Battery Systems Engineer

EV.Careers; Seattle (WA); On-site; USD 120,000 - 170,000; Full time

Benefits offered by this job

Relocation assistance

Fully paid healthcare

Strong 401(k) match

Job summary

EV.Careers is seeking a Battery Systems Engineer for a partner that develops high‑voltage battery and power‑electronics solutions. You will own the design of an 800V stationary battery pack and energy‑storage system from architecture through first production, based in Seattle.

This role hands you pack architecture, safety, BMS interfaces, and validation work to enable a new datacenter backup‑power product. Candidates should have 5+ years of battery design experience and HV Li‑ion knowledge.

Qualifications

• BS in Electrical, Mechanical, or Chemical Engineering.
• 5+ years of battery pack or BMS design experience.
• High-voltage (400V+) Li-ion pack design with module architecture and BMS integration.
• Battery safety and abuse testing experience.
• On-site in the Pacific Northwest; US work eligibility (US Persons only).

Responsibilities

• Own 800V stationary battery pack and ESS design: pack architecture and cell configuration.
• Set cycle-life, calendar-life, and thermal targets for continuous high-uptime duty.
• Own pack-level safety architecture and abuse tolerance.
• Define BMS requirements and interfaces to the converter and rack controls.
• Drive pack-level validation and testing.

Skills

Battery design experience

BMS integration

High-voltage systems

Battery safety testing

Education

BS in Electrical, Mechanical, or Chemical Engineering

Job description

Seattle, United States | Posted on 09/16/2026

EPG is currently seeking a Battery Systems Engineer for one of our partners that is an established high-voltage battery and power-electronics company bringing technology proven in demanding, high-reliability applications to a new backup-power product for AI data centers. In this position, you will own the design of a new 800V stationary battery pack and energy-storage system from architecture through first production.

Responsibilities

• Own 800V stationary battery pack and ESS design: pack architecture and cell configuration.
  
• Set cycle-life, calendar-life, and thermal targets for continuous high-uptime duty.
  
• Own pack-level safety architecture and abuse tolerance.
  
• Define BMS requirements and interfaces to the converter and rack controls.
  
• Drive pack-level validation and testing.
  

Requirements

• BS in Electrical, Mechanical, or Chemical Engineering.
  
• 5+ years of battery pack or BMS design.
  
• High-voltage (400V+) Li-ion pack design, including module architecture and BMS integration.
  
• Battery safety and abuse testing.
  
• This role is onsite in the Pacific Northwest. Must be able to work in the United States without sponsorship (US Persons only, export-control requirement).
  

Preferred Qualifications

• Stationary ESS experience with UL 9540 / UL 9540A.
  
• NMC / Si or other high-energy-density chemistries.
  
• Competitive salary, relocation assistance, fully paid healthcare, and a strong 401(k) match.
  
• Own a clean-sheet 800V battery system built on proven high-voltage battery technology.
  
• Shape the core of a brand-new datacenter product line.