Senior Battery Systems Architect – BESS Leader

ON.energy; Ciudad de México; On-site; MXN 200,000 - 320,000; Full time

Benefits offered by this job

Professional development and growth

Growth opportunities

Equal opportunity workplace

Job summary

ON.energy in Mexico is seeking a Principal Engineer to set the technical direction for our BESS product line and own the roadmap across multiple development cycles. You will architect new products, resolve hard trade-offs, and represent the product engineering team externally to vendors and certifying bodies, traveling up to 25–30%.

You will lead architecture, specs, and design reviews, mentor engineers, and drive cross-functional collaboration to deliver field-ready solutions for data-center

Qualifications

• Bachelor's degree in Electrical Engineering, Power Electronics, or a closely related technical field. MS preferred.
• 10+ years of hands-on engineering experience in BESS, power electronics, UPS, or comparable mission-critical industrial power systems, with a demonstrated record of operating with minimal direction in a senior technical role.
• Owned multiple product development cycles end-to-end and independently. You've personally designed and integrated a BESS at the system level, from engineering through commissioning and into live operation, not just handed it off at FAT, and the products are still in the field.
• Architecture-level decision authority on previous BESS equipment. You've made the trade-off calls others built around, not just executed someone else's architecture.
• Fluency producing and reviewing SLDs, GAs, schematics, and panel layouts; expert with AutoCAD or equivalent E-CAD; comfortable across mechanical drawings.
• Willing to travel up to 25–30% for FAT inspections, site commissioning, customer engagements, and vendor reviews.

Responsibilities

• Set the architecture for the BESS product line and own the technical roadmap across multiple concurrent product cycles.
• Make the hard trade-off calls — cost vs reliability, performance vs lead time, standardization vs customization — and document the reasoning so future decisions inherit context.
• Define the engineering standards, design rules, and review gates that other engineers on the team work to. Own the product-engineering bar.
• Approve major design changes; act as the final technical authority on the change baseline.
• Run multiple product development cycles in parallel — concept through prototype, FAT, field deployment, and revision — without losing depth on any of them.
• Drive cycle cadence: decide what ships when, where the technical risk lives, what gets parallelized vs sequenced.
• Identify and execute the next-generation product moves — higher voltage class, alternate chemistries, new form factors — ahead of customer demand.
• Personally own the hardest pieces of work: novel architectures, first-of-kind designs, advanced component sizing (fuse coordination, busbar thermal optimization, protection coordination across cascaded systems), cabinet thermal modeling, and complex protection schemes.
• Review and approve detailed engineering drawings — SLDs, GAs, schematics, panel layouts — at the level required to sign off, not just consult.

Skills

Communication skills

Vendor relationship management

Design review leadership

AutoCAD / E-CAD proficiency

Technical leadership

Education

Bachelor's degree in Electrical Engineering, Power Electronics, or a closely related technical field

MS preferred

Tools

AutoCAD

Job description

ON.energy in Mexico is seeking a Principal Engineer to set the technical direction for our BESS product line and own the roadmap across multiple development cycles. You will architect new products, resolve hard trade-offs, and represent the product engineering team externally to vendors and certifying bodies, traveling up to 25–30%.

You will lead architecture, specs, and design reviews, mentor engineers, and drive cross-functional collaboration to deliver field-ready solutions for data-center