Welcome Payner to the iFour Winns forum and congrats on the purchase of your 328 Vista.
I think you will find it common practice for most Vista owners to leave their battery chargers on full time while they are at a dock and plugged into shorepower.
Both our fridges on our 328 are AC/DC. While at the dock on shorepower we have the fridges run on AC. When I leave the dock I turn the fridges off AC power and turn the fridges onto DC power. The AC switches for the fridges are found in the top portion of your electrical panel while the DC switches are found in the same electrical panel in the bottom portion.
Our 328 has two starting batteries and one house battery. If your house battery is good, I don't see why the one house battery would not supply both fridges with enough power to last out on the water for at least a minmum of 6 hours or so.
Remember though, if you too only have the one house battery, that when away from your dock that house battery would also power your fridges, your stereo, VHF radio, any lights you have one etc., so its not just the fridges that are drawing down your house battery.
You can use the generator for AC power anytime your have a need for AC power. Like charging your house battery after being away from the dock, running your air conditioning, making popcorn

, etc.
Mike.
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Current Boat
- 2001 Four Winns 328 Vista "Hour Decision"- 2010 310 Mercury Inflatable
Previous Boats
- 30' Doral Prestancia
- 25' Doral Citation