Help: K9 Health Hub 350 Returns Error E302S3 During Startup Over Hilly Terrain

The collar boots to the debug menu and throws "E302S3" before any metrics begin to capture.

Things I've tried so far:

• Reset via the reset button for 30s, then powered off.
• Fully charged a 72V 1500mAh supply (inlay charging cap now > 10.3V).
• Firmware updated to latest version 3.15.
• Synthetically warmed the unit to room temp 21C (using external 22°C heat pad), error still present.

Likely suspect: overheating of internal SOC under GPS/Power spike, flagged by error code "E302S3" (SOC thermal cut‑out). The device has a thermal profile for 6 minutes before stalling. I started at high latitude / sunrise angle – battery gauge near 51%. I use a “GCP-3500” battery with heat shimming, so I've disabled the shimming, but that hasn’t helped. I'm unsure whether the internal CO₂ sensor's firmware also triggers the cutout.

Would appreciate someone who built or patched that SOC model to know if there’s a known patch or voltage cutoff? Additionally, any nuance around "thermal compensation code" values in the spec would help narrow down if it’s firmware or hardware.

P.S. This came after running an uphill test in Pine Ridge Park, and the device tries to gauge trotted steps from a 45% gradient – might that be triggering a hidden loop? Thoughts? 🙂