IF your talking about the Currie kit like this
http://www.ezipusa.com/ everything is already wired and in the little alm. box mounted to the rack. Personally unless you are in love with the bike you would mount this on I would look at just buying the complete bike from Best Buy, Wallie World or another retailer for about the same price. The batteries that come with this kit are SLA (lead) but you can make your own lifepo4 packs that mount in the rack the same as the OEM packs.