battery.sh

#!/bin/bash
# Outputs current battery level %
# Calculated by averaging the battery levels of both the external and internal batteries
# The average isn't weighted because both batteries on my T480 are of the same capacity
# Otherwise $(cat /sys/class/power_supply/BATi/energy_full) should be used for weighting
BAT0=$(cat /sys/class/power_supply/BAT0/capacity)
BAT1=$(cat /sys/class/power_supply/BAT1/capacity)
sum=$((BAT0+BAT1))
avg=$((sum/2))
printf "%s\n" $avg