Why not use a voltmeter at the battery to see if it is being charged? Over 14 volts would guarantee charging, 13 not so much - it could mean charging took place a few hours ago.
I wired my switch at the door to disconnect the house loads rather than the battery. This allows eliminating discharge while allowing solar charging to continue. I do disconnect the battery for winter storage after the solar panel is covered with snow by unhooking a battery cable.