Macbook 12-in — how to disable the charging sound?

I did it with a somewhat horrible hack but I had no time to figure out a better solution, because even launchd does not seem to work on PowerChime anymore (some other agent relaunches it whenever the macbook is plugged in).

First, I disabled SIP by booting in recovery mode and typing "csrutil disable" in the terminal. Then I rebooted and edited /System/Library/LaunchAgents/com.apple.powerchime.plist by deleting the audio file name between the two "string" tags, so that PowerChime can't find the sound it wants to play. Finally, I reenabled SIP.

That isn't a horrible option, what I did is I opened the package in said string, (/System/Library/CoreServices/PowerChime.app/Contents/MacOS/PowerChime), navigated to /Resources/connect_power.aif and I copied that file and edited it so it blank, then replaces it with SIP off. I didn't want to remove the whole string as I thought it could possibly lead to some unintended side effects.

This does not work anymore with High Sierra. PowerChime gets relaunched every time the MacBook is plugged in. Removing it from the launchd list with launchctl also has no effect.

Worked for me too - this sound was really beginning to buy me especially as the MacBook power socket has loosened up so it often disconnects while plugged in and then makes the noise again. Many thanks for giving me and library users peace!

Worked for me on Sierra 10.12. Thanks!

Have you found any new fix for High Sierra?

Have you tried this ... slightly different.

defaults write com.apple.PowerChime ChimeOnAllHardware -bool false;

killall PowerChime