Our 1100 on the tower we use icinga2 to monitor voltage on battery. This router is on battery power

however we receive every now and then "unknown" states sending alarms to tower techs which will respond to this notice

Looking at system health print i see the voltage go missing

fan-mode: auto
use-fan: main
active-fan: main
temperature: 18C
cpu-temperature: 30C
fan1-speed: 8883RPM

then 10-20 seconds later

fan-mode: auto
use-fan: main
active-fan: main
voltage: 29.9V
temperature: 18C
cpu-temperature: 30C

my RB is latest version

routerboard: yes
model: 1100
serial-number: 2C69016B1D67
firmware-type: mpc8544
factory-firmware: 2.30
current-firmware: 6.41.4
upgrade-firmware: 6.41.4


Any idea why this would happen