Battery Systems Engineer II

At WHOOP, we're on a mission to unlock human performance and healthspan. WHOOP empowers members to perform at a higher level through a deeper understanding of their bodies and daily lives.As a Battery Engineer II at WHOOP, you will help ensure the quality, reliability, and performance of the batteries that power our products. Working closely with cross-functional engineering teams, suppliers, and third-party testing labs, you will support the validation and development of next-generation battery systems through testing, failure analysis, supplier qualification, regulatory compliance, and continuous design improvement. You will contribute to advancing battery technology by improving validation processes, testing standards, and technical documentation across the product development lifecycle. This is a hands-on role with the opportunity to drive meaningful impact through experimentation, analysis, and collaboration.RESPONSIBILTIES:Develop, execute, and document battery pack, system, and component-level test plans for design validation, qualification, performance, durability, and safety across NPI programs and internal evaluationsCollaborate with multidisciplinary engineering teams and suppliers across the globe to translate system and cell-level safety and performance requirements into functional battery pack architecturesSupport regulatory certification activities (e.g., UL, CE, IEC), internal safety audits, DFMEA, risk assessments, root cause analysis, and failure investigation workflowsManage testing, review supplier test reports, and support verification and validation for new projects, suppliers, and alternate battery technologiesEvaluate lithium-ion batteries across different designs, use cases, and WHOOP product conditions to assess performance, safety, longevity, and manufacturabilityTravel to supplier sites as needed for line audits, design reviews, builds, and joint problem-solving (up to 15%)QUALIFICATIONS:BS with 2+ years of experience in battery systems, or MS with 1+ years experience Experience in lithium-ion battery development, testing, validation, or related academic research along with designing, modelling and validating rechargeable battery systemsStrong understanding of lithium-ion cell design, battery chemistry, battery testing standards, safety guidelines, and lab instrumentationExperience writing technical reports and documenting test plans, quality findings, supplier assessments, regulatory compliance activities, and test evaluationsStrong communication skills for battery-related technical topics clearly in cross-functional settingsUnderstanding of tolerance stack analysis, mechanical GD&T, and measurement methodsFamiliarity with Python or similar tools for data visualization, analysis, and automationAwareness of emerging battery technologies, materials, and market trendsStrong 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 contributionsThis role is based in the WHOOP office located in Boston, MA. The successful candidate must be prepared to relocate if necessary to work out of the Boston, MA office. Interested in the role, but don’t meet every qualification? We encourage you to still apply! At WHOOP, we believe there is much more to a candidate than what is written on paper, and we value character as much as experience. As we continue to build a diverse and inclusive environment, we encourage anyone who is interested in this role to apply.WHOOP is an Equal Opportunity Employer and participates in E-verify to determine employment eligibility. It is unlawful in Massachusetts to require or administer a lie detector test as a condition of employment or continued employment. An employer who violates this law shall be subject to criminal penalties and civil liability.The WHOOP compensation philosophy is designed to attract, motivate, and retain exceptional talent by offering competitive base salaries, meaningful equity, and consistent pay practices that reflect our mission and core values.At WHOOP, we view total compensation as the combination of base salary, equity, and benefits, with equity serving as a key differentiator that aligns our employees with the long-term success of the company and allows every member of our corporate team to own part of WHOOP and share in the company’s long-term growth and success.The U.S. base salary range for this full-time position is $110,000 - $150,000. Salary ranges are determined by role, level, and location. Within each range, individual pay is based on factors such as job-related skills, experience, performance, and relevant education or training. In addition to the base salary, the successful candidate will also receive benefits and a generous equity package.These ranges may be modified in the future to reflect evolving market conditions and organizational needs. While most offers will typically fall toward the starting point of the range, total compensation will depend on the candidate’s specific qualifications, expertise, and alignment with the role’s requirements.