About the Role
At Redwood Materials, we are architecting the future of grid-scale energy storage by transforming diverse, second-life automotive batteries and new assets into a unified, software-defined Battery Energy Storage System (BESS). We are looking for a deeply technical, hands-on Battery Software & Controls Integration Engineer who lives at the intersection of electrochemistry, embedded BMS firmware, and high-voltage pack hardware.
In this role, you won't just write high-level communication wrappers-you will get your hands dirty in the lab bringing up heterogeneous OEM battery packs off-vehicle, reverse-engineering proprietary BMS architectures, and validating the underlying battery state estimation algorithms. You will evaluate the accuracy of native OEM BMS outputs (SoC, SoH, SoP, cell balancing, and thermal limits) against physical pack behavior, while deploying and integrating Redwood's in-house battery control and estimation algorithms to extract safe, maximum performance from aged and mixed-chemistry assets. You will also serve as the technical anchor with external automotive OEMs, defining the low-level firmware hooks and safety handshakes required for stationary grid operation.
This position is based in our San Francisco office and operates on an onsite work model.
Key Responsibilities
- Hands-On Pack Bring-Up & Reverse Engineering: Lead physical benchtop and lab bring-up of diverse second-life EV battery packs. Probe wiring harnesses, capture and decode proprietary CAN/CAN-FD/LIN/Ethernet traffic, spoof vehicle-level wake/keep-alive and crash/interlock signals, and command pre-charge and main contactor sequencing to run packs safely off-vehicle.
- OEM BMS Algorithm Validation: Design and execute rigorous hardware and HIL test campaigns to audit native OEM BMS algorithms under stationary grid duty cycles. Validate the accuracy of existing BMS state estimations-including State of Charge (SoC), State of Health (SoH), dynamic charge/discharge power limits (SoP), internal resistance growth, and fault thresholds-against true electrochemical and thermal performance.
- In-House Algorithm Integration: Implement and integrate the software for Redwood's proprietary battery state-estimation, degradation-mitigation, and active balancing/derating algorithms (in Rust or C/C++) either atop or in bypass of native OEM BMS telemetry, reconciling discrepancies between legacy automotive logic and second-life pack realities.
- Software Gateways & Deterministic Control Interfaces: Architect and deploy resilient, low-latency software abstraction layers and translation gateways on embedded targets that normalize heterogeneous pack telemetry, manage complex fault state machines, and interface seamlessly with our Power Conversion Systems (PCS) and site controllers.
- Technical OEM & Supplier Leadership: Serve as the primary technical counterpart to external automotive OEMs and Tier-1 BMS suppliers. Drive deep-dive engineering reviews to negotiate custom passive-monitor BMS firmware builds, extract charge/discharge lookup tables, understand pyrotechnic disconnect/fuse curves, and establish deterministic command hooks.
- SIL/HIL & Physical Hardware Verification: Partner with validation and power electronics teams to model pack dynamics, inject sensor and contactor faults on HIL benches (Typhoon HIL/Opal-RT) and physical cyclers, and verify functional safety boundaries before field deployment.
Skills, Knowledge, and Abilities
- Background: MS, or PhD in Electrical Engineering, Computer Engineering, Chemical/Electrochemical Engineering, or a related field, with 5+ years of hands-on experience in BMS firmware/controls development, battery pack bring-up, or EV/BESS battery integration.
- Battery & BMS Domain Mastery: Deep, practical understanding of lithium-ion battery physics (LFP, NMC, etc.), equivalent circuit modeling (ECM), Kalman filtering (EKF/UKF), Coulomb counting, dynamic power/current limit calculation, cell balancing topologies, and high-voltage safety architecture (HVIL, isolation monitoring, contactor weld detection, pyro-fuses).
- Reverse Engineering & Lab Hardware Fluency: Proven ability to walk up to an undocumented or partially documented battery pack and get it running. Expert proficiency with oscilloscopes, logic analyzers, CANalyzer/CANoe/busmaster, high-voltage power supplies/cyclers, and diagnostic protocols (UDS, CCP/XCP, J1939, CAN/CAN-FD, Automotive Ethernet, Modbus).
- Production Software & Controls Toolchain: Strong programming proficiency in Rust and C/C++, within real-time embedded and Linux environments, alongside data analysis and modeling tools (MATLAB/Simulink, Pandas/SciPy) to evaluate and benchmark BMS algorithm performance against lab cycler data.
- Cross-Functional & OEM Authority: Demonstrated success acting as the lead technical point of contact with external OEM engineering teams-possessing the technical depth to dissect their firmware source code or DBC files and the collaborative skill to drive custom engineering modifications.
Bonus Qualifications
- Direct experience characterizing aged or second-life EV batteries, including capacity fade modeling, impedance spectroscopy, or open-circuit voltage (OCV) hysteresis effects across varying state-of-health (SoH) regimes.
- Experience developing or modifying bare-metal/RTOS BMS firmware on automotive-grade microcontrollers (e.g., TI C2000/Hercules, NXP S32K, Infineon Aurix) and interfacing with AFE chips (TI, ADI/LTC, NXP).