13D Filing: Viex Capital Advisors, Llc and Maxwell Technologies Inc (NASDAQ:MXWL)

UNITED STATES

SECURITIES AND EXCHANGE
COMMISSION

Washington, D.C. 20549

SCHEDULE 13D

(Rule 13d-101)

INFORMATION TO BE INCLUDED
IN STATEMENTS FILED PURSUANT

TO § 240.13d-1(a)
AND AMENDMENTS THERETO FILED PURSUANT TO

§ 240.13d-2(a)

(Amendment No. 1)¹

Maxwell Technologies, Inc.

(Name
of Issuer)

Common Stock, $0.10 par value per share

(Title of Class of Securities)

577767106

(CUSIP Number)

ERIC SINGER

VIEX
Capital Advisors, LLC

825 Third Avenue, 33rd Floor

New York, New York 10022

STEVE
WOLOSKY, ESQ.

OLSHAN
FROME WOLOSKY LLP

1325
Avenue of the Americas

New
York, New York 10019

(212)
451-2300

(Name, Address and Telephone Number of Person

Authorized to Receive Notices
and Communications)

April 10, 2017

(Date of Event Which Requires
Filing of This Statement)

If
the filing person has previously filed a statement on Schedule 13G to report the acquisition that is the subject of this Schedule
13D, and is filing this schedule because of §§ 240.13d-1(e), 240.13d-1(f) or 240.13d-1(g), check the following
box ¨.

Note:  Schedules
filed in paper format shall include a signed original and five copies of the schedule, including all exhibits.  See
§ 240.13d-7 for other parties to whom copies are to be sent.

1
The remainder of this cover page shall be filled out for a reporting person’s initial filing on this form with respect to
the subject class of securities, and for any subsequent amendment containing information which would alter disclosures provided
in a prior cover page.

The information required
on the remainder of this cover page shall not be deemed to be “filed” for the purpose of Section 18 of the Securities
Exchange Act of 1934 (“Act”) or otherwise subject to the liabilities of that section of the Act but shall be subject
to all other provisions of the Act (however, see the Notes).

^*This Series One is part of a series of VIEX Opportunities Fund, LP, a series
limited partnership.

The following constitutes
Amendment No. 1 to the Schedule 13D filed by the undersigned (“Amendment No. 1”). This Amendment No. 1 amends the Schedule
13D as specifically set forth herein.

Item 3 is hereby amended
and restated to read as follows:

The Shares purchased
by each of Series One, VSO II and VSO III were purchased with working capital (which may, at any given time, include margin loans
made by brokerage firms in the ordinary course of business) in open market purchases, except as otherwise noted, as set forth in
Schedule A, which is incorporated by reference herein.

The aggregate purchase
price of the 1,230,936 Shares beneficially owned by Series One is approximately $6,103,593, including brokerage commissions.

The aggregate purchase
price of the 27,348 Shares beneficially owned by VSO II is approximately $120,713, including brokerage commissions.

The aggregate purchase
price of the 955,181 Shares beneficially owned by VSO III is approximately $5,314,647, including brokerage commissions.

Item 4 is hereby amended
to add the following:

On April 10, 2017,
the Reporting Persons entered into an agreement (the “Agreement”) with the Issuer. Pursuant to the Agreement, the Issuer
agreed, promptly following the execution of the Agreement, to nominate and appoint John Mutch to serve as a Class III director
of the Issuer with a term expiring at the 2017 Annual Meeting of Stockholders (the “2017 Annual Meeting”). The Board
and the appropriate committee(s) of the Board also agreed to nominate Mr. Mutch and one incumbent director for election at the
2017 Annual Meeting for terms expiring at the 2020 Annual Meeting of Stockholders. Following the conclusion of the 2017 Annual
Meeting, the Issuer agreed to cause the Board to decrease its size to eight members and fix the size of the Board at eight through
the Standstill Period (as defined below). To the extent Mr. Mutch is not appointed to the Board by April 13, 2017, the Issuer has
agreed to extend the deadline for properly presented stockholder proposals, including director nominations, for the 2017 Annual
Meeting until the date Mr. Mutch, or his replacement, is appointed. Mr. Mutch will be appointed to the Issuer’s Strategic
Alliance and Review committee of the Board.

The Reporting Persons
have agreed not to (1) nominate or recommend for nomination any person for election at the 2017 Annual Meeting, directly or indirectly,
(2) submit any proposal for consideration at, or bring any other business before, the 2017 Annual Meeting, directly or indirectly,
or (3) initiate, encourage or participate in any “withhold” or similar campaign with respect to the 2017 Annual Meeting,
directly or indirectly. The Reporting Persons have also agreed to vote all Shares they beneficially own at the 2017 Annual Meeting
in favor of the Issuer’s nominees for election and in accordance with the Board’s recommendations with respect to the
other proposals to be brought before the meeting unless the recommendations of both Institutional Shareholder Services Inc. and
Glass Lewis & Co., LLC differ from the Board’s recommendation with respect to such other proposals.

The Reporting Persons
have also agreed to certain customary “standstill provisions” from the date of this Agreement until the date that is
ten (10) business days prior to the deadline for the submission of stockholder proposals for the 2018 Annual Meeting of Stockholders
pursuant to the Bylaws (the “Standstill Period”).

The foregoing description
of the Agreement is qualified in its entirety by reference to the full text of the Agreement, which is attached as Exhibit 99.1
hereto.

Items 5(a)-(c) are
hereby amended and restated to read as follows:

The aggregate percentage
of Shares reported owned by each Reporting Person is based upon 32,270,725 Shares outstanding, which is the total number of Shares
outstanding as of February 22, 2017, as reported in the Issuer’s Annual Report on Form 10-K for the year ended December 31,
2016, filed with the Securities and Exchange Commission on March 1, 2017.

Percentage: Approximately
3.8%

3. Sole power to dispose or direct the disposition: 0
4. Shared power to dispose or direct the disposition: 1,230,936

Percentage: Less than
1%

4. Shared power to dispose or direct the disposition: 27,348

Percentage: Approximately
3.0%

Percentage: Approximately
3.8%

Percentage: 0%

4. Shared power to dispose or direct the disposition: 27,348

Percentage: Approximately
3.0%

Percentage: Approximately
6.9%

Percentage: Approximately
6.9%

4. Shared power to dispose or direct the disposition: 2,213,465

The filing of this
Schedule 13D shall not be construed as an admission that the Reporting Persons are, for purposes of Section 13(d) of the Securities
Exchange Act of 1934, as amended, the beneficial owners of any of the Shares reported herein. Each Reporting Person disclaims beneficial
ownership of such Shares except to the extent of his or its pecuniary interest therein.

Item 6 is hereby amended
to add the following:

Item 4 is incorporated
herein by reference.

Series One has sold
short in over the counter market American-style put options, referencing 62,300 Shares, which have an exercise price of $5.00 per
Share and expire on September 15, 2017. VSO II has sold short in over the counter market American-style put options, referencing
951,400 Shares, which have an exercise price of $5.00 per Share and expire on September 15, 2017. VSO III has sold short in over
the counter market American-style put options, referencing 32,500 and 100,000 Shares, which each have an exercise price of $5.00
per Share and expire on June 16, 2017 and September 15, 2017, respectively. The Reporting Persons do not have any control over
the exercise of the aggregate put options, and as such, are not deemed to beneficially own the aggregate 1,146,200 Shares underlying
the put options.

Item 7 is hereby
amended to add the following exhibit:

SIGNATURES

After reasonable inquiry
and to the best of his knowledge and belief, the undersigned certifies that the information set forth in this statement is true,
complete and correct.

Dated: April 10, 2017

SCHEDULE A

Transactions in the Securities
During the Past 60 days

VIEX OPPORTUNITIES
FUND, LP – SERIES ONE

VIEX SPECIAL
OPPORTUNITIES FUND II, LP

VIEX SPECIAL
OPPORTUNITIES FUND III, LP

¹ Represents American-Style put option sold short
in the over-the counter market. The put options expire on September 15, 2017.