Some times it makes sense to buy a spool of wire, end connectors, and a crimping tool in order to make your own cables. But once I found BatteryCablesUSA.com, I changed my mind. They are fast, inexpensive, and high quality. It was actually cheaper to buy custom length cables with the exact connectors that I needed. See below for details on how to order a custom cable.
From BatteryCablesUSA.com
Custom made battery cables feature pure copper conductors with copper connectors such as ring terminal cable lugs and top post style battery terminals. We offer many sizes and configurations of battery cables which you can custom design here on the site. The battery cables are organized by wire gauge size. If you don't see a cable style you need please email or call us and we'd be glad to help design the cable for you.