PSA: Our library has 6 drills and nobody borrows the one that works best
I run a small tool library out of a shed behind the VFW hall in Lawrence, and for 8 months I kept a clipboard of what got checked out. The problem was people kept returning the two cordless drills with dead batteries, so I tried something simple: I ziptied each battery charger to its drill and wrote the charge date on a piece of tape across the handle. Checkouts for those drills went from 3 a month to 14, and the swap outs for dead batteries basically stopped. Turns out folks were grabbing the first case they saw and not checking the charge, and the tape made it obvious at a glance. Anyone else label their batteries, or do you just eat the cost of replacing them every year?
Same thing worked for me with our shop vacs, I put a piece of painter's tape on each one with the last time the filter got swapped. People just grab what's in front and never look, so a big obvious label fixes it.