Principal Battery Storage Engineer

ON.energy; Houston (TX); On-site; USD 180,000 - 240,000; Full time

Benefits offered by this job

Medical, dental, and vision insurance

401(k) with company match

Paid time off and holidays

Job summary

ON.energy in Houston is seeking a Principal Engineer to set the technical direction for the BESS and DC Cabinet product lines and own the roadmap across multiple development cycles. This senior technical voice will architect new products, resolve hard trade-offs, and represent ON.energy externally to vendors, customers, and certifying bodies.

You'll lead architecture, set engineering standards, review gates, and partner with vendors while mentoring the team and driving multiple cycles in

Qualifications

• Bachelor's degree in Electrical Engineering or related field; MS preferred.
• 10+ years in BESS, power electronics, UPS, or mission-critical power systems.
• Own multiple product cycles end-to-end with independent leadership on architecture.
• Fluency with SLDs, GAs, schematics and panel layouts; AutoCAD or similar.

Responsibilities

• Set architecture for BESS and DC Cabinet product lines and own technical roadmap.
• Make trade-off decisions on cost, reliability, performance and lead time.
• Define engineering standards, design rules, and review gates for the team.
• Approve major design changes and act as final technical authority.
• Lead multi-cycle development from concept to field deployment and revision.
• Mentor engineers and lead design reviews, ECR/ECN processes.

Skills

Electrical Eng

Power Electronics

BESS

UPS

Data centers

Education

Bachelor's degree in Electrical Engineering

MS preferred

Tools

AutoCAD

Job description

ON.energyis building the backbone of energy and AI infrastructure powering grid-safe data centers and mission-critical facilities. The company supplies and operates hyperscale power systems that solve the toughest resilience challenges, delivering custom solutions for AI data centers, mission-critical facilities, and front-of-the-meter assets. ON recently announced a 5GW partnership, with 3GW currently under construction across multiple hyperscale data center campuses. With patented technology and proprietary software,ON.energydevelops projects worldwide that set new benchmarks for resilience.

Principal Engineer — BESS

Role Overview

We're looking for a Principal Engineer to set the technical direction for our BESS and DC Cabinet product lines and to own the product roadmap across multiple concurrent development cycles. This is the senior technical voice on the product team: you'll architect new products, resolve the hardest engineering trade-offs, set the engineering standards others work to, and represent ON.energy's product engineering externally — to vendors, customers, certifying bodies, and the broader industry. You should be comfortable operating with minimal direction, holding the bar on technical quality, and moving multiple product cycles forward in parallel without losing the thread on any of them.

What You'll Own

Architecture & Technical Direction

• Set the architecture for the BESS and DC Cabinet product lines 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.

Multi-Product Development

• 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.

Detailed Engineering Depth

• 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.

Vendor & Supply Chain Strategy

• Own the strategic relationships with key vendors — DC Cabinet, battery, PCS, BoP. Decide the architecture of those relationships: sole-source vs dual-source, co-development depth, IP boundaries.
• Set the technical qualification process used by the team and enforce it. Run the highest-stakes design reviews and resolve the highest-stakes vendor escalations personally.

Engineering Leadership & Mentorship

• Mentor and develop other engineers on the team. Build their technical judgment, not just their throughput.
• Run design reviews. Lead post-mortems on field issues and turn them into product changes.
• Set the cadence and quality bar for ECR/ECN, FMEA, design reviews, and product handoff.

External & Cross-Functional Representation

• Represent ON.energy's product engineering externally — customer technical reviews, vendor escalations, industry working groups, certifying bodies, conferences.
• Partner with the commercial team on the most technically complex pursuits and proposals — proposing architectures, defending positions, structuring technical exhibits in LTSAs and supply agreements.
• Brief leadership on technical risk and product roadmap decisions.

Required 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 taken more than one product from concept through prototype, FAT, field deployment, and revision — and the products are still in the field.
• Architecture-level decision authority on previous BESS or DC equipment. You've made the trade-off calls others built around, not just executed someone else's architecture.
• Deep, demonstrable skill in detailed component sizing — fuse coordination, busbar sizing, protection device selection, thermal sizing for enclosed cabinets — at the level required to sign off on production designs.
• Fluency producing and reviewing SLDs, GAs, schematics, and panel layouts; expert with AutoCAD or equivalent E-CAD; comfortable across mechanical drawings.
• Strong track record running strategic vendor relationships through design, FAT, serial production, and post-deployment escalation.
• Excellent written and verbal communication — specs, technical positions, design review leadership, board-level briefings.
• Willing to travel up to 25–30% for FAT inspections, site commissioning, customer engagements, and vendor reviews.

Preferred

• Direct experience with data center / UPS / mission-critical power or utility-scale BESS at the architecture level.
• Active involvement in standards bodies (UL, IEC, NFPA, IEEE working groups, CSA TC committees) or technical conference contributions.
• Patents, peer-reviewed publications, or other evidence of recognized technical depth in the field.
• PE license.
• Familiarity with UL 9540 / 9540A, NFPA 855, IEC 62619, IEEE 1547, NEC Article 706, plus the relevant codes for target markets.
• Experience standing up or scaling structured PLM, ECR/ECN, and design-review processes.
• Multi-domain depth — BMS / cell engineering, PCS / power electronics, thermal / mechanical — alongside the EE core.

For US-based roles - What you’ll get:

• Competitive salary + annual performance-based bonus eligibility
• Medical, dental, and vision insurance
• 401(k) with company match
• Paid time off and company holidays

For Mexico-based roles - What you’ll get:

• Competitive salary + annual performance bonus eligibility
• Christmas Bonus (Aguinaldo): 30 days
• Major medical expenses and life insurance
• Paid time off and holidays (per local policy)

For all roles:

• Professional development and growth opportunities
• Opportunity to grow with a mission-driven team shaping the future of clean energy
• Equal Opportunity: ON.energy is committed to equal employment opportunity and to maintaining a work environment free of harassment, discrimination, or retaliation.
• Accommodations: If you need an accommodation during the application process, email [e-mail]
• Benefits vary by role and location and are subject to change.

Agency Notice:

ON.energy does not accept unsolicited resumes from staffing agencies, search firms, or third-party recruiters. Resumes submitted without a fully executed Master Services Agreement (MSA) and a written request from a authorized member of our Talent Acquisition team will be considered the property of ON.energy. No placement fees or compensation will be paid for unsolicited candidate submissions.