Sorry Ron, but the turn-knob battery disconnect like I recommended is not an appliance. It is a solid piece of brass with an electrical connection that is activated by a plastic knob, yes, but if the knob failed, the connection would not. I've had these for decades on every vehicle that should have one with no problem. It is the easiest, most efficient way to do the job...wish had I thought of it first, I'd be proud (and have a few more dollars to play with.)
Sure, you can get out a wrench and disconnect the ground cable and do the same thing I do by turning a knob.
Your choice. If you don't need one because you don't use it enough, great. But how about next year if you do use it a lot, or as a selling feature if you are done with it altogether? You've got seven dollars to lose to prove me wrong. My wife would say it is worth it.
Dougn