Junior BESS Engineer - Energy Infrastructure Projects

ON.energy is building the power infrastructure that makes the AI era possible. As AI demand surges past what the grid and traditional data centers can support, ON.energy provides a new class of power technology proven at gigawatt scale and trusted by the world’s leading cloud and AI companies. Our systems are already deployed across 2.5 GW of hyper-scale campuses, validated by top U.S. national labs, and certified for grid-safe operation by major utilities. With real products in the field, we’re scaling faster than the grid can, transforming power from a bottleneck into a competitive advantage for the companies building the future.

Role Overview

We’re looking for a Jr. BESS Engineer to support the BESS and DC Cabinet product design, documentation, project-specific technical compliance and support the development activities related to these products. This is a product focused role—we need someone with a technical background on both BESS systems and DC cabinets, ideally have knowledge of mission critical applications, and interface with project, commissioning and O&M engineering teams.

What You’ll Do

• Support the business development team by providing technical proposals e.g. SLDs and GAs that meet the customer’s needs.
• SOC analysis for multiple market applications.
• Compile product technical information packages for the project engineering team.
• Co-lead review and validation of the BESS- and DC Cabinet-related topics during the project execution phase.
• Maintain technical documentation including as-built drawings
• Support product development by capturing design improvement feedback from the different project phases: design, commissioning and O&M.
• Support product development by recommending design approaches and vendors of the main equipment.
• Participate in product design sprints with the development team.
• Participate in the product’s commissioning phase.

Required Qualifications

• Bachelor’s degree in Electrical Engineering, Power Electronics Engineering, or similar technical field.
• Entry-level to 1+ yearsof hands-on BESS engineering experience in project-based or industrial settings.
• Understanding of BESS systems integration with power electronics equipment.
• Ability to produce and read single lines and general arrangement drawings
• Excellent communication skills across technical and non-technical teams.
• Willing to travel up to 20% for product FAT inspection and site commissioning witnessing.

Preferred Plus

• Knowledge of Power Electronics, UPS/mission critical applications or utility-scale infrastructure

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 recruitment@onenergystorage.com
• Benefits vary by role and location and are subject to change.