Senior Power Electronics Engineer, Energy Storage

About Redwood Materials Redwood Materials was founded in 2017 by JB Straubel, co-founder and former CTO of Tesla, on a simple but radical idea: the critical minerals powering the energy transition already exist. They just need to come back. Today Redwood is the largest lithium-ion battery recycler in North America — recovering, refining, and redeploying critical minerals from end-of-life batteries back into the supply chain. On the energy side, Redwood has deployed the largest second-life battery project in the world, delivering power to AI data centers in months rather than years using proprietary energy architecture engineered entirely in-house. The company is profitable, the market it operates in is projected to grow 20 to 50 times over the next decade, and Redwood is the only company with the supply chain, the technology, and the operational scale to lead it. As a Power Electronics Engineer for Energy Storage, you will develop Redwood’s next-generation Battery Energy Storage Systems (BESS). In this role, you will design advanced power converters that interface with battery packs, battery modules, photovoltaic (PV) systems, and the grid for large-scale energy storage applications, including AI datacenters. This role involves solving practical circuit- and system-level challenges in converter topology, power-stage component selection (e.g., MOSFETs and magnetics), PCB/PCBA design, thermal analysis, integration, and validation. In addition, you will work with a variety of cross-functional teams such as ME, FW/Control, System, Compliance, Supply Chain, and Manufacturing teams. At Redwood, we build high-efficiency, high-reliability, and low-cost BESS solutions using repurposed batteries, creative engineering approaches, and vertical integration. This creates a unique and rewarding set of technical challenges for engineers who enjoy solving complex power electronics problems. Responsibilities <Power Electronics Hardware Design> • Design high-voltage (800V–1.5kVdc, 480–800Vac) and high-power (10kW–200kW) converters tailored for utility-scale BESS and industrial infrastructure. • Conduct comprehensive topology comparison and trade-off analyses evaluating efficiency, power density, cost, and manufacturability. • Perform power-stage component sizing and Si/SiC MOSFET selection based on loss modeling and thermal management. • Design robust gate driver circuits and dedicated gate driver power supplies to ensure safe, high-frequency switching operations. • Lead the design, modeling, and specification of custom magnetic components, including transformers and inductors utilizing Litz-wire or PCB-winding architectures. • Architect the low-voltage (LV) subsystem, including auxiliary power supplies, sensing circuitry (voltage/current/temperature), and hardware-level protection. • Design and optimize EMI filters, including differential-mode and common-mode inductors, X/Y-caps, and damping elements. • Drive high-voltage, high-power PCB/PCBA layout design, ensuring clearance/creepage rules and signal integrity under high-noise environments. <Cross-Functional Collaboration & Productization> • Review, define, and amend system requirements for power electronics products. • Work with the Mechanical Engineering team to optimize cooling methods and thermal stack-up analysis and product geometry. • Collaborate with the Control and Firmware teams to develop, simulate, and implement converter control algorithms. • Define test specifications and verification methodologies with the validation team. • Work with the Supply Chain team to identify alternative components for dual-sourcing and define technical requirements for critical components (e.g., MOSFETs, film capacitors). • Identify test scopes and technical specifications for mass production testers (ICT, FCT, EOL) in close collaboration with the Manufacturing team. • Provide component-level data and operational profiles to the Reliability team to support rigorous product life cycle and failure analysis. • Work with the Compliance team to achieve industry certifications (e.g., IEEE 1547, UL 1741). Qualifications • MS or PhD in Electrical Engineering, with a focus on power electronics. • 3–5 years of experience in electrical engineering, with a strong focus on power conversion or energy storage products, ideally for mass production. • Hands-on experience in high-voltage (up to 1.5kVdc and 480Vac) hardware design. • Experience with power semiconductor selection, gate drive design, and hardware protection circuits. Deep understanding of power electronics topologies and fundamentals (AC/DC, DC/DC). • Proficiency with circuit simulation, FEA simulation, and CAD tools (e.g., Simulink, LTspice, Ansys Maxwell/Q3D, Altium Designer). • Demonstrated ability to perform detailed layout of high-power, noise-sensitive PCBs in Altium or equivalent CAD software. • Proficiency with lab equipment, including oscilloscopes, impedance analyzers, network analyzers, and signal generators. Excellent written and verbal communication skills, with the ability to effectively collaborate across diverse cross-functional teams. • Foundational knowledge of control theory and embedded systems. • Strong analytical and systematic problem-solving skills. • Proven track record of rapid prototyping and hardware iterations based on cross-functional and supplier feedback. • Strong ability to select circuit components considering both electrical performance and manufacturability (DFM). • Experience mentoring test technicians to execute design verification, interpret test data, and define component maturity criteria. The position is full-time. Compensation will be commensurate with experience. We collect personal information (PI) from you in connection with your application for employment with Redwood Materials, including the following categories of PI: identifiers, personal records, professional or employment information, and inferences drawn from your PI. 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