Project Overview
Turnkey PCBA manufacturing for a European energy-storage system integrator serving residential and commercial storage. The build is a battery management system control board that monitors cell voltage and temperature and drives cell balancing across the pack. Kilandu sourced the components, assembled and tested the board, and shipped it with per-lot records from prototype through pilot into repeat production.
Customer Requirement
- Multi-layer PCB for a multi-cell pack
- Mixed SMT and through-hole assembly
- Cell voltage measurement and temperature sensing
- Cell balancing
- A defined communication interface to the pack supervisor
- Functional test before shipment
- Traceable production records
Engineering Challenges
Component placement on this board is tight for the package mix it uses, which raised placement risk on a board that also has to survive inside a thermally managed enclosure. The functional test is the safety-critical step: it has to exercise cell-voltage measurement, temperature inputs, balancing outputs and the communication interface before the board ships, because a fault in that chain is not a cosmetic defect once the pack is in the field. The customer was also scaling the same board across several storage-system models, so repeat orders had to behave identically to the qualified first build.
Manufacturing Solution
Kilandu reviewed layout, BOM and assembly files in a pre-production DFM stage. Components were sourced build-to-print with no silent substitution, and long-lead parts were surfaced at quotation. The board was assembled on our SMT lines with SPI and AOI; through-hole parts were handled on DIP lines, and selected builds received X-ray inspection.
A customer-approved functional test verified cell-voltage sensing, temperature inputs, balancing outputs and the communication interface before shipment. Per-lot inspection and process records were kept for every build so that a shipped batch can be traced back to its material and process data.
Build and Capability Data
| Parameter | Specification |
|---|---|
| Assembly | Mixed SMT + DIP |
| In-process inspection | SPI + AOI + X-ray |
| Functional test coverage | Cell-voltage measurement, temperature inputs, balancing outputs, communication interface |
| Traceability | Per-lot inspection and process records |
| Quality system | ISO 9001:2015 (CN27125Q0392R0S) |
| Lead time | Prototype 5–8 working days · volume production 2–5 weeks · repeat order 2–3 weeks |
| Cell count, layer count, board size, BOM count, production volume | Available under NDA on request |
Result
First article was inspected, retained and approved in writing before the volume run was released. The board then moved into repeat production across multiple storage-system models using the same approved BOM, process parameters and test limits, so later builds matched the qualified first article rather than being re-tuned per order.
What This Demonstrates
BMS PCBA · energy storage PCBA · battery management system · cell balancing and sensing · functional testing.
What did the functional test cover on this BMS board?
Cell-voltage measurement, temperature inputs, balancing outputs and the communication interface. Those are the four functions whose failure in the field is a safety issue rather than a cosmetic defect, so they are verified before the board ships rather than sampled afterwards.
Why is placement risk a concern on a BMS board?
The package mix leaves little spare spacing, and the board has to operate inside a thermally managed enclosure. Tight placement raises placement risk on a dense board, which is one of the reasons in-line SPI and AOI are run on every build rather than on first articles only.
How were repeat orders handled?
First article was inspected, retained and approved in writing before the volume run was released, and repeat orders across multiple storage-system models ran to the same approved BOM, process parameters and test limits.