Paul I. wrote:
I would & do leave the chargers on all the time. A good charger will float the batteries, so NO harm done. The other reason too, if a seastrainer or anything else lets go. There will be pleaty of power to run the pumps.
Remember too, even with the battery switch is setnto off some things still have power. As in pumps, ACC to radio and there could be more. I would first check, how old are the battery/s, clean battery connectors and look for what could be causing the draw. In that order. Remember too, with out shore power, your fridg could be on now running on 12V, but not with the battery switch to "off".
+1
Leave the shore power on. You're probably draining the house batteries with just normal docked systems running.