After re-reading 96Tony's opening post I personally would :
Ask the dealer how much I was paying for ONE or TWO batteries in my new TT .
The local dealers here will deliver a new trailer with one battery unless it is specifically written in the purchase order that 2 will be on the trailer .
I would ask for a credit for the purchase price of the batteries that the dealer intends to install .
I would purchase either two brand new GC2 6 volt batteries or two brand new exide edge agm marine/rv batteries a few days ahead and plan on hooking them up myself .
It is so much cheaper to install big capacity high grade batteries at the outset , rather than having that double expense later .
The GC2 or EDGE AGM batteries will not be drawn down in percentage as much as the garden variety / cheapest cost battery that the dealer is selling .
The edge agm battery takes a charge faster , has less draw down in use , and a longer life span the a conventional rv battery
I paid $ 140 each at BiMart for my Edge AGM .
GC2 conventionals are cheaper than that , I think .
I replaced my duramax batteries with edge agm and they charge faster for my Jumper Cable to the trailer practice .
We do not require a genny or solar .
Just good batteries and # 2 AWG jumper cables .
It is cheaper to do it in the beginning .