Low battery warning by audio and notification for macos laptops

powerchange.sh

#! /usr/bin/env sh
# When battery has less than 25%, pops up notifier counting down integer % of battery left 24, 23, 22, 21 ... 
# When battery is less than 15% also announces "Low Battery" verbal warning.
# INSTALL: Put this powerchange.sh file in /Users/Shared/ folder on your mac laptop, then chmod a+x *.sh
# And put com.me.powerchange.plist (below) in ~/Library/LaunchAgents/ (or /Library/LaunchAgents/ for every user).
# This file is run by com.me.powerchange.plist whenever charger is disconnected 
# When charger is unplugged, the date of this file changes: Library/Preferences/com.apple.powerlogd.plist
## https://stackoverflow.com/questions/14108471/launchd-watchpaths-will-not-trigger-simple-hello-world-script-os-x-10-8

## See also https://github.com/Goles/Battery/
export PWRINFO=$(ioreg -l | grep ExternalConnected)
export BATT_PCT=$(pmset -g batt | grep -o '[0-9]*%' | tr -d %)
echo -e $PWRINFO ' \t' " % "   $BATT_PCT  | logger -i -t batmom -s   2>> /var/log/batmon.log 
if [[ $BATT_PCT -lt 25 ]]; then
  echo $PWRINFO $BATT_PCT "%" | /usr/local/bin/terminal-notifier 
	if [[ $BATT_PCT -lt 15 ]]; then
		echo "Low Battery  " $BATT_PCT "%" | say	
	fi
fi
#echo $PWRINFO $BATT_PCT "%" 

exit 0

Copy code below line to com.me.powerchange.plist file. Put file in ~/Library/LaunchAgents/ folder

<?xml version="1.0" encoding="UTF-8"?>
<!DOCTYPE plist PUBLIC "-//Apple//DTD PLIST 1.0//EN" "http://www.apple.com/DTDs/PropertyList-1.0.dtd">
<plist version="1.0">
<dict>
        <key>Label</key>
        <string>com.me.powerchange</string>
        <key>ProgramArguments</key>
        <array>
                <string>/Users/Shared/maintlog/powerchange.sh</string>
        </array>
        <key>WatchPaths</key>
        <array>
                <string>/Library/Preferences/com.apple.powerlogd.plist</string>
        </array>
</dict>
</plist>

It's just a quick-and-dirty way I used to keep an eye and ear on battery state when I was having problems with zoom eating up battery.