After reading this topic it has occured to me that perhaps you should scrap the original plan.
Replace the batteries with a fuel cell. This will solve any water shortage problems you may have as fresh water is a byproduct of the process. If you also replace the copper conductors with super conducting ceramics you will save much in resistive losses. Also since the superconductive material requires liquid nitrogen to operate you will be able to tap into that circuit to cool the inside of the tear, eliminating the need for air conditioning.
You will have all the power you need from one fuel cell so there will be no need for paralell circuits thus isolation will be of no concern. Sure this may be a few thousand dollars more expensive, but, hey you will have all the power, water and cooling you need and you will not be taxing those poor batteries to their slow agonizing death.











