I privately wrote Bryan, but one of the replies to the group makes
me a bit curious.  I told Bryan that one would need a voltage regulator
for each path since the batteries might be in different states of discharge.
If one battery sulphated or was, for some reason, discharged more than the
other, the one that was most charged would get an overcharge while the
deader battery was trying to catch up.  Is this possible or am I just mistaken?
The battery with the highest voltage will totally carry the system since the
diodes won't let current flow any other direction.

Martin McCormick