[Crosby, Heafey, Roach & May Letterhead]


                                  May 21, 2002

Enova Systems, Inc.
19850 South Magellan Drive
Torrance, CA  90502

            Re:         Enova Systems, Inc.
                        Form S-1 Registration Statement

Ladies and Gentlemen:

We have acted as counsel to Enova Systems,  Inc., a California  corporation (the
"Company"),  in connection  with the  registration  under the  Securities Act of
1933,  as  amended  (the  "Act"),  of up to Six  Million  Two  Hundred  Thousand
(6,200,000)  shares of the Common Stock of the Company (the "Shares") to be sold
for the account of a selling shareholder pursuant to a Registration Statement on
Form S-1 (File No. 333-85308), filed with the Securities and Exchange Commission
(the "SEC") on April 1, 2002,  as amended  from time to time (the  "Registration
Statement").

This opinion is being furnished in accordance  with the  requirements of Item 16
of Form S-1 and Item 601(b)(5)(i) of Regulation S-K.

As such counsel,  we are familiar with the  proceedings  taken by the Company in
connection with the authorization, issuance and sale of the Shares. In addition,
we have examined originals or copies of (i) the Amended and Restated Certificate
of Incorporation of the Company,  (ii) the Bylaws of the Company;  (iii) certain
resolutions  of the Board of  Directors  of the  Company;  and (iv)  such  other
documents and records as we have deemed  necessary and relevant for the purposes
hereof.  In addition,  we have relied on certificates of officers of the Company
and  certificates of public  officials as to certain matters of fact relating




Enova Systems, Inc.
May 21, 2002
Page 2

to this  opinion  and have made  such  investigations  of law as we have  deemed
necessary and relevant as a basis hereof.

We have assumed the  genuineness  of all  signatures,  the  authenticity  of all
documents, certificates and records submitted to us as originals, the conformity
to  authentic  original   documents,   certificates  and  records  of  all  such
documentation  submitted to us as copies and the  truthfulness of all statements
of facts contained therein.

Based on the  foregoing  and  subject to the  limitations  set forth  herein and
having due regard for such legal  considerations as we deem relevant,  we are of
the  opinion  that the Shares  have been  legally  issued and are fully paid and
nonassessable shares of the Common Stock of the Company.

We  consent  to  the  filing  of  this  opinion  letter  as  Exhibit  5.1 to the
Registration  Statement  and to the  reference  to this firm  under the  caption
"Legal Matters" in the prospectus which is part of the  Registration  Statement.
In giving this consent,  we do not thereby admit that we are within the category
of persons whose  consent is required  under Section 7 of the Act, the rules and
regulations of the SEC promulgated thereunder, or Item 509 of Regulation S-K.

The foregoing opinion is based on and limited to the General  Corporation Law of
the State of California and the relevant federal laws of the United States,  and
we express no opinion with respect to the laws of any other jurisdiction.

This  opinion  letter is rendered  as of the date first  written  above,  and we
disclaim  any  obligation  to  advise  you of  facts,  circumstances,  events or
developments  which  hereafter  may be  brought to our  attention  and which may
alter,  affect or modify the opinion expressed herein.  Our opinion is expressly
limited to the  matters  set forth  above and we render no  opinion,  whether by
implication or otherwise, as to any other matters relating to the Company or the
Shares.


                                              Very truly yours,


                                              CROSBY, HEAFEY, ROACH & MAY,
                                              PROFESSIONAL CORPORATION