My ex once threw away a pair of binoculars, a mini-m@glite, a steel measuring tape, pair of box cutters and a spark plug socket, totally ignorant of the fact that all those were useful little things to have in a car. “You don’t need all that… my, what would you need that for? You don’t.” Puzzled, I inquired if she had really dumped all those things in the dustbin, to which she nodded. “We already have two pairs of binoculars at the house, and several flashlights!”
Easy, batteries on sale at the store, so you buy them, get home and find you still have a batch from the last sale.
Staples and other stores do free after rebate promotions on batteries in 24 packs, so people buy them, pay nothing, take them home and discover they bought AAA and only use AA and vice versa.
I know that people who work in A/V often throw batteries out after every use. At any corporate or college/university presentation, batteries used for lights, wireless mics, receivers, camera flashes, camera wireless control units, etc. are thrown out.
Some decide to use rechargeable, but in some cases where the higher voltage is desired (wireless mics), new batteries are used every time to prevent a mic accidentally running out of juice during an event. For a few dollars, it’s worth using freshly bought batteries if it avoids the embarrassment of running low while the event is still going.
I visit my AV office at my university every 3-4 months and pick up 8 “used” energizer industrial batteries (for wireless mouse). Always at 1.5V, pretty much brand new.
I didn't work much with wireless AV equipment, but that was standard protocol too. Risking a battery going dead in the middle of a gig isn't worth it. Just going wireless is already risky enough.
Different strokes, what is practical for DIY users often isn’t for pro’s. Costs less to put in a fresh battery than to test an old one, and you can enforce practices like never leaving a battery in any stored device. I used to buy broken printers from local University surplus because the first thing the repair shop would do with a problem printer was put in a fresh toner cartridge, then print a test page and assess doing a repair or replacing the printer. If junked the new cart went with the printer. I’d keep the cart for myself, and part out what was still good in the printer.
I know this is a little older now but my friend and I were actually just talking about this last night. I do some pick’n, not only commercial dumpsters but I sometimes hit up the nicer neighborhoods on trash days- some of the best things I have found include a 22” flat panel LCD TV, multiple different flat panel TV wall mounts with all hardware in a bag taped to the mount, a 6’ A-frame aluminum/fiberglass ladder and the best part- one of those huge whistle shaped air blowers that you see at super market’s and are used for drying floors and stuff (about a few hundred dollar piece of equipment). All in perfect condition.
I work in a laboratory where some of our group members are “clutter nazis”. Anything that is not being used they try to throw away for the sake of having a neat workspace. I am quite the opposite. I tend to hide useful stuff that I find from the clutter nazis. A couple of years ago we were instructed to use an analytical method which called for low pressure sodium light, as ordinary fluorescent room lights will degrade the analyte we’re testing for. I rummaged through one of my cabinets and pulled out an old sodium discharge lamp that I had put away some years before. It looked like something out of a Frankenstein movie, but it worked, and we’re still using it to this day! (in addition to some yellow LED’s that I rigged up). Score one for the pack/lab rat!