Test Engineer Intern, ESS (Fall 2026

Job Title:
Test Engineer Intern

Location:
Burlingame, CA

Department:
Engineering

Reports To:
Senior Manager, Test Engineering

Position Type:
Internship (Fall 2026)

Peak Energy is the first American venture to advance globally proven Sodium-Ion battery systems as the storage standard for the new era of renewable energy on a resilient grid.

Sodium-Ion is cheap, readily available and safe, making it the leading contender in a rapidly evolving market.

Our leadership team is powered by decades of expertise in scaling gigawatt-level innovation at world-class companies such as Tesla, Northvolt, Apple, Powin, Enovix, Zipline, Solid Power, and Fluence. We are backed by strategic investment and product partners such as TDK Ventures and Eclipse Ventures.

We are a team of engineers, operators, entrepreneurs, and partners driven by a shared ambition to set the new performance standard for renewable energy and grid resilience.

We are looking for a Test Engineer Intern to support our testing and functional verification efforts for our energy storage systems, from battery to power electronics. This role will work closely with design and simulation teams to understand needs, develop procedures, set up and run tests, and report on findings that directly inform the design direction of our products.

You will interface with design, simulation, and manufacturing engineering partners and gain hands-on experience across a fast-moving, early-stage energy company. Candidates should be available to begin employment in Fall 2026.

The ideal candidate is a self-starter who is hungry for knowledge, holds themselves and others to high standards, and brings a get-it-done attitude to every challenge — big or small.

• Conduct comprehensive testing of functional, high voltage, thermal, and mechanical systems across our energy storage products
• Develop test strategies, plans, and procedures to evaluate key risks
• Spearhead the design and acquisition of testing infrastructure
• Collaborate with engineering teams to ensure design integrity and drive improvements
• Analyze complex test data, report findings, and drive system enhancements
• Identify, diagnose, and resolve intricate technical issues during testing
• Perform root cause analysis on system failures and develop corrective and preventive actions
• Drive innovation in testing methodologies and practices
• Interface tightly with design, simulation, and manufacturing engineering partners to inform design decisions
• Maintain detailed records of tests, analyses, and corrective actions; prepare reports and presentations for internal and external stakeholders
• Drive and participate in a culture of rapid prototyping and automation

• Working towards a Bachelor’s degree in Mechanical Engineering, Electrical Engineering, Aerospace Engineering, or a related field
• Experience in test engineering, preferably within battery storage or renewable energy sectors
• Strong understanding of electromechanical engineering first principles
• Proficiency in data processing and analysis tools
• Excellent problem-solving skills with the ability to think critically and act decisively
• Strong communication skills with the ability to present complex technical information clearly to both technical and non-technical stakeholders
• Ability to work collaboratively in a fast-paced, dynamic environment
• Proactive ownership mindset with a strong sense of accountability

• Experience with battery systems, energy storage, or power electronics testing
• Familiarity with automated test systems or rapid prototyping workflows
• Background in reliability, abuse, or environmental stress testing

Peak Energy is committed to building a diverse and inclusive workforce. We strongly encourage women, people of color, and individuals from underrepresented groups to apply. We value skills, potential, and perspective over specific credentials. If you're excited about this role but your experience doesn't look perfect on paper, we still want to hear from you.

• ** Speed Through Focus** – Move fast but understand why. Focus on the goal, don't sacrifice quality.
• ** Mission Over…