What is your system voltage and where are you storing the batteries? As Arch said above, sailboats are meant to carry ballast but you can't just put them all down in the bilge. They need to be accessible for maintenance (topping off with water, or at least cleaning and checking the terminal connections) Battery manufacturers aren't exactly designing batteries in special shapes with sailboats in mind. How did you overcome all of that
System voltage is 60VDC for the electric drive, switchable to 12VDC for house loads.
They are actually sitting in the bilge! The original Ericson 35 hull is identical (very interesting story...) to an Alberg 35. Very deep bilge, allows 10 Trojan L16's to fit perfectly. (there is still a deeper part of the bilge for water collection, pumps, etc)
Access is through hatches in the salon floor. I've developed the dexterity required to ck SpG every six months. The batterieas are fitted with Hydrocaps to catalise the H2 back into water, avoiding venting issues. Hold downs are installed to hold everything in place if a knockdown should occur.
The total weight of the system is probably about 500lbs greater than having the A4 and associated tanks, trans, etc., but distribution is actually much better for sailing. She heals over normally to about 15 degrees, but gets much stiffer beyond that.
I have some pix of the setup on my blog (to avoid overloading this thread): svdejala.blogspot.com
Like I said: This is not for the faint of heart... but someone has to push the envelope!