Could use some guidance choosing AGM’s.

Big Katuna wrote:
2005 Freightliner Fleetwood, Xantech Freedom 458 inverter/charger connected to four 6V golf cart batteries, which need replacing.

I would like to replace these with either two 6V or two 12V maintenance free AGMs.

We rarely boondocks, have a gas option fridge and if we need to use the microwave, will start the genset.

What we DO do is leave the RV plugged in all the time with AC on low, which fries the GC batteries. I have the watering system installed but still manage to forget and they get dry.

Are there direct replacement size wise for GC batteries?

If you are nearly always at full hook-ups, all you need is a simple 12v house battery to power the inverter/charger.

You are right that 6s don't like to Float very much. Xantrex even has/had their 3-stagers with the option to turn off the third stage for that reason.

It is the high SG of 6v batts which makes them not so good for floating them. Lower SG batts are better for floating, but have less capacity and discharge rates.

If you do want an AGM go for a type that is low SG and meant for floating such as those UPS types. But why spend the money? You could get a single simple sealed flooded starting battery like for a car to meet your requirements looks like.