In an era where remote work, electric vehicle charging, and renewable energy adoption are surging, the demand for reliable home energy storage systems has skyrocketed. A innovative startup recognized this opportunity but faced a critical challenge: lacking a full in-house engineering team to design and build a functional prototype. This prototype was essential for validating their concept, meeting certification requirements, and securing additional investments to bring their residential battery storage unit to market.
Partnering with Goken, a global engineering services provider specializing in product development for manufacturing and energy sectors, the client leveraged expert support to overcome these hurdles. This case study highlights how targeted engineering assistance in battery module design and prototype management accelerated the project's progress in a competitive landscape.
Client Situation
The project involved a startup developing a home energy storage unit. Growing demand from remote work and home-based charging needs created urgency to introduce a residential energy storage product to the market.
However, the organization did not have a complete in-house engineering team to design and build a functional prototype. A working prototype was essential to secure further investment and move toward certification.
Client Requirements
The client required a home energy storage unit that:
Could be wall-mounted or free-standing
Worked with grid and solar power
Met defined power and weight targets
Operated in wide temperature ranges
Met multiple certification requirements
Was cost-efficient and visually appealing
Goken’s Approach
Goken executed the project in three phases:
- Design Maturation
- Prototype Build and Testing
- Certification
Phase 1: Design Maturation
Technical Requirements Gathering
Goken conducted interviews with stakeholders, studied market competitors, gathered technical requirements, and documented assumptions. The work covered concept development, requirement definition, and documentation.
Cell Selection
Cell selection considered parameters such as:
Life cycle and peak discharge
Capacity and energy density
Thermal behavior
Cost and weight
Manufacturability and modularity
C-ratings and discharge behavior
An Analytical Hierarchy Process was used to compare prismatic and cylindrical cells.
Different cell capacities were evaluated against housing size, module layout, busbar design, inverter and BMS integration, thermal management, ECU placement, and cost.
Parallel and series configurations were studied to meet voltage and power requirements.
Supplier selection considered life cycle data, configuration flexibility, production readiness, and approval for energy storage use.
Battery Module and Pack Development
Goken evaluated bonding and joining methods including bolt-nut busbars, ribbon bonding, and laser welding.
Pack structure and thermal layout were designed.
CFD analysis was conducted to study heat distribution and validate results with hand calculations.
Inverter selection considered AC voltage, grid type, phase configuration, physical size, power rating, battery compatibility, number of MPPTs, and voltage limits.
Internal and external inverter concepts were explored.
The structure was designed using Design for Manufacturing principles with weight optimization.
Technical Documentation
DFMEA was developed to identify failure modes.
DVP was created to define validation testing.
Engineering drawings were released and quotations were obtained for prototype build.
Phase 2: Prototype Build and Testing
Goken supported prototype build planning and supplier coordination.
Costs, working concept, functional model, and test sample requirements were defined.
Suppliers across the USA and India were evaluated based on cost, certification needs, and logistics.
Phase 3: Certification
The prototype was prepared for certification activities based on defined DVP and regulatory requirements.
Results
Innovative Design
Complete energy storage system designed from the ground up
ESS designed to work without external components such as inverter or charge controller
Off-the-shelf components were evaluated and selected for quality
Design approved by client for prototype build
Global Delivery Model
Delivered 3D models, 2D drawings, test plans, DVP, DFMEA, BOM, and CFD data
Project management executed from the US
Engineering execution handled from India
Optimized Cost
Global supplier evaluation enabled cost optimization through supply chain selection