Sensorsd - UPS Shutdown

APU# dmesg
uhidev0 at uhub0 port 3 configuration 1 interface 0 "American Power Conversion Smart-UPS_1500 ...
uhidev0: iclass 3/0, 142 report ids
upd0 at uhidev0
uhid0 at uhidev0 reportid 1: input=0, output=0, feature=1
uhid1 at uhidev0 reportid 2: input=0, output=0, feature=1
...
uhid21 at uhidev0 reportid 142: input=0, output=0, feature=4

APU# sysctl hw.sensors
hw.sensors.upd0.indicator0=On (BatteryPresent), OK
hw.sensors.upd0.indicator1=On (Charging), OK
hw.sensors.upd0.indicator2=Off (Discharging), OK
hw.sensors.upd0.indicator3=Off (NeedReplacement), OK
hw.sensors.upd0.indicator4=Off (ShutdownImminent), OK
hw.sensors.upd0.indicator5=On (ACPresent), OK
hw.sensors.upd0.indicator6=Off (Overload), OK
hw.sensors.upd0.percent0=99.00% (RemainingCapacity), OK
hw.sensors.upd0.percent1=100.00% (FullChargeCapacity), OK
hw.sensors.upd0.timedelta0=86400.000000 secs (RunTimeToEmpty), OK

cat << 'EOF' >> /etc/sensorsd.conf

# shutdown servers at 30% capacity
hw.sensors.upd0.percent0:low=30.00%:command=/root/shutdown-low-battery.sh %2 %l

EOF

cat << 'EOF' > /root/shutdown-low-battery.sh
#!/bin/sh

# wait seconds
limit=120

# get the charging state of the UPS
CHARGING=$(sysctl -n hw.sensors.upd0.indicator1)

# If the UPS is currently charging, do nothing.
if [[ "$CHARGING" = "On (Charging), OK" ]]; then
  logger "power is on, do nothing \($1, $2\)"
  return
fi

# If the UPS is on battery and the threshold is below the setting, shutdown in 2min
if [[ "$2" = "below" ]]; then
  logger "battery below $1, shutting down in ${limit} seconds."
  sleep ${limit}
  logger "battery at $1, shutting down now."

  # shutdown other boxes
  ssh root@host1 "halt -p"
  ssh root@host2 "halt -p"
  ssh root@host3 "halt -p"

  # shutdown myself
  halt -p
fi
EOF

chmod 700 shutdown-low-battery.sh

rcctl enable sensorsd
rcctl restart sensorsd