Replacing CMOS battery without resetting BIOS date

[projanen]

Many thanks to ajkula66 and RealBlackStuff for recently pointing out and explaining how an unknown BIOS supervisor PW will wreak havoc once the CMOS battery dies or is removed. I just checked my primary backup system and

I'm not going to ask how to reset a BIOS supervisor PW here (wish I could but understand why not), but I am trying to think of a way to avoid having a dead CMOS battery nearly brick my laptop. I have two ideas, both involving a preemptive CMOS battery replacement:

• 1. Replace the CMOS battery while the system is powered by the main battery and AC adapter. Would this maintain power to CMOS et al during the battery swap? Wishful thinking, I know.
  
  2. Add a second CMOS battery in parallel before removing the old one. If I carefully strip and solder two leads (or even a second CMOS battery jack) onto the existing CMOS battery connector, then I would be able to repeat this battery replacement procedure at periodic intervals in the future. I haven't taken a close look at the motherboard yet, but perhaps I can even connect the proper voltage to CMOS some way, so I can unplug the CMOS battery plug and do the modifications outside the chassis.

Btw, this is on a very nice X61T I purchased elsewhere a year ago.