the value of such property and do not
interfere with the use made and proposed to be made of such property by the
Company and its Subsidiaries. Any real property and facilities held under lease
by the Company and its Subsidiaries are held by them under valid, subsisting and
enforceable leases with such exceptions as are not material and do not interfere
with the use made and proposed to be made of such property and buildings by the
Company and its Subsidiaries.

             (v) Disclosure. The Company confirms that it has not provided the
Purchaser or its agents or counsel with any information that constitutes or
might constitute material non-public information. The Company understands and
confirms that the Purchaser shall be relying on the foregoing representations in
effecting transactions in securities of the Company. All disclosure provided to
the Purchaser regarding the Company, its business and the transactions
contemplated hereby, including the Schedules to this Agreement, furnished by or
on behalf of the Company are true and correct and do not contain any untrue
statement of a material fact or omit to state any material fact necessary in
order to make the statements made therein, in light of the circumstances under
which they were made, not misleading.


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                                                        Stock Purchase Agreement

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         2.2 Representations and Warranties of the Purchaser. The Purchaser
hereby represents and warrants to the Company as follows:

             (a) Organization; Authority. The Purchaser is a corporation duly
organized, validly existing and in good standing under the laws of the
jurisdiction of its incorporation with the requisite corporate power and
authority, to enter into and to consummate the transactions contemplated by the
Transaction Documents and otherwise to carry out its obligations thereunder. The
purchase by the Purchaser of the Securities hereunder has been duly authorized
by all necessary action on the part of the Purchaser. Each of this Agreement and
the Registration Rights Agreement has been duly executed and delivered by the
Purchaser and constitutes the valid and legally binding obligation of the
Purchaser, enforceable against it in accordance with its terms.

             (b) Investment Intent. The Purchaser is acquiring the Securities
for its own account for investment purposes only and not with a view to or for
distributing or reselling such Securities or any part thereof or interest
therein, without prejudice, however, to the Purchaser's right, subject to the
provisions of this Agreement and the Registration Rights Agreement, at all times
to sell or otherwise dispose of all or any part of such Securities pursuant to
an effective registration statement under the Securities Act and in compliance
with applicable state securities laws or under an exemption from such
registration.

             (c) Purchaser Status. At the time the Purchaser was offered the
Shares and the Warrant, it was, and at the date hereof it is, and at each
exercise date under the Warrant, it will be, an "accredited investor" as defined
in Rule 501(a) under the Securities Act.

             (d) Experience of the Purchaser. The Purchaser, either alone or
together with its representatives, has such knowledge, sophistication and
experience in business and financial matters so as to be capable of evaluating
the merits and risks of the prospective investment in the Securities, and has so
evaluated the merits and risks of such investment.

             (e) Ability of the Purchaser to Bear Risk of Investment. The
Purchaser is able to bear the economic risk of an investment in the Securities
and, at the present time, is able to afford a complete loss of such investment.

             (f) Access to Information. The Purchaser acknowledges receipt of
the Disclosure Materials and further acknowledges that it has reviewed the
Disclosure Materials and has been afforded (i) the opportunity to ask such
questions as it has deemed necessary of, and to receive answers from,
representatives of the Company concerning the terms and conditions of the
offering of the Securities and the merits and risks of investing in the
Securities; (ii) access to information about the Company and the Company's
financial condition, results of operations, business, proper ties, management
and prospects sufficient to enable it to evaluate its investment; and (iii) the
opportunity to obtain such additional information which the Company possesses or
can acquire without unreasonable effort or expense that is necessary to make an
informed investment decision with respect to the investment and to verify the
accuracy and completeness of the information contained in the Disclosure
Materials. Neither such inquiries nor any other investigation conducted by or on
behalf of such Purchaser or its representatives or counsel shall modify, amend
or affect such Purchaser's right to rely on the truth, accuracy and completeness
of the Disclosure Materials and the Company's representations and warranties
contained in the Transaction Documents.


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                                                        Stock Purchase Agreement
   10

             (g) General Solicitation. The Purchaser is not purchasing the
Shares as a result of or subsequent to any advertisement, article, notice or
other communication regarding the Shares published in any newspaper, magazine or
similar media or broadcast over television or radio or presented at any seminar.

             (h) Reliance. The Purchaser understands and acknowledges that (i)
the Securities are being offered and sold to it without registration under the
Securities Act in a private placement that is exempt from the registration
provisions of the Securities Act and (ii) the availability of such exemption,
depends in part on, and the Company will rely upon the accuracy and truthfulness
of, the foregoing representations and the Purchaser hereby consents to such
reliance.

             The Company acknowledges and agrees that the Purchaser makes no
representations or warranties with respect to the transactions contemplated
hereby other than those specifically set forth in this Section 2.2.


                                   ARTICLE III
                         OTHER AGREEMENTS OF THE PARTIES

         3.1 Transfer Restrictions. (a) Securities may only be disposed of
pursuant to an effective registration statement under the Securities Act, to the
Company or pursuant to an available exemption from or in a transaction not
subject to the registration requirements of the Securities Act. In connection
with any transfer of Securities other than pursuant to an effective registration
statement or to the Company, except as otherwise set forth herein, the Company
may require the transferor thereof to provide to the Company an opinion of
counsel selected by the transferor, the form and substance of which opinion
shall be reasonably satisfactory to the Company, to the effect that such
transfer does not require registration of such transferred securities under the
Securities Act. Notwithstanding the foregoing, the Company hereby consents to
and agrees to register on the books of the Company and with any transfer agent
for the securities of the Company any transfer of Securities by the Purchaser to
an Affiliate of the Purchaser or to a fund under common management with the
Purchaser, and any transfer among any such Affiliates or funds, provided that
transferee certifies to the Company that it is an "accredited investor" as
defined in Rule 501(a) under the Securities Act and that it is acquiring the
Securities solely for investment purposes. Any such transferee shall agree in
writing to be bound by the terms of this Agreement and shall have the rights of
a Purchaser under this Agreement and the Registration Rights Agreement.

             (b) The Purchaser agrees to the imprinting, so long as is required
by this Section 3.1(b), of the following legend on the Securities:

             NEITHER THESE SECURITIES NOR THE SECURITIES INTO WHICH THESE
       SECURITIES ARE [CONVERTIBLE] [EXERCISABLE] HAVE BEEN REGISTERED WITH THE
       SECURITIES AND EXCHANGE COMMISSION OR THE SECURITIES COMMISSION OF ANY
       STATE IN RELIANCE UPON AN EXEMPTION FROM REGISTRATION UNDER THE
       SECURITIES ACT OF 1933, AS AMENDED (THE "SECURITIES ACT"), AND,
       ACCORDINGLY, MAY NOT BE OFFERED OR SOLD


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                                                        Stock Purchase Agreement

   11

       EXCEPT PURSUANT TO AN EFFECTIVE REGISTRATION STATEMENT UNDER THE
       SECURITIES ACT OR PURSUANT TO AN AVAILABLE EXEMPTION FROM, OR IN A
       TRANSACTION NOT SUBJECT TO, THE REGISTRATION REQUIREMENTS OF THE
       SECURITIES ACT AND IN ACCORDANCE WITH APPLICABLE STATE SECURITIES LAWS.

             The Company shall issue Underlying Shares free of the legend set
forth above (and free of any other legend) if the conversion of Shares, the
payment of dividends thereon, or exercise of the Warrant or other issuances of
Underlying Shares as contemplated hereby, by the Articles of Amendment or the
Warrant occurs at any time while an Underlying Securities Registration Statement
is effective under the Securities Act or, in the event there is not an effective
Underlying Securities Registration Statement at such time, if in the opinion of
counsel to the Company such legend is not required under applicable requirements
of the Securities Act (including judicial interpretations and pronouncements
issued by the staff of the Commission). The Company shall cause its counsel to
issue the legal opinion included in the Transfer Agent Instructions to the
Company's transfer agent on the day that the Underlying Securities Registration
Statement is declared effective by the Commission. The Company agrees that it
will provide the Purchaser, upon request, with a certificate or certificates
representing Underlying Shares that may have been issued with the restrictive
legend set forth above, free from such legend at such time as such legend is no
longer required hereunder (for example, there is an effective Underlying
Securities Registration Statement). The Company may not make any notation on its
records or give instructions to any transfer agent of the Company which enlarge
the restrictions of transfer set forth in this Section.

         3.2 Acknowledgment of Dilution. The Company acknowledges that the
issuance of the Underlying Shares upon (i) conversion of the Shares and payment
of dividends thereon in accordance with the terms of the Articles of Amendment,
and (ii) exercise of the Warrant in accordance with its terms, may result in
dilution of the outstanding shares of Common Stock, which dilution may be
substantial under certain market conditions. The Company further acknowledges
that its obligation to issue Underlying Shares upon (x) conversion of the Shares
and payment of dividends thereon in accordance with the terms of the Articles of
Amendment, and (y) exercise of the Warrant in accordance with its terms, is
unconditional and absolute, subject to the limitations set forth in the Articles
of Amendment or pursuant to the Warrant, regardless of the effect of any such
dilution.

         3.3 Furnishing of Information. So long as the Purchaser owns
Securities, the Company covenants to timely file (or obtain extensions in
respect thereof and file within the applicable grace period) all reports
required to be filed by the Company after the date hereof pursuant to Section
13(a) or 15(d) of the Exchange Act. So long as the Purchaser owns Securities, if
the Company is not required to file reports pursuant to such sections, it will
prepare and furnish to the Purchaser and make publicly available in accordance
with Rule 144(c) promulgated under the Securities Act annual and quarterly
financial statements, together with a discussion and analysis of such financial
statements in form and substance substantially similar to those that would
otherwise be required to be included in reports required by Section 13(a) or
15(d) of the Exchange Act, as well as any other information required thereby, in
the time period that such filings would have been required to have been made
under the Exchange Act. The Company further covenants that it will take such
further action as any holder of Securities may reasonably request, all to the
extent required from time to time to enable 


                                     -10-                  Convertible Preferred
                                                        Stock Purchase Agreement

   12

such Person to sell Underlying Shares without registration under the Securities
Act within the limitation of the exemptions provided by Rule 144 promulgated
under the Securities Act, including the legal opinion referenced above in this
Section. Upon the request of any such Person, the Company shall deliver to such
Person a written certification of a duly authorized officer as to whether it has
complied with such requirements.

         3.4 Blue Sky Laws. In accordance with the Registration Rights
Agreement, the Company shall qualify or exempt the issuance and sale of the
Underlying Shares under the securities or Blue Sky laws of such jurisdictions as
the Purchaser may reasonably request and shall continue such qualification or
exemption at all times until the Purchaser notifies the Company in writing that
it no longer owns Securities; provided, however, that neither the Company nor
its Subsidiaries shall be required in connection therewith to qualify as a
foreign corporation where they are not now so qualified or to take any action
that would subject the Company to general service of process in any such
jurisdiction where it is not then subject.

         3.5 Integration. The Company shall not, and shall use its best efforts
to ensure that, no Affiliate shall, sell, offer for sale or solicit offers to
buy or otherwise negotiate in respect of any security (as defined in Section 2
of the Securities Act) that would be integrated with the offer or sale of the
Securities in a manner that would require the registration under the Securities
Act of the sale of the Securities to the Purchaser.

         3.6 Increase in Authorized Shares. Subject to the operation of any
floor that may then be applicable to the Conversion Price in accordance with the
Articles of Amendment, at such times as the Company would be, if a notice of
conversion or exercise (as the case may be) were to be delivered on such date,
precluded from (a) issuing 200% of the number of Underlying Shares as would then
be issuable upon a conversion in full of the Shares and as payment of any
accrued and unpaid dividends in respect thereof in shares of Common Stock, or
(b) honoring the exercise in full of the Warrant, in either case, due to the
unavailability of a sufficient number of shares of authorized but unissued or
reserved Common Stock, the Board of Directors of the Company shall promptly (and
in any case, within 30 Business Days from such date) prepare and mail to the
stockholders of the Company proxy materials requesting authorization to amend
the Company's Certificate of Incorporation to increase the number of shares of
Common Stock which the Company is authorized to issue to at least such number of
shares as reasonably requested by the Purchaser in order to provide for such
number of authorized and unissued shares of Common Stock to enable the Company
to comply with its conversion, exercise and reservation of shares obligations as
set forth in this Agreement, the Articles of Amendment and the Warrant (the sum
of (x) the number of shares of Common Stock then authorized, (y) the number of
shares of Common Stock then outstanding plus all shares of Common Stock issuable
upon exercise of all outstanding options, warrants and convertible instruments
(other than the Underlying Shares), and (z) subject to the operation of any
floor that may then be applicable to the Conversion Price in accordance with the
Articles of Amendment the sum of (i) 200% of the number of Underlying Shares as
are then issuable upon a conversion in full of all Shares and as payment of
dividends thereon, and (ii) the number of Underlying Shares as are issuable upon
exercise in full of the Warrant, shall be a reasonable number). In connection
therewith, the Board of Directors shall (a) adopt proper resolutions authorizing
such increase, (b) recommend to and otherwise use its best efforts to promptly
and duly obtain stockholder 


                                     -11-                  Convertible Preferred
                                                        Stock Purchase Agreement

   13

approval to carry out such resolutions (and hold a special meeting of the
stockholders no later than the 60th day after delivery of the proxy materials
relating to such meeting) and (c) within five (5) Business Days of obtaining
such stockholder authorization, file an appropriate amendment to the Company's
Certificate of Incorporation to evidence such increase.

         3.7 Listing and Reservation of Underlying Shares. (a) The Company shall
(i) not later than the fifth Business Day following the Closing Date hereunder
prepare and file with the NASDAQ (or such other national securities exchange or
market or trading or quotation facility on which the Common Stock is then
listed) an additional shares listing application covering a number of shares of
Common Stock which is at least equal to the number of shares required to be
reserved pursuant to Section 2.1(d), (ii) take all steps necessary to cause such
shares to be approved for listing in the NASDAQ (as well as on any such other
national securities exchange or market or trading or quotation facility on which
the Common Stock is then listed) as soon as possible thereafter, and (iii)
provide to the Purchaser evidence of such listing, and the Company shall
maintain the listing of its Common Stock thereon. If the number of Underlying
Shares as are issuable upon conversion in full of the then outstanding Shares,
as payment of dividends thereon, and upon exercise of the then unexercised
portion of the Warrant exceeds 85% of the number of Underlying Shares previously
listed on account thereof with NASDAQ (and such other required exchanges), the
Company shall take the necessary actions to immediately list a number of
Underlying Shares as equals the sum of (x) 200% of the number of Underlying
Shares then issuable upon conversion of the Shares and as payment of dividends
thereon and (y) the number of Underlying Shares as are then issuable upon
exercise of the Warrant.

             (b) The Company shall maintain a reserve of Common Stock for
issuance upon conversion of the Shares and for payment of dividends thereupon in
shares of Common Stock pursuant to the terms of the Articles of Amendment and
upon exercise of the Warrant in accordance with its terms, in such amount as may
be required to fulfill obligations in full under the Transaction Documents,
which reserve shall include a number of shares of Common Stock equal to no less
than the Initial Minimum.

         3.8 Conversion Procedures. The Transfer Agent Instructions, Conversion
Notice (as defined in Exhibit A) and Notice of Exercise under the Warrant set
forth the totality of the procedures with respect to the conversion of the
Shares and exercise of the Warrant, including the form of legal opinion, if
necessary, that shall be rendered to the Company's transfer agent and such other
information and instructions as may be reasonably necessary to enable the
Purchaser to convert its Shares and exercise the Warrant as contemplated in the
Articles of Amendment and the Warrant (as applicable).

         3.9 Notice of Breaches. (a) Each of the Company and the Purchaser shall
give prompt written notice to the other of any breach by it of any
representation, warranty or other agreement contained in any Transaction
Document, as well as any events or occurrences arising after the date hereof
which would reasonably be likely to cause any representation or warranty or
other agreement of such party, as the case may be, contained therein to be
incorrect or breached as of the Closing Date. However, no disclosure by either
party pursuant to this Section shall be deemed to cure any breach of any
representation, warranty or other agreement contained in any Transaction
Document.


                                     -12-                  Convertible Preferred
                                                        Stock Purchase Agreement
   14

             (b) Notwithstanding the generality of Section 3.9(a), the Company
shall promptly notify the Purchaser of any notice or claim (written or oral)
that it receives from any lender of the Company to the effect that the
consummation of the transactions contemplated by the Transaction Documents
violates or would violate any written agreement or understanding between such
lender and the Company, and the Company shall promptly furnish by facsimile to
the holders of the Securities a copy of any written statement in support of or
relating to such claim or notice.

         3.10 Conversion and Exercise Obligations of the Company. The Company
shall honor conversions of the Shares and exercises of the Warrant and shall
deliver Underlying Shares in accordance with the respective terms, conditions
and time periods set forth in the respective Articles of Amendment and the
Warrant.

         3.11 Right of First Refusal; Subsequent Registrations. (a) Subject to
the provisions of Section 3.11(b), the Company shall not, directly or
indirectly, without the prior written consent of the Purchaser, offer, sell,
grant any option to purchase, or otherwise dispose of (or announce any offer,
sale, grant or any option to purchase or other disposition) any of its or its
Affiliates' equity or equity-equivalent securities in a transaction intended to
be exempt or not subject to registration under the Securities Act (a "Subsequent
Placement") for a period of 360 days after the Closing Date, except (i) the
granting of options or warrants to employees, officers and directors, and the
issuance of shares upon exercise of options granted, under any stock option plan
heretofore or hereinafter duly adopted by the Company, (ii) shares of Common
Stock issued upon exercise of any currently outstanding warrants and upon
conversion of any currently outstanding convertible securities of the Company,
in each case disclosed in Schedule 2.1(c), (iii) Common Stock issued on a
primary basis pursuant to an underwritten public offering, so long as any shares
of Common Stock sold in such underwritten offering are not sold at a price less
than the average of the Per Share Market Values on the five (5) Trading Days
immediately preceding the sale of such Common Stock and (iv) shares of Common
Stock issued upon conversion of Preferred Stock and as payment of dividends
thereon and upon exercise of the Warrant in accordance with the Articles of
Amendment or the Warrant, respectively, unless (A) the Company delivers to the
Purchaser a written notice (the "Subsequent Placement Notice") of its intention
effect such Subsequent Placement, which Subsequent Placement Notice shall
describe in reasonable detail the proposed terms of such Subsequent Placement,
the amount of proceeds intended to be raised thereunder, the Person with whom
such Subsequent Placement shall be effected, and attached to which shall be a
term sheet or similar document relating thereto and (B) the Purchaser shall not
have notified the Company by 5:00 p.m. (New York City time) on the tenth (10th)
Trading Day after its receipt of the Subsequent Placement Notice of its
willingness to provide (or to cause its sole designee to provide), subject to
completion of mutually acceptable documentation, financing to the Company on
substantially the terms set forth in the Subsequent Placement Notice. If the
Purchaser shall fail to notify the Company of its intention to enter into such
negotiations within such time period, the Company may effect the Subsequent
Placement substantially upon the terms and to the Persons (or Affiliates of such
Persons) set forth in the Subsequent Placement Notice; provided, that the
Company shall provide the Purchaser with a second Subsequent Placement Notice,
and the Purchaser shall again have the right of first refusal set forth above in
this paragraph (a), if the Subsequent Placement subject to the initial
Subsequent Placement Notice shall not have been consummated for any reason on
the terms set forth in such Subsequent Placement


                                     -13-                  Convertible Preferred
                                                        Stock Purchase Agreement
   15

Notice within thirty (30) Trading Days after the date of the initial Subsequent
Placement Notice with the Person (or an Affiliate of such Person) identified in
the Subsequent Placement Notice.

             (b) Notwithstanding anything to the contrary contained in Section
3.11(a), the Company may conduct a Subsequent Placement without affording the
Purchaser its right of first refusal set forth in Section 3.11(a) so long as (i)
the amount of capital to be raised is not in excess of $2,000,000, (ii) the only
investors permitted to participate (directly or indirectly) in the Subsequent
Placement described in this Section 3.11(b) (a "Limited Placement") are Persons
that the Company can prove to the Purchaser's satisfaction were beneficial
owners of the capital stock of the Company on the Closing Date, and the
Purchaser, as provided below, (iii) the securities issued in the Limited
Placement may not be resold and no registration statement covering such shares
or the resale thereof may be filed for a period of one (1) year following the
consummation of such Limited Placement and (iii) (A) the Company shall have
delivered to the Purchaser a written notice ("Limited Placement Notice") of its
intention to effect such Limited Placement which Limited Placement Notice shall
describe in reasonable detail the proposed terms of such Limited Placement, the
amount of proceeds intended to be raised thereunder, the Persons with whom such
Limited Placement shall be effected, and attached to which shall be a term sheet
or similar document relating thereto and (B) the Purchaser shall not have
notified the Company by 5:00 p.m. (New York City time) on the third (3rd)
Trading Day after its receipt of the Limited Placement Notice of its willingness
to provide (or to cause its sole designee to provide), subject to completion of
mutually acceptable documentation, up to forty (40%) percent of the financing in
the Limited Placement on substantially the terms set forth in the Limited
Placement Notice. If the Purchaser shall fail to notify the Company of its
intention to enter into such negotiations within such time period, the Company
may effect the Limited Placement substantially upon the terms and to the Persons
set forth in the Limited Placement Notice; provided, that the Company shall
provide the Purchaser with a second Limited Placement Notice, and the Purchaser
shall again have the right of first refusal set forth above in this paragraph
(b)(i), if the Limited Placement subject to the initial Limited Placement Notice
shall not have been consummated for any reason on the terms set forth in such
Limited Placement Notice within thirty (30) Trading Days after the date of the
initial Limited Placement Notice with the Persons identified in the Limited
Placement Notice; and

             (c) Except for (x) Underlying Shares, (y) other "Registrable
Securities" (as such term is defined in the Registration Rights Agreement) to be
registered, and securities of the Company permitted pursuant to Schedule 6(b) of
the Registration's Rights Agreement to be registered in the Underlying
Securities Registration in accordance with the Registration Rights Agreement,
and (z) Common Stock to be registered for resale in connection with financings
permitted pursuant to paragraph (a)(i) - (iv) of Section 3.11(a), the Company
shall not, without the prior written consent of the Purchaser (i) issue or sell
any of its or any of its Affiliates' equity or equity-equivalent securities
pursuant to Regulation S promulgated under the Securities Act, or (ii) register
for resale any securities of the Company for a period of not less than 90
Trading Days after the date that the Underlying Securities Registration
Statement is declared effective by the Commission. Any days that a Purchaser is
unable to sell Underlying Securities under the Underlying Securities
Registration Statement shall be added to such 90 Trading Day period for the
purposes of (i) and (ii) above.


                                     -14-                  Convertible Preferred
                                                        Stock Purchase Agreement
   16

         3.12 Certain Securities Laws Disclosures; Publicity. The Company shall:
(i) issue a press release acceptable to the Purchaser disclosing the
transactions contemplated hereby on the Closing Date, (ii) file with the
Commission a Report on Form 8-K disclosing the transactions contemplated hereby
within ten (10) Business Days after the Closing Date, and (iii) timely file with
the Commission a Form D promulgated under the Securities Act as required under
Regulation D promulgated under the Securities Act and provide a copy thereof to
the Purchaser promptly after the filing thereof. The Company shall, no less than
two (2) Business Days prior to the filing of any disclosure required by clauses
(ii) and (iii) above, provide a copy thereof to Purchaser. No such filing or
disclosure may be made that mentions the Purchaser by name without the prior
consent of Purchaser.

         3.13 Use of Proceeds. The Company shall use the net proceeds from the
sale of the Securities hereunder for working capital purposes and not for the
satisfaction of any portion of Company debt or to redeem any Company equity or
equity-equivalent securities. Pending application of the proceeds of this
placement in the manner permitted hereby, the Company will invest such proceeds
in interest bearing accounts and/or short-term, investment grade interest
bearing securities.

         3.14 Transfer of Intellectual Property Rights. Except in connection
with the sale of all or substantially all of the assets of the Company, the
Company shall not transfer, sell or otherwise dispose of any Intellectual
Property Rights, or allow any of the Intellectual Property Rights to become
subject to any Liens, or fail to renew such Intellectual Property Rights (if
renewable and it would otherwise lapse if not renewed), without the prior
written consent of the Purchaser.

         3.15 Reimbursement. If the Purchaser, other than by reason of its gross
negligence or willful misconduct, becomes involved in any capacity in any
action, proceeding or investigation brought by or against any Person, including
stockholders of the Company, in connection with or as a result of the
consummation of the transactions contemplated by Transaction Documents, the
Company will reimburse the Purchaser for its reasonable legal and other expenses
(including the cost of any investigation and preparation) incurred in connection
therewith, as such expenses are incurred. In addition, other than with respect
to any matter in which the Purchaser is a named party, the Company will pay the
Purchaser the charges, as reasonably determined by the Purchaser, for the time
of any officers or employees of the Purchaser devoted to appearing and preparing
to appear as witnesses, assisting in preparation for hearings, trials or
pretrial matters, or otherwise with respect to inquiries, hearings, trials, and
other proceedings relating to the subject matter of this Agreement. The
reimbursement obligations of the Company under this paragraph shall be in
addition to any liability which the Company may otherwise have, shall extend
upon the same terms and conditions to any Affiliates of the Purchaser who are
actually named in such action, proceeding or investigation, and partners,
directors, agents, employees and controlling persons (if any), as the case may
be, of the Purchaser and any such Affiliate, and shall be binding upon and inure
to the benefit of any successors, assigns, heirs and personal representatives of
the Company, the Purchaser and any such Affiliate and any such Person. The
Company also agrees that neither the Purchaser nor any such Affiliates,
partners, directors, agents, employees or controlling persons shall have any
liability to the Company or any person asserting claims on behalf of or in right
of the Company in connection with or as a result of the consummation of the
Transaction Documents except to the extent that any losses, claims, damages,
liabilities or expenses incurred by the Company result from the gross negligence
or willful


                                     -15-                  Convertible Preferred
                                                        Stock Purchase Agreement

   17

misconduct of the Purchaser or entity in connection with the transactions
contemplated by this Agreement.

         3.16 Indemnification by the Company. The Company shall, notwithstanding
any termination of this Agreement, indemnify and hold harmless the Purchaser,
the officers, directors, agents, brokers, investment advisors and employees of
the Purchaser, each Person who controls the Purchaser (within the meaning of
Section 15 of the Securities Act or Section 20 of the Exchange Act) and the
officers, directors, agents and employees of each such controlling Person, to
the fullest extent permitted by applicable law, from and against any and all
losses, claims, damages, liabilities, costs (including, without limitation,
costs of preparation and attorneys' fees) and expenses, as incurred, arising out
of or relating the inaccuracy of any of the representations and warranties of
the Company set forth in Section 2.1 hereto.

         3.17 Delivery of Opinion. Within 30 calendar days of the Closing Date,
the Company shall deliver or cause to be delivered to the Company a legal
opinion of outside counsel to the Company reasonably acceptable to the
Purchaser, substantially in the form of Exhibit C. If the Company fails to
deliver to the Purchaser the legal opinion referenced in this Section within 30
calendar days of the Closing Date, the Company shall pay to the Purchaser, in
cash, as liquidated damages and not as a penalty, $20,000 for each day
thereafter ("Opinion Damages") until the Company delivers such legal opinion to
the Purchaser. The Opinion Damages shall be payable weekly to the Purchaser.


                                   ARTICLE IV
                                  MISCELLANEOUS

         4.1 Fees and Expenses. At the Closing the Company shall pay $15,000 to
the Escrow Agent in connection with the preparation and negotiation of the
Transaction Documents. Other than the amounts contemplated in the immediately
preceding sentence, and except as otherwise set forth in the Registration Rights
Agreement, each party shall pay the fees and expenses of its advisers, counsel,
accountants and other experts, if any, and all other expenses incurred by such
party incident to the negotiation, preparation, execution, delivery and
performance of this Agreement. The Company shall pay all stamp and other taxes
and duties levied in connection with the issuance of the Securities.

         4.2 Entire Agreement; Amendments. This Agreement, together with the
Exhibits and Schedules hereto, the Registration Rights Agreement, the Articles
of Amendment, the Transfer Agent Instructions and the Warrant contain the entire
understanding of the parties with respect to the subject matter hereof and
supersede all prior agreements and understandings, oral or written, with respect
to such matters, which the parties acknowledge have been merged into such
documents, exhibits and schedules.

         4.3 Notices. Any and all notices or other communications or deliveries
required or permitted to be provided hereunder shall be in writing and shall be
deemed given and effective on the earliest of (i) the date of transmission, if
such notice or communication is delivered via facsimile


                                     -16-                  Convertible Preferred
                                                        Stock Purchase Agreement

   18

at the facsimile telephone number specified in this Section prior to 8:00 p.m.
(New York City time) on a Business Day, (ii) the Business Day after the date of
transmission, if such notice or communication is delivered via facsimile at the
facsimile telephone number specified below later than 8:00 p.m. (New York City
time) on any date and earlier than 11:59 p.m. (New York City time) on such date,
(iii) the Business Day following the date of mailing, if sent by nationally
recognized overnight courier service, or (iv) upon actual receipt by the party
to whom such notice is required to be given. The address for such notices and
communications shall be as follows:

         If to the Company:         Tanisys Technology, Inc.
                                    12201 Technology Blvd., Suite 125
                                    Austin, TX  78727-6101
                                    Facsimile No.: (512) 257-5351
                                    Attention: Chief Financial Officer

         With copies to:            Mr. Andie Long
                                    c/o Billing Concepts Corp.
                                    7411 John Smith Drive, Suite 1500
                                    San Antonio, TX  78229
                                    Facsimile No.: (210) 949-7024

         If to the
         Purchaser:                 KA Investments LDC
                                    1712 Hopkins Crossroads
                                    Minnetonka, MN  55305
                                    Facsimile No.: (612) 542-4284
                                    Attention: Mr. Bruce Lieberman

         With copies to:            Robinson Silverman Pearce Aronsohn &
                                      Berman LLP
                                    1290 Avenue of the Americas
                                    New York, NY  10104
                                    Facsimile No.:  (212) 541-4630
                                    Attn: Kenneth L. Henderson

or such other address as may be designated in writing hereafter, in the same
manner, by such Person.

         4.4 Amendments; Waivers. No provision of this Agreement may be waived
or amended except in a written instrument signed, in the case of an amendment,
by both the Company and the Purchaser; or, in the case of a waiver, by the party
against whom enforcement of any such waiver is sought. No waiver of any default
with respect to any provision, condition or requirement of this Agreement shall
be deemed to be a continuing waiver in the future or a waiver of any other
provision, condition or requirement hereof, nor shall any delay or omission of
either party to exercise any right hereunder in any manner impair the exercise
of any such right accruing to it thereafter.


                                     -17-                  Convertible Preferred
                                                        Stock Purchase Agreement
   19

         4.5 Headings. The headings herein are for convenience only, do not
constitute a part of this Agreement and shall not be deemed to limit or affect
any of the provisions hereof.

         4.6 Successors and Assigns. This Agreement shall be binding upon and
inure to the benefit of the parties and their successors and permitted assigns.
The Company may not assign this Agreement or any rights or obligations hereunder
without the prior written consent of the Purchaser. Except as set forth in
Section 3.1(a), the Purchaser may not assign this Agreement or any of the rights
or obligations hereunder (other than to an Affiliate of the Purchaser) without
the consent of the Company, except that the Purchaser may assign its rights
hereunder and under the Transaction Documents without the consent of the Company
so long as such assignee demonstrates to the reasonable satisfaction of the
Company its satisfaction of the representations and warranties set forth in
Section 2.2. This provision shall not limit the Purchaser's right to transfer
securities or transfer or assign rights hereunder or under the Registration
Rights Agreement.

         4.7 No Third-Party Beneficiaries. This Agreement is intended for the
benefit of the parties hereto and their respective successors and permitted
assigns, is not for the benefit of, nor may any provision hereof be enforced by,
any other Person.

         4.8 Governing Law. This Agreement shall be governed by and construed
and enforced in accordance with the internal laws of the State of New York
without regard to the principles of conflicts of law thereof. Each party hereby
irrevocably submits to the exclusive jurisdiction of the state and federal
courts sitting in the City of New York, borough of Manhattan, for the
adjudication of any dispute hereunder or in connection herewith or with any
transaction contemplated hereby or discussed herein (including with respect to
the enforcement of the any of the Transaction Documents), and hereby irrevocably
waives, and agrees not to assert in any suit, action or proceeding, any claim
that it is not personally subject to the jurisdiction of any such court, that
such suit, action or proceeding is improper. Each party hereby irrevocably
waives personal service of process and consents to process being served in any
such suit, action or proceeding by mailing a copy thereof to such party at the
address in effect for notices to it under this Agreement and agrees that such
service shall constitute good and sufficient service of process and notice
thereof. Nothing contained herein shall be deemed to limit in any way any right
to serve process in any manner permitted by law.

         4.9 Survival. The representations, warranties, agreements and covenants
contained herein shall survive the Closing and the delivery and conversion or
exercise (as the case may be) of the Shares and the Warrant.

         4.10 Execution. This Agreement may be executed in two or more
counterparts, all of which when taken together shall be considered one and the
same agreement and shall become effective when counterparts have been signed by
each party and delivered to the other party, it being understood that both
parties need not sign the same counterpart. In the event that any signature is
delivered by facsimile transmission, such signature shall create a valid and
binding obligation of the party executing (or on whose behalf such signature is
executed) the same with the same force and effect as if such facsimile signature
page were an original thereof.


                                     -18-                  Convertible Preferred
                                                        Stock Purchase Agreement

   20

         4.11 Publicity. The Company and the Purchaser shall consult with each
other in issuing any press releases or otherwise making public statements or
filings and other communications with the Commission or any regulatory agency or
stock market or trading facility with respect to the transactions contemplated
hereby and neither party shall issue any such press release or otherwise make
any such public statement, filings or other communications without the prior
written consent of the other, which consent shall not be unreasonably withheld
or delayed, except that no prior consent shall be required if such disclosure is
required by law, in which such case the disclosing party shall provide the other
party with prior notice of such public statement, filing or other communication.
Notwithstanding the foregoing, the Company shall not publicly disclose the name
of the Purchaser, or include the name of the Purchaser in any filing with the
Commission, or any regulatory agency, trading facility or stock market without
the prior written consent of Purchaser, except to the extent such disclosure
(but not any disclosure as to the controlling Persons thereof) is required by
law, in which case the Company shall provide the Purchaser with prior notice of
such disclosure.

         4.12 Severability. In case any one or more of the provisions of this
Agreement shall be invalid or unenforceable in any respect, the validity and
enforceability of the remaining terms and provisions of this Agreement shall not
in any way be affecting or impaired thereby and the parties will attempt to
agree upon a valid and enforceable provision which shall be a reasonable
substitute therefor, and upon so agreeing, shall incorporate such substitute
provision in this Agreement.

         4.13 Remedies. In addition to being entitled to exercise all rights
provided herein or granted by law, including recovery of damages, the Purchaser
will be entitled to specific performance of the obligations of the Company under
the Transaction Documents. Each of the Company and the Purchaser agree that
monetary damages may not be adequate compensation for any loss incurred by
reason of any breach of its obligations described in the foregoing sentence and
hereby agrees to waive in any action for specific performance of any such
obligation the defense that a remedy at law would be adequate.

                   [REMAINDER OF PAGE INTENTIONALLY LEFT BLANK
                             SIGNATURE PAGE FOLLOWS]


                                     -19-                  Convertible Preferred
                                                        Stock Purchase Agreement

   21

         IN WITNESS WHEREOF, the parties hereto have caused this Convertible
Preferred Stock Purchase Agreement to be duly executed by their respective
authorized signatories as of the date first indicated above.


                                           TANISYS TECHNOLOGY, INC.


                                           By:
                                              ----------------------------------
                                              Name:
                                              Title:



                                           KA INVESTMENTS LDC


                                           By:
                                              ----------------------------------
                                              Name:
                                              Title: