Well I learned something when I went to pick up some nice 51R AGM blemmy batteries today for <$100, w/ warranty . I was talking to the guys at the battery shop about 24v maintenance chargers and they suggested an inexpensive 2a charger they had on hand. I was a bit surprised and asked what uses 24v. Turns out that electric wheelchairs commonly run on 24v. Thought this may be of value to the group.
24 VDC also found on golf carts and lots in the marine world.
Boat that I am working on now is all 24 vdc - lights, bilge pumps, steering motor, autopilot, heads etc etc