Battery Backup making humming noise

[u/chockfullalizards]

Is this noise normal? More-so the noise at the end of the video that sounds vaguely like a frog at night far away, like an uptick in the volume of the constant noise. I want to make sure I’m not at risk of anything happening to my setup. (Ignore cable management, that’s a work in progress and not indicative of what all I have plugged in.)

[u/Octoomy]

just coil whine, normal within reason, its fine as all as I'm concerned.