BIOS battery query

[CurlyWhirly]

My old PC was around 7 years old and the BIOS battery was still working.

I have therefore come to the conclusion that the BIOS battery is only drained if the PC is completely isolated from the mains supply i.e. the plug is switched off at the socket.

Would I be right in thinking that when the PC is simply switched off, there is a nominal amount of electricity circulating around the motherboard which is just enough to prevent the BIOS battery from being drained (albeit very slowly over the years)

 

[Werewolf]

When the PC is "off" but not turned off at the mains, or at the back of the PSU there is always a "standby" current to the motherboard (which is what allows the motherboard to be woken up by mouse/keyboard and one of the thigns that allows for the simple switch on the front*), hence even with a dead cmos battery as long as the PC isn't unplugged/turned off at the mains it'll remember it's settings these days.





*Going back to AT PSU's the only on/off switch was a mains one that simply turned all power off to the PSU.

 

[CurlyWhirly]

Thanks Werewolf