I've got 3 batteries sitting in the garage for the boat. When they were removed they were pretty low on charge. I've got a Statpower unit on the boat and I "think" when the shorepower unit is plugged in it charges the batteries through that thing, but heck if I know.

If I wanted to charge the batteries at home, what do I use? I'm thinking your standard 12 volt trickle charger is not the way to go as the deep cycle batteries need to be charged in steps.

I think you should be fine useing the trickle charger at least to get a charge in them for now. Especially if they have been low through the cold winter.

Once you get the shore power plugged in, you'll still have to turn the charger on. I've used the trickle charger in the off season without problems (as to step charging, I doubt that it matters as our batteries usually aren't true deep cycles though labeled as such). My current experiment is a 5 watt solar panel/charger that's been topping off my "good" battery for a year and a half now...will be interesting to see how it does (the battery was fully charged last spring when I got on the boat).