Apple /// Clock

[travis@cluracan.org (Ward C. Travis)]

I have two Apple ///'s that both have a large hole in the main logic board
that is labelled "BAT 1" (center right component side with slots at top
left). It looks as if a mercury or lithium watch battery once belonged
there (although if so, there's a small bracket missing). Likewise, SOS
allows me to set the clock on both of these boxes, but once set, the clock
never advances. The clock also loses the current time if the systems are
turned off.

SO: Should there be a battery on the Apple /// (5-volt) motherboard?
      If so -- what type? (The mere fact that I see no type mentioned
      in the TIL makes me think there will be none.)
    Should the Apple /// preserve the time through a power-cycle?

I've checked the TIL and found nothing (perhaps my search was incomplete
or poorly worded) about this.

Thanks for your time on this.

-- 
Ward C. Travis -- @Cluracan.ORG -- Just collecting everything.