I'm planning to bring in super light-weight batteries from the USA.
http://www.brailleauto.com/productcart/ ... dproduct=8
It weighs only 6 pounds and 2 ounces. It's a dry cell type and can be mounted in any angle.
It's suitable for WRX, Sti, Evo, EG6, EP3, DC5, Miata, etc.