I use the Black and Decker VEC1093DBD 40AMP model. It is a backup to my converter and I carry this with me on all my trips in the RV TOOL Box. I went with this 40AMP Smart Mode model as it is the most referenced model amoung RV'er users and it more closly dupicates my smart mode trailer converter/charger unit.
This smart-mode battery charger is one nice unit to have to be used with my 2KW Honda EU20001 Generator... This unit will re-charge your 12VDC deep cycle batteries in a two-three time frame just like the on-board smart-mode converter/chargers will do. It is lightweight and very easy to use even for this old southern Illinois Corn Field dirt farmer from Horse Creek country. This charger has many built-in modes I havent eben played with yet to keep your deep-cycle well batteries maintained. A big part of my PLAN-B compliment of equipment.
photos from Google Images