Hi!
After flashed the @Soebianto mod on my Note 4X, i decompiled MiuiSystemUI.apk and replaced charger sounds with empty audio files.
I'll upload my MiuiSystemUI.apk. To make it work, just put it under /system/priv-app/MiuiSystemUI/, remove the original MiuiSystemUI.apk and set rw-r-r...