To answer the question of whether disconnecting the ground from the
1315 battery separator would force the battery banks to separate, the
answer is no. The 1315 must be able to sense voltage between the
batteries without being grounded. FYI, my 1315 is wired with a manual
boost switch and LED indicator, for what that's worth. That shouldn't
have anything to do with normal operation. I also isolated the 1315
from the frame ground to see if that had any effect and it didn't. So,
it looks like the installation of a main switch on each battery will
do the trick to guarantee isolation of the batteries.

Keith O.
90 Westy Syncro "VikingWagen"