Retired Chief: I'm fully aware of what you say.
I can only tell you that we had a girl at work who was in the habit of removing the main battery from her laptop and leaving it over weekends like that. She then complained that it kept losing the time/date.
I advised her to stop removing the main battery and the problem went away.
I don't know or care why, but it worked and thus I passed on that info to the OP.