What to do with used CR123 batteries?

[theclutch]

Sometimes, when a battery is no longer useful for a particular device, it's still useful for another.  For instance, each time that a AA battery dies from one of my kids' toys, although it no longer works with their toy, I can still put the "dead" battery in a clock and it works perfectly fine for a while.  After that, then I throw it out.

So now, I'm stacking a whole bunch of CR123 batteries off of my Arlo cameras.  It appears that the "dead to Arlo" voltages of these are in the 2.75V range.  So before I throw these batteries out, does anyone out there know of a good use for these batteries?

[TomMac]

there are many flashlights that take 123 size cells ( usu two stacked ), I use my old rechargeables ( ones without circuit protection ) in one

At least you can run them down 100% there