Charge monitoring for dual batteries in e.g. i3 status bar

.i3status.conf

# i3status configuration file.

order += "battery 2"

battery 2 {
integer_battery_capacity = true
last_full_capacity = true
path = "/home/lab/.uevent"
format = "%status %percentage %remaining"
}

batt.sh

#!/bin/bash

while true
do
    paste /sys/class/power_supply/BAT0/uevent /sys/class/power_supply/BAT1/uevent | awk '{split($0,a,"="); split(a[2],b," "); (a[3] == "Charging" || b[1] == "Charging") ? $5 = "Charging" : $5 = (a[3] + b[1])/2; print a[1] "=" $5}' > /home/lab/.uevent
    sleep 30
done