One of the most popular smart chargers is the C-Tek,
these help to extend the working life of your battery.2010 07 18_1460 C-Tek plus accessories.jpg - Bild entfernt (keine Rechte)

I bought one of those to use with the Puck as there was no on-board charger and the battery was missing when I got it.
I had to fit a battery as the 12v lights and water pump to the sink did not work on hookup.
The older pucks were fitted with both 12v and 240v lights but it was a pain not having the tap in the sink working.

They are very good chargers as long as you get one big enough to charge a large liesure battery.

http://www.ctek.com/gb/en/chargers/12v

Eventually I plan to make up a battery box that will plug into the towing socket on the triton as there is no battery fitted to thay either and I may want to use it for weekends where there is no hookup.

Definitely make sure you get the right one, I was advised that the 3.6 was OK for a 110A/Hr battery it wasn;t,...had to buy the 5.0