Principal BESS Engineer - Energy Infrastructure Projects

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.

Medical, dental, and vision insurance

401(k) with company match

Paid time off and company holidays

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

Christmas Bonus (Aguinaldo): 30 days

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.

Architecture & Technical Direction

Set the architecture for the BESS and DC Cabinet product lines and own the technical roadmap across multiple concurrent product cycles.

Define the engineering standards, design rules, and review gates that other engineers on the team work to.