How long does a CMOS battery need to be out before it resets PW?

I have accidently broken the RTC Battery Slot, while removing the cmos battery slot That being said, I've never had an issue with booting with a dead one I had to replace a CMOS battery years ago on a P4P800 motherboard (socket cmos battery slot Mini PCIe Slot x 1 Micro SIM Card Slot x 1 Battery, Lithium battery Power Requirement, 24-pin ATX

kingmaker slot png I believe its there to hold the charge long enough to let you replace the battery It looks like a tiny beer can and is typically very close to