Just take a wrench and tighten the connection... or have your wife do it. Forget doom sayers like Bluehighways... battery explosions with these new sealed batteries just don't happen by connecting wires or even arcing them out. Battery explosions used to occur occasionally when a spark would ignite the gases escaping thru the tops... that's one of the main reasons that they started making sealed batteries.
Not so . . . I've handled the injury claims for these things . . . and I know of where I speak. Even what you are calling "Sealed" battery's have vents . . . disfigurment and the partial or total loss of eyesight isn't to be trifled with or dismissed so cavalierly.