With a mid engine boat, battery layout can be quite a problem. Taking up interior space and avoiding long cable runs are interesting trades. And trying to schlep 8D's through the interior and then replace them was beyond me. The standing chart table shown was a good place to put batteries, directly across from the engine. Electrical panel and electronics are right behind it. Factory layout (I think) was a group 31, group 27, group 24 starting battery, all wets. Since manufacturers don't really know how you are going to use the boat, mostly whatever advertises well and doesn't cost too much seems appropriate. So I needed a lot more battery capacity, and didn't want to fill the lazerette with batteries and cables. First decision was to not use wets so no battery boxes. Second discarded the 4D and 8D batteries both because they wouldn't fit in the space efficiently and were too hard to haul and position. But a little measurement showed that with Gels or AGMs 3-27's along with a starting battery would fit on the lower shelf, 2 more 27's on the upper shelf (behind the gray box) without interfering with things like the SSB chassis and still be able to lift up the front part of the shelf. So 460AH, starting battery, regulators, etc. all crammed in pretty nicely, but I doubt TPI ever planned for it. Modern boats seem to do a little more of this type of thinking on how to do the trades, but no reason they should always come out with the same answers.