#!/bin/sh

while :; do
    energy_full=0
    energy_now=0
    charging=

    for bat in /sys/class/power_supply/*/capacity; do
        bat="${bat%/*}"
        read -r full <"$bat/energy_full"
        read -r now <"$bat/energy_now"
        energy_full=$((energy_full + full))
        energy_now=$((energy_now + now))
    done

    if cat /sys/class/power_supply/*/status | grep -q Charging; then
        charging=+
    fi

    percentage=$((energy_now * 100 / energy_full))

    printf '%s %s ' "$charging$percentage%" "$(date +'%H:%M:%S')"
    sleep 1
done