Senior Thermal Systems Design Engineer

Brelle; California (MO); On-site; USD 130,000 - 180,000; Full time

Benefits offered by this job

Founding Engineer equity via Employee‑

Employee Incentive Plan

Job summary

Brelle, based in California, is hiring a Senior Thermal Systems Design Engineer to own the thermal performance of its battery products through the full development cycle. The role focuses on defining thermal requirements, cooling architecture, and multi-fidelity analyses with test validation.

Ideal candidates have a strong systems view, 7+ years in thermal engineering, and hands-on experience with battery thermal management, 3D CFD, and instrumentation-driven testing.

Qualifications

• Bachelor's degree in Mechanical Engineering, Aerospace Engineering, or related field with strong heat transfer/thermo/fluid foundations.
• 7+ years in thermal engineering on design and analysis for critical hardware.
• First-principles approach to establish thermal requirements and architectures.
• Direct experience with battery/energy-storage thermal systems (pack/module-level).
• Balance thermal with electrical design, safety and cost considerations.
• Proficiency with multi-fidelity modeling (1D networks, CFD) and thermomechanical modeling.
• Hands-on testing with instrumentation and data post-processing.

Responsibilities

• Own thermal performance of Brelle’s battery products across development cycle.
• Define thermal requirements and conceptualize cooling architecture.
• Perform multi-fidelity analysis and CFD simulations; validate with tests.
• Collaborate with electrical, mechanical, safety, and cost teams.

Skills

Heat transfer

Thermodynamics

Fluid mechanics

Battery thermal

Thermal management

Multiphysics

CFD

Test instrumentation

Data analysis

1D tools

Model validation

First-principles

Education

Bachelor's in Mechanical/Aerospace Engineering

Master's degree (preferred)

Tools

CFD tools

1D thermal-network tools

Thermomechanical modeling

Job description

“Energy for what moves us” defines our mission at Brelle. Based in California, Brelle engineers a modular energy platform for the world’s most demanding machines – supercars, superbikes and aerial systems. Our innovations are built on a novel battery pack architecture, a full-stack software platform, and automated manufacturing.

About the Role

We are seeking a Senior Thermal Systems Design Engineer to own thermal performance of Brelle’s battery products. This position spans the full development cycle: defining thermal requirements, conceptualizing the cooling architecture, performing multi-fidelity analysis and simulation, and validating performance through test. The role is intentionally balanced between design and analysis.

Thermal decisions affect electrical, mechanical, materials, safety, and cost outcomes across the product. Candidates with a strong systems perspective and experience in battery systems, energy storage, power electronics, electric-vehicle thermal management, or related fields will be well suited to this role.

Minimum Qualifications

• Bachelor's degree in Mechanical Engineering, Aerospace Engineering, or a related field, with a strong foundation in heat transfer, thermodynamics, and fluid mechanics.
• 7+ years of thermal engineering experience covering both design and analysis on performance-critical or safety-critical hardware.
• Demonstrated first-principles approach to problem solving, with the ability to establish thermal requirements and architecture from limited information and to justify design decisions through fundamental analysis rather than reliance on prior solutions.
• Direct experience with battery or energy-storage thermal systems, including pack- and module-level thermal management, cell thermal behavior, and thermal-runaway and propagation prevention
• Demonstrated ability to balance thermal performance metrics around cell chemistry and form factor, electrical design, controls, safety, and cost.
• Proficiency with multi-fidelity modeling, including 1D thermal-fluid network tools, 3D heat transfer and CFD tools, and thermomechanical model creation.
• Hands-on test experience including instrumentation (thermocouples, RTDs, flow sensors), test plan creation, data post-processing and analysis, and model-to-test correlation.

Preferred Qualifications

• Master's degree in Mechanical Engineering, Aerospace Engineering, or a related field.
• Experience with electronics and power-electronics cooling, including heat sinks, cold plates, junction-to-ambient thermal paths, and the trade-offs between thermal, electromagnetic interference, and sealing requirements.
• Experience with coupled multi-physics modeling, such as thermal-structural, thermal-electrical, or electrochemical-thermal analysis.
• Experience executing designs from concept through prototype, pilot, and volume production.

Compensation & Benefits

Compensation:

• Base Salary: $130,000 to $180,000. Compensation may vary based on experience, training, education, and scope of the role.
• Founding Engineer equity participation through Employee Incentive Plan