Exhibit 4.3


 


FIRST AMENDMENT TO


[AMENDED AND RESTATED] SENIOR SECURED NOTES


 


THIS FIRST AMENDMENT TO [AMENDED
AND RESTATED] SENIOR SECURED NOTES (this “Amendment”) is made and entered into as of April 27, 2017 by and among
Ener-Core, Inc., a Delaware corporation (the “Company”), and the undersigned, and amends those certain Senior
Secured Notes [amended and restated as of December 2, 2016 (as amended to date, the “Notes”), as originally
issued by the Company pursuant to (i) that certain Securities Purchase Agreement, dated April 22, 2015, by and among the Company,
the “Buyers” identified therein, and the Collateral Agent identified therein (as amended to date, the “April
2015 Agreement”); and (ii) that certain Securities Purchase Agreement, dated May 7, 2015, by and among the Company, the
“Buyers” identified therein, and the Collateral Agent identified therein (as amended to date and together with the
April 2015 Agreement, the “Agreements”)] [dated as of December 2, 2016 and December 20, 2016 (as amended to
date, the “Notes”), issued by the Company pursuant to that certain Securities Purchase Agreement, dated November
23, 2016, by and among the Company and the “Buyers” identified therein (as amended to date, the “Agreement”)].
Capitalized terms used herein but not otherwise defined herein shall have the meanings ascribed to such terms in the Notes.


 


RECITALS


 


WHEREAS, pursuant to Section
15 of the Notes, the written consent of the holders of Notes representing at least a majority of the aggregate principal amount
of the Notes then outstanding, including Empery Asset Master, Ltd. (“Empery”) so long as Empery or any of its
Affiliates holds any Notes, and the Collateral Agent (the “Required Holders”), shall be required for any change
or amendment or waiver of any provision of the Notes, provided that any such amendment or waiver does not disproportionately, materially
and adversely affect the rights and obligations of any Holder relative to the comparable rights and obligations of the other Holders;


 


WHEREAS, any amendment or
waiver effected in accordance with Section 15 of the Notes is binding upon all holders of Notes; and


 


WHEREAS, the parties hereto
wish to amend the Notes as set forth below.


 


AGREEMENT


 


NOW, THEREFORE, in consideration
of the mutual covenants herein contained and other good and valuable consideration, the receipt and sufficiency of which are hereby
acknowledged, the parties, intending to be legally bound, agree as follows:  


 


ARTICLE I

AMENDMENTS TO THE NOTES


 


Section 1.1      Backstop
Agreement. Section 30(e) of the Notes is hereby amended and restated as follows:


 


“Backstop
Agreement” means that certain Backstop Security Support Agreement, originally entered into on November 2, 2015 by
and between an individual investor and the Company, as amended pursuant to that certain First Amendment to Backstop Security
Support Agreement, dated as of April 27, 2017, by and between an individual investor and the Company.” 


 






     

     

    

 


article ii

MISCELLANEOUS


 


Section 2.1      Effect of this
Amendment. This Amendment shall form a part of each Note for all purposes, and each holder thereof shall be bound hereby. This
Amendment shall only be deemed to be in full force and effect from and after both the execution of this Amendment by the parties
hereto and the execution of agreements substantially identical to this Amendment by the Company and holders of Notes representing
at least a majority of the sum of the aggregate principal amount of the Notes then outstanding that, together with undersigned,
constitute the Required Holders. From and after such effectiveness, any reference to the Notes shall be deemed to be a reference
to the Notes as amended hereby. Except as specifically amended as set forth herein, each term and condition of the Notes shall
continue in full force and effect.


 


Section 2.2      Entire Agreement.
This Amendment, together with the Notes, contains the entire agreement of the parties and supersedes any prior or contemporaneous
written or oral agreements between them concerning the subject matter of this Amendment.


 


Section 2.3      Governing Law.
This Amendment shall be governed by the internal law of the State of New York.


 


Section 2.4      Counterparts.
This Amendment may be executed in any number of counterparts and by different parties hereto in separate counterparts, each of
which when so executed and delivered shall be deemed an original, but all such counterparts together shall constitute but one and
the same instrument; signature pages may be detached from multiple separate counterparts and attached to a single counterpart so
that all signature pages are physically attached to the same document. This Amendment may be executed by fax or electronic mail,
in PDF format, and no party hereto may contest this Amendment’s validity solely because a signature was faxed or otherwise
sent electronically.


 


[Signature Pages Follow]


 




     

     

    

 


IN WITNESS WHEREOF, the
parties hereto have executed this First Amendment to [Amended and Restated] Senior Secured Notes as of the date first written above.


 


	 	COMPANY:
	 	 
	 	ENER-CORE, INC.
	 	 	 
	 	By:	 
	 	 	Name: 
	 	 	Title:  


 


 


 


 


 


 


 


 


 


 


 


 


 


 


Signature
Page to First Amendment to [Amended and Restated] Senior Secured Notes




 




     

     

    

 


IN WITNESS WHEREOF, the
parties hereto have executed this First Amendment to [Amended and Restated] Senior Secured Notes as of the date first written above.


 


	 	
        HOLDER:

	 	 	 
	 	By:	 
	 	 	Name: 
	 	 	Title: 


 


 


 


 


 


 


 


 


 


 


 


 


 


 






Signature Page
to First Amendment to [Amended and Restated] Senior Secured Notes