Senior to Staff Firmware Engineer - BMS

About 1X

We’re an AI and robotics company based in San Carlos, California, on a mission to build a truly

abundant society through general‑purpose robots capable of performing any kind of work

autonomously.

We believe that to truly understand the world and grow in intelligence, humanoid robots must

live and learn alongside us. That’s why we’re focused on developing friendly home robots

designed to integrate seamlessly into everyday life.

We’re looking for curious, driven, and passionate people who want to help shape the future of

robotics and AI. If this mission excites you, we’d be thrilled to hear from you and explore how you

might contribute to our journey.

Role Overview

We are looking for a cross-functional Firmware or Embedded Engineer to develop and maintain
the battery management firmware for a production humanoid robot. In this role, you will own the
firmware that monitors, protects, and manages a high-energy lithium-ion battery pack operating
under demanding and highly dynamic load conditions.

You will work closely with hardware architects, electrical engineers, systems engineers, and test
engineers to ensure firmware reliably bridges hardware capabilities and higher-level system
requirements across prototype and production platforms.

The battery system in a humanoid robot operates unlike most conventional applications. Load
transients are severe and unpredictable peak currents can cause significant bus voltage sag
within milliseconds as actuators respond to real-time control policies. The pack must sustain
continuous cycling in uncontrolled thermal environments while maintaining cell-level safety and
accurate state estimation. There are no established BMS reference designs for this load profile.

The ideal candidate reasons from electrochemistry and circuit fundamentals, builds reliable
firmware for safety-critical systems, and is comfortable developing novel solutions where
existing vendor toolchains and application notes fall short.

Responsibilities

• Develop and maintain BMS firmware including cell voltage monitoring, current
  measurement, temperature sensing, and protection enforcement across a multi-series
  lithium-ion pack

• Implement state-of-charge (SOC) and state-of-health (SOH) estimation algorithms that
  remain accurate under high-rate transient loads, temperature variation, and cell aging

• Architect cell balancing firmware (passive and/or active) that manages cell-to-cell
  divergence during both operation and charging, accounting for the wide SOC excursions
  typical of this application

• Responsible for the testing, validation, and verification of initial firmware releases to
  ensure functionality, reliability, and performance requirements are met

• Implement pack-level protection logic: overcurrent, overvoltage, undervoltage,
  overtemperature, and short-circuit detection with deterministic response times and safe-
  state transitions

• Design brownout prediction and mitigation firmware characterize and manage bus
  voltage sag under peak actuator loading to prevent cascading subsystem failures

• Develop CAN/CANopen interface firmware for real-time reporting of pack state to the
  central controller, supporting both cyclic status data and diagnostic/configuration
  messaging

• Collaborate with hardware architects to define BMS hardware requirements, sense
  circuit topology, and protection coordination between firmware and hardware safety
  mechanisms

• Implement pre-charge sequencing, power-on/power-off state machines, and
  coordination with the system-level power distribution architecture

• Develop production test hooks and end-of-line validation routines for battery pack
  acceptance, including cell matching verification and impedance measurement

• Document firmware architecture, interfaces, and assumptions; improve code structure,
  readability, and maintainability

Requirements

• Bachelor’s or Master’s degree in Electrical Engineering, Computer Engineering, or a
  related field

• 7+ years of industry experience with embedded systems and real-time firmware
  development

• Proficiency in C and C++ for embedded targets

• Production BMS firmware experience the candidate has developed or substantially
  modified battery management firmware for a multi-cell lithium-ion or lithium-polymer
  pack in a shipped product. Experience should include cell monitoring, protection logic,
  and state estimation, not solely integration of a vendor BMS IC evaluation kit.

• Electrochemical fundamentals working understanding of lithium-ion cell behavior:
  capacity vs. discharge rate, impedance characteristics under temperature and aging,
  thermal runaway mechanisms, and how these translate into firmware protection
  thresholds and estimation algorithms

• High-current / high-transient systems experience with battery packs that supply
  dynamic loads with significant peak-to-average current ratios, where bus voltage
  management and transient response are firmware-level concerns

• Embedded bus fluency — hands-on CAN/CANopen implementation plus additional
  embedded interfaces (SPI, I²C, UART) for communication with analog front-end ICs, fuel
  gauge ICs, and peripheral monitoring devices

• Hardware debug at the firmware boundary experience using oscilloscopes, logic
  analyzers, and current probes to diagnose problems that span firmware behavior, sense
  circuit accuracy, and protection circuit response

• Schematic literacy ability to read analog front-end circuits, current sense topologies
  (shunt, Hall-effect, fluxgate), cell balancing circuits, and protection FET gate drive
  without requiring hardware engineering interpretation

• Comfortable debugging firmware on real hardware using standard lab tools

• Ability to collaborate closely across hardware, systems, and software teams

Preferred Qualifications

• First-principles problem solving a track record of approaching unfamiliar problems
  by building understanding from fundamentals rather than relying on vendor application
  notes or established patterns. The BMS load profile in a humanoid robot does not match
  conventional EV, power tool, or stationary storage assumptions.

• Safety-critical battery systems experience with BMS firmware where protection
  failures have physical consequences (thermal runaway, fire, toxic gas release).

• Familiarity with standards such as IEC 62619, UL 2580, UN 38.3, or IEC 62133 and how

  they translate into firmware requirements.

• EV or high-performance battery packs experience at automotive OEMs, tier-1
  battery suppliers, or EV startups where pack-level firmware must manage hundreds of
  amperes with cell-level granularity under thermal and mechanical stress

• Power tool or robotics battery systems experience with compact, high-discharge-
  rate packs where weight, volume, and thermal constraints are as demanding as
  electrical performance

• SOC/SOH algorithm development implementation of model-based estimation
  (equivalent circuit models, extended Kalman filters, or similar) beyond simple coulomb
  counting, validated against real cell aging data

• Power system integration experience where the BMS firmware must coordinate
  with DC-DC converters, pre-charge circuits, contactors, and system-level power
  sequencing

• EMC awareness experience with BMS subsystems that have contributed to or been
  affected by conducted or radiated emissions, and understanding of how firmware
  behavior (switching frequency, measurement timing) interacts with EMC performance

• Experience contributing to hardware architecture or system-level design decisions

• Familiarity with real-time operating systems (FreeRTOS, SafeRTOS, or similar)

• Experience supporting hardware through prototype and production phases

Benefits & Compensation

• Salary Range: $175,000 - $250,000 + Equity

• Health, dental, and vision insurance

• 401(k) with company match

• Paid time off and holidays

Equal Opportunity Employer

1X is an Equal Opportunity Employer. All qualified applicants will receive consideration for employment without regard to race, color, religion, sex, gender, gender identity or expression, sexual orientation, national origin, ancestry, citizenship, age, marital status, medical condition, genetic information, disability, military or veteran status, or any other characteristic protected under applicable federal, state, or local law.