Senior Battery Cell Engineer

Whoop•Boston, MA

3d•$140,000 - $195,000•Onsite

About The Position

At WHOOP, we're on a mission to unlock and inspire performance for life. WHOOP empowers members to perform at a higher level through a deeper understanding of their bodies and daily lives. WHOOP is hiring a Senior Battery Engineer focused on Cell Engineering to evaluate, qualify, and improve lithium-ion cells for current and future products. You will apply expertise in electrochemistry, cell design, testing, manufacturing, and failure analysis to ensure battery cells meet performance, safety, reliability, and product integration requirements.

Requirements

Bachelor’s degree in Chemical Engineering, Materials Science, Mechanical Engineering, or a related field with 5+ years of relevant experience; or a master’s degree or PhD with 2+ years of relevant experience.
Strong understanding of lithium-ion electrochemistry, cell design, manufacturing processes, and degradation mechanisms.
Hands-on experience with cell characterization, qualification testing, and battery cyclers such as Arbin, Maccor, or similar systems.
Experience analyzing battery data, conducting failure investigations, and developing clear technical recommendations.
Experience collaborating with battery suppliers, manufacturing partners, and cross-functional product development teams.
Experience with Python, MATLAB, Minitab, JMP, or similar tools for data processing, statistical analysis, and visualization.
Familiarity with cell teardown, cross-sectioning, microscopy, CT scanning, gas analysis, or other advanced failure analysis techniques.
Strong commitment to embracing and leveraging AI tools in day-to-day tasks, ensuring AI-assisted work aligns with the same high-quality standards as personal contributions.

Responsibilities

Evaluate new cell designs, chemistries, form factors, and suppliers against product specifications and acceptance criteria.
Develop and execute cell qualification plans across incoming and outgoing quality control, performance, safety, reliability, environmental, and life-cycle testing.
Plan and conduct design of experiments (DOEs) to optimize cells for fit and performance needs.
Collaborate with battery system engineers to translate cell attributes into pack designs that meet overall product requirements.
Operate battery cyclers, environmental chambers, and laboratory equipment; create representative test profiles and analyze electrochemical data.
Partner with suppliers and cross-functional engineering teams to support process qualification, manufacturing readiness, and battery integration.
Lead cell-related failure investigations, root cause analysis, and corrective-action verification with suppliers and third-party laboratories.
Document and communicate qualification results, technical risks, and recommendations through specifications, reports, and design reviews.
Ability to travel up to 15% domestically and internationally to support supplier visits, factory audits, qualification activities, and failure investigations.