Originally Posted by Blue Heron
My new to me boat, has two 12V house batteries. When I am running Generator battery switch is set to "Both" to recharge.
When I am on Shore Power I also set it to "Both"
Battery Charger is also on.
Should I keep Battery Charger to "ON" when on Shore power? Does this act as a charger and float after batteries are charged?
When Shoudl I turn Charger off?
If you really mean what you posted ("My new to me boat, has two 12V house batteries
"), your two house batteries are already connected together in parallel as a "bank" so the switch position doesn't matter. Whatever is connected to one is connected to the other through the cables.
As far as leaving a battery charger on 24/7, you have to know what sort of charger you have. If it's a modern "smart charger", it's designed to be left on and connected 24/7 and it will sense the battery voltage and supply only what charge is needed to maintain the batteries in a fully charged state.
If it's not a smart charger, you should monitor the batteries yourself and turn it off when they are charged. Or, replace it with a smart charger.