Log battery charge (check how fast battery discharges during sleep for example)

battery-log.sh

#!/bin/sh

_now="date +%s"
_power="cat /sys/class/power_supply/BAT0/charge_now"

full_power=$(cat /sys/class/power_supply/BAT0/charge_full)
last=$($_now)
last_power=$($_power)

while true
do
    sleep 0.1
    now=$($_now)
    power=$($_power)

    delta_time=$(($now - $last))
    delta_power=$(($power - $last_power))

    if (( $delta_power != 0 ))
    then
        charged=$(echo "$power / $full_power * 100" | bc -l)
        per_second=$(echo "$delta_power / $delta_time" | bc -l)
        per_hour_percent=$(echo "$delta_power / $full_power / $delta_time * 3600 * 100" | bc -l)
        echo $now \(${delta_time}s\) $power \($(printf %.1f $charged)%\) $delta_power $(printf %.0f $per_second) $(printf %.2f $per_hour_percent)

        last=$now
        last_power=$power
    fi
done