Helpful Hints from joeeze: How to prevent battery-operated appliances from being turned on accidentally — no more dead batteries and nonfunctioning devices

It's one of life's rules that when you most need something to work, it doesn't. 

Just now a great idea occurred to me, a solution to the vexing problem of unwittingly/accidentally turning on a flashlight or radio and having it use up the batteries without your ever knowing it — until it's too late.

I was replacing the batteries in one of my innumerable inexpensive light-and-motion-activated nightlights (top) scattered around my house, which I've had in place ever since I read about Bill Gates's futuristic home thirty or so years ago, which the writer touring it raved about in part because the lights would go on and off whenever a person entered or left a room without any need to locate a light switch.

But I digress.

I inadvertently inserted in my nightlight one of the three (3) AAA batteries with the polarity reversed and the light didn't work.

The penny dropped: what if from now on I insert one battery the wrong way in a flashlight or radio I seldom use or reserve for emergencies? 

In that case the batteries should be good right up till their marked expiration dates rather than dying en route.