Thanks All. It was a fun project.
RoyB wrote:
I am currently planning on installing a TORKLIFT battery box that is 59-inch wide using those same welded on angles and this will stick out across the tongue area over a foot or so on each side... This box will align up with the second upright wall section on the front deck on both sides in the above photo. If this doesn't look good to me for support of the box I will have to put different angles in place on top of the tongue area.
I believe it will be OK for me however... The TORKLIFT box fits perfect inside the two welded on angle sections...
You will be facing the same problem if you ever want to increase to more batteries in the future...
Roy Ken

This should get us through the next 5-6 years I hope (expected lifespan of the batteries).
We currently don't do a ton of boon docking, but do like to get out for up to 5-6 days at a time, so with the generator and possibly a solar panel in the future, this should do. In the future I'd like to swap out to 6v GC batts or true deep cycle batteries, so will tackle that when the time comes. I could probably do like you and make a reinforced bracket that sits on top of the frame rails to house a large pre-fabed battery box. When that time comes though I'm also planning on ditching the stock WFCO converter/charger for a better model as well to help protect/maintain my investment.
PS. I had a similar setup on our last trailer with two equally speced batteries. There must be more parasitic draw from the electronics in this trailer (which doesn't surprise me!) because overnight it pulls the batteries voltage down well below what our old one did (I knew our old one inside and out). I have not spent time yet measuring out and diagnosing what/where the loads on this one ares though. TBD!