January
19, 2012


VIA E-MAIL


Lenders under that certain
Loan Agreement dated as

of November 16, 2011, as amended, with Ener1, Inc.

c/o Bzinfin S.A., as Agent

Avocat

Budin & Associés

20, Rue Jean Sénebier

CP 166

1211 Genève 12

Attention: Patrick Bittel


Dear
Mr. Bittel,


Reference
is made to that certain (i) Loan Agreement dated as of November 16, 2011 (as amended, the “Agreement”) by and among
Ener1, Inc., as borrower, and Bzinfin S.A., Liberty Harbor Special Investments, LLC and Goldman Sachs Palmetto State Credit Fund,
L.P., as lenders, and Bzinfin S.A., as agent; (ii) Letter Amendment dated as of December 23, 2011 (the “First Amendment”)
by and among Ener1, Inc., as borrower, and Bzinfin S.A., Liberty Harbor Special Investments, LLC and Goldman Sachs Palmetto State
Credit Fund, L.P., as lenders, and Bzinfin S.A., as agent; (iii) Amendment No. 2 to Loan Agreement dated as of December 30, 2011
(the “Second Amendment”) by and among Ener1, Inc., as borrower, and Bzinfin S.A., Liberty Harbor Special Investments,
LLC and Goldman Sachs Palmetto State Credit Fund, L.P., as lenders, and Bzinfin S.A., as agent; and (iv) Letter Amendment dated
as of January 6, 2012 (the “Third Amendment”) by and among Ener1, Inc., as borrower, and Bzinfin S.A., Liberty Harbor
Special Investments, LLC and Goldman Sachs Palmetto State Credit Fund, L.P., as lenders, and Bzinfin S.A., as agent. All capitalized
terms used in this Letter Amendment (the “Fourth Amendment”), but not otherwise defined herein, shall have the meanings
ascribed to them in the Agreement.


Borrower
hereby requests that the Lenders unanimously extend the Maturity Date to January 27, 2012 from January 20, 2012 in accordance
with Section 11.4(a)(iii) of the Agreement. Upon the Borrower’s receipt of a fully-executed copy of this Fourth Amendment,
the definition of “Maturity Date” as set forth in the Agreement shall be further amended hereby to state “January
27, 2012.”


In
connection herewith, Borrower hereby represents and warrants to the Lenders that (a) the representations and warranties contained
in the Loan Documents are true and complete in all material respects as of the date hereof (except to the extent such representations
and warranties relate to an earlier date, in which case they are true and complete as of such date) and will continue to be so
true and complete in all material respects immediately after giving effect to this Fourth Amendment, and (b) no Default or Event
of Default has occurred and is continuing as of the date hereof and none will occur immediately after giving effect to this Fourth
Amendment.



    	 



    	 



    




Except
as expressly amended by the First Amendment, Second Amendment, Third Amendment, or Fourth Amendment, the Loan Documents shall
remain in full force and effect and are hereby ratified and confirmed in all respects. This Fourth Amendment constitutes the entire
agreement between the parties hereto with respect to the subject matter hereof and supersedes all prior oral or written understandings
and agreements between the parties hereto with respect to the subject matter hereof. This Fourth Amendment may be executed and
delivered (by facsimile, e-mail or other electronic transmission) in one or more counterparts, each of which shall be deemed an
original and all of which shall constitute one and the same agreement. Section 13.1 (Governing Law; Jurisdiction; Service of Process;
Venue) of the Agreement is hereby incorporated by reference herein and made a part hereof as if fully set forth herein.


[Intentionally
Left Blank; Signature Page Follows]



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If
the foregoing is acceptable to you; please countersign and date this Fourth Amendment in the space provided below and return a
countersigned and dated copy to us by e-mail (nbrunero@ener1.com).


	 	Sincerely,
	 	 
	 	Ener1, Inc.
	 	 	 
	 	By:	/s/ Alex Sorokin
	 	Name:  Alex Sorokin
	 	Title:  Interim Chief Executive Officer





	Acknowledged and Agreed to:	 
	 	 	 
	Lenders:	 
	 	 	 
	Bzinfin S.A.	 
	 	 	 
	By:	/s/ Patrick T. Bittel	 
	Name:  Patrick T. Bittel	 
	Title:  Attorney-in-Fact	 
	 	 
	Date: January 23, 2012	 
	 	 	 
	Liberty Harbor Special Investments, LLC	 
	By: Goldman Sachs Asset Management, L.P.	 
	 	 	 
	By:	/s/ Brendan McGovern	 
	Name:  Brendan McGovern	 
	Title: Managing Director	 
	 	 
	Date:  January 20, 2012	 
	 	 	 
	Goldman Sachs Palmetto State Credit Fund, L.P.	 
	By: Goldman Sachs Asset Management, L.P.	 
	 	 	 
	By:	/s/ Brendan McGovern	 
	Name:  Brendan McGovern	 
	Title: Managing Director	 
	 	 
	Date:  January 20, 2012	 


 



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	Acknowledged and Agreed to the date hereof:	 
	 	 	 
	Guarantors:	 
	 	 	 
	EnerDel, Inc.	 
	 	 	 
	By:	/s/ Alex Sorokin	 
	Name:  Alex Sorokin	 
	Title: Authorized Signor	 
	 	 	 
	EnerFuel, Inc.	 
	 	 	 
	By:	/s/ Alex Sorokin	 
	Name:  Alex Sorokin	 
	Title: Authorized Signor	 
	 	 	 
	NanoEner, Inc.	 
	 	 
	By:	/s/ Alex Sorokin	 
	Name:  Alex Sorokin	 
	Title: Authorized Signor	 






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