Cell-to-Pack (CTP) Design Engineer – Utility-Scale BESS

Role Summary

The Cell-to-Pack (CTP) Design Lead for Utility BESS is responsible for leading the design, architecture, and engineering of battery modules, sub-packs, racks, and container-level pack integration. The role ensures optimal energy density, thermal safety, mechanical robustness, manufacturability, and compliance with global standards. This leader works across electrochemistry, thermal, mechanical, electrical, and controls engineering teams to deliver safe, scalable, and cost-optimized BESS battery packs for grid applications.

Key Responsibilities

Define end-to-end CTP architecture for utility-scale BESS (cell → module → unit → rack → container).
Lead selection of cylindrical, prismatic, or pouch cell platforms based on application: frequency response, energy shifting, and hybrid storage.
Determine series/parallel cell configurations, voltage windows, SOC/SOH limits, and pack topology.
Develop modular, scalable pack/rack designs compatible with PCS, EMS, and container infrastructure.
Optimize energy density, footprint, weight, and structural stability.
Lead mechanical layout of modules, frames, busbars, holders, and pack enclosure.
Conduct structural strength and vibration analysis (simulation + validation).
Ensure tolerance stack-ups, manufacturability, and assembly feasibility.
Design load-bearing frames supporting seismic, transport, lifting, and shock requirements as per relevant standards
Collaborate with thermal engineering to define cooling strategy:
Air-cooled, liquid-cooled, or hybrid CTP approaches.
Ensure cell temperature uniformity, cooling channel placement, and thermal runaway (TR) mitigation.
Drive venting paths, exhaust channels, gas detection, and propagation prevention mechanisms.
Integrate sensors (NTC/PTC, pressure, humidity) into pack design.
Define electrical layout, voltage isolation, creepage/clearance, fuse/circuit protection, HV harnessing, and contactor block integration.
Collaborate with BMS team to ensure: Cell sensing accuracy, Balancing circuit integration
High-voltage interlock loop (HVIL) design
Define pack functional safety per relevant guidelines.
Ensure pack design meets global grid-scale BESS standards:
UL 9540 / 9540A, UL 1973,IEC 62619,NFPA 855 & local certification requirements
Prepare all certification documentation, models, drawings, and test artifacts.
Participate in design reviews and audits with UL/Intertek/TÜV.
Lead prototype build, DVT/PVT testing, pack characterization, and reliability tests.
Define end-of-line (EOL) testing requirements for pack manufacturing.
Manage validation of mechanical vibration, temperature cycling, short-circuit testing, fire propagation, fault injection tests
Support pilot manufacturing, tooling design, and vendor qualification.
Work with system engineering, EMS, thermal, fire safety, and manufacturing teams.
Collaborate with supply chain on cell suppliers, module makers, and component vendors.
Provide technical guidance to BESS product managers on roadmap strategy.
Review customer RFPs and support engineering proposals.

Required Qualifications

Bachelor's or Master's degree in Mechanical Engineering, Electrical Engineering, Energy Systems, or similar. Advanced degree in Battery Technology is a plus.

Technical Skills

Deep understanding of lithium-ion cell chemistry, performance curves, aging, and safety.
Expertise in pack design, module architecture, busbar design, and enclosure engineering.
Proficiency with CAD tools: SolidWorks, CATIA, CREO, NX.
Knowledge of FEA/CFD (ANSYS, Abaqus, Star-CCM+).
Knowledge of BMS architecture, high-voltage design, and thermal systems
Familiarity with battery safety standards and grid energy storage requirements.

Experience

7–10+ years in battery pack/module engineering (EV, UPS, BESS, ESS racks).
Minimum 5+ years leading design teams.
Experience with utility-scale BESS racks and container architectures is a major advantage.

Proven track record of taking battery products from concept → prototype → certification → mass production.

Battery Pack Design Engineer