Power down 737 buzzer/sound

[Boss du Manche]

Hi there,

when you power down the 737, just before you turn off the battery, the 737 gives a distinct sound.

Is it harmfull to turn off the battery while this sound is still on or has Boeing a special purpose with this sound?

I have been told that if you turn off the battery while the sound is still on , the next crew might have a failure/alert upon powering up, because some sort of internal check has not been completed.

Anybody any comment on this.

Thanks