On one of my IIx's, a dead lithium battery keeps my machine from even
attempting to start; no fan, no LED activity, nothing.

	*** USE THE FOLLOWING INFORMATION AT YOUR OWN RISK. ***
      I cannot be held responsible for damage done to your system
	       should you attempt to apply the following.

Since the battery was 3.6V, what I did instead was to take a couple of AA
alkalines in a holder, clip the lithium battery lead near the battery, and
then put the wires coming from the AA holder to the appropriate place on
the board (attaching them to the dead battery's leads).  While I don't
recommend this, it worked for me.

--scott