I have CCR1009-7G-1C connected to buffer power supply 27,6V. At he system /health CCR shows:
cpu-overtemp-check: yes
cpu-overtemp-threshold: 100C
cpu-overtemp-startup-delay: 1m
voltage: 17V
temperature: 30C
cpu-temperature: 46C
So - WHY about 10V less than real DC voltage?