I just recharged my batteries from winter storage (did pull them out of the trailer) and found a LOT of very helpful information at this web site about batteries, chargers, etc. None of my batteries, chargers, testers, etc. came with anywhere near this level of useful information.
Deep Cycle Battery FAQ
Good luck with your batteries. Mine came up to charge, but I do need to find a way to keep them refreshed during the storage seasons.