Hi Agood1, Welcome to The RV Forum!
The battery connects to the converter output on the 12 volt fuse board inside the 6345 enclosure, so the converter will continue to feed the fuse board even if the battery is disconnected. But this isn't a good idea - the 6345 needs the battery to provide some voltage regulation and keep surges out of your 12 volt gear.
To do what you want, you'll have to lift the positive lines that connect the battery and converter from the fuseboard, hook them together elsewhere and put a disconnect between that point and the fuse board.
But I don't recommend it - the 6345 is also notorious for boiling batteries dry if it's left connected to the batteries for long periods (several weeks or more). Modern converters are much nicer on batteries.
Instead, I'd get a separate Battery Minder and use it to keep your batteries charged while the rig is in storage.
Here's one example.
When you put the rig in storage, turn off the AC power going to the 6345 (it should be on one of the AC circuit breakers) and use the disconnect you installed to isolate the battery. Then connect the Battery Minder directly across the battery.
You want to be careful not to run the 6345 without the battery being connected to it - it needs the battery to act as a current sink and provide some voltage regulation. If the battery is disconnected there's nothing to stop voltage surges from getting to your 12 volt lights and appliances.
Out of curiosity, why do you want to remove 12 volt power from your rig?