Battery Percentage Boundary Notification Background Script for macOS

README.md

Battery Percentage Boundary Notification Background Script for macOS

Preface

I'm weird. We all have our weird habits and quirks. Luckily for me, mine only involves my the battery in my macbook computer.

Are you worried about keeping your devices' batteries healthy and keeping a charge? With every device I have owned, battery health has degraded noticeably over time, likely due to my poor charging habits.

I'll be the first to admit, I am no electrochemist. I might be (and likely am) askew, and what I am about to show you may have absolutely no effect on battery performance. But, I like to believe it does :)

I wanted a way to get a notification when my battery reaches 40% and 80%. That's my target range. So I wrote a script to do it (I have no life). It is written in AppleScript, and uses a fancy-pants notification card to display a message when it's time to charge or unplug the charge cable. The script relies on Apple's task scheduler launchd, and by following these instructions, the script will run automatically after login.

Installation

First, you will need to download the two files below BatteryStatusNotification.scpt and battery.monitor.plist. Make sure you edit the plist file to point to the correct script file.

If you want to run the script once, just run osascript BatteryStatusNotification.scpt. This is fine, but won't automatically run the script on login. To do this, copy the plist file battery.monitor.plist to ~/Library/LaunchAgents/. I recommend placing the script under ~/Applications.

Test this out and let me know what you think! You can also easily adjust the boundaries, or modify the script to suit your needs.

Further Reading

Stack Exchange - How to run custom AppleScript in Background

battery.monitor.plist

<?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>battery-status-monitor.job</string>
    <key>ProgramArguments</key>
    <array>
        <string>/usr/bin/osascript</string>
        <string>PATH/TO/YOUR/SCRIPT/FILE/BatteryStatusNotification.scpt</string>
    </array>
    <key>RunAtLoad</key>
    <true/>
</dict>
</plist>

BatteryStatusNotification.scpt

repeat
	set chargeState to do shell script "pmset -g batt | awk '{printf \"%s %s\\n\", $4,$5;exit}'"
	set percentLeft to do shell script "pmset -g batt | egrep -ow '([0-9]{1,3})[%]' | egrep -ow '[0-9]{1,3}'"
	considering numeric strings
		if chargeState contains "Battery Power" and percentLeft ≤ 40 then
			display notification "Time to plug me in :)" with title "Battery Charge Boundary"
		else if chargeState contains "AC Power" and percentLeft ≥ 80 then
			display notification "Time to unplug me :)" with title "Battery Charge Boundary"
		end if
	end considering
	delay 60
end repeat

@brandon1024 thanks for the script. it is working fine..
its just that notifications keeps getting accumulated.. so as suggested by @blakegearin i tried running his code on monterey..
but its not clearing the notifications containing "battery charge boundary"..
I tried looking for apple script documents but did not get clear document on how to click clear button on notification banners using apple script..
pls guide me or point to useful resources if possible..

@brandon1024 Yes, thanks much! I was about to embark on something similar and you saved me a bunch of work. I was just interested in something to monitor charge/discharge state and alert (scream noise...) when it reached ~80% for devices going into storage for several months. So I cobbled together this as an app:

set screamFile to path to resource "Wilhelm.mp3"
try
	repeat
		set chargeState to do shell script "pmset -g batt"
		set percentLeft to do shell script "pmset -g batt | egrep -ow '([0-9]{1,3})[%]' | egrep -ow '[0-9]{1,3}'"
		do shell script "caffeinate -dit 30 > /dev/null 2>&1 &"
		considering numeric strings
			if chargeState contains "Battery Power" and percentLeft < 80 then
				display alert "Charge State" message "Battery is at " & (percentLeft as string) & "%." & return & "Plug in charger to reach optimal charge level (80%)." buttons {"Quit", "Continue"} default button "Continue" cancel button "Quit" giving up after 30
			else if chargeState contains "AC attached" and chargeState contains "not charging" then
				display alert "Charge State" message "Battery charge is holding at " & (percentLeft as string) & "%." buttons {"Quit", "Continue"} default button "Continue" cancel button "Quit" giving up after 30
			else if chargeState contains "AC Power" and percentLeft > 80 then
				display alert "Charge State" message "Battery is at " & (percentLeft as string) & "%." & return & "Unplug charger to reach optimal charge level (80%)." buttons {"Quit", "Continue"} default button "Continue" cancel button "Quit" giving up after 30
			else if chargeState contains "AC Power" and percentLeft < 80 then
				display alert "Charge State" message "Battery is at " & (percentLeft as string) & "% and currently charging to optimal level (80%)." buttons {"Quit", "Continue"} default button "Continue" cancel button "Quit" giving up after 30
			else if chargeState contains "Battery Power" and percentLeft > 80 then
				display alert "Charge State" message "Battery is at " & (percentLeft as string) & "% and discharging." & return & "Please wait for battery to reach optimal charge level (80%)." buttons {"Quit", "Continue"} default button "Continue" cancel button "Quit" giving up after 30
			else if ((percentLeft as string) = "80") then
				do shell script "afplay " & quoted form of (POSIX path of screamFile) & " > /dev/null 2>&1 &"
				display alert "Charge State" message "Battery is now at an optimal charge of " & (percentLeft as string) & "%!" buttons {"Quit", "Continue"} default button "Continue" cancel button "Quit" giving up after 30
			end if
		end considering
	end repeat
end try

BTW, I found that awking the pmset result wasn't strictly necessary as AS's contains will simply search the contents of the string - probably a toss up as far as code efficiency goes..