distilled water only, then recharge hopefully with a smart charger...
take the battery to any auto parts store if it does not recharge... compare shape/size and WEIGHT to the batteries on the shelf. The heavier the battery the more CCA it will have and the more expensive it will be. There are only a few different CCA specs within a size.
ďToo much of anything is bad, but too much good whiskey is barely enough.Ē Ė Mark Twain
The house battery needs to be a deep cycle battery. It is dual purpose. Youíll need enough CCA to turn the engine over when necessary (and to start your generator!) along with enough AH to run your lights and inverter if you have one. You canít go wrong with extra AH. The biggest issue is usually making sure that you get the same size (Group) so it fits where the old ones were. I wouldnít trust dry batteries. Flooded batteries are designed to be wet.