bath cell configuration:

- + - + - + -

Heat is not an issue for me and can be overcome.

How many neutral plates between would I need for this to run efficiently between 12v and 13v?

Is voltage leakage really an issue that needs addressing? If so any ideas on sealing plate edges to prevent leakage? e.g. Epoxy, high temp silocine etc?

Has any one tried using magnets as neutrals?