Automotive Battery Disconnect Controller
Budget: $30 – $250 USD
I’m building a compact controller board that will sit between a 12 V vehicle battery and a high-current contactor, taking care of everything except the full power path itself. The board must:
• drive the contactor coil safely and reliably,
• sense battery and system conditions (voltage, current, temperature as space allows),
• survive and clamp load-dump or other automotive transients,
• run low-current logic so it can stay awake without draining the battery.
I already have a rough block diagram and pinout; what I need from you is a complete, production-ready design package:
1. Schematic with clearly annotated protection, sensing, and driver stages.
2. 2-layer (or more, if justified) PCB layout that meets typical automotive creepage/clearance and vibration guidelines.
3. Verified BOM with automotive-grade components and alternates.
4. Basic firmware or register map outline so the micro can report status and accept commands over a simple serial link (CAN, UART, or I²C—whichever best fits your design).
5. Brief test plan outlining how you would validate coil drive current, transient immunity, and quiescent draw.
I’ll review each milestone, run a quick DFM/DRC check, then move to prototyping right away, so clean documentation and reproducible design files (Altium, KiCad, or Eagle) are important.
If you’ve designed automotive power or safety boards before and can reference AEC-Q components, let’s talk.
• drive the contactor coil safely and reliably,
• sense battery and system conditions (voltage, current, temperature as space allows),
• survive and clamp load-dump or other automotive transients,
• run low-current logic so it can stay awake without draining the battery.
I already have a rough block diagram and pinout; what I need from you is a complete, production-ready design package:
1. Schematic with clearly annotated protection, sensing, and driver stages.
2. 2-layer (or more, if justified) PCB layout that meets typical automotive creepage/clearance and vibration guidelines.
3. Verified BOM with automotive-grade components and alternates.
4. Basic firmware or register map outline so the micro can report status and accept commands over a simple serial link (CAN, UART, or I²C—whichever best fits your design).
5. Brief test plan outlining how you would validate coil drive current, transient immunity, and quiescent draw.
I’ll review each milestone, run a quick DFM/DRC check, then move to prototyping right away, so clean documentation and reproducible design files (Altium, KiCad, or Eagle) are important.
If you’ve designed automotive power or safety boards before and can reference AEC-Q components, let’s talk.