Great, Carl. From a weight perspective, it would have been my preference to split them into two pairs on alternate sides as well. In my engine room, however, it seemed easier to gain access to the batteries with all four placed on the Port side.
I was a bit concerned about the electrical panel and all its wiring being completely open to the engine room. (I think that was a standard "feature", but I'm not certain.) My fear was that the off-gassing during charging would be corrosive to the already precarious panel and electrical connections. I had found quite a few aluminum crimp connectors throughout the boat and these would have disintegrated in short time. The previous bank of batteries in that space were sealed GEL type, so less of a concern for off-gassing.
In the end, I rewired absolutely everything on my boat, removing the old switches and wires, closing off the cabinet and converting all of it to an electrical center. Since the switches and all wires now inside of the cabinet, the concern for off-gassing would have been virtually eliminated.
I did, however, move the raw water strainer from horizontal mounting position (attached to the seacock) to the back of the electrical cabinet, several inches above waterline. This way, should the glass ever break, it cannot flood the boat. This was just one more thing in the way for mounting batteries on the Stbd side. (It's incredible how many things affect every other thing in varying degrees.)
Previous starting batteries and electrical panel. Scary, huh?
Current view of closed off panel. This photo was taken before I was finished,
which explains why not all the wires are connected and bundled, and why
there are no clamps on the cockpit drain hose, etc. There are currently no
longer wires in the engine room that do not belong in the engine room.
Good luck with your access panel, Carl. You have my number... feel free to call if you have any questions.
Jack