Senior Battery Systems Engineer

Relativity; Long Beach (CA); On-site; USD 150,000 - 190,000; Full time

Job summary

Relativity Space is seeking a Battery Systems Lead to own the HV battery architecture for Terran R. You’ll translate mission needs into a traceable battery specification, drive down-selection, and ensure safety while interfacing with mechanical, electrical, BMS, and vehicle teams.

You’ll collaborate with avionics, structures, test, and propulsion engineers to optimize packaging, thermal management, and verification strategies, enabling rapid iteration and producibility as the design matures.

Qualifications

• Bachelor's degree in engineering (mechanical, electrical, aerospace, chemical, or related).
• 5+ years of battery systems development across the product lifecycle.
• Ability to derive top-down requirements with rigorous trade studies and traceable specs.

Responsibilities

• Own battery safety architecture—thermal-runaway detection and mitigation.
• Define verification and qualification strategy for cells and packs.
• Lead program-management for the battery effort across teams.
• Represent the battery in vehicle design reviews and safety boards.
• Collaborate on packaging, thermal management, and interfaces across disciplines.

Skills

Battery systems

Requirements derivation

System architecture

Cross-functional

Program management

Safety & verification

Education

Bachelor's degree in engineering

Job description

At Relativity Space, we’re building rockets to serve today’s needs and tomorrow’s breakthroughs. Our Terran R vehicle will deliver customer payloads to orbit, meeting the growing demand for launch capacity. But that’s just the start. Achieving commercial success with Terran R will unlock new opportunities to advance science, exploration, and innovation, pioneering progress that reaches beyond the known. Joining Relativity means becoming part of something where autonomy, ownership, and impact exist at every level. Here, you're not just executing tasks; you're solving problems that haven’t been solved before, helping develop a rocket, a factory, and a business from the ground up. Whether you’re in propulsion, manufacturing, software, avionics, or a corporate function, you’ll collaborate across teams, shape decisions, and see your work come to life in record time. Relativity is a place where creativity and technical rigor go hand in hand, and your voice will help define the stories we’re writing together. Now is a unique moment in time where it’s early enough to leave your mark on the product, the process, and the culture, but far enough along that Terran R is tangible and picking up momentum. The most meaningful work of your career is waiting. Join us.

About the Team:

The Avionics team is responsible for the full lifecycle of Terran R's nervous system — designing, building, testing, installing, and operating the hardware that connects and controls every major electrical system on the vehicle and ground. Engineers are deeply embedded into other functions within Relativity, working closely with propulsion, GNC, fluids, and stage engineering teams to ensure seamless integration and operation.

About the Role:

You will join the team developing the vehicle's high-voltage battery system and grow into technical ownership of it as a complete product, covering cell, mechanical, thermal, electrical/BMS, and vehicle integration. Early on, you will work closely with experienced battery engineers to learn the current design, its history, and how it flies. Over time, you will take on more of the system's technical direction. You will be the link between the battery's mechanical and electrical disciplines and the rest of the vehicle. You'll help turn mission and vehicle needs into a clear, traceable battery specification, and help shape the architecture that meets it. This is a hands‑on technical role with real cross‑functional influence. As the battery team grows, it offers a clear path to technical leadership, including leading other engineers.

Architecture & Requirements

Partner with the vehicle and power-system architecture team to define battery requirements from the top down — deriving energy, power, voltage, thermal, mass/volume, and life requirements from mission profile, ConOps, and power-system needs rather than anchoring on legacy designs Own and maintain the battery specification — the single source of truth for battery requirements, interfaces, and verification criteria — with full traceability Drive battery architecture and cell down-selection through documented trade studies (requirement driver → options → evaluation criteria → rationale → recommendation), in collaboration with the battery mechanical, test, and BMS engineers Define and manage interface control (electrical, mechanical, thermal, data) between the battery and the vehicle

Cross-Functional Definition

Work with Flight Sciences, ConOps, and the Criteria team to define the battery's environmental and loads requirements — launch and flight vibration/shock, thermal environments, thermal cycling, EMI/EMC, altitude/vacuum, and mission duty cycles Partner with the avionics/EE team to define BMS requirements and scope — cell monitoring, balancing, protection (OVP/UVP/OCP), contactor/heater control, state estimation, and fault management Coordinate with the mechanical and vehicle-integration teams on packaging, mounting, thermal management, and installation interfaces Work with the criteria and structures teams to close structural, thermal, and safety margins

Safety & Verification

Own battery safety architecture — thermal-runaway detection and propagation mitigation, venting/burst-disc strategy, physical cell protection, and hazard analysis Define the verification and qualification strategy — qualification and acceptance test programs at cell and pack level, test-as-you-fly philosophy, and the data systems that turn test results into rapid design feedback Lead FMEA/FTA, reliability analysis, and identification/mitigation of single points of failure

Program & Technical Leadership

Carry technical program-management responsibility for the battery effort — schedule, risk, dependencies, and status — and serve as the organized, single point of communication for battery status across teams Represent the battery at vehicle design reviews (PDR/CDR-class), safety review boards, and cross-functional forums Support supplier and cell-vendor engagement, including benchmarking, RFI/RFQ evaluation, and technical down-selection Contribute to producibility/DFM and NPI as the design matures, and lead structured root-cause and corrective-action (RCCA) for anomalies

About You:

Bachelor's degree in engineering (mechanical, electrical, aerospace, chemical, or related) 5+ years of battery systems development experience across the product lifecycle (concept → design → qualification), including HV lithium-ion packs Demonstrated ability to derive and own requirements top-down, with rigorous trade studies and traceable specifications — not just execute a fixed design Working depth across the battery stack: cell selection/characterization, pack architecture, thermal management, BMS scope, and safety/abuse behavior Strong understanding of battery safety, failure modes, and HV system fundamentals Proven cross-f