Just stops recording and don't know why

I have been trying to record car racing with my One-X2, this is about ~1hr each race. I know the camera breaks it into 30min files (and misses ~5sec when it starts the next chapter, and that the Windows software cannot join the files back together, but that's another story).

However it always seems to just stop recording part-way through and I don't know why. Initially I thought the battery was dying, so I wired up a USB power supply but it's still stopping randomly part-way through a race.

Obviously this kind of footage is a one-time thing, so if it's lost it's a real pain (especially if there is an accident or something that needs to be reviewed afterwards).

Is there any way to know WHY a video was stopped (user pressed stop, battery low, over-temp, stopped automatically for chaptering, SD card full, other)? Can we enable diagnostic logging for this? Is this information embedded in the files on the SD card already?

Thanks

Matthew