Internship Solid State Battery Jobs in California

QuantumScape is on a mission to transform energy storage with solid-state lithium-metal battery technology. The company’s next-generation batteries are designed to enable greater energy density, faster charging and enhanced safety to support the transition away from legacy energy sources toward a lower carbon future.

We are building an integrated PSU+ BBU rack power shelf that combines power conversion and solid-state battery backup into a single high-density platform for hyperscale AI data centers. This product replaces traditional separate PSU and BBU shelves with a unified architecture that leverages the unique safety and performance characteristics of solid-state battery cells.

As Battery / Pack Systems Engineer, you own everything from cell to pack - mechanical integration, BMS architecture, thermal management of the battery section, charge/discharge optimization, safety engineering, and cycle life validation. You are the critical bridge between our cell technology and the power platform, translating evolving cell-level specs into robust pack-level designs in near real-time.

You sit at the center of the entire team's collaboration web. The power electronics lead needs your voltage window and current limits. The firmware engineer needs your BMS algorithms and protection logic. The thermal-mechanical engineer needs your cell thermal requirements. And the cell development team needs your pack-level feedback. Most critically, the safety and longevity story of solid-state batteries in data center racks - the core market differentiator - lives or dies in your design choices.

• Design the cell-to-pack mechanical assembly: cell stacking, compression systems, interconnects (wire bonding, busbar welding, or flex circuit), and structural integration within the shared PSU+ BBU enclosure
• Architect the BMS hardware topology (distributed vs. centralized sensing, passive vs. active balancing) and specify protection FET sizing, sense line routing, and communication interfaces
• Develop and tune state-of-charge and state-of-health estimation algorithms (coulomb counting, extended Kalman filter, impedance-based methods) tailored to solid-state cell electrochemistry
• Co-develop charge/discharge profiles with the firmware engineer - CC-CV curves, temperature-dependent rate limits, fast-charge protocols, and float/maintenance charge strategies optimized for data center duty cycles
• Design the thermal interface between cells and enclosure (thermal pads, gap fillers, heat spreaders, dedicated thermal paths) in collaboration with the thermal-mechanical engineer
• Conduct pack-level FMEA and safety analysis; define and execute abuse test protocols (nail penetration, crush, overcharge, external short circuit) adapted for solid-state cell behavior
• Design accelerated aging test protocols for the data center-specific duty cycle: prolonged high-Soc float hold with infrequent high-power discharge events
• Serve as the primary liaison to the cell development team, translating pack-level requirements into cell-level specs and feeding test/field data back to improve cell design
• Support UL 1973 and UL 9540A safety certification activities

• 8+ years in battery pack/module design with at least one product through prototype validation or production
• Hands-on BMS hardware architecture experience (you don't need to lay out the PCB, but you specify the topology and component selection)
• Cell characterization and modeling skills (impedance spectroscopy, capacity fade analysis, thermal characterization)
• Experience with battery safety standards, specifically UL 1973; UL 9540A exposure strongly preferred
• Proficiency with pack-level thermal modeling and mechanical design (SolidWorks, Creo, or equivalent; thermal simulation a plus)
• Comfortable working with evolving cell specs and making design decisions under incomplete data

• Prior exposure to solid-state, lithium-metal, or other next-generation cell chemistries (even at the research level)
• Experience with data center, telecom, or stationary storage backup battery systems (understands float-then-discharge duty cycles vs. EV cycling)
• Familiarity with electrochemical modeling tools (COMSOL, PyBaMM, AutoLion, or equivalent)
• Experience with IEC 62619 industrial battery safety standard
• Background in applications engineering at a cell manufacturer (translating cell data into customer pack designs)
• Knowledge of functional safety principles (IEC 61508 or equivalent)

This position is required to work onsite 5 days per week to meet the minimum essential duties and requirements of this position. As an on-site R&D and manufacturing operations organization, in-person face to face interaction is essential to building authentic relationships, trust, teamwork, and collaboration.

Expected salary range for this role is from $136,700 to $208,500, and a final salary will be determined by the candidate's experience and educational background. QuantumScape also offers an annual bonus and a generous RSU/Equity package as part of its compensation plan. In addition, we do offer a tremendous benefits plan including employee paid health care, Employee Stock Purchase Plan (ESPP), and other benefits.

We are an equal opportunity employer and value diversity at our company. We do not discriminate on the basis of race, religion, color, national origin, gender, sexual orientation, age, marital status, veteran status, or disability status.

We will ensure that individuals with disabilities are provided reasonable accommodation to participate in the job application or interview process, to perform essential job functions, and to receive benefits and privileges of employment. Please contact us to request an accommodation.