The 7-pin is an easy method, and interesting. The wire gauge (or lack of it) would be the only issue.
Look up "Anderson Plug" on ebay. Get a big'ish one and use heavy gauge wire. 14 g or 12g at least, 8 or 10 better, but that gets hard to use, and keep the wire distance to the battery as short as possible. Anderson plug is popular, but depending on your abilitys there might be easier-to-attach plugs out there that are easier to attach the wire to the plug. The Anderson plug can be soldered, and is how I do mine. I guess it could be crimped too.
