i3bar-battery

#!/bin/bash
BAT=/sys/class/power_supply/BAT1
energy_now=$(cat $BAT/energy_now)
energy_full=$(cat $BAT/energy_full)
power_now=$(cat $BAT/power_now)
status=$(cat $BAT/status)

case "$status" in
  "Charging")
    time=$(echo "scale=0; ($energy_full-$energy_now)*60/$power_now" | bc)
    ;;
  "Discharging")
    time=$(echo "scale=0; $energy_now*60/$power_now" | bc)
    ;;
  *)
    time=0
    ;;
esac

hours=$(echo $time/60 | bc)
minutes=$(echo "$time-$hours*60" | bc)
[ $minutes -le 9 ] && minutes=0${minutes}

echo ${hours}:${minutes}