The problem stems from the fact that when the boat was built, they welded in a battery tray big enough for three batteries - two domestic, one starter, and we now have four. What's worse is that because of where they are, on the curving shelf alongside the engine bay, they can't line up properly. So because of this (wooden boxes shown in red),the wiring ends up looking like this.
Yuck. Unsightly, very difficult to figure out what goes where, and it's not good to have all those wires on one battery post.
I need to rip it all out, resite the battery boxes further up the shelf where I can get them in a nice neat line and redo the cabling in a neat fashion. In the space where I have to work this is a non trivial task, and I suspect I will utter the odd curse or two before I finish. I have to build new boxes and somehow fix them down, and might have to make up a few new cables.
Does anyone know, is it OK to use a bus bar for connecting heavy current items e.g. the electric charger and the inverter?