Bought a $2 mystery bag of assorted batteries at a flea market and my smoke alarm saved the day
Last month I was poking around the flea market in Mesa and this old guy had a sandwich bag full of loose AA and 9 volt batteries taped shut, two bucks, no returns. I figured it was mostly dead junk but the 9 volts looked okay so I handed him the cash. Brought the bag home, grabbed my little tester, and sure enough every single AA was toast, reading under 1 volt. But three of the nine volts held a solid 8.9, so I popped one in my smoke alarm and told my wife I just beat the system. Couple weeks later at 2 in the morning that alarm started chirping its low battery beep and I almost threw the thing across the room. Turns out cheap batteries are cheap for a reason and the tester lied to me because voltage under no load means nothing once a device actually draws current. I swapped in a fresh one from the dollar store and it's been quiet ever since, but now I test every battery twice, once on the meter and once under a load, before I trust it. So my question for you all is, has anyone actually gotten decent life out of flea market batteries, or am I just paying two bucks to learn the same lesson every time?
Wait, you spent two bucks on a bag of batteries that could have been leaking acid all over your hands?? And a smoke alarm battery dying at 2am is literally the worst sound on earth, I would have thrown it too.