Exhibit 99.4
Notice
of Availability of Proxy Materials
for Ballard Power Systems Inc. Annual Meeting
Meeting Date and Time: Wednesday, June 3, 2026, at 1:00 p.m. (Pacific Daylight Time)
Location: https://meetings.lumiconnect.com/400-872-177-983
Please be advised that the proxy materials for the above noted securityholder meeting are available for viewing and downloading online. This document provides an overview of these materials, but you are reminded to access and review the information circular and other proxy materials available online prior to voting. These materials are available at:
www.ballard.com
OR
www.sedarplus.ca
Obtaining Paper Copies of the Proxy Materials
Securityholders may request to receive paper copies of the proxy materials related to the above referenced meeting by mail at no cost. Requests for paper copies must be received by May 20, 2026, in order to receive the paper copy in advance of the meeting. Shareholders may request to receive a paper copy of the Materials for up to one year from the date the Materials were filed on www.sedar.com.
For more information regarding notice-and-access or to obtain a paper copy of the Materials you may contact our transfer agent, Odyssey Trust Company, via https://odysseytrust.com/ca-en/help/ or by phone at 1-888-290-1175 (toll-free within North America) or 1-587-885-0960 (direct from outside North America).
Notice of Meeting
The resolutions to be voted on at the meeting, described in detail in the Management Information Circular, are as follows:
Election of Directors
Appointment of Auditors
Advisory Vote on Executive Compensation
Voting
To vote your securities, please refer to the instructions on the enclosed Proxy or Voting Instruction Form. Your Proxy or Voting Instruction Form must be received by no later than 5:00 p.m. (PDT) on Monday, June 1, 2026.
Stratification
The Issuer is providing paper copies of its Management Information Circular only to those registered shareholders and beneficial shareholders that have previously requested to receive paper materials.
Annual Financial Statements
The Issuer is providing paper copies or emailing electronic copies of its annual financial statements to registered shareholders and beneficial shareholders that have opted to receive annual financial statements and have indicated a preference for either delivery method.