Senior Mechanical Engineer

Better Ventures; Long Beach (CA); On-site; USD 150,000 - 200,000; Full time

Job summary

Critical Loop in Long Beach, California is hiring a Senior Mechanical Engineer to lead the mechanical design of high-power battery energy storage systems and support equipment. Candidates should have 10+ years of experience in mechanical engineering and strong skills in structural analysis and CAD systems.

This hands-on role involves collaborating with electrical engineers and fabricators from concept to field deployment. A competitive compensation between $150K and $200K is offered along with growth opportunities in a diverse, equal opportunity work environment.

Qualifications

• 10+ years of experience in mechanical engineering.
• Experience in at least 3 full product design cycles.
• Ability to work independently as a sole mechanical engineer.

Responsibilities

• Lead mechanical design of energy storage systems and equipment.
• Drive designs from concept through fabrication and assembly.
• Troubleshoot mechanical issues in the field.

Skills

Structural analysis

3D CAD systems

Thermal calculations

Hardware assembly and fabrication

Material selection

Education

BS in Mechanical Engineering or related field

Tools

SolidWorks

OnShape

Job description

About Critical Loop

Critical Loop is shaping the next generation of energy systems by building the integrated edge grid of the future. Specializing in advanced energy management and battery control systems, Critical Loop empowers businesses and communities to seamlessly unite distributed energy resources for faster, more reliable, and affordable grid access. With deep expertise in grid modernization and a passion for creating resilient, responsive energy solutions, Critical Loop drives innovation at the intersection of technology and energy.

The Role

We are hiring a Senior Mechanical Engineer to lead the structural, packaging, and thermal design of our high‑power battery energy storage systems, power conversion systems, and ground support equipment. You will own mechanical problems end to end, from blank‑paper concept through fabrication, validation, and field deployment.

This is a hands‑on, on‑site role. You will work alongside electrical engineers, field ops, and fabricators. You will not hand work off. You stay with the problem until it is solved.

What You Will Do

• Lead the mechanical design of BESS, power conversion systems, and ground support equipment, including large welded and bolted structures for outdoor and on‑road use
• Own all project documentation, CAD models, mechanical drawings, BOMs, and work instructions
• Work within a multidisciplinary environment to identify requirements and design systems that integrate cleanly with electrical and software teams
• Work directly with fabricators and contract manufacturers to get hardware built and assembled to spec
• Drive designs from blank paper through fabricated assembly, including managing schedules and tracking system design decisions
• Identify and resolve design risks proactively, before they become field problems
• Support field deployments and troubleshoot mechanical issues in the field when needed
• Set your own priorities and manage your own workload without waiting for direction

Must‑Haves

• 10 or more years of experience with a BS in Mechanical Engineering or a related field with a mechanical engineering focus, from an accredited university
• Strong ability to conduct structural analysis
• Experience across at least 3 full product design cycles, including at least one as the responsible engineer owning design, BOM, and schedule tracking end to end
• Ability to conduct basic thermal calculations
• Proven ability to take a design from blank paper through fabricated assembly independently
• Hands‑on experience with measurement, assembly, and fabrication of hardware while managing requirements and outline design criteria
• Knowledge of appropriate material selection
• Comfortable functioning as the sole mechanical engineer on a project, setting priorities and managing your own work without a mechanical engineering group to lean on
• 3 or more years with multiple 3D CAD systems; ability to work in SolidWorks and learn OnShape (no OnShape experience required, no certifications required)
• 3 or more years generating mechanical drawings per ANSI standards (GD&T certification not required)
• Able to ask questions, seek solutions, and operate effectively in a fast‑paced R&D and build environment

Nice‑to‑Haves

• Experience with assembly tooling, large weldments, ground support equipment, skids, trailers, lifting equipment, or other industrial hardware
• 3 or more years in thermal and fluid design for air‑cooled or liquid‑cooled electronic systems
• Experience with high voltage systems
• Background in both R&D and production environments
• Prior experience at an energy storage, EV, or industrial equipment company
• Familiarity with manufacturing processes including sheet metal, welding, machining, and plastics
• Finite Element Analysis, Computational Fluid Dynamics experience

Work Authorization

We are not able to offer visa sponsorship for this role. Candidates must be authorized to work in the United States without sponsorship now or in the future.

Critical Loop is an equal opportunity employer. We're committed to building a diverse team and creating an inclusive workplace where everyone can thrive. All qualified applicants will receive consideration for employment without regard to race, color, religion, sex, sexual orientation, gender identity, national origin, disability, veteran status, or any other protected characteristic under applicable law.

Compensation Range: $150K - $200K