Would be nice if it restarts after cooling when overtemp protection is activated. But apparently nobody has seen this function yet, and that is not how some cams with overtemp protection work.
Improperly closed files is abnormal in every way, even with overtemp shutdowns.
It is not acceptable under any circumstances. On this matter I also note another thread concerning file corruption at loss of power. Knowing that bad supercaps can exhibit high electrical resistance which generates heat, it seems plausible to me that both these issues may be due to bad supercaps, or that they at least contribute to the problem.
Unless there is a current-limiting design in the supercap-charging circuit, then excess power draw at the supercaps could leave the cam with insufficient power for normal functioning. Normally such limiting is not necessary; by their nature caps are self-regulating, the caps will draw current till charged and then 'float' allowing essentially full current flow afterward. I doubt there's any such current-limiting in any supercap equipped dashcam.
If Viofo got a batch of bad caps, or the caps being used vary in value at their high-temp range, that would explain why some here have problems and some don't.
@viofo Given the timing involved, I believe Kamkar and I may have cams from the same (first) production batch. He's seeing issues at heats similar to or less than mine as I'm not seeing any kind of issues at all.
This leads me to suspect that the supercaps being used lack good quality control, and are marginal at the heats found in this cam.
Hardly any way for us owners and testers to check out my theory, maybe Nath has the equipment needed but I doubt that any of the rest of us do.
Tomorrow or Saturday I will use my electric heater to push this cam to it's limits and beyond. I hope I don't kill it or the other cam I'll have showing the A139 and hopefully the thermometer will be readable too. Full report here then.
Phil