There was a recent post that showed the underside of the connector. It is funnel shaped to tighten on the terminal as you tighten the nut. If there is room to push it down. I would loosen up the nut a bit, push the terminal all the way against the battery and while holding it, tighten the nut. If that leaves it loose, I think I saw a sleeve you put over the battery post to take up the slack.

Found it
http://www.autozone.com/batteries-st...er/257147_0_0/