Start with platform and duty cycle
Selection begins with application: BESS cabinet, containerized storage, passenger EV, commercial EV, or integrated CDU. Duty cycle (continuous vs peak), ambient temperature, and vibration profile drive thermal and mechanical design.
Write the use case into the RFQ so suppliers do not quote a generic unit that fails integration.
Electrical ratings checklist
- Rated system voltage and the project-specific operating window
- Continuous and peak current per branch and for the main path
- Short-circuit capacity and fuse / breaker coordination
- Pre-charge requirements and maximum allowable inrush
- Insulation and clearance expectations for your region and standard set
Protection and control interfaces
Define which protections are inside the PDU versus upstream/downstream. Map signals to BMS, VCU, PCS, or EMS early.
- Contactor feedback, HVIL, enable / fault lines
- CAN, RS485, or discrete I/O requirements
- Diagnostic coverage needed for OEM service tools
- Functional safety expectations (discuss explicitly; do not assume)
Mechanical, thermal, and environmental
- Envelope, mounting points, and service access
- IP rating (e.g. IP54 cabinet ESS vs IP67 vehicle underbody)
- Cooling method: natural convection vs forced air vs liquid interfaces
- Connector brands / standards preferred by your harness team
- Mass and center-of-gravity constraints for vehicle packaging
Supplier and program criteria (B2B)
For overseas OEM procurement in Europe, North America, and Asia-Pacific, evaluate engineering support and mass-production readiness — not only unit price.
- OEM/ODM customization capability and documentation quality
- Prototype MOQ and lead time
- Series capacity, traceability, and test reports
- RoHS / REACH and project-specific compliance support
- English RFQ response SLA and export packing experience
Selection summary
A high-voltage PDU is selected when electrical ratings, protection logic, packaging, and supplier process capability all align with your SOP plan. Use a structured RFQ: voltage, current map, topology sketch, IP target, interfaces, quantity, and timeline.
Frequently asked questions
Should I buy a catalog PDU or customize?+
Catalog units can accelerate early trials. Most EV and ESS programs customize connectors, busbars, or enclosures before SOP. Plan prototype → pilot → series accordingly.
What documents should suppliers provide?+
At minimum: outline drawing, electrical interface list, preliminary BOM notes, test outline, and commercial terms (MOQ, lead time). Datasheet packages are typically issued after NDA or RFQ qualification.