Battery Systems Application Engineer

Zēlos® Energy is an innovative battery startup headquartered in the San Francisco Bay Area, and a leader in developing safe, sustainable, and proven rechargeable zinc-based chemistries.

Our company is at an exciting juncture from R&D to production, for applications including stationary storage for power backup and data centers.

We are seeking a Battery Systems Application Engineer to assist in commercialization of our advanced battery technology. This is a full-time, on-site position at our lab in San Leandro, California.

This role focuses on battery cell and pack testing, prototype battery system development, and technical engagement with integration partners. The ideal candidate has strong electrical engineering expertise, practical battery testing experience, and working knowledge of mechanical battery pack design and thermal management.

You will work closely with the rest of our technical team to evaluate new cell designs, develop demonstration systems to showcase customers, validate performance, safety, and reliability across a range of applications.

To be considered for the role, it is necessary to be fully authorized to work for any employer in the US. Unfortunately, we are unable to sponsor or transfer visas for this role. Candidates will also need to reside (or relocate) within reasonable commuting distance of San Leandro.

• Lead technical interactions with customers and battery integration partners, understanding application requirements and recommending practical electrical and mechanical design solutions.
• Review battery system architectures and support prototype integration, design reviews, and system validation.
• Design and execute test plans for battery cells, modules, and battery packs, including performance, cycle life, thermal, and safety testing.
• Analyze test data, identify failure mechanisms, and prepare technical reports and recommendations.
• Design, assemble, and validate prototype battery modules and demonstration battery packs.
• Develop electrical systems including battery chargers, Battery Management Systems (BMS), protection circuitry, wiring, and instrumentation.
• Contribute to conceptual battery pack mechanical design, including cell layouts, enclosure concepts, and first-order thermal analysis.
• Collaborate with battery cell engineering team and product engineers to transition new cell designs into practical battery systems.
• Bring a flexible, hands-on approach and a desire to work in a startup.

• Bachelor's or Master's degree in Electrical, Mechanical, or related Engineering field.
• 3+ years of experience developing, testing, or integrating rechargeable battery systems, finding solutions and working safely and collaboratively in a lab and team environment.
• Hands-on experience with battery testing equipment, data acquisition, and laboratory instrumentation.
• Strong understanding of rechargeable battery technologies and battery system integration.
• Proficiency with battery chargers, Battery Management Systems (BMS), low-voltage electrical design, and prototype development.
• Working knowledge of conceptual battery pack mechanical design and first-order thermal analysis.
• Excellent analytical, troubleshooting, and technical communication skills.

• Experience with battery pack architecture for automotive, industrial, aerospace, robotics, or energy storage applications.
• Familiarity with thermal analysis tools sufficient for first-order thermal modeling.
• Knowledge of battery safety standards and qualification testing.
• Experience with CAN, Modbus communication and BMS configuration.
• Familiarity with Python, MATLAB, or LabVIEW for data analysis and test automation.

• Deliver reliable battery performance data that drives product development.
• Build and validate battery demonstration systems that showcase new technology.
• Lead technical discussions with integration partners and guide battery system architecture decisions.
• Recommend practical electrical and mechanical integration solutions that balance performance, safety, manufacturability, and cost.
• Evolve with the role and the company over time, engaging positively and productively with other members of staff and external contacts.

• Full-time compensation of $120K to $145K depending on experience and expertise.
• Excellent medical, dental, and vision benefit options.
• Paid holidays and unlimited PTO.
• Generous 401(k) and stock options.
• Free and abundant all-day parking lot adjacent to I-880, free shuttle from San Leandro BART, bike parking available, complimentary office snacks and beverages.
• Access to Gate 510 incubator space with large common atrium (including readily available work and meeting spaces) and kitchen area with free filtered water, tea, coffee, and occasional building-wide afternoon happy hours.