Exhibit
10.4

     

    THINK
HOLDINGS AS

     

    PROMISSORY
NOTE

     

    
      
        	
                Issue
      Date:  October 1, 2010

              	
                $5,000,000.00

              


      

    

    


    FOR VALUE RECEIVED, THINK
HOLDINGS AS, a
Norwegian limited liability company (the “Company”),
hereby promises to pay to the order of ENER1, INC., or its permitted successors
or assigns (the “Holder”),
the sum of FIVE MILLION U.S. DOLLARS (US$5,000,000.00) in same day funds on or
before November 15, 2010 (the “Maturity
Date”) or as is provided by Section
1(b) below.

     

    1.       
    PAYMENT OF
THIS NOTE.

     

    (a)           Interest
Rate.  From and including the date hereof, this Note shall bear
interest on the unpaid principal amount hereof (“Interest”)
at an annual rate equal to 5%, computed on the basis of a 360-day year and
calculated using the actual number of days elapsed since and including the Issue
Date or the date on which Interest was most recently paid, as the case may
be.

     

    (b)           Payment on Maturity
Date.  The outstanding
principal amount of this Note plus all accrued and unpaid
Interest shall be paid in full on the earlier of (i) the Maturity Date or (ii)
the completion of the new round of Series B Preferred Stock financing by Think
Holdings AS scheduled to close on or about October 31, 2010 (or such other
equity financing approved by the Holder).  All amounts due on this
Note that is not timely paid will accrue interest at the default interest rate
of the lesser of 18% per annum and the maximum interest rate permitted by
applicable law; compounded monthly, until paid.

    


    (c)           Payment in
Cash.  All payments of principal and Interest (including
default interest (if any)) shall be paid in cash by wire transfer of immediately
available funds.

    


    2.        
   MISCELLANEOUS.

     

    (a)           Failure to Exercise Rights
not Waiver.  No failure or delay on the part of the Holder in
the exercise of any power, right or privilege hereunder shall operate as a
waiver thereof, nor shall any single or partial exercise of any such power,
right or privilege preclude any other or further exercise thereof. All rights
and remedies of the Holder hereunder are cumulative and not exclusive of any
rights or remedies otherwise available. In the event that the Company does not
pay any amount under this Note when such amount becomes due, the Company shall
bear all costs incurred by the Holder in collecting such amount, including,
without limitation, reasonable legal fees and expenses.

     

    (b)           Notices. Any notice,
demand or request required or permitted to be given by the Company or the Holder
pursuant to the terms of this Note shall be in writing.


    
      
         


      

      
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    (c)           Amendments
and Waivers.  No
amendment to this Note may be made or given except pursuant to a written
instrument executed by the Company and by the Holder.  No waiver of
any provision of this Note
may be made except pursuant to a written instrument executed by the party against whom such waiver is
sought to be enforced.  Any waiver given pursuant hereto shall be
effective only in the specific instance and for the specific purpose for which
given.

     

    (d)           Lost or Stolen
Note.  Upon receipt by the Company of evidence of the loss,
theft, destruction or mutilation of this Note, and (in the case of loss, theft
or destruction) of indemnity or security reasonably satisfactory to the Company,
and upon surrender and cancellation of the Note, if mutilated, the Company shall
execute and deliver to the Holder a new Note identical in all respects to this
Note.

     

    (e)           Governing
Law.  This Note shall be governed by and construed in
accordance with the laws of Norway and we accept Oslo tingrett as due venue for
any disputes arising hereunder.

     

    (f)           Successors and
Assigns.  The Holder may not sell, transfer or otherwise
dispose of all or any part of this Note (including, without limitation, pursuant
to a pledge) to any person or entity without the Company’s prior written consent
(which shall not be unreasonably withheld).  The Company may not
assign its rights or obligations under this Note without the prior written
consent of the Holder.  The terms and conditions of this Note
shall inure to the benefit of and be binding upon the respective successors
(whether by merger or otherwise) and permitted assigns of the Company and the
Holder.

     

    (f)           Usury.  This
Note is subject to the express condition that at no time shall the Company be
obligated or required to pay interest hereunder at a rate which could subject
the Holder to either civil or criminal liability as a result of being in excess
of the maximum interest rate which the Company is permitted by applicable law to
contract or agree to pay.  If by the terms of this Note, the Company
is at any time required or obligated to pay interest hereunder at a rate in
excess of such maximum rate, the rate of interest under this Note shall be
deemed to be immediately reduced to such maximum rate and the interest payable
shall be computed at such maximum rate and all prior interest payments in excess
of such maximum rate shall be applied and shall be deemed to have been payments
in reduction of the principal balance of this Note.

     

    [Signature
Page to Follow]

     

    
      
         

      

      
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    IN
WITNESS WHEREOF, the Company has caused this Note to be signed in its name by
its duly authorized officer on the date first above written.

     

    THINK
HOLDINGS AS

    


    
      
        	
                By:

              	
                /s/ Barry Engle

              	 
      
	 
      	
                Name:
       Barry Engle

              
	 
      	
                Title: Chief
      Executive Officer

              


      

    

     

    We, the
undersigned, both being of legal age, hereby confirm that the above-mentiond
have signed this Promissory Note in our presence.

    


    
      
        	
                Name:

              	 
      	 
      	
                Name:

              	 
      
	
                Date
      of birth.

              	 
      	 
      	
                Date
      of birth.

              	 
      
	 
      	 
      	 
      	 
      	 
      
	
                Address:

              	 
      	 
      	
                Address:

              	 
      
	
                Signature.

              	 
      	 
      	
                Signature.