RE: Best Batteries
Based on a lot of online discussion and quite a bit of my own research
online, two product lines seem to rise to the top.
Rolls-Surette (most expensive I've seen) and Trojan (a little cheaper but
not much).  Trojan is more avialable locally (at least here around
Seattle).  As for size you'll do the numbers (both amp hours and
dimensions).  Sealed AGM batteries for deep cycle service or marine service
are available.  BUT, again based on list members (and information from other
online forums) my LAST choice would be the Optima, they seem to be the least
value for the dollar and are limited in the range of sizes available.   And
there is competition coming into the market such as Full River.  I'm using a
Full River 110AH AGM as my aux battery (under the back seat) and so far no
problems.