Question for Oscar T. Grouch

Oscar, question for you on the 1415 .... I hadn't used the laptop in a
while, with the main battery removed, and the RTC battery was dead and
CMOS had to be reset.

I know that the RTC/CMOS battery is supposed to take 48 hours to charge
and to "hold" for at least 30 days thereafter.

What I'm not clear on is what I have to do to charge it.  That is, under
which of the following conditions does the CMOS/RTC battery charge:

1.  Laptop turned on
2.  Laptop turned off, but with charged main battery installed
3.  Laptop turned off, but connected to powered AC adapter

Also, please drop me an E-Mail privately.

Thanks,
Barry Watzman