Question Harsh sound after switching from mains to battery power

[George77774455]

Hey guys, i have a harsh sound after switching from mains to battery power when only in a specific situation: disconect the mains power cable while in hibernation, coming back from hibernation (on battery power) the laptop makes a 1 sec. long harsh sound. Can it be the difference in voltage when switching from mains to battery or something like that? Can it be damaging for any component?

 

[wonderwall_85]

Does it sound like spark? 1 second is too long for the spark though.
there should not be any difference in voltage as the computer runs on the same voltage as the battery. the mains power is converted to the same level as the battery.

 

[George77774455]

Does it sound like spark? 1 second is too long for the spark though.
there should not be any difference in voltage as the computer runs on the same voltage as the battery. the mains power is converted to the same level as the battery.

Not at all like a spark, more like a train coming to a screeching stop (very loud screeching)