Architecture
System power architecture
A simpler block-level view of how battery power, switched outputs, local rails, control, and telemetry fit together.
ValidatedBuilt
Darcy Battery Management System
Protected 12-cell battery interface and monitored power-distribution node for vehicle avionics
Design Responsible Engineer
AvionicsPower ElectronicsEmbedded SystemsHigh Current
Schematic
Browse the exported schematic and design sheets.
Layout
Look through the copper layers and routing.
3D Model
Spin around the board model in 3D.
Design Notes
The reasoning, bring-up, bugs, and test results behind the board.
Project overview
What I worked on
12S Li-Ion
Battery Source
5
Controlled Load Paths
Current + Voltage
Power Telemetry
4
Copper Layers
A four-layer battery-management and power-distribution board between the 12S pack and the Darcy avionics. I designed the schematic and PCB, ordered and assembled the hardware, then brought up the protected input, five switched outputs, and measurement paths.
This is the actual Darcy BMS I designed and brought up. The old unrelated 'Darcy BMS Debugging' page is not used anywhere in this case study.
Hardware & test evidence
Photos, measurements, and validation
Built
Assembled Darcy BMS
The assembled four-layer BMS I used for protected-input and controlled-output validation.
PCB
BMS 3D implementation
Altium 3D view of the BMS and power-distribution PCB.
Test history
Bring-up, validation, and revisions
Protected input path
Verify that the battery-input protection and switching path operates correctly before downstream loads are energized.
- Setup
- Current-limited bench bring-up with staged input-path and enable/disable checks.
- Expected
- Protected input follows the intended command/protection behavior without abnormal downstream power states.
- Measured / observed
- The protected input path was validated on assembled hardware. One bring-up issue on the input load-switch path was traced to an assembly/soldering problem rather than the circuit design, then corrected before validation continued.
Controlled output switching
Verify that the five downstream power outputs can be independently enabled and disabled through the board's switched distribution architecture.
- Setup
- Channel-by-channel output checks on the assembled PCB.
- Expected
- Each commanded output switches independently while the protected input remains stable.
- Measured / observed
- Output switching and protection behavior were validated across the assembled board before integration.
Design
Designed
Completed schematic and PCB layout for the protected battery input, auxiliary power, five controlled outputs, measurement paths, and vehicle interfaces.
Fabrication + assembly
Assembled
Boards were ordered and assembled, then brought up in stages before integrated testing.
Hardware validation
Validated
Protected input behavior and downstream output switching were exercised successfully on the assembled board.
Design deep dives
A closer look
Power
12S inputProtected Power Architecture
How battery power enters the board, where protection lives, and how I kept the higher-current paths separate from the measurement side.
Distribution
5 outputsOutput Switching & Telemetry
Why I used five independently switched outputs and how I kept the software-visible power state tied to a real, tested hardware output.
Validation
Built + testedBring-Up & Debug
The staged bring-up flow, including the input load-switch issue that turned out to be soldering rather than a design problem.
1Top
2GND
3GND
4Bottom